JPH08125438A - Resonance circuit board resonance characteristic adjustment method - Google Patents

Abstract

(57) [Summary] [Object] To provide a resonance characteristic adjustment method of a resonance circuit, which can suppress variations in control voltage sensitivity in a voltage controlled oscillator circuit, for example, when adjusting the resonance frequency. According to the present invention, a strip line or a microstrip line 2 having inductor-adjustable conductor patterns 21, 22, ... On a dielectric substrate 1 and conductor patterns 31, 32, 42 capable of adjusting a capacitance component. , 42 ... and a capacitive element 3, 4 arranged so as to be joined to each other, the resonance circuit of the resonant circuit, the resonance characteristics of the resonant circuit, a part 21 of the conductor pattern capable of inductor adjustment,
22 ... and a part 31, 32, 42, 42 ... Of the conductor pattern whose capacitance component can be adjusted are selectively removed to perform the adjustment.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for adjusting the resonance characteristics of a resonance circuit board having a strip line and a microstrip line, which is used in a high frequency voltage controlled oscillator circuit (VCO).

[0002]

2. Description of the Related Art Conventionally, a high-frequency oscillator, such as a voltage controlled oscillator (VCO), has been used for a microstrip line,
It consists of a resonance circuit part consisting of a varicap diode and a capacitor, a negative resistance circuit part consisting of an oscillating transistor, a resistor and a capacitor, and an amplifying circuit part consisting of an amplifying transistor, a microstrip line, a resistor and a capacitor. ing.

The resonance circuit section is, for example, an equivalent circuit shown in FIG. 5, in which the inductor component L, the capacitor C ₁ ,
With C ₂ , C ₃ , and varicap diode Cv, LC
When a predetermined voltage is applied from the control terminal Vt, the capacitance of the varicap diode Cv changes, and in particular, the capacitance component of the LC resonance circuit changes. The resonance frequency will be obtained.

In order to obtain a predetermined resonance frequency according to specifications in the manufacturing process of such a high frequency oscillator, L-
This has been done by adjusting the inductor component or capacitance component of C resonance.

The adjustment of the resonance frequency of the resonance circuit board is shown in FIG. 6B, for example, by removing a part of the conductor pattern having the adjustable capacitance component shown in FIG. 6A corresponding to the capacitor CT. The increase change of the resonance frequency is shown.
6A, 61 and 62 are a pair of capacitive electrode films, 61a, 61b ... Are electrode fingers extending from the capacitive electrode film 61, and 62a, 62b. , The electrode fingers extending from the capacitive electrode film 62, and the mutual electrode fingers 61a, 61b, 62a, 62b ...
During this period, capacity is being generated.

Further, by removing a part of the inductor-adjustable conductor pattern (stub conductor) shown in FIG. 7A, the resonance frequency shows a downward change shown in FIG. 7B. In FIG. 7A, 71 is a ribbon inductor conductor film that mainly derives the inductor component, and 72,
73 are a plurality of stub conductor films connected in a ladder shape to a part of the ribbon inductor conductor film 71.

Further, in FIG. 6 (a) and FIG. 7 (a),
The arrows indicate the electrode fingers 61a, 61 by the laser beam or the like.
b, 62a, 62b ..., Stub conductor films 72, 73.
..Indicates the cutting direction of. Also, FIG. 6B and FIG. 7B
The abscissa axis of each is the adjustable conductor pattern (electrode finger 61).
a, 61b, 62a, 62b ..., Stub conductor film 7
2, 73 ...) are sequentially cut one by one,
The dotted line on the right side of the vertical axis of the characteristic diagram shows one conductor pattern as 1.
It is shown that only one conductor is cut, and the next dotted line shows that one conductor pattern is further cut and a total of two conductors are cut.

Therefore, in order to adjust to the desired resonance frequency, it is necessary to eliminate the difference from the desired resonance frequency while monitoring the resonance frequency when the resonance circuit is constructed in the manufacturing process. One of the adjustable conductor patterns (electrode fingers 61a, 61b, 62a, 62b ... Or a plurality of stub conductor films 72, 73 ...) Was removed. That is, the electrode fingers 61 on the capacitor side that mesh with each other.
By sequentially cutting a, 61b, 62a, 62b, ... To raise the resonance frequency and, for example, to adjust the inductor component, the stub conductor films 72, 73 are used.
.. were sequentially cut to lower the resonance frequency.

As described above, the resonance frequency of the LC resonance circuit is relatively adjusted by selectively removing either the inductor component or the conductor pattern of which the characteristic of the capacitance component is adjustable. Easy to do.

[0010]

However, in the above-described high-frequency oscillator, when the voltage is applied from the control terminal Vt to change the capacitance of the varicap diode of the resonance circuit to control the oscillation frequency, the oscillation frequency In particular, the control sensitivity of is affected by the impedance of the varicap diode, and in the resonance circuit after the resonance frequency is adjusted, the sensitivity of the oscillation frequency may be different from that before the adjustment.

For example, in order to adjust the capacitance component C of the resonance circuit, the electrode fingers 61a and 61 of the capacitance electrode films 61 and 62 are formed.
By sequentially cutting b, 62a, 62b ...
Varicap diode Cv that constitutes this capacitance component C
Impedance increases, which reduces the control voltage sensitivity compared to before adjustment.

Further, for example, in order to adjust the inductance component L of the resonance circuit, the stub conductor films 72, 73 ...
By sequentially disconnecting, the impedance of the varicap diode Cv is relatively reduced, and as a result,
The control voltage sensitivity becomes larger than that before adjustment.

Therefore, in the voltage controlled oscillator (high frequency oscillating device) incorporating the resonant circuit board whose resonant frequency is adjusted as described above, when the control voltage sensitivity is not constant for each device, for example, when incorporated in a communication device or the like. Various obstacles occur. For example, when the control voltage sensitivity is low, even if the channel is changed, it takes more time to change the channel than when the control voltage sensitivity is normal. On the contrary, when the control voltage sensitivity is high, the phenomenon that the frequency is not stable occurs near the predetermined channel frequency.

Further, when the FM modulation is directly applied by the voltage controlled oscillator, the variation of the voltage sensitivity appears as the variation of the modulation degree as it is, and the demodulated signal is changed from the original signal.

This is because the overall impedance of the LC resonant circuit is a combination of the impedances that make up the resonant circuit, and even if the resonant frequency is adjusted during the manufacturing process, the impedance of the entire resonant circuit does not change.

However, in reality, the impedance of each constituent element of the resonance circuit changes with a change in frequency. In particular, the impedance of the varicap diode, which constitutes one of the capacitance components of the resonance circuit and to which the control voltage is directly applied, changes before and after the adjustment of the resonance frequency.

Therefore, it is considered that the capacitance change rate of the varicap diode with respect to the control voltage, that is, the control voltage sensitivity varies depending on the method of adjusting the resonance frequency.

The present invention has been devised in view of the above problems, and an object thereof is to provide a resonance characteristic of a resonance circuit board capable of adjusting a predetermined resonance frequency so that the control voltage sensitivity does not change. It provides an adjustment method.

[0019]

A resonance characteristic adjusting method of a resonance circuit according to the present invention is capable of adjusting a capacitance component and a strip line or a microstrip line having a conductor pattern on the dielectric substrate that allows adjustment of an inductor. The present invention is intended for a resonance circuit board formed by forming a resonance circuit composed of a capacitive element having a conductor pattern. Specifically, it is possible to adjust a part of a conductor pattern in which an inductor can be adjusted and a capacitance component. This is done by selectively removing both and part of the conductor pattern.

[0020]

In the resonance frequency adjusting method of the resonance frequency of the present invention, the desired resonance frequency is adjusted by selectively removing the conductor pattern that allows adjustment of the inductor component L and the capacitance component C. .

That is, in adjusting the desired resonance frequency,
A conductor pattern that allows adjustment of the inductor component L or the capacitance component C is selectively removed to obtain a value that exceeds the desired resonance frequency value, and a conductor pattern that allows adjustment of the capacitance component C or the inductor component L is provided. It is selectively removed to obtain the desired resonance frequency value.

As a result, the resonance frequency can be adjusted to a desired value as a result.

Moreover, since both the conductor pattern for adjusting the inductor component and the conductor pattern for adjusting the capacitance component are removed and adjusted, the impedance change of each element forming the circuit is changed to the resonance frequency. It can be approximated or the same before and after adjustment.

For example, in the variation direction of the impedance of the varicap diode to which the control voltage is applied, the control voltage sensitivity is lowered by adjusting the resonance frequency by the inductor component, and the control voltage sensitivity is changed by adjusting the resonance frequency by the capacitance component. To rise. Therefore, as a result, the changes in the sensitivities cancel each other out, and the impedance can be approximated or equal to the impedance before adjustment of the resonance frequency, so that the sensitivity to the control voltage is stable and the variations between the products are stable. Can be reduced.

[0025]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A resonance characteristic adjusting method for a resonance circuit according to the present invention will be described below in detail with reference to the drawings.

FIG. 1 is a schematic view of a resonance circuit board corresponding to the method of adjusting the resonance characteristics of the resonance circuit of the present invention. In FIG. 1, reference numeral 1 denotes a dielectric substrate, and a conductor film 2 serving as at least a ribbon inductor conductor (for example, a microstrip line) on the surface of the dielectric substrate 1 and a pair of capacitance electrode films 3 and 4.
However, the ground electrode film 5 is formed on the back surface.

A part of the ribbon inductor conductor film 2 has a plurality of stub conductor films 2 for adjusting inductor components.
, 22 are connected to each other and are formed on the surface of the dielectric substrate 1 by printing and baking a thick film conductive paste.
Its shape is a straight line having a predetermined width and a predetermined length. A plurality of stub conductor films 21, 22 ... Are connected in a ladder shape (connected in parallel to each other) to one end of the ribbon inductor conductor film 2.

Further, the pair of capacitance electrode films 3 and 4 are formed of comb-teeth-shaped electrodes that mesh with each other, and the electrode fingers 31, 32, ... The electrode fingers 41, 42, ... Extend from the common electrode of the comb-teeth-shaped electrode that becomes the capacitor electrode film 4, and the electrode fingers 31, 32 ,. Mesh with each other,
They are arranged side by side on the surface of the dielectric substrate 1.

As a result, a predetermined capacity is generated depending on the length of meshing between the electrode fingers 31, 32, ..., 41, 42, ... . That is, a capacitive element having a conductor pattern with adjustable capacitance is achieved.

One end of such a ribbon inductor conductor film 2 is connected to, for example, a part of the capacitance electrode film 3, and the other end is connected to the ground electrode film 5. Further, a part of the capacitance electrode film 4 is connected to the ground electrode film 5.

As a result, mainly the inductor component of the ribbon inductor conductor film 2 and the capacitance components of the capacitance electrode films 3 and 4 (actually, the fixed capacitors C ₁ and C ₂ and the capacitance Cv of the varicap diode shown in FIG. 5 are combined. Are connected in parallel with each other, and an LC resonance circuit is achieved.

The ribbon inductor conductor film 2, the capacitor electrode films 3 and 4, and the ground electrode film 5 are printed or printed with a conductive paste on the dielectric substrate 1 or are conductive on an unfired dielectric substrate. It is formed by printing a conductive paste and is formed by simultaneous firing.

Specifically, on a dielectric material such as alumina or barium titanate, or on a dielectric substrate 1 containing these dielectric materials and a glass component, an Ag system (Ag simple substance, A
A conductive paste containing, as a main component, a low resistance material such as an Ag alloy such as g-Pd), a Cu-based material, or a high melting point material such as molybdenum or tungsten is printed, dried, and then baked. The firing conditions differ depending on the conductive material. For example, when Ag is the main component, the firing treatment is performed in an air atmosphere or a neutral atmosphere. When Cu is the main component, the firing process is performed in a reducing atmosphere or a neutral atmosphere.

The ribbon inductor conductor film 2 and the capacitor electrode films 3 and 4 formed on the surface of the substrate 1 and the ground electrode films 5 formed on both surfaces of the substrate 1 are not misaligned when printed with a conductive paste. Bleeding will occur. In particular, if printing deviation or bleeding occurs in the ribbon inductor conductor film 2 and the capacitor electrode films 3 and 4, which greatly affect the characteristics, as a result, the inductor component and the capacitance component are slightly deviated from their intended states, For example, the resonance frequency varies between the circuit boards. In order to prevent such variations, for example, the root portions of the electrode fingers 31, 32, ... 41, 42, ... Of the capacitive electrode films 3 and 4 meshing with each other or the intermediate portions thereof are sequentially cut by a required number. , The capacitance component is substantially reduced to increase the resonance frequency, and conversely, a plurality of stub conductor films 21, 22 ... Formed on a part of the inductor conductor film 2 are sequentially cut by a required number. , The resonance frequency was decreased by substantially increasing the inductor component. Thereby, the resonance frequency is adjusted to the desired frequency. In the cutting / removing process described above, for example, a probe of a resonance frequency measuring device is applied to the ground electrode film 5 and the other end of the ribbon inductor conductor film 2, and the YAG is monitored while monitoring the resonance frequency.
By irradiating / scanning with a laser or the like, electrode fingers 31, 32, ... 41, 42 ... Of a predetermined number of capacitive electrode films 3, 4 ...
... is sequentially cut by the required number. Alternatively, the amount of change in the resonance frequency when one stub conductor film 21 or the electrode finger 31 is cut may be set in advance, and laser irradiation / scanning processing may be performed according to the measured resonance frequency.

However, as a result of repeated studies by the present inventors,
Even if the variation of the resonance frequency is adjusted, it is not sufficient to sufficiently adjust the variation of the resonance circuit board. Especially, when the resonance circuit board is used for the voltage controlled oscillator circuit, the sensitivity to the control voltage varies. It was found that the state remained.

When the plurality of stub conductor films 21, 22, 23 ... Of the ribbon inductor conductor film 2 are cut, the electrode fingers 31, 32 ... 41, 42 ...
It is considered that the degree of change in the impedance of the varicap diode Cv when each is cut is different, and as a result, the sensitivity of the control voltage changes.

FIG. 2 shows the sensitivity of the control voltage when a plurality of stub conductor films 21, 22, 23 ... Of the ribbon inductor conductor film 2 are sequentially cut, and FIG. 3 shows the electrode fingers of the capacitor electrode films 3 and 4. The control voltage sensitivity obtained by sequentially cutting 31, 32, ..., 41, 42 ,.

As shown in the figure, in order to adjust the increase of the resonance frequency, the electrode fingers 31, 32, ...
Although the resonance frequency can be substantially adjusted by cutting off 1, 42, ..., The sensitivity of the control voltage is lowered.

On the contrary, in order to lower the resonance frequency, the stub conductor films 21 and 2 of the ribbon inductor conductor film 2 are adjusted.
Although the resonance frequency can be substantially adjusted by cutting 2, 23, ..., The sensitivity of the control voltage is increased.

Therefore, the resonance frequency adjusting method of the present invention adjusts the resonance frequency in order to prevent the sensitivity of the control voltage from changing even after the resonance frequency is adjusted. Stub conductor film 2
, 22 are cut and removed, and the electrode fingers 31, 32, ..., 41, 42 of the capacitive electrode films 3 and 4 are cut and removed to cancel the changing direction of the sensitivity of the control voltage. do it,
The sensitivity is similar to or the same as the sensitivity of the control voltage before the adjustment of the resonance frequency.

For example, as shown in FIG. 4 (a), in the first step, if the frequency fo before adjustment of the resonance frequency is higher than the desired resonance frequency f, first, the ribbon inductor conductor 2 The plurality of stub conductor films 21, 22 ... Are sequentially cut, and the resonance frequency is adjusted by adjusting the inductor. The resonance frequency f ₁ at the end of this first step is a low value compared with the desired frequency f.

Subsequently, as a second step, the electrode fingers 31, 32, ..., 41, 42, ... Of the capacitor electrode films 3 and 4 are sequentially cut, and the resonance frequency is adjusted by adjusting the capacitance. . The adjustment is performed by recovering the frequency f ₁ set by exceeding the desired resonance frequency value f in the first stage adjustment to the desired resonance frequency f.

In FIG. 4 (a), conventionally, the adjustment is completed at the horizontal axis XT during the adjustment of the inductor, and the adjustment is completed at the desired resonance frequency, which is point X in the figure.

In the explanation of FIG. 4 (a), the inductor component is adjusted in the first stage to lower the resonance frequency, and then the capacitance component is adjusted in the second stage to set the resonance frequency f _O to the desired value. The resonance frequency f is set to
It is also possible to adjust the capacitance component in the step of, and then adjust the induction component in the second step. Preferably, the inductor adjustment of the first stage or the adjustment of the inductor of the first stage is performed so as to be between the resonance frequency f _O before the adjustment and the resonance frequency f ₁ at the end of the first stage and the desired resonance frequency value f. The capacitance is adjusted, and then the second capacitance or the inductor is adjusted. This is because the adjustment width is narrowed from the resonance frequency f ₁ at the end of the first stage to the desired resonance frequency f _O , and the time required for the adjustment is shortened.

According to the above adjustment method, since the adjustment parameter is increased by two-step adjustment as compared with the conventional method, it is possible to adjust to the desired resonance frequency relatively easily.

Moreover, as described above, the plurality of stub conductor films 21, 22, ... And the electrode fingers 31, 32, 41, 42.
・ Since each of and is cut and removed, the L component and C
The ratio in which the components contribute to the operation can be set to a state close to the ratio before adjustment, and each cutting cancels the changing direction of the impedance of the varicap diode Cv of the ribbon inductor conductor film 2 and the capacitor electrode films 3 and 4. Thus, the change in voltage sensitivity before and after the adjustment of the resonance frequency can be made small or the same.

For example, a change in the control voltage sensitivity in a voltage controlled oscillator, for example, is adjusted according to the adjustment shown in FIG.
Referring to in FIG. 4 (b), first, a control voltage sensitivity K _O before adjustment, when the control voltage sensitivity K _O by performing an inductor adjustment, the control voltage sensitivity is reduced, the first stage is completed Thus, the voltage control sensitivity becomes K ₁ . In the next second step, the voltage sensitivity K ₁ was reduced to K ₁ is the capacity adjustment, the control voltage sensitivity increases, eventually the voltage sensitivity K.

In the past, since the adjustment was completed on the horizontal axis XT, the control voltage sensitivity was K ₂ , and the difference between the control voltage sensitivity before the adjustment and the control voltage sensitivity after the adjustment was relatively large. Thus, the adjusting method of the present invention can reduce the difference between the adjusted control voltage sensitivity K and the adjusted control voltage sensitivity.

As described above, since the characteristics at the level of the resonance circuit board, that is, the variations in the resonance frequency and the impedance of the specific element can be suppressed and stably adjusted, the voltage-controlled oscillation incorporating this resonance circuit is achieved. In a communication device using a circuit, the time required to reach the desired oscillation frequency derived from the voltage control type oscillation circuit can be shortened and stabilized, and stable followability even when the communication channel changes. Can be achieved.

In the above-mentioned embodiment, the ribbon inductor conductor film 2 is formed on the front surface of the dielectric substrate 1 and is formed on the back surface of the substrate 1 so as to face the earth electrode film 5. The film 2 may be provided inside the dielectric substrate 1, and only a plurality of stub conductor films 21, 22, 23, ... May be formed on the substrate surface via via-hole conductors. It does not matter if the earth electrode film 5 is not opposed.

Further, the capacitor electrodes 3 and 4 are comb-teeth shaped electrodes and are arranged side by side on the surface of the substrate so that the electrode fingers 31, 32, 41, 42 .. Alternatively, a rectangular electrode film may be superposed by interposing a dielectric material between the electrode films, and a part of the superposed electrode films may be removed to reduce the facing area. Further, the trimming capacitors having the above-mentioned comb-teeth-shaped electrodes may be connected to the fixed capacitive components that are superimposed on each other.

In the embodiment, the inductor conductor film 2 and the plurality of stub conductor films 21, 22 ... Are provided on the resonance circuit board.
.., capacitive electrode films 3, 4, electrode fingers 31, 32, 41, 42
, But electronic components necessary for circuit construction, such as a varicap diode, a chip capacitor, a chip resistor, and a transistor, may be arranged on the dielectric substrate 1, respectively.

[0053]

As described above, according to the present invention, a plurality of stub conductor films capable of adjusting the inductor component of the ribbon inductor conductor, and both electrode fingers are cut and removed so that the capacitance component can be adjusted, The characteristics are adjusted in two stages.

Therefore, the resonance frequency can be adjusted relatively easily as in the prior art, and the variation of the impedance of each element forming the resonance circuit can be reduced. The difference between before and after the adjustment can be reduced, and the variation between products can be reduced.

For example, when the resonance circuit board is used in a voltage control type oscillation circuit, it is possible to reduce variations in voltage sensitivity, control the applied control voltage with a stable oscillation frequency, and stabilize the derivation of the oscillation frequency. Will be done.

[Brief description of drawings]

FIG. 1 is a schematic view of a resonant circuit board according to the present invention.

FIG. 2 is a characteristic diagram showing a change in sensitivity of a control voltage when a plurality of stub conductor films of a ribbon inductor conductor film are sequentially cut.

FIG. 3 is a characteristic diagram showing control voltage sensitivity when the electrode fingers of the capacitive electrode film are sequentially cut.

FIG. 4A is a characteristic diagram showing a change state of the resonance frequency in the adjustment process by the adjustment method of the present invention, and FIG. 4B is a characteristic diagram showing a corresponding change in the control voltage sensitivity.

FIG. 5 is a circuit diagram showing a resonance circuit portion in a voltage controlled oscillator circuit.

6A is a plan view showing a planar structure of a capacitor electrode film, and FIG. 6B is a characteristic diagram showing a change in resonance frequency.

7A is a plan view showing a planar structure of a ribbon inductor film, and FIG. 7B is a characteristic diagram showing a change in resonance frequency.

[Explanation of supplements]

 DESCRIPTION OF SYMBOLS 1 ... Dielectric substrate 2 ... Ribbon inductor conductor film 3, 4 / Capacitance electrode film 21, 22 ... Stub conductor film 31, 32, 41, 42 ... Electrode finger 5 ... Earth electrode film

Claims (1)

[Claims] 1. A resonance circuit board having a dielectric substrate and a ribbon inductor conductor film having a conductor pattern capable of adjusting an inductor, and a resonance circuit comprising a capacitance element having a conductor pattern capable of adjusting a capacitance component. A resonance characteristic of the resonance circuit board, wherein a predetermined resonance characteristic of the resonance circuit is adjusted by removing a part of a conductor pattern capable of adjusting an inductor and a part of a conductor pattern capable of adjusting a capacitance component. How to adjust the characteristics.