JP3208936B2 - Surface acoustic wave device, circuit connected thereto, measuring method therefor, and communication device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a surface acoustic wave device, a peripheral circuit, a measuring method therefor, and a communication device using the same.

[0002]

2. Description of the Related Art A surface acoustic wave device has interdigital electrodes as a part of its structure. The interdigital transducer converts an electric signal into a surface wave or a surface wave into an electric signal. Usually, a bidirectional electrode having the same transmission efficiency (or reception efficiency) in the forward direction (the direction in which the transmission or reception target is arranged) and the reverse direction is often used. On the other hand, in view of a demand for low loss, a unidirectional electrode having higher forward transmission efficiency (or higher reception efficiency) than that in the reverse direction has been studied.

[0003] The acoustic reflection on the forward side of the interdigital transducer is referred to as a so-called triple trans-electrode (Triple Tran).
(Site Echo, TTE), which may cause a phenomenon such as a ripple in the frequency characteristic and the group delay time characteristic. For this reason, it is necessary to sufficiently suppress the acoustic reflection on the forward side of the IDT.

[0004] In a unidirectional electrode, the structure with low loss does not always coincide with the structure for suppressing TTE.
In such a case, it is necessary to clarify the conditions of a structure having high directivity (ratio of forward and reverse transmission efficiencies) and suppressing TTE as much as possible.

[0005] Analysis of a surface acoustic wave device is often performed by an equivalent circuit calculation using admittance matrix elements and scattering matrix elements. For example, the Institute of Electrical and Electronics Engineers, Sonics and Ultrasonics, Vol. 26, No. 6, pp. 426-428 (IEEE Transactions on Sonics and Ultr).
asonics, Vol. SU-26, No. 6, p. 426-p. 428) contains a mixture matrix of admittance matrix elements and scattering matrix elements (P-matrix).
The analysis is performed by using. However, it is hard to say that the relationship between the structure of the interdigital transducer and its acoustic reflection is clear.

[0006] The acoustic reflection of the surface acoustic wave device and the interdigital transducer is limited to the case where there is no internal dissipation of the interdigital transducer.
Pp. 164 to 164 (Jpn. J. Appl. Phys. Vol. 22 (198
3), pp. 163 to 164). However,
There are no reports of internal dissipation.

[0007] Regarding the unidirectional interdigital electrode structure, a report of a group-type unidirectional interdigital electrode is described in the Technical Report of the Institute of Electronics and Communication Engineers, US75-15, pp. 25-30. In this report, the structure of the interdigital transducer called "120 degree phase type" and "90 degree phase type" is proposed.

[0008]

A novel structure having a frequency characteristic and a group delay time characteristic in which ripples are suppressed by clarifying the acoustic reflection suppression conditions of the IDT when there is internal dissipation in the IDT and peripheral circuits. It is desired to provide

In particular, the unidirectional interdigital transducer clarifies acoustic reflection suppression conditions including low loss, and achieves low loss and
It is desired to provide a novel structure having frequency characteristics and group delay time characteristics in which ripples are suppressed.

Further, some unidirectional electrodes require a phase shifter to reduce the loss by improving the directionality.
There are problems that peripheral circuits of the surface acoustic wave device become complicated and that the surface acoustic wave device becomes large. For this reason, it is desired to provide a new structure having a frequency characteristic and a group delay time characteristic with little ripple and a low loss while having few phase shifters.

[0011]

When the radiation conductance of the surface acoustic wave device is Ga and the external load (or signal source) conductance of the surface acoustic wave device is Gl, the loss of the surface acoustic wave device is minimized. Gl / Ga = 1. In addition, when there is no internal dissipation, when Gl / Ga = 1, the TTE also becomes minimum. However, when there is internal dissipation, TTE is not always minimized when Gl / Ga = 1. Then, as shown below, conditions for obtaining a low-loss surface acoustic wave device while sufficiently suppressing the TTE were derived using a scattering matrix, and the following conditions were obtained.

The interdigital transducer having internal dissipation and the peripheral circuit are regarded as one circuit, and a forward acoustic terminal for transmitting or receiving waves is a terminal 1, a reverse acoustic terminal is a terminal 2, and an electric terminal is a terminal 3. In the equivalent circuit described above, the scattering matrix representing the unidirectional electrode is (S), the complex conjugate matrix of (S) is (S *), and the matrix generated by multiplying (S) and (S *) is (α). the directional coefficient ^{_{κ (= | S 23 | 2}} / | S 13 | 2), the theta ₁ arg
(S ₁₃ ² s ₃₃ * s ₁₁ *), θ ₂ is arg (α ₁₃ * s ₃₃ s)
₁₃ *), the _{θ 3 arg (α 13 * s} 13 s 11 *), the μ α ₁₃ / |
s ₁₃ |

[0013]

(Equation 16)

The value of is set to 1/3 or less.

Next, in the interdigital electrode and the peripheral circuit,
When the internal dissipation of the interdigital electrode is a unidirectional electrode that is negligibly small, the electrodes added to the reflective electrode are Pi,
When the power applied to the transmitting electrode is Pq and the geometric phase difference between the reflecting electrode and the transmitting electrode is Φm, Pi / Pq = exp (−jΦm) (where exp is a power of the base of natural logarithm, and j is If it satisfies the imaginary unit), by changing Φm, the conventionally known “90 ° phase type” or “120 ° phase type”
The TTE can be sufficiently suppressed even with a geometric phase difference different from that described above, and a low-loss unidirectional electrode can be obtained.

Further, there is shown an electrode pattern of a unidirectional IDT which does not require a phase shifter. Let λ be the wavelength of a surface acoustic wave of any frequency. At this time, the length in the short direction of the conductive thin-film electrode whose length in the longitudinal direction is arbitrary is,
The first electrode is λ / 8, the second electrode is 3λ / 8, and the third electrode is λ / 8.
/ 8, the fourth electrode is λ / 8, the fifth electrode is λ / 8, the sixth electrode is λ / 8, the distance between the first electrode and the second electrode is λ / 8,
The distance between the electrodes and the third electrode is λ / 8, the distance between the third and fourth electrodes is λ / 4, the distance between the fourth and fifth electrodes is λ / 4, and the distance between the fifth and sixth electrodes is λ / 8. λ / 8 are arranged as one cycle, and the first, third, fifth, and fifth
The sixth electrode is electrically connected to each other, and forms an interdigital electrode with the electrically connected second and fourth electrodes to form an electric terminal pair. By changing the length of each of the conductive thin-film electrodes in the transverse direction of the interdigital transducer, a surface acoustic wave device that sufficiently suppresses TTE, has low loss, and does not require a phase shifter can be obtained.

[0017]

According to this method, the TT of the surface acoustic wave device can be
An apparatus configuration condition for suppressing E can be provided, and ripples in the frequency characteristic and the group delay time characteristic can be reduced. Further, with respect to the unidirectional electrode, the loss can be reduced, the phase shifter can be reduced, and the size of the device can be reduced. Thus, a high-performance surface acoustic wave device with small ripple and low loss can be provided.

[0018]

FIG. 1 schematically shows a surface acoustic wave device using the present invention. On the surface acoustic wave substrate 4, an input unidirectional IDT 5, an output bidirectional IDT 6 connected to an output electric terminal 14, and a sound absorbing material 7 for suppressing a reflected wave from the end face of the substrate are provided. It has been applied. The input unidirectional IDT 5 is formed of two electrode regions 8 and 9. The input electric terminal 3 has a phase shifter element 10,
A so-called group-type unidirectional electrode configuration to which the electrodes 11 are connected is formed. The power supply 13 and the power supply conductance 12 are connected to the input electric terminal 3. Further, a load conductance 15 is connected to the output electric terminal 14. Usually, 128 ° Y−
X LiNbO ₃ or the like is used.
8000 μm aluminum is used.

FIG. 2 shows the electrode configuration of the group type unidirectional electrode.
Shown in Energy is radiated in one direction by the electric phase difference provided by the phase shifter 16 and the geometric phase difference caused by the electrode arrangement. Here, as shown in FIG. 4, a unidirectional electrode including a phase shift circuit is regarded as one circuit, and a forward direction is defined as a terminal 1, a reverse direction is defined as a terminal 2, and an electric terminal is defined as a terminal 3. FIG. 3 schematically shows the configuration of the internal reflection type unidirectional electrode. In this unidirectional electrode, reflection (Mass-Electrical Lo) is caused by a difference in characteristic impedance with respect to surface acoustic waves between a portion having an electrode and a portion having no electrode.
a single direction is obtained by canceling reflection (Regenerated Wave, RW) determined by an electrical load (Ming) and an electrical load. Again, in this case,
As described above, the forward direction is defined as terminal 1, the reverse direction is defined as terminal 2, and the electrical terminal is defined as terminal 3. According to the definition of this terminal, a general unidirectional electrode (not including a group type, including the internal reflection type unidirectional electrode shown in FIG. 3, for example) can be represented by an equivalent circuit as shown in FIG. It is. In the figure, the same parts as those in FIG. 1 are denoted by the same reference numerals. A characteristic impedance 17 is connected to the acoustic terminal. In the unidirectional electrode as described above, internal dissipation such as conductor loss occurs in a circuit or in an interdigital electrode.

The scattering matrix (S) in the above circuit is expressed as follows: (S) (S *) = (α) (1) Here, (S) and (α) are a matrix of 3 rows and 3 columns.

The case where the scattering matrix element is a complex number physically corresponds to a case where there are no restrictions on the connection conditions at the frequency and the electric terminals. From Equation 1, the following three relational expressions are obtained.

[0022] ^{_{| s 11 | 2 + | s}} 12 | 2 + | s 13 | 2 = α 11 ......... ( number ^{_{2) | s 13 | 2 +}} | s 23 | 2 + | s 33 | 2 = α 33 (Equation 3) s ₁₃ s ₁₁ * + s ₂₃ s ₁₂ * + s ₃₃ s ₁₃ * = α ₁₃ (Equation 4) From the above equations 2, 3, and 4, | s ₁₃ | ² = (α ₃₃ −Γ ² ) / (1 + κ) (forward direction) (Equation 5) | s ₂₃ | ² = κ (α ₃₃ −Γ ² ) / (1 + κ) (Reverse direction) (Equation 6)

[0023]

(Equation 7)

The following relationship is obtained. Here, κ≡ | s ₂₃ | ² / | s ₁₃ | ² (directionality coefficient) (Equation 8)

[0025]

(Equation 9)

B≡Gl / Ga (Equation 10) a≡Bt / Ga (Equation 11) μ≡ | α ₁₃ / s ₁₃ | (Equation 12) θ ₁ arg (s ₁₃ ² s ₃₃ * s ₁₁ *) (Equation 13) θ ₂ ≡arg (s ₃₃ s ₁₃ *)… (Equation 14) θ ₃ ≡arg (s ₁₃ s ₁₁ *)… (Equation 15) ). Here, Gl is the external load (or signal source) conductance, Ga is the radiation conductance, and Bt is the combined susceptance with the circuit. Where the acoustic reflection of equation 7 is T
It causes TE.

For example, the TTE causes a screen ghost failure in a television receiver or the like, and an echo disturbance in voice communication or the like. The allowable ghost detection limit of the television receiver is -30 to -40 dB, and the allowable interference detection limit of voice communication or the like is -20 to -30 dB. Therefore, the necessary minimum degree of suppression of the TTE can be defined as -20 dB. Since the TTE is doubly reflected between the input and output interdigital electrodes, the amount of reflection at one interdigital electrode is determined to be about 1/3. Therefore,

[0028]

(Equation 16)

Setting the value of の to １ ／ or less is a necessary minimum condition required for the interference characteristics of the equipment. In the first embodiment, the above value is set to 1/10. As described above, according to the present embodiment, a surface acoustic wave device having good characteristics with suppressed TTE can be obtained.

At the main response frequency of the IDT,
When the imaginary part of is canceled out, since the scattering matrix element is a real number, a = 0 (Equation 17) θ ₁ = θ ₂ = θ ₃ = 0 (Equation 18) , 6, and 7, the following equation is obtained.

S ₁₃ ² = (α ₃₃ −γ ² ) / (1 + κ) (forward direction) (Equation 19) s ₂₃ ² = κ (α ₃₃ −γ ² ) / (1 + κ) (reverse direction) ...... (Equation 20)

[0032]

(Equation 21)

Κ≡s ₂₃ ² / s ₁₃ ² (directionality coefficient) (Equation 22) γ≡s ₃₃ = (b−1) / (b + 1) (Electrical reflection) (Equation 23) μ ≡α ₁₃ / s ₁₃ (Equation 24) Therefore, as described above,

[0034]

(Equation 25)

By setting the value of の to １ ／ or less, acoustic reflection can be suppressed. In the second embodiment, the value of the above equation 25 was reduced to 1/10 at the center frequency with the imaginary part of the electric terminal canceled. As described above, according to the present embodiment, a surface acoustic wave device having good in-band flatness was obtained.

It has been found that the above case is represented by a relatively simple equivalent circuit as shown in FIGS. In FIG. 5, the same parts as those in FIG. 1 are indicated by the same symbols. FIG. 5 is a parallel equivalent circuit in which internal dissipation is represented by parallel conductance, and FIG. 6 is a series equivalent circuit in which internal dissipation is represented by series resistance.
In the figure, the radiation conductance 18 in the forward direction is (κ + 1)
Ga, and the radiation conductance 19 in the reverse direction is (κ +
1) Expressed as Ga / κ. Further, a parallel conductance 20 representing internal dissipation and a series resistor ru21 are connected to each circuit. The acoustic reflection S ₁₁ and the insertion loss S ₁₃ when using the circuit of FIG.

[0037]

(Equation 26)

[0038]

[Equation 27]

Further, using the above-mentioned b and g ／ gu / Ga (Expression 28),

[0040]

(Equation 29)

[0041]

[Equation 30]

## EQU2 ## As mentioned above,

[0043]

(Equation 31)

By making the absolute value of 1/3 or less,
Good characteristics are obtained. Similarly, when the circuit of FIG. 6 is used, the acoustic reflection S ₁₁ and the insertion loss S ₁₃ are

[0045]

(Equation 32)

Is

[0047]

[Equation 33]

Further, by using the aforementioned b and r ru · Ga = ru / Ra (Expression 34),

[0049]

(Equation 35)

[0050]

[Equation 36]

Is represented by As mentioned above,

[0052]

(37)

By making the absolute value of 1/3 or less,
Good characteristics are obtained. Further, when the above value is expressed in dB units, P ₁₁ = 20 log (S ₁₁ ) (Equation 38) P ₁₃ = 20 log (S ₁₃ ) (Equation 39)

FIGS. 7 to 12 show calculation results for some examples. 7 to 9 show the case where the internal dissipation is represented in parallel, FIG. 7 shows the case of a bidirectional electrode (κ = 1), and FIG. 8 shows the case of an incomplete unidirectional electrode (κ = 0.5). FIG. 9 shows the case of a completely unidirectional electrode (κ = 0). In addition, the solid line indicates the insertion loss, and the broken line indicates the acoustic reflection suppression degree. Overall, when there is internal dissipation (gu / Ga =
0.5), the loss minimum point has shifted to the right (the side where Gl / Ga is large), and the acoustic reflection suppression point has the left side (Gl / Ga).
/ Ga is smaller). 10 to 1
2 is a case where internal dissipation is represented in series, FIG. 10 shows a case of a bidirectional electrode (κ = 1), FIG. 11 shows a case of an incomplete unidirectional electrode (κ = 0.5), and FIG. This is the case of a completely unidirectional electrode (κ = 0). In addition, the solid line indicates the insertion loss, and the broken line indicates the acoustic reflection suppression degree. Overall,
When there is internal dissipation (ru · Ga = 0.5), the minimum loss point shifts to the left side (Gl / Ga is small), and the acoustic reflection suppression point is on the right side (Gl / Ga is large). Has moved to. In normal circuits (including interdigital electrodes)
Since the dissipated component of the equivalent circuit is 5% or more, r ≧ 0.
05, g ≧ 0.05. Therefore, for example, when the internal dissipation is represented by FIG. 6, the condition for maximizing the acoustic reflection suppression degree is obtained by setting equation (35) to zero,
As a condition of b including all directions (0 ≦ κ ≦ 1), a condition that b is 1.05 or more is required. Also,
The internal dissipation is represented in FIG. 5 and is completely unidirectional (κ = 0)
In the case of, the condition that b is smaller than 0.95 is obtained. In the third embodiment, when the internal dissipation is shown in FIG. 5, κ = 0 (complete one-way) and g = 0.5, b = 0.
As 5, a good acoustic reflection characteristic was obtained. Further, in the fourth embodiment, in the case where the internal dissipation is shown in FIG. 6, good acoustic reflection characteristics were obtained with κ = 0 (complete unidirectionality) and r = 0.5, b = 2.0. As is clear from FIG. 12 and FIG. 9, the acoustic reflection suppression area is enlarged by intentionally increasing the internal dissipation (g, r, 0 → 0.5). As a result, characteristic changes due to variations in element values of the surface acoustic wave element and peripheral elements are small. As described above, according to the third and fourth embodiments, a circuit having a small characteristic variation of the device can be obtained.

In the above embodiment, since the conductance (or resistance) value relating to internal dissipation is intentionally inserted, its value is clear. However, in an actual circuit, when the internal dissipation is not intentionally included as in the above-described example. But inevitably there is internal dissipation in the elements and circuits. Therefore, in order to obtain good acoustic reflection suppression characteristics, it is necessary to know the conductance (or resistance) value related to internal dissipation. FIG. 13 shows the conductance frequency characteristic 22 of the IDT including the peripheral circuit.
4 is a resistance frequency characteristic 23 of the IDT including the peripheral circuit.
Is shown. As shown in the figure, a constant relating to internal dissipation can be obtained from the conductance (or resistance) value of the pole frequency and the value at the main response frequency. As described above, according to the present embodiment, good acoustic reflection suppression characteristics can be obtained even when internal dissipation is not intentionally included.

According to the study of the inventors, the coefficient α ₃₃ relating to the internal dissipation of the interdigital electrode is:

[0057]

(Equation 40)

It was found that Especially when the conductor loss in the circuit (e.g., phase shifter loss, etc.) is large, first-order term contribution (1 + either claim sections or 1-s ₃₃ of s ₃₃₎ increases. When internal dissipation is represented by the equivalent circuit of FIG.
₃₃ is

[0059]

[Equation 41]

In the case shown in FIG. 6,

[0061]

(Equation 42)

Is obtained. In such a case, α ₃₃ is

[0063]

[Equation 43]

Is expressed as follows. ξ has combined the meanings of both correction coefficient of the phase error measured with the previous sign of S _33.

For confirmation, a comparison with an experiment was performed. The experiment was performed using a center frequency of 53.5 MHz, an opening of 1000 μm, and 2 to 15 groups of unweighted electrodes formed on an X-112 ° LiTaO ₃ substrate. The forward and reverse characteristics were measured by disposing a monitor electrode having a small number of electrode pairs in each direction. FIG. 15 shows the measurement results. The internal dissipation matrix element α ₃₃ was obtained by using Expression 15. The obtained result is shown by a broken line in FIG. It shows a large frequency dependence. Next, using Equation 46 to determine the alpha ₃₃ from the electrical reflection s _33. At this time, the constants α ₀ and β ₁ are obtained by fitting the experimental values at three points of the first zero point frequency (52 MHz, 55 MHz) and the second zero point frequency (50 MHz), which have little influence on the radiation characteristics. , Ξ was determined. As a result, values of α ₀ = 0.41, β ₁ = 0.5, and ξ = 117 ° were obtained. The solid line in FIG. 16 shows the result of calculation based on Expression 22. It shows the same tendency as the above measurement results, and both are in good agreement.

FIG. 17 is a system block diagram of a television receiver using the surface acoustic wave device of the present invention. The signal input from the antenna 24 is output by the tuner 25
The video signal is converted to an intermediate frequency (IF), passes through the surface acoustic wave device 26 of the present invention, and is demodulated by the demodulation unit 27 to a terminal 28.
Then, the audio signal is output to the terminal 29. Since the surface acoustic wave device 26 of the present invention is used for the intermediate frequency filter, the IF having high flatness of the group delay time and high linearity of the detection is used.
A circuit becomes possible. As described above, according to the present embodiment, a television receiver having good demodulation performance can be obtained.

FIG. 18 is a system block diagram of a mobile communication telephone using the surface acoustic wave device of the present invention. Antenna 3
The signal input from 0 passes through the first-stage reception duplexer filter 31, and is mixed with the signal sent from the voltage variable oscillator 32 by the mixer 33, so that the unidirectional IDT electrode of the present invention is used. The signal for one channel is selected by the used intermediate frequency filter 34, converted into an audio signal by the demodulation and logic circuit 35, and output to the audio output terminal 36. On the other hand, the reference signal for intermediate frequency conversion is sent from the demodulation logic circuit 35 to the control circuit 37 of the variable voltage oscillator 32. At the same time, the audio signal sent from the audio input terminal 38 is sent to the modulation circuit 39 by the demodulation and logic circuit 35. The modulation circuit 39 modulates the signal by mixing the modulation signal from the variable voltage oscillator 40. Further, the modulated signal passes through the transmission duplexer filter 41 and is output from the antenna. A control signal is also sent from the variable voltage oscillator 40 to the control circuit 37 for reception, and synchronization is established.
Since the elasticity table device of the present invention having a low loss and a high flatness of the group delay time is used for the intermediate frequency filter 34, the use of this embodiment can provide a demodulation performance with good sensitivity and high linearity, and high performance. A high performance mobile phone is obtained.

First, the arrangement conditions of the components of the unidirectional electrode are obtained.

T when the surface acoustic wave device is unidirectional
The TE suppression condition is obtained by substituting κ = 0 in Expressions 31 and 37. Therefore, the TTE suppression condition of the perfect unidirectional electrode whose internal dissipation is so small as to be negligible is given by the following expression 44.

B = 1 (Equation 44) (where Gl is the admittance of the power supply and Ga is the admittance of the electric terminal of the surface acoustic wave device, b = Gl / Ga
Next, regarding a group-type unidirectional electrode, which is an example of a surface acoustic wave device, a completely unidirectional configuration when the geometric phase difference between the transmitting and reflecting electrodes is not an odd multiple of π / 2. The condition is derived by a method using a scattering matrix.

FIG. 19 shows a configuration diagram of a group type unidirectional electrode.

In this configuration example, the transmitting electrode 51 and the reflecting electrode 5
2, a meander electrode 53, and an electric circuit 54.

Generally, the group-type unidirectional electrode is composed of a substrate having piezoelectricity and a sending electrode 5 provided on the substrate.
1, a reflection electrode 52 and a meander electrode 53, and a peripheral phase shifter for providing an electrical phase difference between the transmission / reflection electrodes is required as shown in FIG.

Elements necessary for exhibiting the performance of the surface acoustic wave device are represented by an electric circuit (including a phase shifter) 54, and the group-type unidirectional electrodes are represented by connection of an n-terminal circuit represented by a scattering matrix. This is shown in FIG.

In FIG. 20, S indicates a transmission electrode, T indicates a reflection electrode, U indicates an electric circuit, and P indicates a propagation path of a surface acoustic wave between the transmission and reflection electrodes.

The derivation of the configuration conditions by the equivalent circuit shown in FIG. 20 was performed under the following conditions.

First, the first condition relates to the transmitting / reflecting electrode, and a. Reversibility between each terminal, b. Symmetry between acoustic terminals, c. The unitary property of the scattering matrix was used as a condition.

Next, the second condition relates to an electric circuit, and a. Reversibility between each terminal, b. The power supply and the terminal 3 must be matched.

Further, the third condition relates to the propagation path, and a. Absence of reflection, b. The condition was that there was no propagation loss.

Further, as a fourth condition, in order to obtain the configuration conditions of the surface acoustic wave device, the frequency domain was set near the propagation center frequency.

The conditions a and b of the third condition are both approximately the actual surface acoustic wave devices.

Using these conditions and considering the interaction between the transmitting and reflecting electrodes and deriving the perfect unidirectional configuration condition of the group-type unidirectional electrode, the following expression 45 is obtained.

Pi / Pq = exp (−jΦm) (Equation 45) (where Pi is the power applied to the reflective electrode, and Pq is
Exp is the power of the base of the natural logarithm, j is the imaginary unit, Φm is the geometric phase difference between the reflecting electrode and the transmitting electrode, and Φm ≠ (180 · n) °,
(n: integer) FIG. 21 shows an example of the frequency characteristic and the group delay time characteristic of the surface acoustic wave filter according to the seventh embodiment of the present invention.

This filter uses a ST-cut crystal as a substrate, deposits Al on the substrate, and forms a 0.5 μm-thick interdigital electrode by etching.

When the geometric phase difference between the input electrodes is 4π / 3, 1
60 pairs of group-type unidirectional electrodes are used, and 190 pairs of weighted bidirectional electrodes are used as output electrodes.

FIG. 47 shows a configuration example of the seventh embodiment.

This configuration is similar to that of the group type unidirectional electrode 56,
It has a bidirectional electrode 57, a phase shifter element (coil) 58, and a power supply.

By applying the condition of Equation 44 to the input-side unidirectional electrode, it is possible to sufficiently suppress the component caused by RW in the TTE.

As a result, as shown in FIG. 21, a surface acoustic wave filter in which no ripple exists in the signal pass band and the group delay time deviation (ripple of the group delay time deviation) is sufficiently compressed is obtained. Is achieved.

The configuration conditions shown in Equation 44 can be applied to not only the substrate and electrode configuration shown in the seventh embodiment but also all other types of substrates and unidirectional electrode configurations.

FIG. 23 shows an electrode configuration diagram of a surface acoustic wave device according to an eighth embodiment of the present invention.

The electrode has a sending electrode 51, a reflecting electrode 52 and a meandering electrode 53.

Reference numeral 55 denotes a geometric phase difference between the transmitting / reflecting electrodes. Note that this electrode represents one group of unidirectional electrodes.

Λ represents the wavelength of the surface acoustic wave at the center frequency in the signal pass band.

In this embodiment, the geometric phase difference between the transmitting and reflecting electrodes can be set to any value by changing L in the figure.

As shown in Equation 45, there is no particular restriction on the geometric phase difference, and the width of each electrode finger of the transmitting electrode and the reflection electrode is equal to the value of the electrode if the electrode structure satisfies Equation 45. Is not a problem.

This electrode configuration is used for part or all of the surface acoustic wave device electrodes, and by arranging the electrodes so as to satisfy the condition of Expression 44, it is possible to suppress the component of the TTE caused by RW. Thus, it is possible to reduce the ripple in the signal pass band and suppress the group delay time deviation.

FIG. 24 shows an electrode configuration diagram of a surface acoustic wave device according to a ninth embodiment of the present invention.

Also in this embodiment, the electrode is the sending electrode 5.
1. It has a reflective electrode 52 and a meander electrode 53. L represents a geometric phase difference between the transmitting / reflecting electrodes.

The present electrode represents one group of unidirectional electrodes, and is designed to satisfy the condition of Expression 45 derived so as to satisfy the condition of Expression 44.

Since there is no constraint on the geometric phase difference between the transmitting and reflecting electrodes in the condition of Equation 45, if L is set to an appropriate value, the absolute value of each admittance of the transmitting and reflecting electrodes will be different. By doing so, complete unidirectionality can be realized even with one phase shifter element.

By using this electrode configuration for part or all of the electrodes of the surface acoustic wave device, the component caused by RW in the TTE is suppressed, so that the ripple in the signal pass band is reduced and the group delay is reduced. The time deviation can be suppressed, and a surface acoustic wave device in which the number of phase shifter elements is reduced to one can be configured. Also in this case, as long as the electrode finger width L of the sending electrode / reflection electrode satisfies Expression 45, there is no problem irrespective of the value.

FIG. 25 is a diagram showing an electrode configuration of a surface acoustic wave device according to a tenth embodiment of the present invention.

Also in this embodiment, the electrode is the sending electrode 5
1, a reflective electrode 52 and a meander electrode 53.

This electrode also represents one group of unidirectional electrodes,
It is manufactured to satisfy the condition of Expression 45, which is derived so as to satisfy the condition of Expression 44, and further has a configuration for suppressing MEL.

Under the construction conditions of Equation 45, there is no constraint on the geometric phase difference between the transmitting and reflecting electrodes.
It is possible to adopt a configuration in which MEL is completely suppressed.

Further, as in the above embodiment, complete unidirectionality can be realized even if only one phase shifter element is provided.

By using this electrode configuration for part or all of the surface acoustic wave device electrodes, it is possible to reduce ripples in the signal pass band due to suppression of TTE and suppression of group delay time deviation. A surface acoustic wave device in which the number of elements is reduced to one can be configured.

In this case as well, there is no restriction on the geometric phase difference, as shown by Equation 45, and the width of each electrode finger of the sending electrode and the reflecting electrode satisfies Equation 45, and the distance between the sending electrode and the reflecting electrode is Any structure may be used as long as it has an electrode structure in which the absolute value of each admittance is set to a different value and suppresses MEL.

FIG. 26 shows an electrode configuration diagram of a surface acoustic wave device according to an eleventh embodiment of the present invention.

Also in this embodiment, the electrode is the sending electrode 5
1, a reflective electrode 52 and a meander electrode 53.

As in the tenth embodiment, the electrodes represent one group of unidirectional electrodes, and are manufactured so as to satisfy the condition of Expression 45, which is derived to satisfy the condition of Expression 44. It is configured to suppress MEL.

Further, as in the tenth embodiment, complete unidirectionality can be realized even with one phase shifter element.

The tenth embodiment and the eleventh embodiment each have an electrode configuration of a surface acoustic wave device which can suppress MEL in accordance with the change of L in the ninth embodiment.

In both the tenth embodiment and the eleventh embodiment, there is no constraint condition on the geometric phase difference corresponding to L in the ninth embodiment, the MEL can be suppressed, and the phase shifter element is used. This is a configuration that requires only one.

FIG. 27 shows an electrode configuration diagram of a surface acoustic wave device according to a twelfth embodiment of the present invention.

Also in this embodiment, the electrode is the delivery electrode 5
1, a reflective electrode 52 and a meander electrode 53.

The present electrode also represents one group of unidirectional electrodes, and is derived so as to satisfy the condition of Expression 44.
And the component caused by the RW in the TTE can be suppressed, the ripple in the signal pass band can be reduced, and the group delay time deviation can be suppressed, as in the ninth embodiment. Becomes

The present electrode is designed such that the admittances of the transmitting electrode and the reflecting electrode are different and their absolute values are equal. The number of phase shifter elements provided is one or less, and complete unidirectionality is realized. It is a configuration that can be done.

By using this electrode configuration for part or all of the electrodes of the surface acoustic wave device, it is possible to reduce ripples in the signal pass band and suppress group delay time deviation due to TTE suppression. A surface acoustic wave device in which the number of device elements is reduced to one or less is obtained.

Also in this case, as shown in Equation 45, there is no constraint on the geometric phase difference, and the electrode finger widths of the sending electrode and the reflecting electrode satisfy Equation 45, and the sending electrode and the reflecting electrode As long as the admittances of the electrodes are different and the electrode structure makes the absolute value of each admittance equal, the value does not matter.

FIG. 53 shows an electrode configuration diagram of a surface acoustic wave device according to a thirteenth embodiment of the present invention.

Also in this embodiment, the electrode is the sending electrode 5
1, a reflective electrode 52 and a meander electrode 53.

This electrode also represents one group of one-way electrodes, and is derived so as to satisfy the condition of Expression 44.
And the MEL
Is suppressed.

The construction condition expressed by Equation 45 has no constraint on the geometric phase difference between the transmitting and reflecting electrodes.
A configuration that completely suppresses L can be realized.

Further, as in the eleventh embodiment, complete unidirectionality can be realized even with one or less phase shifter elements.

By using the present electrode configuration for part or all of the surface acoustic wave device electrodes, it is possible to reduce ripples in the signal pass band and suppress group delay time deviation due to suppression of the TTE. A surface acoustic wave device in which the number of elements is reduced to one or less can be obtained.

In this case as well, there is no constraint on the geometric phase difference as shown in Equation 45, and the electrode finger widths of the sending electrode and the reflecting electrode satisfy Equation 45, and the sending electrode and the reflecting electrode The electrode finger width does not matter as long as the electrode structure is such that the absolute value of each admittance is different and the structure can be configured to suppress MEL.

FIG. 29 is a diagram showing an electrode configuration of a surface acoustic wave device according to a fourteenth embodiment of the present invention.

Also in this embodiment, the electrode is the delivery electrode 5
1, a reflective electrode 52 and a meander electrode 53.

As in the twelfth embodiment, the electrodes represent one group of unidirectional electrodes, and are configured to satisfy the condition of Expression 45 derived so as to satisfy the condition of Expression 44. , MEL are suppressed. Further, as in the above embodiment, complete unidirectionality can be realized even with one or less phase shifter elements.

The thirteenth embodiment and the fourteenth embodiment both have an electrode configuration of a surface acoustic wave device capable of suppressing MEL in accordance with the change of L in the twelfth embodiment.

In both the thirteenth and fourteenth embodiments, there is no constraint on the geometric phase difference corresponding to L of the twelfth embodiment, MEL can be suppressed, and the phase shifter element can be used. A configuration that requires only one or less is sufficient.

FIG. 30 shows an electrode configuration diagram of a surface acoustic wave device according to a fifteenth embodiment of the present invention.

In the present embodiment, the transmitting electrode 51 and the reflecting electrode 5
2. It has a meander electrode 53 and a capacitive electrode pattern 59.

This electrode represents one group of one-way electrodes, and is derived by satisfying the expression (45) to satisfy the condition of expression (44).
Is satisfied so that the TTE can be suppressed, the ripple in the signal pass band can be reduced, and the group delay time deviation can be suppressed, similarly to the above embodiment.

This electrode is manufactured so that the admittances of the sending electrode and the reflecting electrode are different from each other and the absolute values thereof are equal. Configuration.

On a piezoelectric substrate, a phase shifter element as shown in FIG.
By providing the capacitive electrode pattern 59 configured as shown in (1), the surface acoustic wave device does not require any phase shifter element.

As described above, since at least one of the capacitive and inductive electrode patterns is provided on the piezoelectric element substrate as the phase shifter element, an elastic phase shifter element that does not require an external phase shifter element is required. A surface acoustic wave device can be configured.

By using the present electrode configuration for part or all of the surface acoustic wave device electrodes, it is possible to reduce ripples in the signal pass band and suppress group delay time deviation due to suppression of TTE. A surface acoustic wave device that does not require a phase element can be obtained.

In this case as well, as shown in Equation 45, there is no constraint on the geometric phase difference, and the electrode finger widths of the transmitting electrode and the reflecting electrode satisfy Equation 45, and the transmission electrode It is sufficient that the admittance of the reflective electrode is different and the electrode structure has the same absolute value.

As described above, in order to obtain complete unidirectionality, each electrode is arranged under predetermined configuration conditions, and in order to further suppress MEL, a gap is formed in the meander electrode. A surface acoustic wave device having a configuration provided with is also considered.

By the way, various application examples of the present apparatus are also conceivable.

First, a surface acoustic wave device provided with at least one surface acoustic wave device is also conceivable.

Further, a communication device including at least one surface acoustic wave device described above, using the surface acoustic wave device as an electric signal filter, and incorporating the surface acoustic wave device is also conceivable.

FIG. 31 shows a configuration diagram of a communication apparatus according to a sixteenth embodiment of the present invention.

This communication device comprises a filter 61, an antenna 6
0, mixer 63, down-converter PLL synthesizer, up-converter PLL synthesizer, IF filter, modulator, demodulator, T / R switch, and amplifier 62.

The filter 61 employs the surface acoustic wave device according to the present invention.

Mixer 63, down-converter PLL synthesizer, up-converter PLL synthesizer, IF
Filter, modulator, demodulator, T / R switch, amplifier 6
2 can be realized by, for example, a resistor, a transistor, a coil, a capacitor, various CMOSs, a dedicated LSI, or the like.

The signal is modulated by the modulator, and the modulated signal and the signal of the up-converter PLL synthesizer are mixed by the mixer 63. The mixing signal is amplified by the amplifier 62 and then filtered by the filter 61, and the T / R switch is set to the “T” side (t
When the antenna 6 is connected to the
A signal is transmitted to a predetermined area via 0.

This is the operation at the time of transmission. The operation at the time of reception is as follows.

The signal received via the antenna 60 is
When the T / R switch is connected to the "R" side (receive side), the signal is filtered by the filter 61 and then amplified by the amplifier 62. The amplified signal is mixed with the output signal of the down converter PLL synthesizer and the mixer. At 63, the IF signal is mixed.

After passing through the IF filter, the IF signal is demodulated by a demodulator to obtain a desired signal.

The above is the description of the operation of the communication apparatus shown in FIG.

Since various types of communication devices are required to be small and lightweight at the time of manufacture, it is preferable that the peripheral elements required for the surface acoustic wave filter be as small as possible.

By using the surface acoustic wave filter according to the present invention, it is possible to improve the performance of the communication device shown in FIG. 31 and to reduce the size by reducing the number of phase shifter elements.

When the number of phase shifter elements is reduced, it is possible to simplify various adjustments required to cope with variations in phase shifter elements.

As described above, by arranging the transmitting electrode, the reflecting electrode, the meandering electrode, and the like under predetermined configuration conditions, it is possible to realize a surface acoustic wave device that realizes suppression of the TTE and, consequently, complete unidirectionality. Various application devices are also conceivable.

FIG. 32 shows a surface acoustic wave device according to a seventeenth embodiment of the present invention.
1 and a conductive thin film electrode formed on the substrate.

Further, in the present embodiment, the conductive thin-film electrode comprises an interdigital transmitter electrode 73 and an interdigital reflective electrode 7.
4 and a meander electrode 75. Reference numeral 76 denotes a surface acoustic wave absorber.

In this embodiment, the meander electrode is provided, but the meander electrode may not be necessarily used.

The surface acoustic wave device according to the present embodiment functions, for example, as a filter for a high-frequency electric signal. The electrode finger film thickness is 0.015λ (the center wavelength of the surface acoustic wave is λ), and the frequency characteristics of the insertion loss in the forward and reverse directions of the surface acoustic wave energy propagation are, for example, as shown in FIG. Is shown.

In FIG. 35, the horizontal axis indicates the frequency of the surface acoustic wave, and the vertical axis indicates the amount of attenuation, which means that the amount of attenuation increases as going downward. Numerals 77 and 78 are curves showing the frequency characteristics of the insertion loss in the forward and reverse directions, respectively.

FIGS. 33 and 34 show the relationship between the electrode finger width, the electrode finger thickness, and the directivity, which is the difference between the forward and reverse directions of the frequency characteristics of the insertion loss of surface acoustic wave energy.

FIGS. 33 and 34 correspond to FIG.
6 shows characteristics in the pattern shown in FIG.

As a result, the electrode finger width and the electrode finger thickness are not limited to the values shown in the following embodiments, and the electrode finger width is not changed at the center position of each electrode finger, but is partially changed. ,
Alternatively, all of the values are set to a value obtained by expanding the width by a certain width in the range of 0 ≦ increase width of the electrode finger <λ / 8, or a value obtained by reducing the width by a certain width in the range of 0 ≦ reduction width of the electrode finger <λ / 8. It can be seen that the direction of the surface acoustic wave energy to be propagated can be controlled. At this time, the electrode finger thickness is also 0.002λ to 0.05λ.
By changing the characteristic impedance per electrode finger, the directionality can be changed as shown in FIG. That is, it is understood that the surface acoustic wave device can be configured so as to obtain a desired directionality.

That is, considering the one-period configuration of the electrode pattern, if the acoustic reflection of the surface acoustic wave energy at each electrode edge is superimposed, the amplitude and phase are different in the forward and reverse directions, This is because the surface wave has directionality with respect to propagation.

Hereinafter, a representative pattern will be described which gives a higher value of directionality as the number of phase shifters can be reduced.

FIG. 36 shows a first example of the surface acoustic wave device according to the present invention.
FIG. 14 shows an eighth embodiment, and is a pattern diagram of a conductive thin-film electrode arranged on a surface acoustic wave substrate. Reference numeral 73 denotes an interdigital sending electrode, 74 denotes an interdigital reflecting electrode, and 75 denotes a meander electrode.

In the present embodiment, the film thickness is 0.015λ. At this time, as shown in FIG. 36, the electrode pattern of one period has a meander electrode finger width λ / 8 and a gap λ.
/ 8, electrode finger width of the sending electrode 3λ / 8, gap λ / 8, meander electrode finger width λ / 8, gap λ / 4, reflective electrode electrode finger width λ / 8, gap λ / 4, meander electrode finger width λ / 8, gap λ
/ 8, meander electrode finger width λ / 8, and gap λ / 8.

As shown in the seventeenth embodiment, if the arrangement of the electrodes and the gaps is in the above order, the electrode finger width and the electrode finger film thickness are not limited to these values. The width does not change the center position of each electrode finger.
Alternatively, each is set to a value obtained by expanding the width by a certain width in the range of 0 ≦ increase width of the electrode finger <λ / 8, or a value obtained by shrinking the width by a certain width in the range of 0 ≦ reduction width of the electrode finger <λ / 8. By doing so, the directionality of the propagating surface acoustic wave energy can be controlled. Also, by setting the electrode finger thickness in the range of 0.002λ to 0.05λ, the directionality of the surface acoustic wave energy can be controlled. This is true for all embodiments of the present invention. For example, as can be seen with reference to FIG. 52, the electrode finger width of the electrode pattern per cycle is, as can be seen from FIG. 52, the meander electrode finger width λ / 16, the gap 3λ / 16, and the sending electrode electrode finger width 5λ /.
16, gap 3λ / 16, meander electrode finger width λ / 16, gap 5λ / 16, reflective electrode electrode finger width λ / 16, gap 5λ
/ 16, meander electrode finger width λ / 16, air gap 3λ / 16,
In some cases, the meander electrode finger width λ / 16 and the gap 3λ / 16 are arranged in this order.

FIG. 37 shows a nineteenth embodiment of the surface acoustic wave device according to the present invention, and is a pattern diagram of conductive thin-film electrodes arranged on a surface acoustic wave substrate. 73
Is an interdigital sending electrode; 74 is an interdigital reflecting electrode;
Reference numeral 5 denotes a meander electrode.

In this embodiment, the film thickness is 0.015λ. At this time, as shown in FIG. 37, the electrode pattern of one period has a meander electrode finger width λ / 8 and a gap λ / 8, electrode finger width 3λ / 8, gap λ / 8, meander electrode finger width 3λ / 16, gap λ / 4, electrode finger width λ / 8 of reflective electrode, gap λ / 4, meander electrode finger width λ / 8,
The gap λ / 8, the meander electrode finger width λ / 16, and the gap λ / 8 are arranged in this order.

As in the above embodiment, if the arrangement of the electrodes and the gaps is in the above order, the electrode finger width and the electrode finger thickness are not limited to these values.
The center position of each electrode finger is not changed, and a part or all of the electrode finger is extended from the above width by a certain width in the range of 0 ≦ increase width of electrode finger <λ / 8, or 0 ≦ electrode finger. The directionality of the surface acoustic wave energy to be propagated can be controlled by setting the value to be reduced by a certain width in the range of the reduction width <λ / 8. Also, by setting the electrode finger thickness in the range of 0.002λ to 0.05λ, the directionality of the surface acoustic wave energy can be controlled.

FIG. 38 shows a twentieth embodiment of a surface acoustic wave device according to the present invention, and is a pattern diagram of conductive thin-film electrodes arranged on a surface acoustic wave substrate. 73
Is an interdigital sending electrode; 74 is an interdigital reflecting electrode;
Reference numeral 5 denotes a meander electrode.

In this embodiment, the film thickness is 0.015λ. At this time, as shown in FIG. 38, the electrode pattern of one period has a meander electrode finger width λ / 8 and a gap λ.
/ 8, electrode finger width 3λ / 8, gap λ / 8, meander electrode finger width λ / 4, gap λ / 4, reflective electrode electrode finger width λ / 8, gap λ / 4, meander electrode finger width λ / 8, gap λ
/ 4.

As in the above-described embodiment, if the arrangement of the electrodes and the gaps is in the order described above, the electrode finger width and the electrode finger thickness are not limited to these values.
The center position of each electrode finger is not changed, and a part or all of the electrode finger is extended from the above width by a certain width in the range of 0 ≦ increase width of electrode finger <λ / 8, or 0 ≦ electrode finger. The directionality of the surface acoustic wave energy to be propagated can be controlled by setting the value to be reduced by a certain width in the range of the reduction width <λ / 8. Also, by setting the electrode finger thickness in the range of 0.002λ to 0.05λ, the directionality of the surface acoustic wave energy can be controlled.

FIG. 39 shows a twenty-first embodiment of a surface acoustic wave device according to the present invention, and is a pattern diagram of conductive thin-film electrodes arranged on a surface acoustic wave substrate. 73
Is an interdigital sending electrode; 74 is an interdigital reflecting electrode;
Reference numeral 5 denotes a meander electrode.

In this embodiment, the film thickness is 0.015λ. At this time, as shown in FIG. 39, the electrode pattern of one period has a meander electrode finger width λ / 8 and a gap λ.
/ 8, electrode finger width 3λ / 8, gap λ / 8, meander electrode finger width 5λ / 16, gap λ / 4, electrode finger width λ / 8 of reflective electrode, gap λ / 4, meander electrode finger width λ / 8 and a gap 3λ / 16.

As in the above embodiment, if the arrangement of the electrodes and the gaps is in the order described above, the electrode finger width and the electrode finger thickness are not limited to these values.
The center position of each electrode finger is not changed, and a part or all of the electrode finger is extended from the above width by a certain width in the range of 0 ≦ increase width of electrode finger <λ / 8, or 0 ≦ electrode finger. The directionality of the surface acoustic wave energy to be propagated can be controlled by setting the value to be reduced by a certain width in the range of the reduction width <λ / 8. Also, by setting the electrode finger thickness in the range of 0.002λ to 0.05λ, the directionality of the surface acoustic wave energy can be controlled.

FIG. 40 shows a twenty-second embodiment of a surface acoustic wave device according to the present invention, and is a pattern diagram of conductive thin-film electrodes arranged on a surface acoustic wave substrate. 73
Is an interdigital sending electrode; 74 is an interdigital reflecting electrode;
Reference numeral 5 denotes a meander electrode.

In this embodiment, the film thickness is 0.015λ. At this time, as shown in FIG. 40, the electrode pattern of one period has a meander electrode finger width λ / 8 and a gap λ.
/ 8, electrode finger width 3λ / 8, gap λ / 8, meander electrode finger width λ / 8, gap λ / 4, electrode finger width λ / 8 of reflective electrode, gap λ / 8, meander electrode finger width 5λ / 8, air gap λ / 8, electrode finger width of reflective electrode λ / 8, air gap λ / 4, meander electrode finger width λ / 8, air gap λ / 8, meander electrode finger width λ
/ 8 and the gap λ / 8.

As in the above embodiment, if the arrangement of the electrodes and the gaps is in the above order, the electrode finger width and the electrode finger thickness are not limited to these values.
The center position of each electrode finger is not changed, and a part or all of the electrode finger is extended from the above width by a certain width in the range of 0 ≦ increase width of electrode finger <λ / 8, or 0 ≦ electrode finger. The directionality of the surface acoustic wave energy to be propagated can be controlled by setting the value to be reduced by a certain width in the range of the reduction width <λ / 8. Also, by setting the electrode finger thickness in the range of 0.002λ to 0.05λ, the directionality of the surface acoustic wave energy can be controlled.

FIG. 41 shows a twenty-third embodiment of a surface acoustic wave device according to the present invention, and is a pattern diagram of conductive thin-film electrodes arranged on a surface acoustic wave substrate. 73
Is an interdigital sending electrode; 74 is an interdigital reflecting electrode;
Reference numeral 5 denotes a meander electrode.

In this embodiment, the film thickness is 0.015λ. At this time, as can be seen from FIG. 41, the electrode pattern of one period has a meander electrode finger width λ / 8 and a gap λ.
/ 8, electrode finger width 3λ / 8, gap λ / 8, meander electrode finger width 3λ / 16, gap λ / 4, electrode finger width λ / 8 of reflective electrode, gap λ / 8, meander electrode finger width 5λ / 8,
Gap λ / 8, electrode finger width λ / 8 of the reflective electrode, gap λ / 4,
The meander electrode finger width λ / 8, the gap λ / 8, the meander electrode finger width λ / 16, and the gap λ / 8 are arranged in this order.

As in the above embodiment, if the arrangement of the electrodes and the gaps is in the order described above, the electrode finger width and the electrode finger thickness are not limited to these values.
The center position of each electrode finger is not changed, and a part or all of the electrode finger is extended from the above width by a certain width in the range of 0 ≦ increase width of electrode finger <λ / 8, or 0 ≦ electrode finger. The directionality of the surface acoustic wave energy to be propagated can be controlled by setting the value to be reduced by a certain width in the range of the reduction width <λ / 8. Also, by setting the electrode finger thickness in the range of 0.002λ to 0.05λ, the directionality of the surface acoustic wave energy can be controlled.

FIG. 42 shows a twenty-fourth embodiment of a surface acoustic wave device according to the present invention, and is a pattern diagram of conductive thin-film electrodes arranged on a surface acoustic wave substrate. 73
Is an interdigital sending electrode; 74 is an interdigital reflecting electrode;
Reference numeral 5 denotes a meander electrode.

In this embodiment, the film thickness is 0.015λ. At this time, as can be seen from FIG. 42, the electrode pattern of one period has a meander electrode finger width λ / 8 and a gap λ.
/ 8, electrode finger width 3λ / 8, gap λ / 8, meander electrode finger width λ / 4, gap λ / 4, reflective electrode electrode finger width λ / 8, gap λ / 8, meander electrode finger width 5λ / 8, the gap λ / 8, the electrode finger width λ / 8 of the reflective electrode, the gap λ / 4, the meander electrode finger width λ / 8, and the gap λ / 4.

As in the above embodiment, if the arrangement of the electrodes and the gaps is in the order described above, the electrode finger width and the electrode finger thickness are not limited to these values.
The center position of each electrode finger is not changed, and a part or all of the electrode finger is extended from the above width by a certain width in the range of 0 ≦ increase width of electrode finger <λ / 8, or 0 ≦ electrode finger. The directionality of the surface acoustic wave energy to be propagated can be controlled by setting the value to be reduced by a certain width in the range of the reduction width <λ / 8. Also, by setting the electrode finger thickness in the range of 0.002λ to 0.05λ, the directionality of the surface acoustic wave energy can be controlled.

FIG. 43 shows a twenty-fifth embodiment of the surface acoustic wave device according to the present invention, and is a pattern diagram of conductive thin-film electrodes arranged on a surface acoustic wave substrate. 73
Is an interdigital sending electrode; 74 is an interdigital reflecting electrode;
Reference numeral 5 denotes a meander electrode.

In this embodiment, the film thickness is 0.015λ. At this time, as shown in FIG. 43, the electrode pattern of one period has a meander electrode finger width λ / 8 and a gap λ.
/ 8, electrode finger width 3λ / 8, gap λ / 8, meander electrode finger width 5λ / 16, gap λ / 4, reflection electrode electrode finger width λ / 8, gap λ / 8, meander electrode finger width 5λ / 8,
Gap λ / 8, electrode finger width λ / 8 of the reflective electrode, gap λ / 4,
The meander electrode finger width λ / 8 and the gap 3λ / 16 are arranged in this order.

As in the above embodiment, if the arrangement of the electrodes and the gaps is in the order described above, the electrode finger width and the electrode finger thickness are not limited to these values.
The center position of each electrode finger is not changed, and a part or all of the electrode finger is extended from the above width by a certain width in the range of 0 ≦ increase width of electrode finger <λ / 8, or 0 ≦ electrode finger. The directionality of the surface acoustic wave energy to be propagated can be controlled by setting the value to be reduced by a certain width in the range of the reduction width <λ / 8. Also, by setting the electrode finger thickness in the range of 0.002λ to 0.05λ, the directionality of the surface acoustic wave energy can be controlled.

FIG. 44 shows a twenty-sixth embodiment of a surface acoustic wave device according to the present invention, and is a pattern diagram of conductive thin-film electrodes arranged on a surface acoustic wave substrate. 73
Denotes an interdigital sending electrode, and 74 denotes an interdigital reflecting electrode. In other words, the meander electrode is not provided.

In this embodiment, the film thickness is 0.015λ. At this time, as shown in FIG. 44, the electrode pattern of one period has an electrode finger width λ / 8 of the reflective electrode and a gap λ. / 8, sending electrode electrode finger width 3λ / 8, gap λ / 8, reflecting electrode electrode finger width λ / 8, gap λ / 4, sending electrode electrode finger width λ / 8, gap λ / 4, reflecting electrode Electrode finger width λ / 8,
The gap λ / 8, the electrode finger width λ / 8 of the reflective electrode, and the gap λ / 8 are arranged in this order.

As in the above embodiment, if the arrangement of the electrodes and the gaps is in the order described above, the electrode finger width and the electrode finger thickness are not limited to these values.
The center position of each electrode finger is not changed, and a part or all of the electrode finger is extended from the above width by a certain width in the range of 0 ≦ increase width of electrode finger <λ / 8, or 0 ≦ electrode finger. The directionality of the surface acoustic wave energy to be propagated can be controlled by setting the value to be reduced by a certain width in the range of the reduction width <λ / 8. Also, by setting the electrode finger thickness in the range of 0.002λ to 0.05λ, the directionality of the surface acoustic wave energy can be controlled.

FIG. 45 shows a twenty-seventh embodiment of the surface acoustic wave device according to the present invention, and is a pattern diagram of conductive thin-film electrodes arranged on a surface acoustic wave substrate. 73
Denotes an interdigital sending electrode, and 74 denotes an interdigital reflecting electrode.

In this embodiment, the film thickness is 0.015λ. At this time, as shown in FIG. 45, the electrode pattern of one period has an electrode finger width λ / 8 of the reflective electrode and a gap λ. / 8, electrode finger width of the sending electrode 3λ / 8, gap λ / 8, electrode finger width of the reflecting electrode 3λ / 16, gap λ / 4, electrode finger width of the sending electrode λ / 8, gap λ / 4, reflecting electrode Electrode finger width λ /
8, gap λ / 8, electrode finger width λ / 16 of reflective electrode, gap λ
/ 8.

As in the above embodiment, if the arrangement of the electrodes and the gaps is in the order described above, the electrode finger width and the electrode finger film thickness are not limited to these values.
The center position of each electrode finger is not changed, and a part or all of the electrode finger is extended from the above width by a certain width in the range of 0 ≦ increase width of electrode finger <λ / 8, or 0 ≦ electrode finger. The directionality of the surface acoustic wave energy to be propagated can be controlled by setting the value to be reduced by a certain width in the range of the reduction width <λ / 8. Also, by setting the electrode finger thickness in the range of 0.002λ to 0.05λ, the directionality of the surface acoustic wave energy can be controlled.

FIG. 46 shows a twenty-eighth embodiment of the surface acoustic wave device according to the present invention, and is a pattern diagram of conductive thin-film electrodes arranged on a surface acoustic wave substrate. 73
Denotes an interdigital sending electrode, and 74 denotes an interdigital reflecting electrode.

In this embodiment, the film thickness is 0.015λ. At this time, as can be seen from FIG. 46, the electrode pattern of one period has an electrode finger width λ / 8 of the reflective electrode and a gap λ. / 8, sending electrode electrode finger width 3λ / 8, gap λ / 8, reflecting electrode electrode finger width λ / 4, gap λ / 4, sending electrode electrode finger width λ / 8, gap λ / 4, reflecting electrode Electrode finger width λ / 8,
The gaps are arranged in the order of λ / 4.

As in the above embodiment, if the arrangement of the electrodes and the gaps is in the above order, the electrode finger width and the electrode finger thickness are not limited to these values.
The center position of each electrode finger is not changed, and a part or all of the electrode finger is extended from the above width by a certain width in the range of 0 ≦ increase width of electrode finger <λ / 8, or 0 ≦ electrode finger. The directionality of the surface acoustic wave energy to be propagated can be controlled by setting the value to be reduced by a certain width in the range of the reduction width <λ / 8. Also, by setting the electrode finger thickness in the range of 0.002λ to 0.05λ, the directionality of the surface acoustic wave energy can be controlled.

FIG. 47 shows a twenty-ninth embodiment of a surface acoustic wave device according to the present invention. FIG. 47 is a pattern diagram of a conductive thin film electrode disposed on a surface acoustic wave substrate.
The interdigital electrode 74 indicates an interdigital electrode.

In this embodiment, the film thickness is 0.015λ. At this time, as shown in FIG. 47, the electrode pattern of one period has an electrode finger width λ / 8 of the reflection electrode and a gap λ. / 8, electrode finger width of the sending electrode 3λ / 8, gap λ / 8, electrode finger width of the reflecting electrode 5λ / 16, gap λ / 4, electrode finger width of the sending electrode λ / 8, gap λ / 4, reflecting electrode Electrode finger width λ /
8, the gap 3λ / 16.

As in the above embodiment, if the arrangement of the electrodes and the gaps is in the order described above, the electrode finger width and the electrode finger film thickness are not limited to these values.
The center position of each electrode finger is not changed, and a part or all of the electrode finger is extended from the above width by a certain width in the range of 0 ≦ increase width of electrode finger <λ / 8, or 0 ≦ electrode finger. The directionality of the surface acoustic wave energy to be propagated can be controlled by setting the value to be reduced by a certain width in the range of the reduction width <λ / 8. Also, by setting the electrode finger thickness in the range of 0.002λ to 0.05λ, the directionality of the surface acoustic wave energy can be controlled.

FIG. 48 shows a thirtieth embodiment of a surface acoustic wave device according to the present invention, and is a pattern diagram of conductive thin-film electrodes arranged on a surface acoustic wave substrate. 73
Denotes an interdigital sending electrode, and 74 denotes an interdigital reflecting electrode.

In this embodiment, the film thickness is 0.015λ. At this time, as shown in FIG. 48, the electrode pattern of one period has an electrode finger width λ / 8 of the reflective electrode and a gap λ. / 8, sending electrode electrode finger width 3λ / 8, gap λ / 8, reflecting electrode electrode finger width λ / 8, gap λ / 4, sending electrode electrode finger width λ / 8, gap λ / 8, reflecting electrode Electrode finger width of 5λ /
8, gap λ / 8, electrode finger width λ / 8 of the sending electrode, gap λ /
4, the electrode finger width λ / 8 of the reflection electrode, the gap λ / 8, the electrode finger width λ / 8 of the reflection electrode, and the gap λ / 8 in this order.

As in the above embodiment, if the arrangement of the electrodes and the gaps is in the order described above, the electrode finger width and the electrode finger thickness are not limited to these values.
The center position of each electrode finger is not changed, and a part or all of the electrode finger is extended from the above width by a certain width in the range of 0 ≦ increase width of electrode finger <λ / 8, or 0 ≦ electrode finger. The directionality of the surface acoustic wave energy to be propagated can be controlled by setting the value to be reduced by a certain width in the range of the reduction width <λ / 8. Also, by setting the electrode finger thickness in the range of 0.002λ to 0.05λ, the directionality of the surface acoustic wave energy can be controlled. FIG.
FIG. 9 shows a thirty-first embodiment of the surface acoustic wave device according to the present invention, and is a pattern diagram of conductive thin-film electrodes arranged on a surface acoustic wave substrate. Reference numeral 73 denotes an interdigital electrode, and 74 denotes an interdigital reflective electrode.

In this embodiment, the film thickness is 0.015λ. At this time, as shown in FIG. 49, the electrode pattern of one period has an electrode finger width λ / 8 of the reflective electrode and a gap λ. / 8, sending electrode electrode finger width 3λ / 8, gap λ / 8, reflecting electrode electrode finger width 3λ / 16, gap λ / 4, sending electrode electrode finger width λ / 8, gap λ / 8, reflecting electrode Electrode finger width of 5λ
/ 8, gap λ / 8, electrode finger width λ / 8 of sending electrode, gap λ
/ 4, the electrode finger width λ / 8 of the reflective electrode, the gap λ / 8, the electrode finger width λ / 16 of the reflective electrode, and the gap λ / 8.

As in the above embodiment, if the arrangement of the electrodes and the gaps is in the order described above, the electrode finger width and the electrode finger thickness are not limited to these values.
The center position of each electrode finger is not changed, and a part or all of the electrode finger is extended from the above width by a certain width in the range of 0 ≦ increase width of electrode finger <λ / 8, or 0 ≦ electrode finger. The directionality of the surface acoustic wave energy to be propagated can be controlled by setting the value to be reduced by a certain width in the range of the reduction width <λ / 8. Also, by setting the electrode finger thickness in the range of 0.002λ to 0.05λ, the directionality of the surface acoustic wave energy can be controlled.

FIG. 50 shows a thirty-second embodiment of the surface acoustic wave device according to the present invention, and is a pattern diagram of conductive thin-film electrodes arranged on a surface acoustic wave substrate. 73
Denotes an interdigital sending electrode, and 74 denotes an interdigital reflecting electrode.

In this embodiment, the film thickness is 0.015λ. At this time, as shown in FIG. 50, the electrode pattern of one period has an electrode finger width λ / 8 of the reflection electrode and a gap λ. / 8, sending electrode electrode finger width 3λ / 8, gap λ / 8, reflecting electrode electrode finger width λ / 4, gap λ / 4, sending electrode electrode finger width λ / 8, gap λ / 8, reflecting electrode Electrode finger width of 5λ /
8, gap λ / 8, electrode finger width λ / 8 of the sending electrode, gap λ /
4, the electrode finger width λ / 8 of the reflective electrode, and the gap λ / 4.

As in the above embodiment, if the arrangement of the electrodes and the gaps is in the order described above, the electrode finger width and the electrode finger thickness are not limited to these values.
The center position of each electrode finger is not changed, and a part or all of the electrode finger is extended from the above width by a certain width in the range of 0 ≦ increase width of electrode finger <λ / 8, or 0 ≦ electrode finger. The directionality of the surface acoustic wave energy to be propagated can be controlled by setting the value to be reduced by a certain width in the range of the reduction width <λ / 8. Also, by setting the electrode finger thickness in the range of 0.002λ to 0.05λ, the directionality of the surface acoustic wave energy can be controlled.

FIG. 51 shows a thirty-third embodiment of a surface acoustic wave device according to the present invention, and is a pattern diagram of a conductive thin film electrode disposed on a surface acoustic wave substrate. 73
Denotes an interdigital sending electrode, and 74 denotes an interdigital reflecting electrode.

In this embodiment, the film thickness is 0.015λ. At this time, as can be seen from FIG. 51, the electrode pattern of one period has the electrode finger width λ / 8 of the reflective electrode and the gap λ. / 8, electrode finger width of the sending electrode 3λ / 8, gap λ / 8, electrode finger width of the reflecting electrode 5λ / 16, gap λ / 4, electrode finger width of the sending electrode λ / 8, gap λ / 8, reflecting electrode Electrode finger width of 5λ
/ 8, gap λ / 8, electrode finger width λ / 8 of sending electrode, gap λ
/ 4, the electrode finger width λ / 8 of the reflective electrode, and the gap 3λ / 16.

As in the above embodiment, if the arrangement of the electrodes and the gaps is in the order described above, the electrode finger width and the electrode finger thickness are not limited to these values.
The center position of each electrode finger is not changed, and a part or all of the electrode finger is extended from the above width by a certain width in the range of 0 ≦ increase width of electrode finger <λ / 8, or 0 ≦ electrode finger. The directionality of the surface acoustic wave energy to be propagated can be controlled by setting the value to be reduced by a certain width in the range of the reduction width <λ / 8. Also, by setting the electrode finger thickness in the range of 0.002λ to 0.05λ, the directionality of the surface acoustic wave energy can be controlled.

FIG. 52 shows a third embodiment of the surface acoustic wave device according to the present invention.
FIG. 6 illustrates a fourth example, and is a pattern diagram of a conductive thin-film electrode arranged on a surface acoustic wave substrate. Reference numeral 73 denotes an interdigital sending electrode, 74 denotes an interdigital reflecting electrode, and 75 denotes a meander electrode.

In this embodiment, the film thickness is 0.015λ. At this time, one period of the electrode pattern has a meander electrode finger width of λ / 16, a gap of 3λ / 16, and an electrode finger width of the sending electrode of 5λ / λ. 16, gap 3λ / 16, meander electrode finger width λ /
16, gap 5λ / 16, electrode finger width λ / 16 of the reflective electrode,
Air gap 5λ / 16, meander electrode finger width λ / 16, air gap 3λ
/ 16, meander electrode finger width λ / 16, and gap 3λ / 16.

As in the above embodiment, if the arrangement of the electrodes and the gaps is in the above order, the electrode finger width and the electrode finger film thickness are not limited to these values.
The center position of each electrode finger is not changed, and a part or all of the electrode finger is extended from the above width by a certain width in the range of 0 ≦ increase width of electrode finger <λ / 8, or 0 ≦ electrode finger. The directionality of the surface acoustic wave energy to be propagated can be controlled by setting the value to be reduced by a certain width in the range of the reduction width <λ / 8. Also, by setting the electrode finger thickness in the range of 0.002λ to 0.05λ, the directionality of the surface acoustic wave energy can be controlled.

FIG. 53 shows a third example of the surface acoustic wave device according to the present invention.
FIG. 5 illustrates a fifth embodiment, and is a pattern diagram of a conductive thin-film electrode arranged on a surface acoustic wave substrate. Reference numeral 73 denotes an interdigital sending electrode, 74 denotes an interdigital reflecting electrode, and 75 denotes a meander electrode.

In this embodiment, the film thickness is 0.015λ. At this time, one period of the electrode pattern has a meander electrode finger width of λ / 16, a void of 7λ / 32, and a feed electrode electrode finger width of 4λ /. 16, air gap 7λ / 32, meander electrode finger width λ /
16, gap 5λ / 16, electrode finger width λ / 16 of the reflective electrode,
Air gap 5λ / 16, meander electrode finger width λ / 16, air gap 3λ
/ 16, meander electrode finger width λ / 16, and gap 3λ / 16.

As in the above-described embodiment, if the arrangement of the electrodes and the gaps is in the order described above, the electrode finger width and the electrode finger thickness are not limited to these values.
The center position of each electrode finger is not changed, and a part or all of the electrode finger is extended from the above width by a certain width in the range of 0 ≦ increase width of electrode finger <λ / 8, or 0 ≦ electrode finger. The directionality of the surface acoustic wave energy to be propagated can be controlled by setting the value to be reduced by a certain width in the range of the reduction width <λ / 8. Also, by setting the electrode finger thickness in the range of 0.002λ to 0.05λ, the directionality of the surface acoustic wave energy can be controlled.

FIG. 54 shows a third embodiment of the surface acoustic wave device according to the present invention.
6 shows six examples.

This apparatus comprises an antenna 79, a transmission / reception switch 80, a reception filter 81, and a reception amplifier 8
2, a receiver including a mixer for reception 83, a down-converter PLL synthesizer 84, an intermediate frequency filter 85, and a demodulator 86; an antenna 79, a transmission / reception center switch 82, a transmission filter 88, and a transmission amplifier 89 , A transmission mixer 90, an up-converter PLL synthesizer 91, and a transmitter including a modulator 92.

As the antenna 79, for example, a parabolic antenna, a lot type antenna or the like may be used.

Transmission / reception change-over switch 80, reception filter 81, reception amplifier 82, reception mixer 83, down-converter PLL synthesizer 84, demodulator 86, transmission filter 88, transmission amplifier 89, transmission mixer 9
0, an up-converter PLL synthesizer 91, a modulator 92, etc.
M, various CMOS, various TTL, transistor, resistance,
It can be realized by electronic devices such as capacitors and coils.

Here, by using a filter device using the surface acoustic wave device according to the present invention as the intermediate frequency filter 85, the number of peripheral elements such as phase shifters can be reduced, and the size of the device can be reduced. it can.

Next, the operation of the present apparatus will be described.

First, a given transmission signal is applied to a modulator 92.
Is modulated. This modulated signal and the upconverter P
The signal sent from the LL synthesizer 91 is input to the transmission mixer 90 and mixed, and the mixed signal is amplified by the transmission amplifier 89. The amplified signal is filtered by a transmission filter 88, and transmitted in a desired direction by an antenna 79 via a transmission / reception switch 82 currently selected on the transmission side.

The reception signal received by the antenna 79 is filtered by the reception filter 81 via the transmission / reception switch 82 selected on the reception side, and further amplified by the reception amplifier 82. You. The amplified signal and the down-converter PLL synthesizer 84
Is input to the receiving mixer 83 to generate an intermediate frequency signal. The intermediate frequency signal is filtered by an intermediate frequency filter 85 and finally demodulated by a demodulator 86 to obtain a desired signal.

In this embodiment, the surface acoustic wave device according to the present invention is used for the communication device shown in FIG. 54, but it goes without saying that the application is not limited to the communication device.

[0231]

According to the present invention, a novel structure of a surface acoustic wave device having frequency characteristics and group delay time characteristics in which ripples are suppressed by suppressing acoustic reflection and a peripheral circuit thereof can be provided.

In particular, the unidirectional electrode has frequency characteristics and group delay time characteristics in which ripples are suppressed,
It is possible to provide a novel structure with a low loss while having a small number of phase shifters, and it is possible to simplify peripheral circuits and to reduce the size and performance of the device.

Furthermore, the performance of the communication device can be improved.

[Brief description of the drawings]

FIG. 1 is a schematic diagram of a surface acoustic wave device.

FIG. 2 is a schematic view of a group type unidirectional interdigital transducer.

FIG. 3 is a schematic view of an internal reflection type unidirectional interdigital transducer.

FIG. 4 is a general equivalent circuit diagram of a unidirectional electrode.

FIG. 5 is a parallel equivalent circuit including internal dissipation.

FIG. 6 is a series equivalent circuit including internal dissipation.

FIG. 7 is a relationship (normal internal equivalent dissipation circuit) of normalized conductance, insertion loss, and acoustic reflection in a bidirectional electrode (κ = 1).

FIG. 8 is a relation (normal internal equivalent dissipation circuit) of normalized conductance, insertion loss, and acoustic reflection in an imperfect unidirectional electrode (κ = 0.5).

FIG. 9 is a graph showing the relationship between normalized conductance, insertion loss, and acoustic reflection in a completely unidirectional electrode (κ = 0) (parallel internal dissipation equivalent circuit).

FIG. 10 is a graph showing the relationship between normalized conductance, insertion loss, and acoustic reflection in a bidirectional electrode (κ = 1) (series internal dissipation equivalent circuit).

FIG. 11 is a graph showing the relationship between normalized conductance, insertion loss, and acoustic reflection in a partially incomplete unidirectional electrode (κ = 0.5) (series internal dissipation power equivalent circuit).

FIG. 12 is a relationship (normal series internal dissipation equivalent circuit) between normalized conductance, insertion loss, and acoustic reflection in a completely unidirectional electrode (κ = 0).

FIG. 13 is a frequency characteristic of the conductance of the IDT including internal dissipation.

FIG. 14 is a frequency characteristic of interdigital electrode resistance including internal dissipation.

FIG. 15 is a measurement result of a scattering matrix element of a unidirectional electrode.

FIG. 16 is a frequency characteristic of a coefficient relating to internal dissipation of the unidirectional electrode.

FIG. 17 is a system block of a television receiver.

FIG. 18 is a system block diagram of a mobile communication terminal.

FIG. 19 is a configuration diagram of an example of a group-type unidirectional electrode.

FIG. 20 is a connection diagram in which a group represents a unidirectional electrode by a scattering matrix.

FIG. 21 is an example of a frequency characteristic and a group delay time characteristic of a surface acoustic wave filter.

FIG. 22 is a configuration diagram example of a surface acoustic wave filter.

FIG. 23 is an explanatory diagram of a group-type unidirectional electrode pattern (1).

FIG. 24 is an explanatory diagram of a group-type unidirectional electrode pattern (2).

FIG. 25 is an explanatory diagram of a group-type unidirectional electrode pattern (3).

FIG. 26 is an explanatory diagram of a group-type unidirectional electrode pattern (4).

FIG. 27 is an explanatory diagram of a group-type unidirectional electrode pattern (5).

FIG. 28 is an explanatory diagram of a group-type unidirectional electrode pattern (6).

FIG. 29 is an explanatory diagram of a group-type unidirectional electrode pattern (7).

FIG. 30 is an explanatory diagram of a group-type unidirectional electrode pattern (8).

FIG. 31 is an explanatory diagram of an application example to a communication device.

FIG. 32 is an explanatory diagram of a surface acoustic wave device.

FIG. 33 is a graph showing the relationship between directionality and electrode finger width when a surface acoustic wave device is used.

FIG. 34 is a graph showing the relationship between directionality and electrode finger width when a surface acoustic wave device is used.

FIG. 35 shows insertion loss frequency characteristics when a surface acoustic wave device is used.

FIG. 36 is an explanatory diagram of a surface acoustic wave device.

FIG. 37 is an explanatory diagram of a surface acoustic wave device.

FIG. 38 is an explanatory diagram of a surface acoustic wave device.

FIG. 39 is an explanatory diagram of a surface acoustic wave device.

FIG. 40 is an explanatory diagram of a surface acoustic wave device.

FIG. 41 is an explanatory diagram of a surface acoustic wave device.

FIG. 42 is an explanatory diagram of a surface acoustic wave device.

FIG. 43 is an explanatory diagram of a surface acoustic wave device.

FIG. 44 is an explanatory diagram of a surface acoustic wave device.

FIG. 45 is an explanatory diagram of a surface acoustic wave device.

FIG. 46 is an explanatory diagram of a surface acoustic wave device.

FIG. 47 is an explanatory diagram of a surface acoustic wave device.

FIG. 48 is an explanatory diagram of a surface acoustic wave device.

FIG. 49 is an explanatory diagram of a surface acoustic wave device.

FIG. 50 is an explanatory diagram of a surface acoustic wave device.

FIG. 51 is an explanatory diagram of a surface acoustic wave device.

FIG. 52 is an explanatory diagram of a surface acoustic wave device.

FIG. 53 is an explanatory diagram of a surface acoustic wave device.

FIG. 54 is a configuration explanatory diagram of a communication device using a surface acoustic wave device.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Forward acoustic terminal, 2 ... Reverse acoustic terminal, 3 ... Electric terminal, 4 ... Surface acoustic wave board, 5 ... Input interdigital electrode,
6 output interdigital electrode, 7 sound absorbing material, 8 electrode area, 9
... Electrode area, 10, 11 ... Phase shifter element, 12 ... Power conductance, 13 ... Power supply, 14 ... Output electric terminal, 15 ...
Load conductance, 16: phase shifter, 17: characteristic impedance, 18: forward radiation conductance, 19:
Reverse radiation conductance, 20: parallel conductance representing internal dissipation, 21: series resistance representing internal dissipation, 22: conductance frequency characteristics of IDT,
23 ... resistance frequency characteristics of IDTs including peripheral circuits,
24 antenna, 25 tuner section, 26 surface acoustic wave device, 27 demodulation section, 28 video signal terminal, 29 audio signal terminal, 30 antenna, 31 duplexer filter for reception, 32 voltage variable Oscillator, 33 mixer, 34 surface acoustic wave device, 35 logic circuit, 36 audio output terminal, 37 control circuit, 38 audio input terminal, 39 modulation circuit, 40 variable voltage oscillator, 41 transmission Credit splitter filter, 51: sending electrode, 52: reflecting electrode, 53: meander electrode, 54: electric circuit including phase shifter, 55: geometric phase difference between sending / reflecting electrode, 56: group type Directional electrode, 57 bidirectional electrode, 58 phase shifter element (coil), 59 capacitive electrode pattern, 60 antenna, 6
DESCRIPTION OF SYMBOLS 1 ... Filter, 62 ... Amplifier, 63 ... Mixer, 71 ... Surface acoustic wave substrate, 72 ... Wave receiving electrode, 73 ... Interdigital sending electrode, 74 ... Interdigital reflecting electrode, 75 ... Meander electrode, 7
6 Absorber, 77 Forward frequency characteristic, 78 Reverse frequency characteristic, 79 Antenna, 80 Transmission / reception switch, 81 Filter for reception, 82 Amplifier for reception, 83 Mixer for reception, 84 Down converter PL
L synthesizer, 85: intermediate frequency filter, 86: demodulator, 87: transmission / reception switch, 88: transmission filter, 89: transmission amplifier, 90: transmission mixer, 9
1. Upconverter PLL synthesizer, 92. Modulator.

────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Katsumi Ito 292 Yoshida-cho, Totsuka-ku, Yokohama-shi, Kanagawa Pref. JP-A-60-117907 (JP, A) JP-A-2-156716 (JP, A) JP-A-55-37091 (JP, A) JP-A-61-290812 (JP, A) JP-A-59-178816 (JP JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) H03H 9/145 H04B 1/26

Claims (21)

(57) [Claims] 1. Three types of electrodes A, B, and 3 are provided on a surface acoustic wave substrate.
C, electrode A forms an interdigital electrode with electrode C, and electrode B also forms an interdigital electrode with electrode C.
Is meandering, and if the wavelength of the surface acoustic wave excited by the surface acoustic wave substrate is λ, the electrode finger width of the electrode A is not less than λ / 4 and less than λ / 2, and the center of the electrode finger and the electrode C The distance from the electrode A side electrode finger end to 5λ / 16, and the electrode B
Is less than λ / 4, the distance between the center of the electrode finger and the end of the electrode C on the electrode B side is 5λ / 16, and the film thickness of each of the electrodes A, B, and C is , Which is not less than 0.002λ and not more than 0.05λ. 2. Three types of electrodes A, B, and 3 on a surface acoustic wave substrate.
C, electrode A forms an interdigital electrode with electrode C, and electrode B also forms an interdigital electrode with electrode C.
Is meandering, and if the wavelength of the surface acoustic wave excited by the surface acoustic wave substrate is λ, the electrode finger width of the electrode A is not less than λ / 4 and less than λ / 2, and the center of the electrode finger and the electrode C The distance from the electrode A side electrode finger end to 5λ / 16, and the electrode B
Is less than λ / 4, and the distance between the center of the electrode finger and the end of the electrode C on the electrode B side is 5λ / 16 or 3λ / 1.
6, and the film thickness of each electrode finger of the electrodes A, B, and C is
A unidirectional electrode type surface acoustic wave device having a thickness of 0.002λ or more and 0.05λ or less. 3. Three types of electrodes A, B, and 3 on a surface acoustic wave substrate.
C, electrode A forms an interdigital electrode with electrode C, and electrode B also forms an interdigital electrode with electrode C.
Is a meandering shape, assuming that the wavelength of the surface acoustic wave excited by the surface acoustic wave substrate is λ, the first electrode finger of the electrode C has a width less than λ / 4, and the electrode finger of the electrode A has a width of λ / 4. λ / 4 or more and less than λ / 2, the distance between the electrode finger centers of the electrode C and the first electrode finger is 3λ / 8, and the width of the second electrode finger of the electrode C is λ / 4.
And the distance between the electrode finger centers of the electrode C and the first electrode finger is 3
λ / 4, the width of the electrode finger of the electrode B is less than λ / 4, the distance between the electrode finger centers of the electrode C and the first electrode finger is 9λ / 8,
The third electrode finger of the electrode C has a width less than λ / 4,
The distance between the center of the electrode finger and the electrode finger is 3λ / 2, the width of the fourth electrode finger of the electrode C is less than λ / 4, and the center distance of the electrode finger between the electrode C and the first electrode finger is 7λ / 4. , And electrodes A,
The film thickness of each of the electrode fingers B and C is 0.002λ or more and 0.05.
A one-way electrode type surface acoustic wave device characterized by being equal to or less than λ. 4. Three types of electrodes A, B, and 3 on a surface acoustic wave substrate.
C, electrode A forms an interdigital electrode with electrode C, and electrode B also forms an interdigital electrode with electrode C.
Is a meandering shape, assuming that the wavelength of the surface acoustic wave excited by the surface acoustic wave substrate is λ, the first electrode finger of the electrode C has a width less than λ / 4, and the electrode finger of the electrode A has a width of λ / 4. λ / 4 or more and less than λ / 2, the distance between the electrode finger centers of the electrode C and the first electrode finger is 3λ / 8, and the width of the second electrode finger of the electrode C is 5λ /
It is less than 16 and the distance between the electrode finger centers of the electrode C and the first electrode finger is 25λ / 32. The width of the electrode finger of the electrode B is less than λ / 4 and the distance between the electrode finger centers of the electrode C and the first electrode finger. Distance 19λ
/ 16, and the width of the third electrode finger of the electrode C is less than λ / 4,
The distance between the electrode finger center of the electrode C and the first electrode finger is 25λ / 1.
6, the width of the fourth electrode finger of the electrode C is less than 3λ / 16,
The distance between the electrode finger center of the electrode C and the first electrode finger is 57λ / 3.
2, and the film thickness of each electrode finger of the electrodes A, B, and C is
A unidirectional electrode type surface acoustic wave device having a thickness of 0.002λ or more and 0.05λ or less. 5. Three types of electrodes A, B, and 3 on a surface acoustic wave substrate.
C, electrode A forms an interdigital electrode with electrode B, and electrode B also forms an interdigital electrode with electrode C.
Is a meandering shape, assuming that the wavelength of the surface acoustic wave excited by the surface acoustic wave substrate is λ, the first electrode finger of the electrode C has a width less than λ / 4, and the electrode finger of the electrode A has a width of λ / 4. λ / 4 or more and less than λ / 2, the distance between the electrode finger centers of the electrode C and the first electrode finger is 3λ / 8, and the width of the second electrode finger of the electrode C is 3λ /
The distance between the center of the electrode C and the first electrode finger is 13λ / 16, the width of the electrode finger of the electrode B is smaller than λ / 4, and the center of the electrode C is the center of the electrode C. 5λ /
4, the width of the third electrode finger of the electrode C is less than λ / 4, the distance between the electrode finger centers of the electrode C and the first electrode finger is 13λ / 8, and the respective electrodes A, B, and C The thickness of the finger is 0.
A one-way electrode type surface acoustic wave device characterized by being at least 002λ and at most 0.05λ. 6. Three types of electrodes A, B, and 3 on a surface acoustic wave substrate.
C, electrode A forms an interdigital electrode with electrode C, and electrode B also forms an interdigital electrode with electrode C.
Is a meandering shape, assuming that the wavelength of the surface acoustic wave excited by the surface acoustic wave substrate is λ, the first electrode finger of the electrode C has a width less than λ / 4, and the electrode finger of the electrode A has a width of λ / 4. λ / 4 or more and less than λ / 2, the distance between the electrode finger centers of the electrode C and the first electrode finger is set to 3λ / 8, and the width of the second electrode finger of the electrode C is 7λ /
When the distance between the electrode fingers of the electrode C and the first electrode finger is less than 16, the width of the electrode finger of the electrode B is less than λ / 4, and the center of the electrode finger with the first electrode finger of the electrode C is less than λ / 4. Distance between 21λ
/ 16, and the width of the third electrode finger of the electrode C is less than λ / 4,
The distance between the center of the electrode C and the first electrode finger is 27λ / 1.
6, and the film thickness of each electrode finger of the electrodes A, B, and C is
A unidirectional electrode type surface acoustic wave device having a thickness of 0.002λ or more and 0.05λ or less. 7. Three types of electrodes A, B, and 3 on a surface acoustic wave substrate.
C, electrode A forms an interdigital electrode with electrode B, and electrode B also forms an interdigital electrode with electrode C.
Is a meandering shape, assuming that the wavelength of the surface acoustic wave excited by the surface acoustic wave substrate is λ, the first electrode finger of the electrode C has a width less than λ / 4, and the electrode finger of the electrode A has a width of λ / 4. λ / 4 or more and less than λ / 2, the distance between the electrode finger centers of the electrode C and the first electrode finger is 3λ / 8, and the width of the second electrode finger of the electrode C is λ / 4.
And the distance between the electrode finger centers of the electrode C and the first electrode finger is 3
λ / 4, the first electrode finger of the electrode B has a width less than λ / 4,
The distance between the center of the electrode C and the first electrode finger is set to 9λ / 8, the width of the third electrode finger of the electrode C is less than 3λ / 4,
The distance between the center of the electrode finger and the first electrode finger is 13λ / 8,
The second electrode finger of the electrode B has a width less than λ / 4 and the first electrode finger of the electrode C
The distance between the center of the electrode finger and the electrode finger is 17λ / 8, and the electrode C
The width of the fourth electrode finger is less than λ / 4, the distance between the electrode finger centers of the electrode C and the first electrode finger is 5λ / 2, and the width of the fifth electrode finger of the electrode C is less than λ / 4. The distance between the center of the electrode finger and the first electrode finger of C is set to 11λ / 4.
Wherein the thickness of each electrode finger is 0.002λ or more and 0.05λ or less. 8. Three types of electrodes A, B, and 3 on a surface acoustic wave substrate.
C, electrode A forms an interdigital electrode with electrode B, and electrode B also forms an interdigital electrode with electrode C.
Is a meandering shape, assuming that the wavelength of the surface acoustic wave excited by the surface acoustic wave substrate is λ, the first electrode finger of the electrode C has a width less than λ / 4, and the electrode finger of the electrode A has a width of λ / 4. λ / 4 or more and less than λ / 2, the distance between the electrode finger centers of the electrode C and the first electrode finger is 3λ / 8, and the width of the second electrode finger of the electrode C is 5λ /
The distance between the center of the first electrode finger of the electrode C and the center of the electrode finger is set to 25λ / 32, the width of the first electrode finger of the electrode B is smaller than λ / 4, and the width of the first electrode finger of the electrode C is smaller than λ / 4. 19 to center distance
λ / 16, the width of the third electrode finger of the electrode C is λ / 2 or more and 3
If it is less than λ / 4, the distance between the electrode finger centers of the electrode C and the first electrode finger is 27λ / 16, and the width of the second electrode finger of the electrode B is λ /
4, the distance between the center of the electrode C and the first electrode finger is 35λ / 16, and the width of the fourth electrode finger of the electrode C is less than λ / 4, and the width of the electrode C is equal to the first electrode finger. 41 finger center distance
λ / 16, the fifth electrode finger of the electrode C has a width of less than 3λ / 16, and the distance between the electrode finger centers of the electrode C and the first electrode finger is 89λ.
/ 32, and the thickness of each of the electrode fingers of the electrodes A, B, and C is 0.002λ or more and 0.05λ or less. 9. Three types of electrodes A, B, and 3 on a surface acoustic wave substrate.
C, electrode A forms an interdigital electrode with electrode B, and electrode B also forms an interdigital electrode with electrode C.
Is a meandering shape, assuming that the wavelength of the surface acoustic wave excited by the surface acoustic wave substrate is λ, the first electrode finger of the electrode C has a width less than λ / 4, and the electrode finger of the electrode A has a width of λ / 4. λ / 4 or more and less than λ / 2, the distance between the electrode finger centers of the electrode C and the first electrode finger is 3λ / 8, and the width of the second electrode finger of the electrode C is 3λ /
The distance between the center of the electrode C and the first electrode finger is 13λ / 16, the width of the first electrode finger of the electrode B is smaller than λ / 4, and the width of the electrode C is less than λ / 4. 5λ between finger centers
/ 4, and the third electrode finger of the electrode C has a width of λ / 2 or more and 3λ / 4.
And the distance between the electrode finger centers of the electrode C and the first electrode finger is 7
λ / 4, the second electrode finger of the electrode B has a width smaller than λ / 4, the distance between the electrode finger centers of the electrode C and the first electrode finger is 9λ / 4, and the fourth electrode finger of the electrode C has a width λ. / 4, the distance between the electrode finger centers of the electrode C and the first electrode finger is set to 21λ / 8, and the film thickness of each of the electrodes A, B, and C is 0.002λ.
A unidirectional electrode type surface acoustic wave device characterized by being less than 0.05λ. 10. Three types of electrodes A,
B and C, the electrode A forms an interdigital electrode with the electrode B, and the electrode B also forms an interdigital electrode with the electrode C.
When the electrode C has a meandering shape and the wavelength of the surface acoustic wave excited by the surface acoustic wave substrate is λ, the first electrode C
The width of the electrode finger is less than λ / 4, and the width of the electrode finger of the electrode A is λ.
/ 4 or more and less than λ / 2, the distance between the electrode finger centers of the electrode C and the first electrode finger is 3λ / 8, the width of the second electrode finger of the electrode C is less than 7λ / 16, The distance between the center of the electrode finger and the electrode finger is set to 27λ / 32, the width of the first electrode finger of the electrode B is less than λ / 4, and the distance between the center of the electrode finger and the first electrode finger of the electrode C is set to 21λ / 16. , The width of the third electrode finger of the electrode C is λ /
2 or more and less than 3λ / 4, the distance between the electrode finger centers of the electrode C and the first electrode finger is 29λ / 16, the width of the second electrode finger of the electrode B is less than λ / 4, and the first electrode of the electrode C The distance between the center of the electrode finger and the finger is set to 37λ / 16, the width of the fourth electrode finger of the electrode C is smaller than λ / 4, and the center distance between the electrode finger and the first electrode finger of the electrode C is set to 43λ / 16; Further, the film thickness of each of the electrode fingers of the electrodes A, B, and C is not less than 0.002λ and not more than 0.05λ. 11. Two types of electrodes A and B on a surface acoustic wave substrate.
When the electrode A and the electrode B form an interdigital electrode and the wavelength of the surface acoustic wave excited by the surface acoustic wave substrate is λ, the first electrode finger of the electrode B has a width of λ / 4, the width of the first electrode finger of the electrode A is not less than λ / 4 and less than λ / 2, and the distance between the center of the electrode finger and the first electrode finger of the electrode B is 3λ /.
8, the width of the second electrode finger of the electrode B is less than λ / 4, the distance between the electrode finger centers of the electrode B and the first electrode finger is 3λ / 4,
The second electrode finger of the electrode A has a width of less than λ / 4 and the first electrode finger of the electrode B
The distance between the center of the electrode finger and the electrode finger is 9λ / 8, the width of the third electrode finger of the electrode B is less than λ / 4, and the distance between the center of the electrode finger and the first electrode finger is 3λ / 2. The width of the fourth electrode finger of the electrode B is less than λ / 4, the distance between the electrode finger centers of the electrode B and the first electrode finger is 7λ / 4, and the thickness of each electrode finger of the electrodes A and B is Is a unidirectional electrode type surface acoustic wave device having a thickness of 0.002λ or more and 0.05λ or less. 12. Two kinds of electrodes A and B on a surface acoustic wave substrate.
When the electrode A forms an interdigital electrode with the electrode B, and the wavelength of the surface acoustic wave excited by the surface acoustic wave substrate is λ, the first electrode finger of the electrode B has a width of λ / 4, the width of the first electrode finger of the electrode A is not less than λ / 4 and less than λ / 2, and the distance between the center of the electrode finger and the first electrode finger of the electrode B is 3λ /.
8, the width of the second electrode finger of the electrode B is less than 5λ / 16,
Distance between the electrode finger center of electrode B and the first electrode finger 25λ / 32
The width of the second electrode finger of the electrode A is less than λ / 4,
The distance between the center of the electrode finger and the first electrode finger is 19λ / 16, the width of the third electrode finger of the electrode B is less than λ / 4, and the distance between the center of the electrode finger and the first electrode finger is 25λ. / 16
The width of the fourth electrode finger of the electrode B is less than 3λ / 16, the distance between the electrode finger centers of the electrode C and the first electrode finger is 57λ / 32,
Further, the thickness of each electrode finger of the electrodes A and B is 0.002λ.
A one-way electrode type surface acoustic wave device characterized by being not less than 0.05λ. 13. Two types of electrodes A and B on a surface acoustic wave substrate.
When the electrode A forms an interdigital electrode with the electrode B, and the wavelength of the surface acoustic wave excited by the surface acoustic wave substrate is λ, the first electrode finger of the electrode B has a width of λ / 4, the width of the first electrode finger of the electrode A is not less than λ / 4 and less than λ / 2, and the distance between the center of the electrode finger and the first electrode finger of the electrode B is 3λ /.
8, the width of the second electrode finger of the electrode B is less than 3λ / 8, and the distance between the electrode finger centers of the electrode B and the first electrode finger is 13λ / 16.
The width of the second electrode finger of the electrode A is less than λ / 4,
The distance between the center of the electrode finger and the first electrode finger is 5λ / 4, the width of the third electrode finger of the electrode B is less than λ / 4, and the distance between the center of the electrode finger and the first electrode finger is 13λ. / 8, and
The thickness of each electrode finger of the electrodes A and B is 0.002λ or more.
A unidirectional electrode type surface acoustic wave device having a wavelength of not more than 05λ. 14. Two types of electrodes A and B on a surface acoustic wave substrate.
When the electrode A forms an interdigital electrode with the electrode B, and the wavelength of the surface acoustic wave excited by the surface acoustic wave substrate is λ, the first electrode finger of the electrode B has a width of λ / 4, the width of the first electrode finger of the electrode A is not less than λ / 4 and less than λ / 2, and the distance between the center of the electrode finger and the first electrode finger of the electrode B is 3λ /.
8, the width of the second electrode finger of the electrode B is less than 7λ / 16,
The distance between the electrode finger center of the electrode B and the first electrode finger is set to 27λ / 3.
2, the width of the second electrode finger of the electrode A is less than λ / 4, the distance between the electrode finger centers of the electrode B and the first electrode finger is 21λ / 16, and the width of the third electrode finger of the electrode B is λ / 4. / 4, the distance between the electrode finger centers of the electrode B and the first electrode finger is set to 27λ / 16,
Further, the thickness of each electrode finger of the electrodes A and B is 0.002λ.
A one-way electrode type surface acoustic wave device characterized by being not less than 0.05λ. 15. Two types of electrodes A and B on a surface acoustic wave substrate.
When the electrode A forms an interdigital electrode with the electrode B, and the wavelength of the surface acoustic wave excited by the surface acoustic wave substrate is λ, the first electrode finger of the electrode B has a width of λ / 4, the width of the first electrode finger of the electrode A is not less than λ / 4 and less than λ / 2, and the distance between the center of the electrode finger and the first electrode finger of the electrode B is 3λ /.
8, the width of the second electrode finger of the electrode B is less than λ / 4, the distance between the electrode finger centers of the electrode B and the first electrode finger is 3λ / 4,
The second electrode finger of the electrode A has a width of less than λ / 4 and the first electrode finger of the electrode B
The distance between the center of the electrode finger and the electrode finger is 9λ / 8, the width of the third electrode finger of the electrode B is less than 3λ / 4, and the distance between the center of the electrode finger and the first electrode finger is 13λ / 8. , The third of electrode A
The width of the electrode finger is less than λ / 4, the distance between the electrode finger centers of the electrode B and the first electrode finger is 17λ / 8, and the width of the fourth electrode finger of the electrode B is less than λ / 4, The distance between the center of the electrode finger and the center of the electrode finger is set to 5λ / 2, and the fifth electrode finger of the electrode B has a width of λ /
Less than 4, the distance between the electrode finger centers of the electrode B and the first electrode finger is 11λ / 4, and the thickness of each electrode finger of the electrodes A and B is 0.002λ or more and 0.05λ or less. A one-way electrode type surface acoustic wave device characterized by the above-mentioned. 16. Two types of electrodes A and B on a surface acoustic wave substrate.
When the electrode A forms an interdigital electrode with the electrode B, and the wavelength of the surface acoustic wave excited by the surface acoustic wave substrate is λ, the first electrode finger of the electrode B has a width of λ / 4, the width of the first electrode finger of the electrode A is not less than λ / 4 and less than λ / 2, and the distance between the center of the electrode finger and the first electrode finger of the electrode B is 3λ /.
8, the width of the second electrode finger of the electrode B is less than 5λ / 16,
The distance between the first electrode finger of the electrode B and the center of the electrode finger is 25λ / 32
The width of the second electrode finger of the electrode A is less than λ / 4,
The distance between the center of the electrode finger and the first electrode finger is 19λ / 16, the width of the third electrode finger of the electrode B is λ / 2 or more and less than 3λ / 4, and the center of the electrode finger of the electrode B with the first electrode finger is 27λ
/ 16, the width of the third electrode finger of the electrode A is less than λ / 4,
The distance between the electrode finger center of the electrode B and the first electrode finger is 35λ / 1.
6, the width of the fourth electrode finger of the electrode B is less than λ / 4, the distance between the electrode finger centers of the electrode C and the first electrode finger is 41λ / 16, and the width of the fifth electrode finger of the electrode B is 3λ / Less than 16, electrode B
The distance between the center of the electrode finger and the first electrode finger is set to 89λ / 32, and the film thickness of each electrode finger of the electrodes A and B is 0.00
A one-way electrode type surface acoustic wave device characterized by being at least 2λ and at most 0.05λ. 17. Two types of electrodes A and B on a surface acoustic wave substrate.
When the electrode A forms an interdigital electrode with the electrode B, and the wavelength of the surface acoustic wave excited by the surface acoustic wave substrate is λ, the first electrode finger of the electrode B has a width of λ / 4, the width of the first electrode finger of the electrode A is not less than λ / 4 and less than λ / 2, and the distance between the center of the electrode finger and the first electrode finger of the electrode B is 3λ /.
8, the width of the second electrode finger of the electrode B is less than 3λ / 8, and the distance between the electrode finger centers of the electrode B and the first electrode finger is 13λ / 16.
The width of the second electrode finger of the electrode A is less than λ / 4,
The distance between the center of the electrode finger and the center of the electrode finger is 5λ / 4, the width of the third electrode finger of the electrode B is not less than λ / 2 and less than 3λ / 4, and the distance between the center of the electrode finger of the electrode B and the first electrode finger. Let the distance be 7λ / 4,
The third electrode finger of the electrode A has a width of less than λ / 4, the distance between the electrode finger centers of the electrode B and the first electrode finger is 9λ / 4, and the fourth electrode finger of the electrode B has a width of less than λ / 4, The distance between the center of the electrode B and the first electrode finger is set to 21λ / 8, and the electrodes A and B
Wherein the thickness of each electrode finger is 0.002λ or more and less than 0.05λ. 18. Two types of electrodes A and B on a surface acoustic wave substrate.
When the electrode A forms an interdigital electrode with the electrode B, and the wavelength of the surface acoustic wave excited by the surface acoustic wave substrate is λ, the first electrode finger of the electrode B has a width of λ / 4, the width of the first electrode finger of the electrode A is not less than λ / 4 and less than λ / 2, and the distance between the center of the electrode finger and the first electrode finger of the electrode B is 3λ /.
8, the width of the second electrode finger of the electrode B is less than 7λ / 16,
The distance between the electrode finger center of the electrode B and the first electrode finger is set to 27λ / 3.
2, the width of the second electrode finger of the electrode A is less than λ / 4, the distance between the electrode finger centers of the electrode B and the first electrode finger is 21λ / 16, and the width of the third electrode finger of the electrode B is λ / 4. / 2 or more and less than 3λ / 4, and the distance between the electrode finger centers of the electrode B and the first electrode finger is 29λ.
/ 16, the width of the third electrode finger of the electrode A is less than λ / 4,
The distance between the electrode finger centers of the electrode B and the first electrode finger is 37λ / 1.
6, the width of the fourth electrode finger of the electrode B is less than λ / 4, the distance between the electrode finger centers of the electrode C and the first electrode finger is 43λ / 16, and the electrodes A, B, and C The thickness of the finger is 0.
A one-way electrode type surface acoustic wave device characterized by being at least 002λ and at most 0.05λ. 19. A unidirectional electrode type surface acoustic wave device in which two or more interdigital electrodes are arranged on a surface acoustic wave substrate, and at least one of the interdigital electrodes is arranged therein. The internal electrode or the circuit connected thereto has internal dissipation, and the IDT having internal dissipation and the circuit connected thereto are regarded as one circuit, and the direction of the IDT in which the transmitting or receiving wave is opposed (however, The scattering matrix when a unidirectional electrode is represented by an equivalent circuit with terminal 1 as the transmitting or receiving direction when one interdigital electrode is provided, terminal 2 as the reverse direction, and terminal 3 as the electric terminal is represented by ( S), the complex conjugate matrix (S *), the directional coefficient ^{_{κ (= S 23 2 / S}} 13 2),
The radiated conductance of the interdigital transducer viewed from the electric terminal 3 is Ga, and the conductance on the power supply (or load) side is Gl.
In the case where the internal dissipation of the interdigital transducer of the unidirectional electrode type surface acoustic wave device and the circuit connected thereto is represented by a conductance component gu connected in parallel to the electric terminal, g is represented by gu / Ga, b is Gl / Ga, and the absolute value of [｛(κ-1) / (κ + 1)｝ (b + g) +1] / (1 + b + g) (31) is not more than 1/3. In a unidirectional electrode type surface acoustic wave device and a circuit connected thereto,
As means for determining the radiation conductance of the interdigital transducer having internal dissipation and the circuit connected thereto as Ga and the parallel conductance component gu representing internal dissipation,
A method for measuring a unidirectional electrode type surface acoustic wave device, comprising using a measurement of an admittance frequency characteristic of an electric terminal. 20. A unidirectional electrode type surface acoustic wave device in which two or more interdigital electrodes are arranged on a surface acoustic wave substrate and at least one or more interdigital electrodes are arranged. The internal electrode or the circuit connected thereto has internal dissipation, and the IDT having internal dissipation and the circuit connected thereto are regarded as one circuit, and the direction of the IDT in which the transmitting or receiving wave is opposed (however, The scattering matrix when a unidirectional electrode is represented by an equivalent circuit with terminal 1 as the transmitting or receiving direction when one interdigital electrode is provided, terminal 2 as the reverse direction, and terminal 3 as the electric terminal is represented by ( S), the complex conjugate matrix (S *), the directional coefficient ^{_{κ (= S 23 2 / S}} 13 2),
The radiated conductance of the interdigital transducer viewed from the electric terminal 3 is Ga, and the conductance on the power supply (or load) side is Gl.
When the internal dissipation of the interdigital transducer of the unidirectional electrode type surface acoustic wave device and the circuit connected thereto is represented by a resistance component ru connected in series to the electric terminal,
r is ru · Ga, b is Gl / Ga, and the absolute value of {(κ−1) / (κ + 1) + 1 / b + r} / (1 + 1 / b + g) (Expression 37) is set to 1/3 or less. The unidirectional electrode type surface acoustic wave device according to claim 1 and a circuit connected to the device, wherein the IDT having the internal dissipation and the radiation conductance of the circuit connected to the IDT are Ga and A method for measuring a unidirectional electrode type surface acoustic wave device, characterized in that a measurement of an impedance frequency characteristic of an electric terminal is used as means for obtaining a parallel conductance component ru representing dissipation. 21. A one-way electrode type surface acoustic wave device according to any one of claims 1 to 18, and one of the circuits connected thereto, or the one-way electrode type surface acoustic wave device according to claim 19 or 20. A communication device using a wave device measurement method.