JP3130857B2 - High frequency circuit bias circuit and high frequency matching circuit - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a bias circuit for supplying a bias voltage or a bias current (hereinafter referred to as "bias") to a high-frequency circuit, and a high-frequency matching circuit for matching the high-frequency circuit. The present invention relates to a high-frequency circuit bias circuit and a high-frequency matching circuit using lines.

[0002]

2. Description of the Related Art When a bias circuit for a high frequency circuit for supplying a bias to a transistor amplifier, a diode attenuator or the like at a high frequency such as a microwave band is constituted by a microstrip line (line) or a strip line, the bias circuit is used. Λ / 4 (1/4 wavelength) from the branch of the signal line (line) at the operating frequency in order to prevent the line for use (bias line) from exhibiting harmful reactance such as capacitance and inductance.
Is defined as a high-frequency ground point (GND). In the bias circuit having such a configuration, the length of the bias line must be changed according to the operating frequency of the high-frequency circuit.

One of the conventional means for adjusting the length of a microstrip line is disclosed in Japanese Patent Application Laid-Open No. 4-3502 (title of invention: high-frequency circuit impedance adjustment method). FIG. 5 is a top view substantially showing the bias circuit for the transistor amplifier shown in FIGS. 1 and 2 of the above publication. This top view shows the top surface of the microstrip substrate. On the upper surface, there are microstrip conductors (lines) such as the bias line 1A and the signal line 2A, and mounting components such as the transistor 7A, and the entire back surface is generally covered with a conductor.

In the bias circuit shown in FIG. 5, a collector terminal of a transistor 7A, which is an amplifying element for a high frequency signal, is connected to one end of a signal line 2A. The bias line (line) 1A branches off from the signal line 2A near the collector terminal, and the end thereof is finally connected to a power supply 8A for supplying a positive bias to the collector. An adjustment pattern 6A, which is a bent line having a substantially constant line interval, is formed at an intermediate portion of the bias line 1A. The adjustment pattern 6A includes an impedance adjustment component 5A.
Can be connected between the tracks. Impedance adjustment component 5
A can be a microstrip line component having a resistance value of 0Ω, a component exhibiting inductance, a component exhibiting capacitance, or the like. One end of a capacitor 3A is connected to a bias line 1A located at a predetermined distance from the branch portion of the signal line 2A including the adjustment pattern 6A. The other end of the capacitor 3A is connected to the GND 4A, and the GND 4A is further connected to a conductor on the back surface to serve as a ground potential point. As the capacitor 3A, a capacitor of a type and a capacity that exhibit a sufficiently small impedance at the operating frequency is selected.

In this bias circuit section, the signal line 2A
Through the short-circuit capacitor 3 of the high-frequency signal to GND 4A, and the passing (use) frequency of λ
/ 4. That is, when the impedance adjustment component 5A is not connected, the adjustment pattern 6
The electrical length of the series circuit of the bias line 1A including the capacitor A and the capacitor 3A is set to approximately λ / 4 of the passing frequency. Also, the impedance adjusting component 5A is connected to the adjusting pattern 6.
When connecting between the lines A, the electric length of the bias line 1A including this parallel circuit is set to λ / 4 of the passing frequency. The impedance adjustment component 5A has a resistance value of 0Ω, for example.
Microstrip line, the adjustment pattern 6
Most of the high-frequency signal passing through A passes through the impedance adjustment component 5A. Therefore, this bias circuit section can be used as a bias circuit for a plurality of frequencies by changing the connection position of the impedance adjusting component 5A.

[0006]

However, in the above-described conventional bias circuit for a high-frequency circuit, when the impedance adjustment component is connected to the adjustment pattern, the parallel circuit portion of the adjustment pattern is connected to the stub by the bias line. Is added, that is, the bias line appears as a stray capacitance, so that the influence of the bias line on the signal line cannot be completely eliminated.

Further, the above-described technique of the bias circuit for a high-frequency circuit can be applied to a high-frequency matching circuit for achieving impedance matching in a high-frequency circuit, but also has a disadvantage that the stub effect on a signal line cannot be ignored. .

[0008]

A bias circuit for a high-frequency circuit according to the present invention is a bias circuit for a high-frequency circuit for applying a bias voltage or a bias current from a bias supply circuit to a high-frequency circuit using a microstrip line as a signal line. A first bias line branched from the line, a second bias line having one end connected to the bias supply circuit, and grounded at a predetermined position by a capacitor at a high frequency, and a second bias line using a microstrip line.
Three bias lines and a tip of the first bias line
And the other end of the second bias line directly connected to
As an impedance adjusting member, when the first impedance adjustment part is not connected, one end is connected directly with the front end portion of said first bias line, the other end directly to one end of the third bias line When the connected second impedance adjustment component is not connected to the first impedance adjustment component, one end is directly connected to the other end of the second bias line, and the other end is connected to the third bias line. A third impedance adjusting component directly connected to the other end of the line.

In a high-frequency matching circuit according to the present invention, a first signal line and a second signal line separated from the first signal line are provided in a high-frequency matching circuit using a microstrip line as a signal line. A third signal line separated from the first and second signal lines, and a first impedance for directly connecting one end of the first signal line and one end of the second signal line. An adjusting component, when the first impedance adjusting component is not connected , a second impedance having one end directly connected between one end of the first signal line and one end of the third signal line; When the adjustment component and the first impedance adjustment component are not connected, a third end whose one end is directly connected between one end of the second signal line and the other end of the third signal line. Impeder And a to adjust parts.

In the present invention, by completely separating the adjustment pattern from the bias line and the signal line, it is possible to prevent the portion of the adjustment pattern from exhibiting a stray capacitance, to reduce the signal loss, and to reduce the number of the plurality of adjustment patterns. It provides a high frequency circuit bias circuit and a high frequency matching circuit that can handle frequencies.

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, the present invention will be described with reference to the drawings.

FIG. 1 is a top view showing one embodiment of a bias circuit for a high-frequency circuit according to the present invention.

In FIG. 1, the signal line 2, capacitor 3, GND 4, transistor 7 and power supply 8 are the same as the signal line 2A, capacitor 3A, GND 4A, transistor 7A and power supply 8A of FIG. The transistor 7 can be an FET transistor. In this case, the drain terminal is connected to the signal line 2, the gate terminal is connected to the other signal line, and the source terminal is connected to the ground potential. In the description of the embodiment according to the present invention, a microstrip circuit will be described below. However, it is needless to say that a similar circuit can be formed by a strip line.

A bias line 1a branches from the signal line 2 connected to the collector terminal of the transistor 7. However, the bias line 1a is not directly connected to the power supply 8. One end of a bias line 1b is connected to a power supply 8 which is a bias supply circuit. Bias line 1
The leading end of “a” and the other end of the bias line 1b are bent so that the line interval can be connected to the impedance adjusting component a5. The bias line 1b connects one end of the capacitor 3 at a predetermined position described later. The other end of the capacitor 3 is connected to GND 4 which is connected to the back surface of the microstrip substrate by a through hole or the like and is at the ground potential, and is grounded at a high frequency. Therefore, it can be considered that the bias line 1b is grounded at a high frequency at the position of the capacitor 3.

As described above, the tip of the bias line 1a and the other end of the bias line 1b can be connected to the impedance adjusting component a5. This bias circuit further includes an adjustment pattern 6 which is a microstrip line. One end of the adjustment pattern 6 can be connected to the tip of the bias line 1a via the impedance adjustment component c10, and the other end of the adjustment pattern 6 is connected to the other end of the bias line 1b via the impedance adjustment component b9. It is possible. Note that the above bias line and
Note that the impedance adjustment component is
The components are directly connected to each other by a conventional method such as soldering or thermocompression bonding.
Connected. This is the same as the bias line described later
The same applies to the connection with the impedance adjustment component.

This bias circuit for a high-frequency circuit can be used at two different frequencies. In the case of a high frequency, the bias lines 1a and 1a are connected via the impedance adjusting component a5.
b and impedance adjustment parts b9 and c1
0 is set to OPEN (release). At this time, signal line 1
The electrical length from the branch of a to GND 4 via the capacitor 3 is set to approximately λ / 4 for a high frequency. When the frequency is low, the tip of the bias line 1a and the other end of the bias line 1b are connected via the impedance adjusting parts b9 and c10, and the impedance adjusting part a5 is connected to the OP.
Set to EN. At this time, the electrical length from the branch of the signal line 1a to GND 4 via the capacitor 3 is set to λ / 4 for a low frequency.

Here, the impedance adjusting parts 5, 9 and 10 can be an inductance circuit composed of a 0Ω resistor, a resistor having a predetermined resistance value or a microstrip line having a high impedance. When a 0Ω resistor is used as the impedance adjusting component, a single high-frequency circuit bias circuit that can reduce signal loss and can handle two types of frequencies can be configured.
Further, when an inductance circuit is used as the impedance adjusting component, there is an advantage that the bias circuit for a high-frequency circuit can be reduced in size. Further, when a resistor having a predetermined resistance value is used as the impedance adjustment component, signal loss increases, but there is an advantage that the bias setting circuit can be downsized.

FIG. 2 is a top view showing another embodiment of the high-frequency circuit bias circuit according to the present invention.

The embodiment of FIG. 2 is an example in which the high-frequency circuit bias circuit of FIG. 1 is used on both the signal input side and the signal output side of the high-frequency amplifier transistor 7. A GaAs FET is used for the transistor 7. Signal line 2
a is the input side connected to the gate terminal of transistor 7,
The signal line 2b is the output side connected to the drain terminal. The input terminals correspond to the 0Ω resistors a11, c13, and d14 each having a resistance value of approximately 0Ω including electrodes and conductor patterns, and the output terminals correspond to the same 0Ω resistors, respectively. Vessel b12,
e15 and f16. Bias lines 1a and 1b, capacitor 3, GND 4 and adjustment pattern 6
Also, the input side and the output side are the same as those in FIG. Power supply 8
Is a power supply 8a for the gate terminal and a power supply 8b for the drain terminal
And separated.

In the high-frequency amplifier (high-frequency circuit) shown in FIG.
To the signal line 2a on the signal input side, adjustment capacitors a17 and c19 using a ceramic capacitor or the like for impedance adjustment on the gate terminal side are connected, and the signal line 2b on the signal output side is used for adjusting the impedance on the drain terminal side. Adjustment capacitors b18 and d similar to
20 are connected. Adjustment capacitors a17, b1
The other ends of 8, c19 and d20 are connected to GNDs 4a, 4c, 4bd and 4d, respectively, which are connected to the back surface of the substrate, and are grounded.

Here, consider the case where the amplifier of FIG. 2 is operated in both the 2.3 GHz band and the 1.5 GHz band. 0 Ω resistor a11 on the gate terminal side, 0 on the drain terminal side
The electrical length from the branch of the bias line 1a to the GND 4 through the capacitor 3 via the Ω resistor b12 is approximately λ / 4 at 2.3 GHz.
On the gate terminal side, 0Ω resistors c13 and d1
4, 0Ω resistors e15 and f16 on the drain terminal side
The electrical length from the branch from the signal lines 2a and 2b to the GND 4 through the capacitor 3 is approximately λ / 4 at 1.5 GHz. Further, adjustment capacitors a17 and b18
Is connected to a position where the impedance matching of the gate terminal and the drain terminal can be obtained at 2.3 GHz, and the adjusting capacitors c19 and d20 are connected to 1.5 GHz.
It is connected to a position where impedance matching of the gate terminal and the drain terminal can be obtained at Hz.

When the amplifier is designed in the above-described manner and operates in the 2.3 GHz band, the 0 Ω resistor a1
1 and b12 and adjusting capacitors a17 and b18
And 0Ω resistors c13, d14, e15 and f
16 and the adjusting capacitors c19 and d20 are OPEN.
To When operating in the 1.5 GHz band, 0
Ω resistors c13, d14, e15 and f16 and adjustment capacitors c19 and d20 are connected to form a 0Ω resistor a11
And b12 and the adjusting capacitors a17 and b18 are merely opened. Therefore, this transistor (high frequency) amplifier can support two frequencies using the same microstrip substrate. In addition, since the difference in operating frequency can be dealt with only by the presence or absence of components, automatic mounting is easy.

FIG. 3 is a top view showing still another embodiment of the high-frequency circuit bias circuit according to the present invention.

The high-frequency circuit bias circuit shown in FIG.
The bias circuit of the present invention is adapted to cope with two signal frequencies and also to cope with three signal frequencies. The signal line 2, capacitor 3, GND 4, impedance adjusting parts a5, b9 and c10, transistor 7, and power supply 8 of this bias circuit are the same as those in FIG. The microstrip line bias lines 1c and 1d and the adjustment pattern 6 have the same shape as the components of the same name in FIG. 1, but are selected to have an appropriate electrical length and shape according to the operating frequency of this amplifier (high-frequency circuit).

In this bias circuit, the same impedance adjustment components e22 and f23 as described above are provided between the impedance adjustment components b9 and c10 and the adjustment pattern 6.
Can be additionally connected. for that reason,
A land 24 as a connection pattern is connected between the impedance adjustment component b9 and the impedance adjustment component e22.
Lands 25 for connection are provided between the impedance adjustment component c10 and the impedance adjustment component f23. An impedance adjusting component d21 can be connected between the lands 24 and 25.

Assuming that the length of the bias line 1c is equal to the length of the bias line 1a in the above configuration, one end of the impedance adjustment component a5 is connected to the tip of the bias line 1c, and the other end of the impedance adjustment component a5 is connected to the bias. The other ends of the line 1d are connected to each other, and the connection of the impedance adjusting parts b9 and c10 is OPEN.
Then, a good bias circuit functions at a high frequency in FIG. Also, one end of the impedance adjustment component b9 is connected between the other end of the bias line 1d and the land 24, one end of the impedance adjustment component c10 is connected between the tip of the bias line 1c and the land 25, and the impedance adjustment component d21 is connected. Connected between lands 24 and 25,
When the impedance adjusting parts a5, e22 and f23 are connected to OPEN, a good bias circuit functions at a low frequency in FIG. Furthermore, in addition to the impedance adjusting parts b9 and c10, impedance adjusting parts e22 and f23 are connected between the land 24 and the adjusting pattern 6 and between the land 25 and the adjusting pattern 6, and the impedance adjusting parts a5 and d21 are connected. Connection O
By using PEN, it is possible to cope with a lower frequency than the above low frequency.

That is, the high frequency circuit bias circuit of FIG. 3 can handle three frequencies of high, medium and low. If the number of connection stages of the impedance adjustment component is increased to four or five, the corresponding frequency can be further increased to four or five.

FIG. 4 is a top view showing one embodiment of the high-frequency matching circuit according to the present invention. This high-frequency matching circuit uses a microstrip circuit or a strip circuit, and forms a matching circuit between the transistor 26 which is the amplifying element of the unit amplifier and the transistor 26. This matching circuit is of a type that adjusts the length of a signal line connecting the transistor 7 for the first-stage amplifier and the transistor 26 for the second-stage amplifier.

One end of the signal line 2c, which is a microstrip line, is connected to the drain terminal of the transistor 7, and one end of the signal line 2d is connected to the gate terminal of the transistor 26, and the two are separated. Further, the above-described microstrip line adjustment pattern 6a is formed separately from the signal lines 2c and 2d. Both ends of the adjustment pattern 6a are connected to the impedance adjustment component b9.
And c10 can be connected to the other end of the signal line 2c and the other end of the signal line 2d, respectively.

The impedance adjusting component a5 can be connected to the other end of the signal line 2c and the other end of the signal line 2d. When the impedance adjusting parts b9 and c10 are connected and the connection of the impedance adjusting part a5 is eliminated,
The interstage distance between transistors 7 and 26 is longer. On the other hand, both ends of the impedance adjustment component a5 are connected to the signal line 2
When connected to the other end of the signal line c and the other end of the signal line 2d, respectively, the interstage distance between the transistors 7 and 26 becomes shorter. Therefore, this high-frequency matching circuit can be selected by connecting the impedance adjusting parts a5, b9, and c10.
At one frequency, matching between transistors 7 and 26 will be possible.

[0031]

As described above, the bias circuit and the high-frequency matching circuit for the high-frequency circuit according to the present invention completely separate the adjustment pattern of the high-frequency circuit from the bias line or the signal line so that the portion of the adjustment pattern can be obtained. Since stray capacitance can be prevented from being exhibited (stub effect), there is an effect that signal loss is further reduced and a plurality of frequencies can be handled.

[Brief description of the drawings]

FIG. 1 is a top view showing one embodiment of a high-frequency circuit bias circuit according to the present invention.

FIG. 2 is a top view showing another embodiment of the high-frequency circuit bias circuit according to the present invention;

FIG. 3 is a top view showing still another embodiment of the high frequency circuit bias circuit according to the present invention;

FIG. 4 is a top view showing one embodiment of the high-frequency matching circuit according to the present invention.

FIG. 5 is a top view showing a conventional bias circuit for a high-frequency amplifier.

[Explanation of symbols]

1, 1a-1d Bias line 2, 2a-2d Signal line 3 Capacitor 4, 4a-4d GND (ground potential point) 5a, 9, 10, 21-23 Impedance adjustment component 6, 6a Adjustment pattern 7, 26 Transistor 8 , 8a, 8b Power supply 11-160Ω resistor 17-20 Adjustment capacitor 24, 25 Land

Continuation of the front page (56) References JP-A-9-64601 (JP, A) JP-A-8-186402 (JP, A) JP-A-6-237102 (JP, A) JP-A-5-335802 (JP) , A) JP 7-101801 (JP, B2) JP 1-19761 (JP, B2) (58) Fields investigated (Int. Cl. ⁷ , DB name) H01P 1/00 H01P 1/24 H03F 3/60

Claims (11)

(57) [Claims] 1. A high-frequency circuit bias circuit for applying a bias voltage or a bias current from a bias supply circuit to a high-frequency circuit using a microstrip line as a signal line, comprising: a first bias line branched from the signal line; A second bias line connected to a bias supply circuit and grounded at a predetermined position at a high frequency by a capacitor, and a third bias line using a microstrip line
Path , the tip of the first bias line and the second bus.
First impedance directly connected to the other end of the ias line
When the impedance adjustment component is not connected to the first impedance adjustment component, one end is directly connected to the tip of the first bias line, and the other end is directly connected to one end of the third bias line. When the second impedance adjustment component is not connected to the first impedance adjustment component, one end is connected to the other end of the second bias line.
Directly connected , the other end is connected to the other end of the third bias line
A bias circuit for a high-frequency circuit, comprising: a third impedance adjustment component directly connected . 2. An electric length between a branch point between the signal line and the first bias line and a ground point of the capacitor , regardless of whether the third bias line is connected or not.
2. The high-frequency circuit bias circuit according to claim 1, wherein the signal frequency of the high-frequency circuit is set to approximately one quarter wavelength. 3. The bias circuit for a high-frequency circuit according to claim 2, wherein said high-frequency circuit is a transistor amplifier. 4. The method according to claim 1, wherein the first impedance adjusting component is provided at a front end.
When not connected to the first and second bias lines
In addition, a fourth impedance adjusting component has one end connected to the first line.
Connected to the second impedance adjustment component via
And the other end through the second land.
Connected to the first impedance adjustment component and the fourth impedance adjustment component.
If the impedance adjustment component is not connected,
The impedance adjustment component is connected to the first land and the third bar.
It is connected between one end of the ias line and the sixth
The impedance adjustment component is configured such that the second land and the third land
2. The high frequency circuit bias circuit according to claim 1, wherein the bias circuit is connected between the other end of the bias line . 5. The first to sixth impedance adjustments.
Integer part article, according to claim 1 or 2 or 3 or 4 high frequency circuit for a bias circuit, wherein the respective a 0Ω resistor or inductance circuit. 6. A high-frequency circuit bias circuit for applying a bias voltage or a bias current from a bias supply circuit to a high-frequency circuit using a microstrip line as a signal line, wherein the first bias line branched from the signal line and one end are provided. A second bias line connected to a bias supply circuit and grounded at a predetermined position by a capacitor at a high frequency; a third bias line separated from the first and second bias lines; Of the first bias line and the other end of the second bias line, respectively, to electrically connect the two ends of the bias line to the ground point of the capacitor from the branch of the first bias line. With respect to the signal frequency of the high-frequency circuit
And a first and a second impedance adjusting component for adjusting the wavelength to / 4 wavelength. 7. The first and second impedance adjusting components are separated from the first and second bias lines, and a leading end of the first bias line and another end of the second bias line are used instead. And a third impedance adjusting component which is connected directly to the first bias line to make the electrical length from the branch portion of the first bias line to the ground point of the capacitor approximately 1/4 wavelength with respect to the signal frequency of the high frequency circuit. 7. The bias circuit for a high-frequency circuit according to claim 6, wherein: 8. The apparatus according to claim 1, wherein said impedance adjusting component is 0Ω.
The bias circuit for a high-frequency circuit according to claim 6, wherein the bias circuit is a resistor or an inductance circuit. 9. A high-frequency matching circuit using a microstrip line as a signal line, comprising: a first signal line; a second signal line separated from the first signal line; A third signal line separated from the signal line, a first impedance adjustment component for directly connecting one end of the first signal line and one end of the second signal line, and When the impedance adjustment component is not connected , a second impedance adjustment component having one end directly connected between one end of the first signal line and one end of the third signal line, When the impedance adjustment component is not connected , a third impedance adjustment component having one end directly connected between one end of the second signal line and the other end of the third signal line is provided. Features High frequency matching circuit. 10. A collector terminal of the first transistor and the other end portion of said first signal line to amplify the high-frequency signal or is connected to the drain terminal, the other end portion of the second signal line is high-frequency signal The high-frequency matching circuit according to claim 9 , wherein the high-frequency matching circuit is connected to a base terminal or a gate terminal of a second transistor for amplifying the signal. 11. The high-frequency matching circuit according to claim 9, wherein said first to third impedance adjusting components are 0Ω resistors or inductance circuits.