JPH05335835A - Oscillation circuit - Google Patents

Abstract

(57) [Summary] (Correction) [Purpose] To easily and accurately adjust the oscillation frequency in an oscillation circuit that has a triplate strip line. [Structure] This oscillator circuit includes a microstrip line 5
A triplate-type strip line including an intermediate substrate 1 on which the intermediate substrate 1 is formed, and a pair of ground substrates 2 and 3 which are arranged so as to sandwich the intermediate substrate 1 and on which ground patterns 6 and 7 are formed, An oscillation frequency adjusting substrate 4 is arranged such that at least one of the pair of grounding substrates 2 and 3 is sandwiched between the intermediate substrate 1 and the oscillation frequency adjusting substrate 4 is electrically connected to the microstrip line 5. A conductive pattern 8 for adjusting the oscillation frequency that is electrically connected is formed. The conductive pattern 8 and the ground pattern 6 form an adjusting capacitance component. Moreover, a plurality of stubs can be formed by the conductive pattern 8 to adjust the inductance.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an oscillating circuit, and more particularly to an oscillating circuit having a triplate type strip line using a multilayer circuit board having a wiring layer of a microstrip line therein.

[0002]

2. Description of the Related Art Conventionally, an oscillating circuit using a microstrip line has been adopted in a variable frequency oscillator for mobile communication represented by a car telephone. The microstrip line used in this oscillator is generally
It is composed of a substrate made of a dielectric material, a strip conductor formed on the front surface of the substrate, and a ground pattern formed on the rear surface of the substrate.

In such an oscillator circuit, the oscillation frequency varies due to variations in the line width and line length of the microstrip line. To adjust the variation of the oscillation frequency, connect the other end of the microstrip line with one end grounded to the comb-teeth-shaped trimming capacitor formed by the line pattern on the substrate surface, and use this laser to trim the trimming capacitor. There is a way to disconnect. There is also a method of forming a stub for adjusting the oscillation frequency in a line pattern on a side portion of the microstrip line and cutting the stub with a laser or the like to perform the adjustment.

On the other hand, for the purpose of suppressing the radiation loss from the microstrip line, a substrate having the microstrip line is sandwiched between a pair of substrates having a ground pattern formed on the surface thereof. An oscillation circuit having a line has been conventionally proposed. In the oscillator circuit having such a triplate type strip line, the oscillation frequency is adjusted by scraping off the ground pattern formed on the outer substrate surface.

[0005]

In the conventional structure in which a trimming capacitor or stub is formed in a line pattern on the surface of the substrate to adjust the oscillation frequency, the line pattern is occupied when the frequency adjustment range is widened. This increases the area and hinders the miniaturization of the circuit. Also,
In the structure using the triplate type strip line, the frequency is adjusted by scraping off the ground pattern, so that it is difficult to accurately adjust the frequency.

An object of the present invention is to make it possible to easily and accurately adjust the oscillation frequency in an oscillation circuit having a triplate type strip line.

[0007]

An oscillator circuit according to the present invention comprises an intermediate substrate on which a microstrip line is formed,
The oscillation circuit includes a triplate-type strip line including a pair of grounding substrates arranged so as to sandwich an intermediate substrate and having a grounding pattern formed on the surface. A substrate for oscillation frequency adjustment is arranged so as to sandwich at least one of the pair of ground substrates between the substrate and the intermediate substrate, and the surface of the oscillation frequency adjustment substrate is electrically connected to the microstrip line. A conductive pattern for adjusting the oscillation frequency is formed.

[0008]

In the oscillator circuit according to the present invention, with respect to the substrate on which the microstrip line forming the oscillator circuit is formed,
A substrate for oscillation frequency adjustment, in which a conductive pattern is formed, is arranged with a ground substrate interposed therebetween. Therefore, if the capacitance component is formed inside the substrate sandwiched by the conductive pattern and the ground pattern of the ground substrate, the capacitance component can be changed by cutting the conductive pattern with a laser or the like easily and The oscillation frequency can be adjusted accurately. Further, by forming a plurality of stubs by the conductive pattern and connecting the stubs to the microstrip line of the intermediate substrate by using through holes or the like, the inductance component is adjusted by cutting the stubs and the oscillation frequency is adjusted. be able to. Also in this case, the adjustment can be performed easily and accurately.

When forming a trimming stub as a conductive pattern, the stub and the microstrip line must be connected by a through hole.
Since the size of the through hole is usually about 150 μm to 200 μm, the width of the stub becomes wider than that and the adjustment range of the oscillation frequency becomes large. Therefore, it is preferable that the conductive pattern is a conductive pattern for forming a capacitance.

[0010]

FIG. 1 shows an oscillator circuit according to an embodiment of the present invention. As shown in the figure, this oscillation circuit is configured such that an intermediate substrate 1, a pair of ground substrates 2 and 3 provided so as to sandwich the intermediate substrate 1, and an intermediate substrate 1 above the ground substrate 2 are grounded. It has a substrate 4 for frequency adjustment arranged so as to sandwich the substrate 2.

A microstrip line 5 is formed on the surface of the intermediate substrate 1. Further, ground patterns 6 and 7 are formed on substantially the entire surface between the ground substrates 2 and 3. Further, on the surface of the substrate 4 for adjusting the oscillation frequency, a plurality of conductive patterns 8 for forming trimming capacitors inside the substrate 4 are arranged in a matrix.
The three conductive patterns 8 lined up in the Y direction in the figure respectively include connection wires 9a and 9b for fine adjustment and connection wires 9c and 9d.
And connection wirings 9e and 9f, respectively. The three conductive patterns located at the ends of the three conductive patterns arranged in the Y direction are connected to each other in the X direction of FIG. 1 by the coarse adjustment connection wirings 10a and 10b. The plurality of conductive patterns 8 are connected to the connection pattern 12 by the connection wiring 11.
The connection pattern 12 is formed on the intermediate substrate 1 through the through hole.
Is electrically connected to one end of the microstrip line 5. The other end of the microstrip line 5 is connected to the ground patterns 6 and 7 of the ground substrates 2 and 3 on both sides via through holes.

In the oscillation circuit having such a configuration, the coarse adjustment connection wirings 10a and 10b are cut off, and then the fine adjustment connection wirings 9e and 9f are cut off. Can be adjusted. Further, by cutting the coarse adjustment connection wiring 10a and then cutting the fine adjustment connection wirings 9c and 9d, the oscillation frequency can be adjusted according to the characteristic shown in FIG. Further, fine adjustment connection wirings 9a, 9
By cutting b, the oscillation frequency can be adjusted according to the characteristic shown in FIG.

As described above, the connection wiring connecting the conductive patterns 8 on the substrate 4 for adjusting the oscillation frequency is cut by
The C (capacitor) component forming the LC resonant circuit can be changed, and the oscillation frequency can be roughly and finely adjusted. Therefore, the oscillation frequency can be easily and accurately adjusted to the target frequency. Moreover, since the additional capacitance component is formed inside the substrate 4, the frequency change rate can be easily changed by changing the thickness and the dielectric constant of the substrate 4.

FIG. 3 is a circuit diagram of a voltage controlled oscillator circuit having an oscillator circuit according to an embodiment of the present invention. This oscillation circuit is composed of a resonance circuit section 20, a negative resistance circuit section 21, and an amplification circuit section 22. Resonant circuit section 20
Is for determining the variable range of the voltage-controlled oscillation frequency, the microstrip line SL1 with the trimming capacitor for frequency adjustment shown in FIG. 1, the varicap Cv whose capacitance changes with the control voltage, the bypass capacitors C1 and C2. Capacitor C3 and capacitors C4 and C5,
Resistors R1 and R2 and other microstrip line SL2
It consists of and. Further, the negative resistance circuit unit 21 is
A transistor Q1, capacitors C6, C7, C9,
It is composed of a resistor R6. Furthermore, the amplification circuit unit 2
2 is a transistor Q2 and a microstrip line S
L3 and capacitors C8, C10, C11, C12,
It is composed of resistors R3 and R4.

The capacitor C4 in the resonance circuit section 20 corresponds to the additional capacitance (trimming capacitor) formed by the conductive pattern 8 in FIG. [Other Embodiments] (a) In the above embodiments, the oscillation frequency is adjusted by cutting the connection wirings 9a to 9f, 10a, 10b connecting the plurality of conductive patterns 8. However, the shapes of the plurality of conductive patterns are adjusted. For example, the capacitance values formed by the conductive patterns may be different by changing the above, and the frequency may be roughly adjusted or finely adjusted.

(B) FIG. 4 shows another embodiment. In this embodiment, similarly to the above, the microstrip line 3 is used.
0 formed intermediate board 31, a pair of ground boards 32, 33 arranged on both sides of the intermediate board 31 so as to sandwich the intermediate board 31, and a frequency adjusting board arranged above the ground board 32. And a substrate 34. A pair of ground boards 3
The ground patterns 35,
36 is formed. Further, a pair of comb-teeth-shaped conductive patterns 37, 3 are formed on the surface of the oscillation frequency adjusting substrate 34.
8 is formed. One pair of comb-shaped conductive patterns 3
Nos. 7 and 38 are arranged so that the projections of the comb teeth are inserted between the projections of the comb teeth of the mating pattern, and a line-to-line capacitance is formed between the projections. ing. In addition, the one conductive pattern 37 is formed on the surface of the intermediate substrate 31 through the through hole.
Is connected to one end of. The other conductive pattern 3
Reference numeral 8 is connected to the ground pattern 35 on the surface of the ground substrate 32 via a through hole. The other end of the microstrip line 30 is connected to the ground patterns 35 and 36 of the ground substrates 32 and 33 on both sides of the microstrip line 30 through through holes.

In such an embodiment, the conductive pattern 3
By cutting the comb teeth of 7, 38 or the portion connecting the comb teeth with a laser or the like, the C component forming the LC resonance circuit can be changed in the same manner as described above, and the oscillation frequency can be easily adjusted. (C) FIG. 5 shows still another embodiment. In this embodiment, an intermediate substrate 41 on which the microstrip line 40 is formed, and a pair of ground substrates 42, 4 arranged on both sides of the intermediate substrate 41 so as to sandwich the intermediate substrate 41 therebetween.
3 and a substrate 44 for adjusting the oscillation frequency, which is arranged on the ground substrate 42. Ground patterns 45 and 46 are formed on substantially the entire surfaces of the ground substrates 42 and 43. On the other hand, on the surface of the frequency adjustment board 44, a plurality of stubs 47a, 47b, 47c are arranged in parallel. One end of each stub 47a to 47c has a connection pattern 48.
Connected by. The connection pattern 48 is formed on the surface of the ground substrate 42 through the through hole.
Connected to 5. The other ends of the stubs 47a to 47c are connected to the side portions 40a, 40b of the microstrip line 40 on the intermediate substrate 41 via the through holes, respectively.
It is connected to 40c. Microstrip line 40
One end of is connected to the ground patterns 45 and 46 of the ground substrates 42 and 43 through through holes.

In such an oscillator circuit, the stubs 47a ...
By cutting 47c, the L (inductance) component that constitutes the LC resonance circuit can be adjusted, and the oscillation frequency can be adjusted. Stubs 47a to 47 at this time
FIG. 6 shows the relationship between the cut point of c and the variation width of the oscillation frequency. Here, when the stub for the L component is formed, each stub must be connected to the microstrip line by a through hole. Through hole is usually 150 ~
Since the diameter of 200 μm is required, the width of the stub becomes wider than that. For this reason, the rate of change of frequency per line becomes large. This is apparent by comparing FIG. 6 with FIG. 2 in the previous embodiment.

For this reason, when fine adjustment is necessary, as shown in FIG.
It is more preferable to adjust the oscillation frequency by adjusting the C component as shown in FIG. (D) In each of the embodiments, the oscillation frequency adjusting substrate is provided only on the side of one ground substrate, but the oscillation frequency adjusting substrate is also provided on the other ground substrate side to adjust the frequency. You may do it.

[0020]

As described above, according to the present invention, in the oscillation circuit provided with the triplate type strip line, the oscillation frequency adjusting substrate is provided and the conductive pattern for oscillation frequency adjustment is formed on the surface thereof. It is possible to easily and accurately adjust the oscillation frequency by forming a capacitance for adjusting the oscillation frequency with the conductive pattern or forming a stub for adjusting the inductance.

[Brief description of drawings]

FIG. 1 is an exploded perspective view of an oscillator circuit according to an embodiment of the present invention.

FIG. 2 is a diagram showing the oscillation frequency adjustment characteristic.

FIG. 3 is a circuit diagram of an oscillator circuit employing the oscillator circuit.

FIG. 4 is an exploded perspective view of an oscillator circuit according to another embodiment of the present invention.

FIG. 5 is an exploded perspective view of an oscillator circuit according to still another embodiment of the present invention.

6 is a diagram showing the adjustment characteristic of the oscillation frequency according to the embodiment of FIG.

[Explanation of symbols]

 1, 31, 41 Intermediate substrate 2, 3, 32, 33, 42, 43 Ground substrate 4, 34, 44 Oscillation frequency adjusting substrate 5, 30, 40 Microstrip line 6, 7, 35, 36, 45, 46 Ground Patterns 8, 37, 38 Conductive patterns 47a, 47c Stubs

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Yasuyuki Tanaka 1-1 Yamashita-cho, Kokubun-shi, Kagoshima Prefecture Kyocera Stock Company Kagoshima Kokubun Plant (72) Inventor Shigeo Nakamura 1-1 Yamashita-cho, Kokubun-shi, Kagoshima Prefecture Kyocera Stock Company Kagoshima Kokubun Factory (72) Inventor Yasuhito Fujii 1-1 Yamashita-cho, Kokubun-shi, Kagoshima Prefecture Kyocera Stock Company Kagoshima Kokubun Factory (72) Inventor Satoru Tanaka 1-1 Yamashita-cho, Kokubun-shi, Kagoshima Kagoshima Kokubu Factory Within

Claims (1)

[Claims] 1. An oscillation provided with a triplate type strip line including an intermediate substrate on which a microstrip line is formed, and a pair of ground substrates arranged so as to sandwich the intermediate substrate and having a ground pattern formed on the surface thereof. In the circuit, a substrate for oscillation frequency adjustment is arranged so that at least one of the pair of ground substrates is sandwiched between the substrate and the intermediate substrate, and the surface of the oscillation frequency adjustment substrate is electrically connected to the microstrip line. An oscillation circuit, wherein a conductive pattern for adjusting an oscillation frequency to be connected is formed.