JP2016116034A - Impedance matching circuit - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an impedance matching circuit which achieves wide-band impedance transformation without causing enlargement of circuit size.SOLUTION: A first line 21 and a second line 22 constituted of the first line 21 having a cubic spiral structure in which wiring is performed over an upper wiring layer and a lower wiring layer possessed by a microwave integrated circuit so that an insulation film of the microwave integrated circuit is located in the center, and the second line 22 having the cubic spiral structure in which wiring in parallel to the first line 21 is performed over the upper wiring layer and the lower wiring layer so that the insulation film is located in the center are electrically connected to each other by a via hole 23.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a small impedance matching circuit having an impedance transformation function at an operating frequency.

Non-Patent Document 1 below describes an impedance matching circuit having an impedance transformation function at a fundamental frequency.
This impedance matching circuit constitutes a low-pass filter in which a plurality of inductors are connected in series and a plurality of capacitors are connected in parallel between an input terminal and an output terminal.

Supervised by Yoshihiro Konishi, written by Kazuhiko Honjo, “Basics and Development of Microwave Semiconductor Circuits”, published in 1993 by Nikkan Kogyo Shimbun.

  Since the conventional impedance matching circuit is configured as described above, it is possible to realize impedance transformation in a desired frequency band, but when the frequency is low, it is necessary to use a large inductor and capacitor. There was a problem that the circuit size would increase. In addition, even when the frequency is high, if the operating frequency bandwidth is wide, it is necessary to increase the number of stages of inductors and capacitors required for impedance transformation, resulting in a problem that the circuit size increases.

  The present invention has been made to solve the above-described problems, and an object thereof is to obtain an impedance matching circuit capable of realizing impedance transformation without causing an increase in circuit size.

  The impedance matching circuit according to the present invention is a first line having a three-dimensional spiral structure that is wired over a plurality of wiring layers of the microwave integrated circuit so that the insulating film of the microwave integrated circuit is located at the center. And a second line having a three-dimensional spiral structure wired in parallel with the first line over a plurality of wiring layers so that the insulating film is located at the center.

  According to the present invention, the first line of the three-dimensional spiral structure wired across the plurality of wiring layers of the microwave integrated circuit so that the insulating film of the microwave integrated circuit is positioned at the center, Since the insulating film is composed of a second line having a three-dimensional spiral structure wired in parallel with the first line over a plurality of wiring layers so that the insulating film is located at the center, the circuit size is increased. There is an effect that impedance transformation can be realized without incurring.

It is a conceptual diagram which shows the structure of the impedance matching circuit by Embodiment 1 of this invention. It is a block diagram which shows the impedance matching circuit by Embodiment 1 of this invention. FIG. 3 is an equivalent circuit diagram of the impedance matching circuit of FIG. 2. An impedance matching circuit in which the start point of the first line 21 is the port (1), the start point of the second line 22 is the port (2), and the end points of the first line 21 and the second line 22 are connected to the ground. FIG. FIG. 5 is an equivalent circuit diagram of the impedance matching circuit of FIG. 4. It is explanatory drawing which shows the calculation result of S parameter (S11, S21, S22). An impedance matching circuit in which a capacitor 41 is connected between the start point of the first line 21 and the start point of the second line 22, and the end points of the first line 21 and the second line 22 are connected to the ground. It is a block diagram. FIG. 8 is an equivalent circuit diagram of the impedance matching circuit of FIG. 7. It is explanatory drawing which shows the calculation result of S parameter (S11, S21, S22). A configuration showing an example in which the start points of the first line 21 and the second line 22 are connected to the ground via the capacitors 51 and 52, and the end points of the first line 21 and the second line 22 are connected to the ground. FIG. FIG. 11 is an equivalent circuit diagram of the impedance matching circuit of FIG. 10. It is explanatory drawing which shows the calculation result of S parameter (S11, S21, S22). It is a block diagram which shows the example in which the substantially middle point (middle part) of the 1st track | line 21 is connected with the ground, and the end point of the 2nd track | line 22 is connected with the ground. FIG. 14 is an equivalent circuit diagram of the impedance matching circuit of FIG. 13. It is explanatory drawing which shows the calculation result of S parameter (S11, S21, S22, S31, S33). It is a block diagram which shows the impedance matching circuit by Embodiment 5 of this invention. FIG. 17 is an equivalent circuit diagram of the impedance matching circuit of FIG. 16. It is explanatory drawing which shows the calculation result of S parameter (S11, S22, S31, S32, S33). It is a block diagram which shows the high frequency amplifier which the impedance matching circuit by Embodiment 6 of this invention applies. FIG. 20 is an equivalent circuit diagram of the high frequency amplifier of FIG. 19. 21 is an equivalent circuit when the amplifier 70 of FIG. 20 is configured by a single-stage microwave transistor 72. It is a block diagram which shows the high frequency amplifier which the impedance matching circuit by Embodiment 6 of this invention applies. It is an equivalent circuit schematic of the high frequency amplifier of FIG.

Hereinafter, in order to describe the present invention in more detail, modes for carrying out the present invention will be described with reference to the accompanying drawings.
Embodiment 1 FIG.
In the first embodiment, the impedance matching circuit is formed in a microwave integrated circuit (MMIC: Monolithic Microwave Integrated Circuit) having a plurality of wiring layers, and an insulating film is filled between the plurality of wiring layers. Assumes something.
1 is a conceptual diagram showing a configuration of an impedance matching circuit according to Embodiment 1 of the present invention, and FIG. 2 is a configuration diagram showing an impedance matching circuit according to Embodiment 1 of the present invention.
FIG. 3 is an equivalent circuit diagram of the impedance matching circuit of FIG.

In FIG. 1, a first line 11 is a three-dimensional helical structure line that functions as an inductor.
The second line 12 is a three-dimensional spiral structure line that functions as an inductor.
The first line 11 and the second line 12 are wired in parallel to each other to form a double spiral structure.
An insulator 13 is placed at the center of the first line 11 and the second line 12.

FIG. 2 shows a state in which the impedance matching circuit of FIG. 1 is formed on the MMIC. The MMIC has a plurality of wiring layers, and an insulating film is filled between the plurality of wiring layers.
FIG. 2 shows an example in which the MMIC has two wiring layers, and an insulating film is filled between the upper wiring layer and the lower wiring layer.
The first line 21 is equivalent to the first line 11 in FIG. 1, and is wired across the upper wiring layer and the lower wiring layer in the MMIC so that the insulating film of the MMIC is located at the center. It is a three-dimensional spiral structure track.
The second line 22 is equivalent to the second line 12 in FIG. 1, and is wired across the upper wiring layer and the lower wiring layer in the MMIC so that the insulating film of the MMIC is located at the center. It is a three-dimensional spiral structure track.

In FIG. 2, the first line 21 and the second line 22 wired in the upper wiring layer are shown in gray, and the first line 21 and the second line 22 wired in the lower wiring layer. Is written in black.
Note that the first line 21 and the second line 22 wired in the upper wiring layer in the MMIC and the first line 21 and the second line 22 wired in the lower wiring layer in the MMIC are via holes. 23 is electrically connected.
In this example, the MMIC has two wiring layers, but the MMIC has two wiring layers. The MMIC has three or more wiring layers. Then, the first line 21 and the second line 22 may be wired over three or more wiring layers.

In FIG. 3, an inductor 31 indicates an inductor in which the first line 21 in FIG. 2 functions, and an inductor 32 indicates an inductor in which the second line 22 in FIG. 2 functions.
The insulator 33 corresponds to an insulating film of MMIC located at the center of the first line 21 and the second line 22.
As is clear from the equivalent circuit diagram of FIG. 3, the impedance matching circuit of FIG. 2 can be regarded as a transformer having the insulator 33 as a magnetic circuit.

Here, it is assumed that the start point and end point of the first line 21 in the impedance matching circuit of FIG. 2 constitute an input terminal pair, and the start point and end point of the second line 22 constitute an output terminal pair.
In FIG. 4, the start point of the first line 21 constituting the input terminal pair is the port (1), the start point of the second line 22 constituting the output terminal pair is the port (2), the first line 21 and the second line. An example in which the end point of the line 22 is connected to the ground is shown. FIG. 5 shows an equivalent circuit of the impedance matching circuit of FIG.

The impedance matching circuit of FIG. 4 operates as a transformer, as is apparent from the equivalent circuit diagram of FIG.
For example, the spiral diameter of the first line 21 is 110 μm, the line width is 10 μm, the number of turns is 11, the spiral diameter of the second line 22 is 70 μm, the line width is 10 μm, the number of turns is 5, and the insulator 33 When the S parameter (S11, S21, S22) is calculated assuming that the dielectric constant is 6, the port impedance of the port (1) is 30Ω, and the port impedance of the port (2) is 45Ω, the S parameter (S11, S21, S22) The calculation result is as shown in FIG.
From FIG. 6, it can be seen that S21 is about −1.8 dB, S11 and S22 are about −18 dB with 13 GHz as the center frequency, and the transformer is operating normally.

Since the impedance matching circuit in FIG. 4 operates normally as a transformer, impedance transformation can be realized. The first line 21 and the second line 22 form a double spiral structure, and the first line 21 and the second line 22 can be arranged in a space for forming one inductor. Therefore, downsizing can be achieved.
By applying the impedance matching circuit of FIG. 4 to the input circuit, output circuit, or interstage circuit of a high frequency amplifier that amplifies high frequency, impedance transformation from a low impedance transistor to a desired impedance, or a high impedance transistor Impedance transformation from the desired impedance to the desired impedance can be realized.
Further, by applying the impedance matching circuit of FIG. 4 to the high frequency amplifier, the high frequency amplifier can be reduced in size.

The impedance matching circuit of FIG. 4 has a DC cut function for cutting a direct current component because the input terminal pair and the output terminal pair are insulated by an insulator 33, and a DC cut capacitor is omitted. It is possible.
Further, the impedance matching circuit of FIG. 4 can be realized by only two layers of metal wiring (the first line 21 and the second line 22), and the impedance matching circuit of FIG. Unlike the wiring, no insulation coating is required for the wiring. Therefore, the size of the structure can be reduced by the amount of the insulating coating, and the magnetic loss due to the insulating coating can be reduced.

Embodiment 2. FIG.
FIG. 7 is a block diagram showing an impedance matching circuit according to Embodiment 2 of the present invention. That is, in FIG. 7, the capacitor 41 is connected between the start point of the first line 21 and the start point of the second line 22, and the end points of the first line 21 and the second line 22 are connected to the ground. An example is shown. FIG. 8 shows an equivalent circuit of the impedance matching circuit of FIG.

In the impedance matching circuit of FIG. 7, a capacitor 41 is connected between the port (1) and the port (2). The capacitor 41 operates as a coupling capacitance to the transformer so as to supplement the magnetic field coupling.
In the impedance matching circuit of FIG. 7, since there are two couplings between the input and output terminals, magnetic coupling and capacitive coupling, multiple resonances occur and a large number of transmission modes occur.
At this time, if the capacitance value of the capacitor 41 is selected so as to realize impedance matching at a desired impedance for the ports (1) and (2), the reflection loss at the ports (1) and (2) is reduced. be able to.

On the contrary, if the capacitance value of the capacitor 41 is selected so that the coupling coefficient as a transformer is increased, the transmission amount of the transformer can be improved in a range where the capacitance value is smaller than a predetermined value. When the capacitance value of the capacitor 41 is made larger than a predetermined value, the transmission amount of the transformer has two peaks, so that a broadband transmission characteristic is obtained.
Further, when the capacitance value of the capacitor 41 is increased, the peak frequencies are separated from each other, so that two bands are provided. At this time, since the movement of the peak frequency can be controlled by changing the lengths of the first line 21 and the second line 22, three bands can be provided.

For example, the spiral diameter of the first line 21 is 110 μm, the line width is 10 μm, the number of turns is 11, the spiral diameter of the second line 22 is 70 μm, the line width is 10 μm, the number of turns is 5, and the insulator 33 When the S parameter (S11, S21, S22) is calculated assuming that the dielectric constant is 6, the port impedance of the port (1) is 30Ω, the port impedance of the port (2) is 45Ω, and the capacitance value of the capacitor 41 is 0.6 pF. , S parameter (S11, S21, S22) calculation results are as shown in FIG.
From FIG. 9, it can be seen that S21 is about −0.6 dB, S11 is about −19 dB, and S22 is about −25 dB with 10 GHz as the center frequency, and is operating normally as a wideband transformer.
Also, with 22 GHz as the center frequency, S21 is about -0.4 dB, S11 and S22 are about -13 dB, and it can be seen that the device is operating normally as a wideband transformer. Therefore, two band characteristics are obtained.

Since the impedance matching circuit in FIG. 7 operates normally as a wideband transformer, impedance transformation can be realized. The first line 21 and the second line 22 form a double spiral structure, and the first line 21 and the second line 22 can be arranged in a space for forming one inductor. Therefore, downsizing can be achieved.
By applying the impedance matching circuit of FIG. 7 to the input circuit, output circuit, or interstage circuit of a high frequency amplifier that amplifies a high frequency, impedance transformation from a low impedance transistor to a desired impedance, or a high impedance transistor Impedance transformation from the desired impedance to the desired impedance can be realized.
Further, by applying the impedance matching circuit of FIG. 7 to the high frequency amplifier, the high frequency amplifier can be reduced in size.

The impedance matching circuit of FIG. 7 has a DC cut function for cutting a direct current component because the input terminal pair and the output terminal pair are insulated by an insulator 33, and a DC cut capacitor is omitted. It is possible.
Further, the impedance matching circuit of FIG. 7 can be realized with only two layers of metal wiring (first line 21 and second line 22), and the impedance matching circuit of FIG. Unlike the wiring, no insulation coating is required for the wiring. Therefore, the size of the structure can be reduced by the amount of the insulating coating, and the magnetic loss due to the insulating coating can be reduced.
Furthermore, the impedance matching circuit of FIG. 7 can realize a wider band characteristic than the impedance matching circuit of FIG. 4 according to the first embodiment. In addition, wideband characteristics can be realized for two or more bands.

Embodiment 3 FIG.
FIG. 10 is a block diagram showing an impedance matching circuit according to Embodiment 3 of the present invention. That is, in FIG. 10, the starting points of the first line 21 and the second line 22 are connected to the ground via the capacitors 51 and 52, and the end points of the first line 21 and the second line 22 are connected to the ground. An example is shown. FIG. 11 shows an equivalent circuit of the impedance matching circuit of FIG.

  In the impedance matching circuit of FIG. 10, the start points of the first line 21 and the second line 22 are connected to the ground via capacitors 51 and 52, and the end points of the first line 21 and the second line 22 are connected to the ground. Although connected, each of the capacitors 51 and 52 operates as impedance matching for the transformer constituted by the first line 21 and the second line 22, and compensates for the inductor component of the transformer.

For example, the spiral diameter of the first line 21 is 110 μm, the line width is 10 μm, the number of turns is 11, the spiral diameter of the second line 22 is 70 μm, the line width is 10 μm, the number of turns is 5, and the insulator 33 Assuming that the dielectric constant is 6, the port impedance of the port (1) is 52Ω, the port impedance of the port (2) is 62Ω, the capacitance value of the capacitor 51 is 0.05 pF, and the capacitance value of the capacitor 52 is 0.064 pF. When (S11, S21, S22) is calculated, the calculation results of the S parameters (S11, S21, S22) are as shown in FIG.
From FIG. 12, it can be seen that S21 is about −1.2 dB, S11 is about −21 dB, and S22 is about −25 dB with 15 GHz as the center frequency, so that it is operating normally as a wideband transformer.
Also, with 22 GHz as the center frequency, S21 is about -35 dB, S11 and S22 are about -3 dB, and it can be seen that the broadband transformer is operating normally. Therefore, two band characteristics are obtained.

Since the impedance matching circuit in FIG. 10 operates normally as a wideband transformer, impedance transformation can be realized. The first line 21 and the second line 22 form a double spiral structure, and the first line 21 and the second line 22 can be arranged in a space for forming one inductor. Therefore, downsizing can be achieved.
By applying the impedance matching circuit of FIG. 10 to the input circuit, output circuit or interstage circuit of a high frequency amplifier that amplifies high frequency, impedance transformation from a low impedance transistor to a desired impedance, or a high impedance transistor Impedance transformation from the desired impedance to the desired impedance can be realized.
Further, by applying the impedance matching circuit of FIG. 10 to the high frequency amplifier, the high frequency amplifier can be reduced in size.

The impedance matching circuit of FIG. 10 has a DC cut function for cutting a direct current component because the input terminal pair and the output terminal pair are insulated by an insulator 33, and a DC cut capacitor is omitted. It is possible.
Further, the impedance matching circuit of FIG. 10 can be realized by only two layers of metal wiring (first line 21 and second line 22), and the impedance matching circuit of FIG. Unlike the wiring, no insulation coating is required for the wiring. Therefore, the size of the structure can be reduced by the amount of the insulating coating, and the magnetic loss due to the insulating coating can be reduced.
Furthermore, the impedance matching circuit of FIG. 10 can realize better reflection matching than the impedance matching circuit of FIG. 4 according to the first embodiment.

Embodiment 4 FIG.
FIG. 13 is a block diagram showing an impedance matching circuit according to Embodiment 4 of the present invention. That is, FIG. 13 shows an example in which a substantially middle point (halfway portion) of the first line 21 is connected to the ground, and an end point of the second line 22 is connected to the ground. FIG. 14 shows an equivalent circuit of the impedance matching circuit of FIG.
The impedance matching circuit of FIG. 13 has a balun function by connecting the substantially middle point of the first line 21 to the ground and connecting the end point of the second line 22 to the ground.

For example, the spiral diameter of the first line 21 is 110 μm, the line width is 10 μm, the number of turns is 11, the spiral diameter of the second line 22 is 70 μm, the line width is 10 μm, the number of turns is 5, and the insulator 33 Assuming that the dielectric constant is 6, the port impedance of the port (1) is 29Ω, the port impedance of the port (2) is 29Ω, and the port impedance of the port (3) is 32Ω, the S parameter (S11, S21, S22, S31, S33). ) Is calculated, the S parameter (S11, S21, S22, S31, S33) calculation results are as shown in FIG.
From FIG. 15, the center frequency is 26 GHz, S21 and S31 are about −5.6 dB, S11 is about −20 dB, S22 is about −6 dB, S33 is about −7.5 dB, and the balun is operating normally. I understand that.

Since the impedance matching circuit in FIG. 13 operates normally as a balun, impedance transformation can be realized. The first line 21 and the second line 22 form a double spiral structure, and the first line 21 and the second line 22 can be arranged in a space for forming one inductor. Therefore, downsizing can be achieved.
By arranging the impedance matching circuit of FIG. 13 before and after the transistor constituting the high frequency amplifier that amplifies the high frequency, a balanced amplifier can be easily realized on the MMIC.
Further, by applying the impedance matching circuit of FIG. 13 to the high frequency amplifier, the high frequency amplifier can be reduced in size.

The impedance matching circuit of FIG. 13 has a DC cut function for cutting a direct current component because the input terminal pair and the output terminal pair are insulated by an insulator 33, and a DC cut capacitor is omitted. It is possible.
Further, the impedance matching circuit of FIG. 13 can be realized with only two layers of metal wiring (the first line 21 and the second line 22), and the impedance matching circuit of FIG. Unlike linear baluns, no insulation coating is required for the wiring. Therefore, the size of the structure can be reduced by the amount of the insulating coating, and the magnetic loss due to the insulating coating can be reduced.

Embodiment 5 FIG.
FIG. 16 is a block diagram showing an impedance matching circuit according to Embodiment 5 of the present invention, and FIG. 17 shows an equivalent circuit of the impedance matching circuit of FIG.
In the fifth embodiment, two sets of the first line 21 and the second line 22 are mounted. Hereinafter, 61 represents the first set of the first line 21 and the second line 22, and 62 represents The second set of the first line 21 and the second line 22 is represented.

In the impedance matching circuit of FIG. 16, the start point of the first line 21 (inductor 31) of the first set 61 and the start point of the second line 22 (inductor 32) of the second set 62 are the first external connection points. Is connected to port (1).
Further, the port (2) in which the start point of the second line 22 (inductor 32) of the first set 61 and the start point of the first line 21 (inductor 31) of the second set 62 are the second external connection points. Connected with.
Further, the end point of the first line 21 (inductor 31) of the first set 61 and the end point of the first line 21 (inductor 31) of the second set 62 are connected, and the second line of the second set 62 is reached. The end point 22 (inductor 32) is connected to the port (3) which is the third external connection point.
Further, the end point of the second line 22 (inductor 32) of the first set 61 is connected to the ground.
In the impedance matching circuit of FIG. 16, the first line 21 and the second line 22 of the first set 61 and the first line 21 and the second line 22 of the second set 62 are connected as described above. Therefore, it has a balun function.

For example, the spiral diameter of the first line 21 in the first set 61 and the second set 62 is 110 μm, the line width is 10 μm, the number of turns is 11, and the second line 22 in the first set 61 and the second set 62 The spiral diameter is 70 μm, the line width is 10 μm, the number of turns is 5, the dielectric constant of the insulator 33 is 6, the port impedance of the port (1) is 18Ω, the port impedance of the port (2) is 18Ω, and the port (3) When the S parameter (S11, S22, S31, S32, S33) is calculated assuming that the port impedance is 38Ω, the calculation result of the S parameter (S11, S22, S31, S32, S33) is as shown in FIG.
From FIG. 18, it can be seen that the center frequency is 11.3 GHz, S31 and S32 are about −4.6 dB, S11 is about −20 dB, S22 and S33 are about −8 dB, and the balun is operating normally.

Since the impedance matching circuit in FIG. 16 operates normally as a balun, impedance transformation can be realized. The first line 21 and the second line 22 form a double spiral structure, and the first line 21 and the second line 22 can be arranged in a space for forming one inductor. Therefore, downsizing can be achieved.
A balanced amplifier can be easily realized on the MMIC by arranging the impedance matching circuit of FIG. 16 before and after the transistor constituting the high frequency amplifier that amplifies the high frequency.
Further, by applying the impedance matching circuit of FIG. 16 to the high frequency amplifier, the high frequency amplifier can be reduced in size.

The impedance matching circuit of FIG. 16 has a DC cut function for cutting a direct current component because the input terminal pair and the output terminal pair are insulated by an insulator 33, and a DC cut capacitor is omitted. It is possible.
Further, the impedance matching circuit in FIG. 16 can be realized by only two layers of metal wiring (first line 21 and second line 22), and the impedance matching circuit in FIG. Unlike linear baluns, no insulation coating is required for the wiring. Therefore, the size of the structure can be reduced by the amount of the insulating coating, and the magnetic loss due to the insulating coating can be reduced.

Embodiment 6 FIG.
FIG. 19 is a block diagram showing a high frequency amplifier to which an impedance matching circuit according to Embodiment 6 of the present invention is applied, and FIG. 20 shows an equivalent circuit of the high frequency amplifier of FIG.
In the sixth embodiment, two sets of impedance matching circuits of FIG. 4 operating as transformers are mounted, and an amplifier 70 is connected between the two sets of impedance matching circuits.
FIG. 21 shows an equivalent circuit when the amplifier 70 of FIG. 20 is configured by a single-stage microwave transistor 72. 71 is an input matching circuit, and 73 is an output matching circuit.

The general microwave transistor 72 has an input impedance lower than 50Ω and an output impedance different from 50Ω (when the drain voltage or collector voltage is high, the output impedance is higher than 50Ω and the drain voltage or collector voltage is If it is low, the output impedance is lower than 50Ω).
The deviation of the impedance of the microwave transistor 72 from 50Ω can be corrected by impedance matching by the impedance matching circuit.

When the impedance matching circuit operating as a transformer is not connected, the input matching circuit 71 and the output matching circuit 73 play a role of correcting the impedance divergence. However, the larger the impedance transformation ratio, the more the input matching circuit 71 and the output matching circuit. There arises a problem that the operating band of the circuit 73 is limited.
Therefore, in order to increase the bandwidth of the input matching circuit 71, the output matching circuit 73, and the microwave transistor 72, it is necessary to reduce the impedance transformation ratio of the input matching circuit 71 and the output matching circuit 73.
In the sixth embodiment, an impedance matching circuit operating as a transformer is connected, and this impedance matching circuit can play a role of correcting the impedance divergence. Therefore, the input matching circuit 71 and the output matching circuit 73 are connected to each other. The impedance transformation ratio can be reduced. As a result, the input matching circuit 71, the output matching circuit 73, and the microwave transistor 72 can be widened.

FIG. 22 shows an equivalent circuit of a high-frequency amplifier operating as a balun instead of a transformer, and two amplifiers 70 are connected between two sets of impedance matching circuits.
FIG. 23 shows an equivalent circuit when the amplifier 70 of FIG. 22 is configured by a single-stage microwave transistor 72.

As described above, the general microwave transistor 72 has an impedance deviating from 50Ω.
The deviation of the impedance of the microwave transistor 72 from 50Ω can be corrected by impedance matching by the impedance matching circuit.
When the impedance matching circuit that operates as a balun is not connected, the input matching circuit 71 and the output matching circuit 73 connected before and after the two microwave transistors 72 play a role of correcting the impedance divergence. As the transformation ratio is larger, the operation band of the input matching circuit 71 and the output matching circuit 73 is limited.
Therefore, in order to increase the bandwidth of the input matching circuit 71, the output matching circuit 73, and the microwave transistor 72, it is necessary to reduce the impedance transformation ratio of the input matching circuit 71 and the output matching circuit 73.

In the sixth embodiment, since an impedance matching circuit operating as a balun is connected, a balanced amplifier is formed in which two microwave transistors 72 are bundled into one.
Thereby, since the total gate width per transistor can be reduced, the impedance of the microwave transistor 72 can be doubled. As a result, the input matching circuit 71, the output matching circuit 73, and the microwave transistor 72 can be widened.
Further, by providing an impedance transformation function to the balun, the impedance transformation ratio between the input matching circuit 71 and the output matching circuit 73 can be reduced, and the input matching circuit 71, the output matching circuit 73, and the microwave transistor 72 can be wideband. Can be achieved.
In the sixth embodiment, the same effects as in the first to fifth embodiments can be obtained.

  In the present invention, within the scope of the invention, any combination of the embodiments, or any modification of any component in each embodiment, or omission of any component in each embodiment is possible. .

  11 First Line, 12 Second Line, 13 Insulator, 21 First Line, 22 Second Line, 23 Via Hole, 31 Inductor, 32 Inductor, 33 Insulator, 41 Capacitor, 51, 52 Capacitor, 61 1st set, 62 2nd set, 70 amplifier, 71 input matching circuit, 72 microwave transistor, 73 output matching circuit.

Claims (7)

In an impedance matching circuit formed in a microwave integrated circuit having a plurality of wiring layers and filled with an insulating film between the plurality of wiring layers,
A first line of a three-dimensional spiral structure wired across the plurality of wiring layers so that the insulating film is located at the center;
It is composed of a second line having a three-dimensional spiral structure that is wired in parallel with the first line over the plurality of wiring layers so that the insulating film is located at the center. Impedance matching circuit.   2. The impedance matching circuit according to claim 1, wherein a start point and an end point of the first line constitute an input terminal pair, and a start point and an end point of the second line constitute an output terminal pair.   The capacitor is connected between the start point of the first line and the start point of the second line, and the end points of the first and second lines are connected to the ground. Impedance matching circuit.   3. The impedance matching circuit according to claim 2, wherein start points of the first and second lines are connected to the ground via a capacitor, and end points of the first and second lines are connected to the ground. .   The impedance matching circuit according to claim 2, wherein an intermediate portion of the first line is connected to the ground, and an end point of the second line is connected to the ground. Two sets of the first and second lines are formed,
A starting point of the first line of the first set and a starting point of the second line of the second set are connected to the first external connection point;
A start point of the second line of the first set and a start point of the first line of the second set are connected to a second external connection point;
The end point of the first line of the first set and the end point of the first line of the second set are connected,
An end point of the second line of the second set is connected to a third external connection point;
The impedance matching circuit according to claim 1, wherein an end point of the second line of the first set is connected to a ground.   7. The first and second lines are mounted on at least one of an input circuit, an output circuit, and an interstage circuit of a high-frequency amplifier that amplifies a high frequency. The impedance matching circuit according to claim 1.

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