JPH0463568B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a tuning device that can be used in transmitters and receivers of televisions, radios, stereo tuners, personal radios, and other communication devices in general.

Conventional configurations and their problems In recent years, the number of broadcast waves from televisions and radios and communication waves from communication devices has increased, and the performance of the tuning device that selects the desired radio waves requires high tuning accuracy, stability, and reliability. Demand is increasing. On the other hand, reducing the manufacturing costs of these receivers, transmitters, and communication devices is also a major issue, and drastic technological development is required especially for frequency selection circuits in the high frequency section, which is difficult to rationalize.

A conventional tuning device will be described below with reference to the drawings. Figure 1 is a circuit diagram of a conventional tuning device, where 1 is a tuning coil, 2 is a trimmer capacitor,
Reference numeral 3 denotes voltage variable capacitance diodes, each of which constitutes a tuning circuit 4. The voltage variable capacitance diode 3 was supplied with a voltage obtained by variably dividing the voltage of a DC power supply 6 by a potentiometer 7 via a resistor 5 for blocking an AC signal.

Furthermore, FIG. 2 is a conventional component configuration diagram for the tuning circuit 4 in FIG. Ta.

However, in the above configuration, the inductor parts and capacitor parts are larger in size than other high-frequency parts, and the height dimension in particular hinders miniaturization and thinning of the device.

The inductance of an inductor component tends to shift due to mechanical vibration, and since the ferrite core has a large temperature dependence, the inductance is unstable and the tuning frequency fluctuates greatly.

The inductor component and capacitor component exist as separate components and are connected by a conductor routing circuit, resulting in a large amount of lead inductance and stray capacitance, making the circuit operation unstable.

Since it is a collective circuit of individual parts with independent minimum unit functions, there are limits to reducing the number of parts and rationalizing manufacturing.

Furthermore, the control voltage for the voltage variable capacitance diode is unstable, thus significantly degrading the tuning accuracy.

It is not possible to respond to the industrial trend of digitization and LSI as configuration technology for control systems, and it is not possible to realize advanced multi-functional control of tuning devices and equipment that use them.

It had the following problems.

Purpose of the Invention The purpose of the present invention is to realize a tuned circuit block that integrates an inductor component and a capacitor component, and to make it possible to control the tuning frequency of a tuner including the tuned circuit block that is integrated with a digital signal. This makes the form of the tuning circuit block ultra-thin and compact, and it is also stable against mechanical vibrations, improves the tuning accuracy of the tuning frequency, has small temperature dependence of the tuning frequency, and has a connection lead. The objective is to eliminate the negative effects of turbulence, ensure high frequency stability, and reduce the number of parts, making it possible to rationalize the manufacturing process.

Structure of the Invention The tuning device of the present invention is arranged such that the ground terminals of the electrodes that are disposed opposite to each other via a dielectric or on the surface of the dielectric are set so as to be opposite to each other. Connect a voltage variable reactance element to the open terminal of the electrode, and
- A tuning control code is input to a control section consisting of an A converter, and the analog output voltage of the control section is supplied to the voltage variable reactance element, whereby one electrode is connected between opposing electrodes. acts as a distributed inductor, and by facing this electrode and the other electrode, a distributed constant circuit with an open tip is formed, and the generated negative reactance realizes a distributed capacitor, which acts in parallel with the above distributed inductor. This is a tuning circuit whose basic function is to set the tuning frequency by setting the digital code which is the tuning control signal by using the output voltage of the D-A converter as the control voltage of the voltage variable reactance connected to this tuning circuit. This acts to variably control the

DESCRIPTION OF EMBODIMENTS Next, the operating principle of the tuner used in the tuning device of the present invention will be explained.

The operation of the tuner of this embodiment configured as described above will be described below.

3a to 3e are equivalent circuits for explaining the operation of the tuner of the present invention. In FIG. 3a, transmission line electrodes 270 and 27 each have an electrical length and have their ground terminals set in opposite directions.
Assume that a signal source 272 that generates a voltage e is connected to a transmission path electrode 270 and supplies a signal to the transmission path formed by the transmission path 1. As a result, a traveling wave voltage e _A is excited at the open terminal at the tip of the transmission line electrode 270. On the other hand, since the transmission line electrode 271 is disposed close to and facing the transmission line electrode 270 or arranged in parallel, a voltage is induced by mutual induction. Let e _B be the traveling wave voltage induced in the open terminal at the tip of the transmission line electrode 271.

Here, since the respective ground terminals of the transmission line electrodes 270 and 271 are set in opposite directions, the induced traveling wave voltage e _B has an opposite phase to the excited traveling wave voltage e _A. Since the tips of the transmission paths of the traveling wave voltages e _A and e _B are open, voltage standing waves are formed in the transmission path formed by the transmission path electrodes 270 and 271. Here, the voltage distribution coefficient indicating the distribution mode of voltage standing waves in the transmission line electrode 270 is K.
The voltage distribution coefficient at the transmission line electrode 271 can be expressed as (1-K).

Next, the potential difference V generated at any opposing portion of the transmission line electrodes 270 and 271 can be expressed as V=Ke _A A-(1-K)e _B (1). Here, if the respective transmission line electrodes 270 and 271 have the same electrical length, e _B = -e _A ...(2), so the potential difference V in the first equation is V = Ke _A + (1- K) e _A = e _A ...(3). That is, a potential difference V can be generated in all parts where the transmission line electrodes 270 and 271 face each other.

Here, it is assumed that the transmission line electrodes 270 and 271 have an electrode width W (the thickness of the electrodes is thin), and are opposed to each other at a distance d with a dielectric material having a dielectric constant ε _s interposed therebetween. In this case, the capacitance C _O formed per unit length of the transmission path is C _O =Q/V=Q/e _A ...(4) Q=ε _{p ε s} W・V/d=ε _p ε _s W・e _A /d ...(5), therefore, C _O =ε _p ε _s W/d ...(6).

Therefore, the transmission line shown in Figure 3a can be found using the formula 6 for each unit length as shown in Figure 3b.
This becomes a transmission path including a C _O distributed capacitor 273.

Furthermore, this transmission path, as shown in Figure 3c,
Comprehensive distributed inductors 277 and 27 due to the distributed inductor component of the transmission line and the lumped inductor component generated by the bent shape of the transmission line, respectively.
8 and a distributed capacitor 273.

Next, the relationship between the formation of the distributed capacitor 273 and the electrical length of the transmission path will be explained.
The characteristic impedance Z _O per unit length in a balanced mode transmission line as shown in Figure 4a is as shown in Figure 4b.
It can be expressed by the equivalent circuit shown in Its characteristic impedance Z _O is generally becomes. If the transmission path is lossless, then becomes. This assumption can be applied to many of the embodiments of the tuner of the present invention, and to simplify the explanation, the characteristic impedance Z _O
Use. The capacitance Z _O in the eighth equation is the same as the capacitance C _O per unit in the transmission path determined in the sixth equation. In other words, the characteristic impedance per unit length of the transmission line Z _O
is a function of the capacitance C _O , which is also a function of the dielectric constant _{ε s} ' of the dielectric material involved in the capacitor C _O , the width W of the transmission line electrodes, and the installation spacing d of the respective transmission line electrodes.

As described above, the characteristic impedance per unit length of the transmission line is Z _O , its electrical length is , and the equivalent reactance X generated at the terminal of the transmission line when the end is open is X = -Z _O cotθ can be expressed as (9). Here, θ=2π/λ...(10), and especially in the case of θ=O~π/2 θ=π~3/4π...(11), the equivalent reactance X is X≦O...(12) becomes. In other words, the equivalent reactance at the terminal of the transmission line can be the capacitive reactance. Therefore, θ depends on the electrical length of the transmission path.
When formula 11 is satisfied, a capacitor can be formed by setting the electrical length to λ/4 or less, for example. And the capacitance C of the capacitor that can be formed is As expressed by , any capacitance C can be realized by changing θ, that is, by setting the electrical length of the transmission path.

FIG. 5 is a diagram illustrating the operation mode of the transmission line explained in Equations 9 to 13 below. FIG. 5 shows how the equivalent reactance X generated at the terminal changes as the electrical length of the transmission path is open. As is clear from Figure 5, when the electrical length of the transmission line is less than λ/4 or between λ/2 and 4λ/3, it is possible to form a negative terminal reactance, that is, equivalent can form a capacitor. Furthermore, by arbitrarily setting the electrical length of the transmission line under conditions that generate negative terminal reactance,
It is possible to realize the capacitance C to any value.

The capacitor C thus formed can be equivalently replaced as a lumped capacitor 279 shown in FIG. 5d. The inductor formed by combining the distributed inductor component existing in the transmission path and the lumped inductor component generated by bending the transmission path can be equivalently replaced as the lumped constant inductor 280. If the ground terminal is made common in FIG. 3d, it will eventually become equivalent to a parallel resonant circuit consisting of a lumped constant capacitor 279 and a lumped constant inductor 280, as shown in FIG. 3e, and the tuned can be realized.

Although the configuration and operation described above realize the tuner of the present invention, the configuration of the tuner of the present invention and its operating principle are completely different from those of conventional tuners.
Therefore, in order to prove that the tuner according to the present invention is completely different from conventional tuners or those having other configurations even if they use the same transmission line as the tuner of the present invention. To,
The construction and operation of conventional tuners or tuners with other transmission line configurations will now be described and contrasted. This clarifies the difference from the tuner according to the present invention and also clarifies the novelty of the tuner according to the present invention.

FIG. 6 shows the operation when the transmission line electrodes are made of the same material as, for example, used in the tuner of the present invention, but the difference is that the ground terminals are set in the same direction. be. 6th
In Figure a, it is assumed that a transmission line with an open end consisting of transmission line electrodes 281 and 282 is driven by a signal source 283 that generates a voltage e. As a result, a standing wave voltage e _A is generated at the open terminal at the tip of the transmission line electrode 281.
Transmission line electrode 2 installed opposite or in parallel with it
The open terminal at the tip of 82 has a standing wave voltage.
Let e _B be induced. Here, since the ground terminals of the respective transmission line electrodes 281 and 282 are set in the same direction, the respective standing wave voltages e _A and e _B are in phase with each other. Therefore, the respective voltage distribution coefficients at transmission line electrodes 281 and 282 have the same K. As a result, the potential difference V at any part where the transmission line electrodes face each other becomes V=Ke _A −Ke _B (14). Here, if the electrical lengths of the transmission line electrodes 281 and 282 are the same, e _A = e _B (15), and therefore the potential difference V in Equation 14 is V = Ke _A - Ke _A =O...(16) In other words, no potential difference occurs in any part of the transmission path. FIG. 6b shows a configuration in which the signal source 283 in FIG. 6a is replaced at the end of the transmission line, and is equivalent to installing an unbalanced signal source 284 that generates voltage e'. In this equivalent circuit, there are only parallel transmission lines with no potential difference between them. In other words, it is clear that this is equivalent to the case where only one transmission line electrode 285 exists, as shown in FIG. 6c. Then, by equivalently replacing the signal source 283 and the ground terminal with the original circuit as shown in FIG. 6a, the circuit shown in FIG. 6d is obtained. In other words, only an equivalent lumped constant inductor consisting of a distributed inductor component of the transmission line and a lumped inductor component generated by the curved shape of the transmission line is formed. As is clear from the above, since a capacitor cannot be formed in parallel with an inductor, the intended parallel resonant circuit tuner cannot be realized.

FIG. 7 shows a general microstrip line in which the transmission line electrode on one side is made of the same material as, for example, in the tuner of the present invention, but the electrode facing the transmission line electrode has a sufficiently wide ground. This shows the operation when the curved points are different. In FIG. 7a, a transmission line electrode 287 faces a sufficiently wide ground electrode 288, is driven by a signal source 289 that generates a voltage e, and a standing wave voltage e _A is excited at the open terminal at the tip of the transmission line. It is assumed that the voltage distribution coefficient K is the voltage distribution coefficient K. On the other hand, assuming that a standing wave voltage e _B having a voltage distribution coefficient K is virtually generated at the ground electrode 288, the potential difference V at any part where the transmission line electrode 287 and the ground electrode 288 face each other is V= It is expressed as Ke _A − Ke _B ……(17). However, the standing wave voltage e _B at the ground electrode 288 is uniformly at the ground potential (zero potential), and e _B =O (18). Therefore, there is no voltage distribution coefficient at ground electrode 288 either. As a result, the potential difference V becomes V=Ke _A (19). This allows the transmission line electrode 287 to form a distributed capacitor between the ground electrode 288. However, the transmission line electrode 28
7 closely faces the ground electrode 288, the two ends of the transmission line electrode 287 are almost in a shot state due to mutual induction. Therefore, the Q performance of the inductor component in the transmission line electrode 287 is significantly degraded. That is, this microstrip line has an equivalent loss resistance of 290 as shown in FIG. 7b.
A parallel resonant circuit is formed by a lumped constant inductor 291 and a lumped constant capacitor 292, respectively. Here, since the equivalent loss resistance 290 actually has a considerably large resistance value, the loss in the resonant circuit becomes very large. Therefore, it is obvious that only a tuner with very low Q performance can be realized, and is not suitable for practical use.

FIG. 8 shows the circuit configuration of a λ/4 resonator, which is most commonly used in the past, and the present invention has been improved in each of the settings of the end condition and length of the transmission path, as well as the setting of the ground. This shows that the tuner is completely different from the tuner of In FIG. 8, balanced mode transmission line electrodes 293 and 29
4 has an electrical length of λ/4 at the resonant frequency.
and the tip is shot. It is assumed that each transmission line electrode is driven in a balanced mode by a balanced signal source 295 that generates voltage e. The ground terminal is set at the neutral point of the balanced signal source 295, and does not specifically ground any terminal in the transmission line electrode. In this case, the equivalent terminal reactance X generated at the terminal of the transmission line is as follows, where Z _O is the characteristic impedance of the transmission line: X=Z _O tanθ (20). Here, the characteristic impedance Z _O is the same as that shown in the 8th equation, and θ is also the same as that shown in the 10th equation. In this resonator, the electrical length of the transmission path is =λ/4...(21), so θ=π/2...(22). Therefore, _the terminal reactance X in Equation 20 is as follows: However, when comparing the configuration of this λ/4 resonator with the configuration of the tuner of the present invention, first of all, regarding the terminal conditions of the transmission line, the tuner of the present invention is in an open state, whereas the conventional λ/4 resonator has an open state. It is clear that the /4 resonator is in a short state and therefore has a completely different configuration in terms of terminal conditions. Furthermore, regarding the setting of the electrical length of the transmission line, in the tuner of the present invention, it is set to λ/4 or less of the tuning frequency, and in practice it is set to a very short length of about λ/16. However, the conventional λ/4
In the resonator, the resonant frequency is strictly set to λ/4, and it is therefore clear that the configuration is fundamentally different in setting the electrical length of the transmission path. Furthermore, due to the difference in the electrical length of the transmission path in the configuration, even if both are designed to have the same tuning frequency or resonant frequency, the tuner of the present invention can be made smaller;
In the case of four resonators, it is necessary to provide a very long transmission path, which has the disadvantage of increasing the size. Conventional λ/
4.In order to downsize the resonator, there are some cases in which the length of the transmission path is shortened by interposing a dielectric material with a very high permittivity, but the dielectric material with a high permittivity used for this purpose generally has a dielectric loss tanδ. It is very large, and therefore has the disadvantage that the Q performance as a resonator is significantly reduced. Furthermore, the temperature dependence of the dielectric constant of a dielectric material having a high dielectric constant is generally large, and therefore there is also the disadvantage that it is difficult to ensure the stability of the resonant frequency.

Next, in order to clarify the superiority of the performance of the tuner of the present invention, experimental results will be shown and explained in comparison with the performance of a conventional tuner. FIG. 9 is a graph showing the experimental results of measuring the temperature dependence of the tuning frequency. FIG. 10 is a graph showing the experimental results of measuring the temperature dependence characteristics of resonance Q. In Figures 9 and 10, characteristic (A)
is the temperature dependence of the tuner in the present invention, and is an experimental result when an alumina ceramic material or a resin printed circuit board is used as the dielectric. On the other hand, characteristic (B), as shown in FIG. 2, is a temperature-dependent characteristic of the tuner most commonly used in the past. From these experimental results, it is clear that in the tuner of the present invention, even if it is constructed using a general dielectric material, its tuning frequency is extremely stable, and furthermore, the resonance Q is high and it is stable. On the other hand, in conventional tuners, the tuning frequency and It was difficult to ensure the stability of resonance Q. Thereby, other temperature compensation components or other self-stabilizing compensation circuits were added to compensate for the instability.

Next, embodiments of the present invention will be described with reference to the drawings.

FIG. 11 shows a configuration circuit diagram of a tuning device in an embodiment of the present invention. 13 is a transmission line electrode that acts as a distributed inductor, and 14 is a transmission line electrode that is disposed opposite to the transmission line electrode 13 via a dielectric (not shown) and generates a distributed capacitor. The respective transmission line electrodes 13 and 14 are grounded in opposite directions to form a parallel circuit 15 of an inductor and a capacitor. A voltage-capable capacitance diode 16 is connected to the open terminal 14 a of the transmission line electrode 14 to constitute a tuner 17 . The voltage variable capacitance diode 16 has a resistor 18 for blocking AC signals.
The analog output voltage of the DA converter 19 is supplied through the DA converter 19. A digital signal code for tuning control is input to an input terminal 20 of the DA converter 19.

FIG. 12 shows a configuration circuit diagram of a tuning device in another embodiment of the present invention. Reference numeral 17 designates the same tuner as explained in FIG. 11 above, and the connection configuration of resistor 18 and DA converter 19 is also the same as that explained in FIG. 11 above. On the other hand, the input terminal 2 of the D-A converter
0 is supplied with the output of a digital signal processor 21 consisting of a latch, RAM, or ROM. This digital signal processor 21 has an input terminal 2
It functions to store the digital signal code for tuning control inputted to 2 or to convert it into another digital signal code.

FIG. 13 shows a configuration circuit diagram of a tuning device in another embodiment of the present invention. 17 to 2
2 has the same configuration as that explained in FIG. 12 above. On the other hand, the output of the code converter 23 is supplied to the input terminal 22 of the digital signal processor 21 . This code converter 23 functions to convert a serial digital signal code for tuning control inputted to an input terminal 24 into a parallel digital signal code.

FIGS. 14 to 21 show embodiments of the inductor and capacitor parallel circuit 15 described in FIGS. 11 to 13. In FIG. 14, a shows a front view, b shows a side view, and c shows a back view. (The same applies to FIGS. 15 to 21 below) In FIG. 14, 100 is a dielectric substrate;
Reference numerals 101 and 102 are electrodes forming a distributed constant circuit to realize a distributed inductor and a distributed capacitor. The ground terminals of the electrodes 101 and 102 are set so that the opposing electrodes are on arbitrary opposite sides, as shown in FIG. (Similarly in FIGS. 15 to 21 below) A side and B shown in FIG. 14a and A side and B shown in FIG. In FIG. 15, electrodes 104 and 105 each having one bend are placed facing each other with a dielectric substrate 103 in between.

In FIG. 16, electrodes 107 and 108 each having a plurality of bent portions are placed facing each other with a dielectric substrate 106 interposed therebetween.

In FIG. 17, meander-shaped electrodes 110 and 111 are placed facing each other with a dielectric substrate 109 in between.

In FIG. 18, spiral-shaped electrodes 113 and 114 are placed facing each other with a dielectric substrate 112 in between.

In FIG. 19, electrodes 116 and 117 are installed on the surface of a dielectric substrate 115, facing each other laterally.

In FIG. 20, electrodes 119 and 120 are provided inside a dielectric substrate 118, facing each other.

In FIG. 21, an electrode 122 is installed inside a dielectric substrate 121, an electrode 123 is installed on the surface of the dielectric substrate 121, and the electrodes 122 and 123 are opposed to each other.

In the embodiments shown in FIGS. 14 to 21, the opposing electrodes have the same shape and completely face each other across the entire surface. However, even if one electrode has a different equivalent length than the other electrode, It can also be realized by partially opposing the partner electrodes. Further, the shapes of the electrodes used in the embodiments shown in FIGS. 19 to 21 can also be realized using the shapes shown in the embodiments shown in FIGS. 15 to 18.

The operation of the tuner used in the tuning device of this embodiment configured as described above will be described below.
FIG. 22 shows an operational equivalent circuit of the tuner. 22nd
In FIG. a, the grounding of electrodes 124 and 125, which are placed opposite to each other with a dielectric (not shown) in between, is set in opposite directions, and the open terminal 126 of the electrode 124 is connected to the voltage variable capacitance element 12.
7 are connected to form a basic circuit.
If an AC signal is applied to the open terminal 126 at this point, the ground terminals of the electrodes 124 and 125 are set in opposite directions, so each electrode 1
The alternating currents driven into electrodes 124 and 125 are in antiphase with each other, thereby causing electrodes 124 and 125 to
A distributed capacitance can be generated between the two. This situation is shown in FIG. 22b, where the distributed capacitor 128 is formed and the 22nd
The inductive component of the electrode 125 shown in Figure a is canceled and becomes equivalent to the ground plane 129. electrode 12
There is a distributed inductance in Figure 22c.
As shown in FIG. 2, a distributed inductor 130 is formed and a distributed capacitor 128 constitutes a distributed constant circuit. If this is equivalently converted into a lumped constant circuit, a parallel resonant circuit of the inductor 131, capacitor 132, and voltage variable capacitance element 127 will be constructed. By changing the tuning control voltage applied to the control terminal 133 of the voltage variable capacitance element 127, the tuning frequency of this tuner can be variably controlled.

The operation of the tuning device in the embodiment of the present invention including the tuner configured as described above will be described below, using the tuning device shown in FIG. 13 as a representative example. A tuning control signal in the form of a serial digital signal code supplied to the input terminal 24 is converted into a parallel digital signal code by the code converter 23 and input to the digital signal processor 21 . When a latch is used as this digital signal processor 21, the digital signal code input to it is temporarily stored as is and stored in RAM or
When a ROM is used, the digital signal code is arbitrarily converted according to the stored contents written in advance. The digital signal code processed by one of them is supplied to the DA converter to obtain an analog output voltage corresponding to the digital signal code, and the analog output voltage is supplied to the voltage variable capacitance element 16. By changing the serial digital signal code input to the input terminal 24 in this manner, the tuning frequency of the tuner 17 can be variably set in accordance with the code. The tuning device in the embodiment of FIG.
The tuning device in the embodiment of FIG. 12 supplies the parallel digital signal code directly to the input terminal 22 of the digital signal processor 21. The tuning devices of the embodiments shown in FIGS. 11 to 13 all operate to variably set the tuning frequency of the tuner 17 using a digital signal code. Here the 11th
By cutting off a required portion of the electrode 13 of the tuner in the tuning device of the embodiment shown in FIGS. 13 to 13, the distributed capacitance can be variably set, and the tuning frequency band can be arbitrarily set.

In the configuration of the tuner of the tuning device in each of the above embodiments, the voltage variable capacitance element is connected to the open terminal at the tip of the electrode, but the desired purpose can be achieved even if the voltage variable capacitance element is connected to the terminal at any part of the electrode. In each of the above embodiments, metal conductors, printed conductors, or thin film conductors can be used as the electrodes of the tuner, and alumina ceramic, plastic, Teflon, glass, mica, etc. can be used as the dielectric substrate. I can do it.

Effects of the Invention As is clear from the above description, the present invention forms a tuning section using opposing electrodes with a thin dielectric layer interposed therebetween, and also varies the control voltage of the voltage variable reactance element using a digital signal code. Because of this structure, the inductor and capacitor parts of the tuner can be integrated with a simple structure.

An ultra-thin and compact tuner can be realized.

Since the inductor and capacitor of the tuner are connected in a leadless manner, there is no influence of the lead inductor or the stray capacitor, and therefore the operation of the tuning device is extremely stable and the tuning accuracy is improved.

It is possible to reduce the number of parts in the tuner, which enables rationalization of manufacturing and cost reduction.

Furthermore, it is possible to obtain a very stable tuning control voltage by using the tuning control method using a digital signal code and the conversion function of a stable D-A converter, and it is possible to significantly improve the tuning accuracy of the tuning device.

It is possible to connect to a computer-applied multi-functional digital control system, and it is possible to realize advanced multi-functional control of the tuning device and equipment using it.

This excellent effect can be obtained.

[Brief explanation of the drawing]

Fig. 1 is a circuit diagram of a conventional tuner, Fig. 2 is a configuration diagram of a tuner used in a conventional tuning device, and Fig. 3 a-
e, Figures 4a and b, and Figure 5 are explanatory diagrams showing the operating principle of the tuner used in the tuning device of the present invention, and Figure 6a.
~d, Figures 7a and b, and Figure 8 are explanatory diagrams showing the operating principle of the conventional tuner. Figures 9 and 10 are the tuning frequency and resonance Q of the present invention and the conventional tuner with respect to temperature changes. 11 to 13 are configuration circuit diagrams of a tuning device in an embodiment of the present invention, and FIGS. 14 to 21 are configuration diagrams of a tuner used in a tuning device in an embodiment of the present invention. In each case, a is a front view, b is a side view, c is a back view, and FIG. 22 is an explanatory diagram of the operating principle of a tuner used in a tuning device in an embodiment of the present invention. 13, 14, 101, 102, 104, 10
5,107,108,110,111,113,
114, 116, 117, 119, 120, 12
2,123,124,125...electrode, 16,1
27... Voltage variable capacitance element, 19...
DA converter, 21... digital signal processor, 23... code converter.

Claims (1)

[Claims] 1. The terminals connected to the ground of the electrodes that are placed opposite to each other with a dielectric interposed therebetween or arranged side by side on the surface of the dielectric are arranged in a different facing positional relationship so that they do not face each other. A voltage variable reactance element is connected to a predetermined terminal of one electrode of each of the above-mentioned electrodes, and the control system further comprises a D-A converter and a digital signal processor and code exchanger installed in front of the D-A converter. A tuning device characterized in that a tuning device is provided with a control section and supplies an analog output voltage of a D-A converter in the control section to the voltage variable reactance element. 2. The tuning device according to claim 1, wherein a latch is installed as a digital signal processor in the control section. 3. The tuning device according to claim 1, wherein a RAM or ROM is installed as a digital signal processor in the control section. 4. The tuning device according to any one of claims 1 to 3, wherein a code converter for converting a serial input code into a parallel output code is installed as a code converter in the control unit. 5. Claim 1 in which an electrode having at least one bending portion exhibiting a predetermined bending angle or bending rate and a predetermined bending direction is used.
The tuning device according to any one of items 1 to 4. 6. The tuning device according to any one of claims 1 to 4, using an electrode having a spiral shape. 7. Claim 1, in which the length of one electrode is set shorter than the length of the other electrode, and the length of the electrode is set to be shorter than the length of the other electrode, and the length of the electrode is set to be opposite to or arranged in parallel at a predetermined portion.
7. The tuning device according to any one of items 6 to 6. 8. The tuning device according to any one of claims 1 to 7, wherein each electrode or a portion or all of a predetermined one side of the electrode is installed inside the dielectric. 9. The tuning device according to any one of claims 1 to 8, wherein the respective electrodes are installed on the inner circumference or the outer circumference of a cylindrical or prismatic dielectric body.