JP3465114B2 - Half-wavelength resonator and dielectric filter using the same - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a distributed constant type dielectric resonator and a filter used in a high frequency band such as a microwave band.

[0002]

2. Description of the Related Art The applicant of the present application has disclosed in Japanese Patent Application No. 4-220056 that a conductor electrode is sandwiched between elongated dielectrics having a length corresponding to a quarter wavelength of a resonance frequency. A plurality of quarter-wave resonator elements, each of which is covered with a ground conductor, is short-circuited with the conductor electrode in the center and the ground conductors above and below each other by a short-circuit conductor provided at one end of the dielectric, We proposed a dielectric filter in which the opposite ends, open ends, are arranged in parallel so that they are alternately arranged. As an example thereof, an example using two resonant elements is shown in FIG.

In the figure, two resonant elements 50, 51 are shown.
Are conductor electrodes 54 sandwiched by elongated dielectrics 52, 53 each having a length corresponding to a quarter wavelength of the resonance frequency, and only the upper and lower surfaces of these dielectrics 52, 53 are covered with ground conductors 55, 56, respectively. In addition, the central conductor electrode 54 and the upper and lower ground conductors 55 and 56 are connected to the dielectric 5
The short-circuit conductors 57 provided at one ends of the reference numerals 2, 53 are short-circuited to each other.

This type of resonance element is called a triplate type because it has three conductors, a central conductor electrode 54 and upper and lower ground conductors 55 and 56.

The resonance elements 50 and 51 are arranged in parallel on the case 58 with their lower surface side ground conductors 56 in contact with a case 58 serving as a grounding substrate and with their open ends facing away from each other. It is arranged. In addition, the case upper lid 59 serves as the upper ground conductor 5 of the resonant elements 50 and 51.
It is put in contact with 5.

Electrostatic coupling elements 63 and 64 connected to input / output terminals 61 and 62 are provided in the vicinity of the open ends on the side surfaces of the resonance elements 50 and 51 arranged in parallel opposite to each other.
Is provided.

Each of the electrostatic coupling elements 63 and 64 includes a dielectric plate 6
5 is formed with a conductor film 66, and the conductor film is connected to the input / output terminals 61 and 62, respectively. Thus, the dielectric filter is constructed.

An equivalent circuit of this dielectric filter is shown in FIG. In the figure, C ₁ and C ₂ are capacitances by the electrostatic coupling elements 63 and 64, and C ₃ is the resonance elements 50 and 51.
The two L and C parallel circuits are parallel resonant circuits realized by the resonant elements 50 and 51, respectively.

A resonator is constructed by providing the above-mentioned one resonance element and the electrostatic coupling element on the side surface thereof. The equivalent circuit in that case is shown by C ₁ in FIG. 7 and one LC parallel resonance circuit connected thereto.

Further, as the resonance element, a double plate type is known in which one conductor electrode and one earth conductor are respectively formed on the upper and lower surfaces of the dielectric, instead of the triplate type.

Such triplate-type and double-plate-type resonance elements are collectively referred to as a planar-type resonance element to distinguish them from the coaxial-type resonance element. That is, the planar resonator is a dielectric resonance element having a conductor electrode and a ground conductor with a dielectric material sandwiched therebetween.

[0012]

Both of the above-mentioned tri-plate type and double-plate type have a drawback that spurious is significantly present in the quarter-wavelength type resonance element, and therefore, as a resonator and a filter. Is also not preferable. Furthermore, the presence of the short-circuit conductor has a drawback that the constant loss becomes large, and in particular, it is not preferable because the filter has a large attenuation in the pass band.

Therefore, an object of the present invention is to provide a planar dielectric resonator having a small spurious and a dielectric filter having a small spurious and a low passband attenuation.

[0014]

A half-wave resonator according to a first aspect of the present invention comprises a first ground conductor and a first dielectric.
Body, conductor electrode, second dielectric, second ground conductor in this order
Each of the first and second dielectrics has a laminated structure, and each of the first and second dielectrics has a length of ½ wavelength of the resonance frequency. A planar resonance element having short-circuit conductors for short-circuiting the conductor electrode and the first and second ground conductors on both end surfaces, and a coupling element connected to an external terminal on one side surface of the resonance element are provided.

In the half-wave resonator according to the first aspect, it is preferable that the coupling element is provided at the center of one side surface of the resonance element.

The half-wave resonator according to the second aspect of the present invention comprises a first ground conductor, a first dielectric, a conductor electrode and a first ground conductor.
It has a structure in which the second dielectric and the second ground conductor are laminated in this order.
However, each of the first and second dielectrics has half the resonance frequency.
A planar resonance element having a wavelength length and having both end surfaces of the first and second dielectrics opened, and a coupling element connected to an external terminal are provided on one side surface of the resonance element.

In the half-wave resonator according to the second aspect, the coupling element is provided on one side surface of the resonance element from one end of the dielectric to a position of about 1/6 of the length of the dielectric. desirable.

The dielectric filter according to the present invention comprises a first filter.
Source conductor, first dielectric, conductor electrode, second dielectric, first
A configuration in which a plurality of planar resonance elements having a structure in which two ground conductors are stacked in this order are arranged in parallel on the ground plate in a state in which the first ground conductor is in contact with the ground plate at a distance from each other. Have.

According to the first aspect of the present invention, in the dielectric filter, each of the first and second dielectrics has a length corresponding to a half wavelength of the resonance frequency and is adjacent to each other. each resonance element as the facing end surface is shifted in the length direction of the resonator element is arranged obliquely, the outer resonant elements provided on both sides
Coupling on the side for connecting to the input / output terminals respectively
It characterized Rukoto a provided element.

According to a second aspect of the present invention, in the dielectric filter, each of the first and second dielectrics has a length corresponding to a half wavelength of a resonance frequency. Each other resonant element is a double-ended short-circuited resonant element having short-circuit conductors that short-circuit this conductor electrode and the first and second ground conductors on both end surfaces of the first and second dielectrics, and the remaining resonance It is characterized in that the element is an open-ended resonant element having no short-circuit conductor.

[0021]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 shows a half-wave resonator according to an embodiment of the present invention. The illustrated half-wave resonator is a triplate resonator, and includes a resonator body 11 and a dielectric plate 12 for electrostatic coupling attached to one central portion of one side surface thereof.
And have. The resonator body 11 includes two dielectrics 13a and 13b each having a rectangular prism shape and a conductor electrode 14, and the dielectrics 13a and 13b are the conductor electrode 14
They are fixed to each other by soldering or the like so as to sandwich them. Furthermore, the longitudinal direction of the resonator body 11 (direction of arrow A)
Both end faces of the are short-circuited ends by the short-circuit conductors 15a and 15b, respectively. Such a half-wave resonator is called a both-end short-circuited half-wave resonator. Here, the short-circuited end means metal plating (conductive metal plating such as copper or silver) on the end face.
It means that you are giving. The open end means that such a process is not performed.

The top and bottom of the resonator body 11 are covered with ground conductors 16a and 16b, respectively. The dimensions of each part of the half-wave resonator of this embodiment are as follows. Width W = 1.4 mm, height T = 2.8 mm, length L
= 24.0 mm. The dielectric constant of the dielectric is 90.

As shown in FIG. 1, the electrostatic coupling dielectric plate 12 is provided at the center of one side surface of the resonator body 11. Further, the conductor film 1 is formed on the surface of the dielectric plate 12 for electrostatic coupling.
7 is formed, and the conductive film 17 has an input / output terminal 1 for electrical connection.
8 is connected.

This half-wave resonator has a resonance wavelength of 1
It has a length L of / 2 (L = λ / 2). Therefore, when a signal having a frequency equal to the resonance frequency f of the half-wavelength resonator is input to the electrical connection input / output terminal 18, the half-wavelength resonator short-circuited at both ends has zero power at both ends (vibration). Resonates in the mode. Here, the resonance frequency f
Is represented by f = c / λ where c is the speed of light of the dielectric.

FIG. 2 shows the resonance mode of the short-circuited half-wave resonator shown in FIG. As shown in FIG. 2, as the resonance mode, in addition to the fundamental wave of the resonance frequency f, there are harmonics of a frequency nf (n is an integer of 2 or more) that is a multiple thereof. Here, in the case of a half-wave resonator with both ends short-circuited, in an even-numbered resonance mode in which n is an even number of 2 m (m is a natural number), the power is zero at the center of the side surface of the resonator body 11, and n is an odd number ( 2m-1) in the odd-order resonance mode, the resonator body 11
It can be seen that the power becomes maximum (antinode of vibration) at the center of the side surface of.

Therefore, as shown in FIG. 1, when the electrostatic coupling dielectric plate 12 is provided at the center of the side surface of the resonator body 11,
No even-order resonance mode having an even frequency of 2 mf is induced in the electrical connection input / output terminal 18. In other words, only the odd resonance mode of the odd multiple frequency (2m-1) f is taken out from the electrical connection input / output terminal 18, and the present 1/2 wavelength resonator has the odd multiple frequency (2m-1) f. Only the signal is excited. Therefore, in the short-circuited half-wave resonator of the present embodiment, spurious can be reduced.

In the above, the both-end short-circuit type half-wave resonator has been described, but by removing the short-circuit conductors 15a and 15b from the half-wave resonator of FIG.
It is possible to easily construct a half-wave resonator with both ends open. The open-ended ½ wavelength resonator resonates in a mode in which the electric power at both ends is maximum (antinode of vibration).

FIG. 3 shows the resonance mode of the half-wave resonator of which both ends are open. As shown in FIG. 3, as the resonance mode, in addition to the fundamental wave of the resonance frequency f, a frequency nf which is a multiple thereof
There are harmonics (n is an integer of 2 or more). Here, in the case of a half-wave resonator with both ends open, in an even-numbered resonance mode in which n is an even number of 2 m (m is a natural number), the power becomes maximum at the center of the side surface of the resonator body, and n is an odd number (2 m− In the odd-order resonance mode of 1), it can be seen that the power becomes zero (node of vibration) at the center of the side surface of the resonator body.

Therefore, by providing the dielectric plate for electrostatic coupling as shown in FIG. 1 at the position of the vibration node on the side surface of the resonator body, one harmonic wave in the resonance mode can be eliminated. . For example, by providing a dielectric plate for electrostatic coupling on one side surface of a half-wavelength open-ended resonator at a position approximately ⅙ of the resonator length from the end surface of the resonator, the frequency is 3f. The third harmonic of can be extinguished. However, all other resonance modes remain.

Hereinafter, a dielectric filter using only a plurality of open-ended 1/2 wavelength resonators or a plurality of open-ended 1/2 wavelength resonators, a short-circuited 1 / 2-wave resonator and a open-ended 1 A dielectric filter using both a / 2 wavelength resonator will be described.

FIG. 4 shows first to fourth open-ended half-wavelength resonators 21-1, 21-2, 21-3 and 21-4.
Shows a dielectric filter using. First to fourth illustrated
The half-wave resonators 21-1 to 21-4 whose both ends are open are
The lower ground conductors (not shown in the drawing) are arranged in parallel with each other on the lower ground plate 22 so as to be in contact with the lower ground plate 22. Figure 4
As shown in FIG. 5, the dielectric filter of this embodiment is configured so that the first to fourth adjacent half-wave resonators 21-1 to 21-2 are opened.
Half-wave resonators 21-1 to 21-4 with both ends open are obliquely arranged so that the opposing end surfaces of 1-4 are displaced in the length direction.

The upper ground conductors 23 of the first to fourth half-wave resonators 21-1 to 21-4 whose both ends are open are in contact with the upper ground plate 24. That is, the first to fourth half-wave resonators 21-1 to 21-4 whose both ends are open are covered with the lower earth plate 22 and the upper earth plate 24 from above and below. At this time, the lower ground plate 2
Both ends of 2 and the upper ground plate 24 are in electrical contact with each other. The input / output terminals 25-1 and 25 are provided on the outer surfaces of the first and fourth both-end open half-wave resonators 21-1 and 21-4 provided on both sides, respectively.
-26 for electrostatic coupling for pulling out -2 to the outside
(In the drawing, a fourth both-end open type half-wave resonator 21-4
(Only the side is shown), but from the one end faces of the first and fourth both-end open half-wave resonators 21-1 and 21-4 to the resonator length L.
Is provided at a position of about 1/6. As a result, as described above, the third harmonic having the frequency 3f that is three times the resonance frequency f can be eliminated. Therefore, the dielectric filter of the present embodiment can reduce spurious.
Further, since the both-end open type 1/2 wavelength resonator has both ends open, the power loss at both ends is small. Therefore,
As in this embodiment, the half-wave resonator 21-opened at both ends
The dielectric filter configured by 1 and 21-4 can suppress the attenuation amount in the pass band to be low.

In the dielectric filter shown in FIG. 4, only a plurality of open-ended 1/2 wavelength resonators as shown in FIG. 3 are used. Instead, as shown in FIG. 1 and FIG.
Only a plurality of wavelength resonators may be used. However, in this case, the electrostatic coupling dielectric plate for pulling out the input / output terminals to the outside is provided at the center of one side surface of the two short-circuited half-wave resonators arranged on both sides. Needless to say, a dielectric plate for electrostatic coupling is not necessary for the both-end short-circuited half-wave resonator arranged in the central portion. As a result, as described above, spurious waves having an even multiple of the resonance frequency can be eliminated.

FIG. 5 shows a dielectric filter in which both short-circuited half-wave resonators and open-ended half-wave resonators are mixed. The illustrated dielectric filter includes first and second short-circuited half-wavelength resonators 31-1 and 31-2, first and second open-ended half-wavelength resonators 32-1 and 32-1. 32-2. These 1/2 wavelength resonators 31-1,
31-2, 32-1 and 32-2 are inclined on the lower ground plate 33 with their lower ground conductors (not shown in the drawing) in contact with the lower ground plate 33, spaced apart from each other. It is arranged in parallel without.

The illustrated dielectric filter comprises, in order from the left side of the drawing, a first short-circuited half-wave resonator 31-1,
First both-end open type half-wave resonator 32-1, second both-end short-circuit half-wave resonator 31-2, second both-end open type 1
The / 2 wavelength resonator 32-2 is arranged. That is,
Short-circuited half-wave resonators and open-ended half-wave resonators are alternately arranged.

In addition, these half-wavelength resonators 31-1,
Upper ground conductor 34 of 31-2, 32-1 and 32-2
Contacts the upper ground plate 35. That is, the half-wave resonators 31-1, 31-2, 32-1 and 32-2 are covered with the lower ground plate 33 and the upper ground plate 35 from above and below. At this time,
Both ends of the lower ground plate 33 and both ends of the upper ground plate 35 are in electrical contact with each other. The first both-end short-circuited half-wave resonator 31-1 provided on the left side of the drawing
A dielectric plate (not shown) for electrostatic coupling for drawing out the first input / output terminal 36-1 to the outside is provided on the outer surface of the first.
It is provided at the center of the half-wave resonator 36-1 with both ends short-circuited. As a result, as described above, it is possible to eliminate even harmonics having a frequency 2mf that is an even multiple 2m of the resonance frequency f.

On the other hand, on the outer surface of the second open-ended 1/2 wavelength resonator 32-2 provided on the right side of the drawing, the second
The dielectric plate 37 for electrostatic coupling for pulling out the input / output terminal 36-2 to the outside of the second half open-ended half-wave resonator 32-2 is approximately 1 / l of the resonator length L from the one end surface thereof. It is provided at position 6. As a result, as described above, the third harmonic having the frequency 3f that is three times the resonance frequency f can be eliminated.

Therefore, the dielectric filter of this embodiment can reduce spurious. In addition, the short-circuited half-wave resonator and the open-ended half-wave resonator are alternately arranged so that mutual electromagnetic coupling is efficiently performed, so that the amount of attenuation in the pass band is reduced. It can be kept low.

[0040]

[0041]

As is apparent from the above description, according to the present invention, the first ground conductor, the first dielectric, and the conductor electrode are provided.
A structure in which the pole, the second dielectric, and the second ground conductor are laminated in this order.
Since each of the first and second dielectrics has a structure, and each of the first and second dielectrics is a planar resonator having a length of 1/2 wavelength of the resonance frequency, a planar dielectric resonator having a small spurious can be obtained. To be Further, a plurality of planar type resonant elements having a length of the dielectric corresponding to 1/2 wavelength of the resonant frequency are arranged in parallel on the earth plate at intervals and are provided on both sides.
I / O terminals and
Since the coupling element for connection is provided, it is possible to obtain a dielectric filter having a small spurious and a low passband attenuation amount.

[Brief description of drawings]

FIG. 1 is a perspective view showing a ½ wavelength resonator with short-circuited ends according to an embodiment of the present invention.

FIG. 2 is a diagram showing a resonance mode of the short-circuited half-wave resonator shown in FIG.

FIG. 3 is a diagram showing a resonance mode of a half-wavelength open-ended resonator according to another embodiment of the present invention.

FIG. 4 is an exploded perspective view showing a dielectric filter according to a first embodiment of the present invention, which uses a plurality of open-ended 1/2 wavelength resonators shown in FIG.

5 is a second embodiment of the present invention in which the short-circuited half-wave resonator shown in FIG. 1 and the open-end half-wave resonator shown in FIG. 3 are used in a mixed manner. It is an exploded perspective view showing a dielectric filter.

FIG. 6 is an exploded perspective view showing a conventional dielectric filter.

7 is a circuit diagram showing an equivalent circuit of the dielectric filter of FIG.

[Explanation of symbols]

11 Resonator body 12 Dielectric plate for electrostatic coupling 13a, 13b dielectric 14 Conductor electrode 15a, 15b Short-circuit conductor 16a, 16b Ground conductor 17 Conductor film 18 Input / output terminals for electrical connection 21-1 to 21-4 Open-ended 1/2 wavelength resonator 22 Lower earth plate 23 Upper ground conductor 24 Upper ground plate 25-1, 25-2 input / output terminals 26 Dielectric plate for electrostatic coupling 31-1, 31-2 Short-Circuited Half Wave Resonator 32-1 and 32-2 open-ended half-wave resonator 33 Lower earth plate 34 Upper ground conductor 35 Upper ground plate 36-1, 36-2 input / output terminals 37 Dielectric plate for electrostatic coupling

─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Shigekazu Ishikawa 398, Komokuchi, Takatsu-ku, Kawasaki-shi, Kanagawa Tokin Co., Ltd. (72) Inventor Ken Ken Yano, 398, Kozu-guchi, Takatsu-ku, Kawasaki, Kanagawa (58) ) Reference JP-A-6-314901 (JP, A) JP-A-62-120101 (JP, A) JP-A-60-54502 (JP, A) Mattei, et. al, MIC ROWAVE FILTERS IMP EDANCE-MACHING NET WORKS, AND COUPLING STRUCTURES, 1964, p. 586 (58) Fields surveyed (Int.Cl. ⁷ , DB name) H01P 1/205 H01P 1/212 H01P 7/08

Claims (10)

(57) [Claims] 1. A first ground conductor, a first dielectric, and a conductor.
The electrode, the second dielectric, and the second ground conductor were laminated in this order.
A structure, each of the first and second dielectrics has a length of ½ wavelength of the resonance frequency, and
The conductor electrodes and the first and the second electrodes are formed on both end surfaces of the second dielectric.
A half-wave resonator comprising a planar resonance element having a short-circuit conductor for short-circuiting a second ground conductor and a coupling element connected to an external terminal on one side surface of the resonance element. 2. A first ground conductor, a first dielectric, and a conductor.
The electrode, the second dielectric, and the second ground conductor were laminated in this order.
A structure, each of the first and second dielectrics has a length of ½ wavelength of the resonance frequency, and
The conductor electrodes and the first and the second electrodes are formed on both end surfaces of the second dielectric.
A half-wave resonator comprising a planar resonance element having a short-circuit conductor that short-circuits a second ground conductor, and a coupling element that is connected to an external terminal in the center of one side surface of the resonance element. 3. A first ground conductor, a first dielectric, and a conductor.
The electrode, the second dielectric, and the second ground conductor were laminated in this order.
A structure, each of the first and second dielectrics has a length of ½ wavelength of the resonance frequency, and
A planar resonant element in which both end surfaces of the second dielectric are open;
A half-wave resonator in which a coupling element connected to an external terminal is provided on one side surface of the resonant element. 4. A first ground conductor, a first dielectric, and a conductor.
The electrode, the second dielectric, and the second ground conductor were laminated in this order.
A structure, each of the first and second dielectrics has a length of ½ wavelength of the resonance frequency, and
A planar resonant element in which both end surfaces of the second dielectric are open;
On one side of the resonant element at a position of substantially 1/6 of the length of said first and said second dielectric from one end of said first and said second dielectric, coupling to be connected to the external terminal A half-wave resonator provided with an element. 5. A first ground conductor, a first dielectric, and a conductor.
A plurality of planar resonance elements having a structure in which an electrode, a second dielectric, and a second ground conductor are laminated in this order are spaced apart from each other, and the first ground conductor is in contact with the ground plate. In the state, in the dielectric filter having a configuration of being arranged in parallel on the ground plate, the first and the
Each of the second dielectrics has a length corresponding to a half wavelength of the resonance frequency, and the opposing end faces of the adjacent resonance elements are arranged so as to be displaced in the length direction, and are provided on both sides.
Connected to the input / output terminals on the outer surface of the resonant element
Dielectric filter according to claim Rukoto such is provided a coupling element for. 6. The dielectric filter according to claim 5, wherein both end faces of each of the planar resonant elements are open. 7. The dielectric filter according to claim 5, wherein the conductor electrodes are provided on both end faces of each of the planar resonance elements.
A dielectric filter having a short-circuit conductor that short-circuits the first and second ground conductors. 8. A first ground conductor, a first dielectric, and a conductor.
A plurality of planar resonance elements having a structure in which an electrode, a second dielectric, and a second ground conductor are laminated in this order are spaced apart from each other, and the first ground conductor is in contact with the ground plate. In the state, in the dielectric filter having a configuration of being arranged in parallel on the ground plate, the first and the
The length of each of the length of the second dielectric is equivalent to a half wavelength of the resonance frequency, said each of the resonant elements of every other
The first and the and the conductor electrodes on the end surfaces of the second dielectric
It is characterized by comprising both-end short-circuit type resonance elements having a short-circuit conductor for short-circuiting the first and second earth conductors, and the remaining resonance elements being both-end open type resonance elements not provided with the short-circuit conductor. Dielectric filter. 9. The dielectric filter according to claim 8, wherein the resonance element coupled to the input / output terminal is of a short-circuit type at both ends, and the coupling element connected to the input / output terminal is a longitudinal center of a side surface of the resonance element. A dielectric filter, characterized in that it is provided in the section. 10. The dielectric filter according to claim 8, wherein
The resonant element coupled to the input / output terminal is open at both ends,
The coupling element connected to the input / output terminal is on the side surface of the resonant element from one end of the dielectric body to approximately 1/6 of the length of the dielectric body.
The dielectric filter is provided at the position of.