JPH10270960A - High frequency power amplifier - Google Patents

Abstract

(57) [Summary] (with correction) [PROBLEMS] To greatly reduce current consumption when low-frequency power is output from a high-frequency power amplifier. A high frequency power amplifier, the operation is and the current-voltage characteristics by a positive voltage is applied and a subsequent stage of the RF power transistor Tr ₂ which changes greatly to the input terminal,
A third macrostrip line S ₃ as an input bias circuit, a fourth microstrip line S ₄ as an output bias circuit, an interstage impedance matching circuit 2 as an input impedance matching circuit, and an output impedance matching circuit 3 , A positive voltage generation circuit 4. Positive voltage generating circuit 4 includes a resistor R ₁₁ as a detection circuit, a diode D ₁₁ as a rectifier circuit, has a capacitor C ₁₁ and resistor R ₁₂ as the smoothing circuit, a part of the detected high-frequency power And outputs a positive voltage that increases or decreases in accordance with the increase or decrease in the input terminal of the _third macrostrip line S3 without interposing a DC power supply.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a high-frequency power amplifier, and more particularly to a high-frequency power transistor, an input bias circuit connected to an input terminal of the high-frequency power transistor, and an output bias connected to an output terminal of the high-frequency power transistor. Circuit, input impedance matching circuit connected to the input terminal of the high-frequency power transistor, output impedance matching circuit connected to the output terminal of the high-frequency power transistor, and bias voltage generation for generating a DC bias voltage required for the input bias circuit The present invention relates to a high-frequency power amplifier provided with a circuit.

[0002]

2. Description of the Related Art A high-frequency power amplifier is used in a transmission unit of a mobile communication device and has a function of amplifying a modulated signal to a predetermined output power.

[0003] At present, mobile phones have a frequency of 1 GHz to 2 GHz.
Are most frequently used, and the output power at the time of transmission of high-frequency power having these frequencies is about 20 dBm to 36 dBm. In order to output the high-frequency power in this range, a multi-stage high-frequency power amplifier having a two-stage configuration or a three-stage configuration and having a gain of about 30 dB is generally used as the high-frequency power amplifier. A multi-stage high-frequency power amplifier amplifies a modulated wave output of about 0 dBm to a transmission output of about 30 dBm, and the amplified transmission output is transmitted as a radio wave from an antenna.

As a high-frequency power transistor used in a high-frequency power amplifier, a MOSFET or a bipolar transistor formed on a silicon substrate, a MESFET or a heterogeneous transistor formed on a compound semiconductor substrate such as gallium arsenide (GaAs) is used. An FET having a junction is used. In order to use such a high-frequency power transistor with less distortion and good gain, a DC bias power supply is connected to an input terminal and an output terminal of the high-frequency power transistor, and a predetermined bias current is supplied from the DC bias power supply. In general, high-frequency power is input while flowing through the high-frequency power transistor to cause the high-frequency power transistor to perform an amplifying operation.

A high-frequency power amplifier according to a first conventional example having the above configuration will be described below with reference to FIG.

[0006] Figure 15 shows a circuit configuration of a radio frequency power amplifier according to the first conventional example, in FIG. 15, Tr _a
For front of the RF power transistor, the Tr _b a subsequent stage of the high frequency power transistor, these upstream and downstream of the high-frequency transistor Tr _a, the source terminal of Tr _b is grounded.

[0007] The input terminal of the front stage of the high frequency power transistor Tr _a (gate terminal), the input impedance matching circuit 1 consisting of an inductor L and a capacitor C are connected, the input impedance matching circuit 1, the external input by performing impedance matching between the input impedance of the RF power impedance and front of the RF power transistor Tr _a inputted from terminal RF _in, and thereby reducing the reflection and loss of high-frequency input power.

[0008] Input terminals of the preceding stage of the RF power transistor Tr _a is one end of the first microstrip line S ₁ having a length of 1/4 wavelength as a first input bias circuit is connected, first of the other end of the microstrip line S ₁ and the negative power -VGG ₁ is connected, the negative power supply -
Negative DC bias voltage is supplied to the VGG ₁ and the input terminal of the first microstrip line of the preceding stage by S ₁ high frequency power transistor Tr _a. Negative power supply-VGG ₁
The high frequency power is suppressed by suppressing the oscillation of the high frequency power.
Bypass condenser C to prevent going around VGG _1
b1 is connected. As the first input bias circuit, a resistor of several KΩ can be used instead of the _first microstrip line S ₁ having a length of 波長 wavelength.

[0009] The output terminal of the preceding stage of the RF power transistor Tr _a (drain terminal), the positive through the second microstrip line S ₂ with a length of 1/4 wavelength as a first output bias circuit power + VDD ₁ is connected, a positive DC bias voltage is applied to the output terminal of the preceding stage of the RF power transistor Tr _a.

Similarly to the high-frequency power transistor Tr _{a of the} preceding stage, the third high-frequency power transistor Tr _b has, at its input terminal, a third micro-wavelength of 1/4 wavelength as a second input bias circuit. through the strip line S ₃ with the negative power supply -VGG ₂ is connected to the output terminal, via the fourth microstrip line S ₄ of which having a length of 1/4 wavelength as a second output bias circuit positive power source + VDD ₂ is connected Te.

The output terminal of the high-frequency power transistor Tr _a of the preceding stage and the input terminal of the high-frequency power transistor Tr _b of the subsequent stage are connected between the output terminal of the high-frequency power transistor T _b
An inter-stage impedance matching circuit 2 for performing impedance matching between the output impedance of r _a and the input impedance of the subsequent high-frequency power transistor Tr _b is connected. Similarly, it is composed of an inductor L and a capacitor C. Incidentally, interstage impedance matching circuit 2, in the high-frequency power amplifier of the multi-stage configuration consisting of a plurality of high-frequency power transistor, the impedance matching between a front of the RF power transistor Tr _a and the rear stage of the RF power transistor Tr _b However, the former high-frequency power transistor Tr _a has the function of an output impedance matching circuit, and the latter high-frequency power transistor Tr _b has the function of an input impedance matching circuit.

[0012] The output terminal of the latter stage of the RF power transistor Tr _b, and from the inductor L and the capacitor C are connected is constituted output impedance matching circuit 3, the output impedance matching circuit 3, downstream of the high-frequency power and the output impedance of the use transistor Tr _b,
Impedance matching with the impedance of the high-frequency power output from the external output terminal RF _out is performed.

A high-frequency power amplifier according to a first conventional example includes:
The radio frequency power fed from the external input terminal RF _in (RF signal), after being amplified by the front stage of the high frequency power transistor Tr _a and the subsequent high-frequency power transistor Tr _b, output from the external output terminal RF _out.

In the high-frequency power amplifier according to the first conventional example, the high-frequency power transistors Tr _a ,
Tr _b has a current-voltage characteristic as shown in FIG. That is, the gate voltage V _g is a negative voltage such as -
At 2 V, only a small drain current I _ds flows, and when the gate voltage V _g changes from the negative voltage to the 0 V side, a large drain current I _ds flows. Therefore, in order to reduce the drain current I _ds , a DC bias power supply for reducing the gate voltage V _g from −1 V to about −1.5 V is required.

Therefore, in the high frequency power amplifier according to the first conventional example, the high frequency transistors T
r _a, the DC bias voltage of Tr _b is set as follows. In other words, negative power supply -VGG ₁ of about minus number V to the input terminals with connecting (-VGG _2), the positive power source + VDD ₁ of about plus 6V to the output terminals (+ VDD ₂₎
, And a predetermined bias current, for example, a drain current of 100 mA flows through the negative power supply and the positive power supply.

However, the high frequency power amplifier according to the first conventional example has a first problem concerning the complexity of setting the bias current as described below. That is, the negative power supply -VGG ₁ (-
VGG ₂ ) and a positive power supply + VDD ₁ (+ VDD ₂ ), which is a positive DC bias power supply, require the provision of two types of DC bias power supplies, which complicates the configuration of the DC bias power supply and peripheral circuits. Further, unless the bias voltage of these DC bias power supplies is set to an accuracy of 10% or less, the high-frequency power transistor Tr _a (T
r _b) or impedance no longer performed reliably changed to impedance matching, or can no longer ensure good distortion characteristics and gain.

Further, the high frequency power amplifier according to the first conventional example has a second problem relating to an increase in operating current as described below. That is, in the high-frequency power amplifier according to the first conventional example, since the fixed DC bias current is set to flow, the DC bias current flows even when the output of the high-frequency power is small. There is a problem that consumption of is large. That is, as shown in FIG. 16B, even if the output of the high-frequency power becomes small, the operating current does not decrease much.

For example, a portable telephone emits a radio wave at a maximum output when it is far from a base station, and emits a radio wave at a low output when it is near a base station to prevent battery consumption. For longer use of the battery. However, even when radio waves are emitted with low high-frequency power near the base station, the idle current necessary to produce the maximum output flows, so that the battery is wasted when the output is low.

Accordingly, Electronics Letters Vol. 32 No.
In a paper on page 17: 1533, a high-frequency power amplifier that changes a DC bias current according to an input high-frequency power is proposed.

The high-frequency power amplifier described in this paper will be described below as a second conventional example with reference to FIG. In FIG. 17, the same members as those of the first conventional example shown in FIG. Input impedance matching circuit 1,
The interstage impedance matching circuit 2 and the output impedance matching circuit 3 are shown by blocks for convenience of illustration. The voltage-current characteristics of the pre-stage of the RF power transistor Tr _a and the subsequent high-frequency power transistor Tr _b, similarly to the first conventional example is as shown in FIG. 16 (a).

The high-frequency power amplifier according to the second conventional example has a high-frequency power detection circuit including a resistor R ₁ and a diode D ₁ at the output terminal of the output impedance matching circuit 3 as shown by a dashed line in FIG. , A negative DC bias power supply V _c (−5 V), and divided resistors R ₂ , R ₃ and R
And a negative bias voltage generating circuit having a voltage dividing circuit composed of _four . The negative bias voltage generation circuit includes:
At power detection point E, output impedance matching circuit 3
Detecting a portion of the high frequency power from the high frequency power output from, based on a portion of the high-frequency power detected by changing the DC bias voltage output from the negative DC bias power supply V _c, the direct current bias voltage from a negative bias voltage output point D via the third microstrip line S ₃ and outputs to the input terminal of the rear stage of the RF power transistor Tr _b.

As described above, when the high frequency power detected at the power detection point E is large, the bias voltage output from the negative bias voltage output point D has a shallow negative value and is close to -1V. On the other hand, when the high-frequency power detected at the power detection point E is small, the value of the bias voltage output from the negative bias voltage output point D becomes deep and drops to -5V. Thus, the idle current when the input high-frequency power is small is reduced. Therefore, as shown in FIG. 18, the operating current when the input high-frequency power is small is smaller than that of the first conventional example shown in FIG. 16B.

[0023]

[SUMMARY OF THE INVENTION However, in the second conventional example, the peripheral circuit has a negative DC bias power supply V _c, the negative of about -5V to the DC bias power supply V _c of the negative in order to generate a voltage, the negative voltage generating circuit for generating a negative voltage based on the positive voltage output from the positive supply + VDD ₂ is required. Since a current of about 10 mA always flows through the negative voltage generating circuit, the second conventional example is insufficient in reducing current consumption when the input high-frequency power is small.

In view of the above, it is an object of the present invention to further reduce current consumption when high-frequency power input to a high-frequency power amplifier is small.

[0025]

In order to achieve the above object, the present invention provides a high-frequency power transistor which operates when a negative DC voltage is applied to its input terminal and whose current-voltage characteristic changes greatly. Instead of the transistor having the characteristic (see FIG. 16A), the transistor operates when a positive voltage is applied to the input terminal and has a characteristic in which the current-voltage characteristic greatly changes (see FIG. 13A). And outputs a positive voltage that increases or decreases in accordance with an increase or decrease in the detected high-frequency power to the input terminal of the transistor.

A first high-frequency power amplifier according to the present invention comprises:
A high-frequency power transistor that operates when a positive voltage is applied to the input terminal and has a large change in current-voltage characteristics; an input bias circuit connected to the input terminal of the high-frequency power transistor; and an output terminal of the high-frequency power transistor , An input impedance matching circuit connected to the input terminal of the high-frequency power transistor, an output impedance matching circuit connected to the output terminal of the high-frequency power transistor, and an input terminal connected to the high-frequency power transistor. Connected to the input or output side of
A detection circuit that detects and outputs a part of high-frequency power from high-frequency power input to the high-frequency power transistor or high-frequency power output from the high-frequency power transistor; A rectifier circuit that rectifies a part of the high-frequency power output from the circuit and outputs a pulsating positive voltage, an input terminal connected to the output terminal of the rectifier circuit, and an output terminal connected to the input terminal of the input bias circuit, A smoothing circuit that smoothes the pulsating positive voltage output from the circuit and outputs a positive voltage, and applies a positive voltage that increases or decreases in accordance with an increase or decrease in the detected high-frequency power to an input terminal of the input bias circuit. And a positive voltage generating circuit for outputting without a DC power supply.

According to the first high-frequency power amplifier, the high-frequency power transistor operates when a positive voltage is applied to the input terminal and has a large change in current-voltage characteristics, and responds to an increase or decrease in a part of the detected high-frequency power. And a positive voltage generating circuit that outputs a positive voltage that increases or decreases through an input bias circuit to an input terminal of a high-frequency power transistor without an intervening DC power supply, as in the second conventional example. Since it is not necessary to provide a negative DC bias power supply in the bias voltage generation circuit, a negative voltage generation circuit for generating a negative voltage in the negative DC bias power supply is not required.

In the first high-frequency power amplifier, it is preferable that an input terminal of the detection circuit is connected to an input terminal of the input impedance matching circuit or an output terminal of the output impedance matching circuit.

In the first high-frequency power amplifier, it is preferable that an input terminal of the detection circuit is connected to an output terminal of the input impedance matching circuit or an input terminal of the output impedance matching circuit.

In the first high-frequency power amplifier, it is preferable that an input terminal of the detection circuit is connected to an output bias circuit.

In the first high-frequency power amplifier, it is preferable that the rectifier circuit includes a pair of diodes connected in parallel with each other in opposite directions and outputs a double pulsating positive voltage.

In the first high-frequency power amplifier, it is preferable that the smoothing circuit has a capacitor and a variable resistor, and outputs a positive voltage that changes according to a change in the resistance value of the variable resistor.

In the first high-frequency power amplifier, the high-frequency power transistor is an N-channel MOSFET, NP
N-type bipolar transistor, N-channel MESFET
Alternatively, it is preferable that the FET is an N-channel heterojunction FET and has a normally-off type, an enhancement mode type, or a current-voltage characteristic similar thereto.

In the first high-frequency power amplifier, the high-frequency power transistor, the input bias circuit, the output bias circuit, the input impedance matching circuit, the output impedance matching circuit, and the positive voltage generating circuit are formed on the same semiconductor substrate. Is preferred.

In the first high-frequency power amplifier, the high-frequency power transistor, input bias circuit, output bias circuit, input impedance matching circuit, and output impedance matching circuit are preferably formed on the same semiconductor substrate.

A second high-frequency power amplifier according to the present invention comprises:
A first-stage high-frequency power transistor that operates when a positive voltage is applied to an input terminal and whose current-voltage characteristics change significantly, a first input bias circuit connected to an input terminal of the first-stage high-frequency power transistor, A first output bias circuit connected to the output terminal of the preceding high-frequency power transistor; a first input impedance matching circuit connected to the input terminal of the preceding high-frequency power transistor; A first output impedance matching circuit connected to the output terminal, a high-frequency power transistor at a later stage that operates when a positive voltage is applied to the input terminal and has a large change in current-voltage characteristics, and a high-frequency power transistor at a latter stage A second input bias circuit connected to the input terminal of A second output bias circuit connected to the input terminal, a second input impedance matching circuit connected to the input terminal of the subsequent high-frequency power transistor, and a second output bias circuit connected to the output terminal of the subsequent high-frequency power transistor. Output impedance matching circuit, and an input terminal connected to the input side or output side of the subsequent high-frequency power transistor, and the high-frequency power input to the subsequent high-frequency power transistor or the high-frequency power output from the subsequent high-frequency power transistor A detection circuit for detecting and outputting some high-frequency power from the power, and an input terminal connected to the output terminal of the detection circuit,
A rectifier circuit for rectifying a part of the high-frequency power output from the detection circuit to output a pulsating positive voltage, an input terminal connected to the output terminal of the rectifier circuit, and an output terminal connected to the first bias circuit and the second input terminal; A smoothing circuit that is connected to each input terminal of the bias circuit and smooths the pulsating positive voltage output from the rectifier circuit and outputs a positive voltage. A positive voltage generating circuit that outputs a positive voltage to each input terminal of the first input bias circuit and the second input bias circuit without a DC power supply.

According to the second high-frequency power amplifier, the positive voltage that increases or decreases according to the increase or decrease of the detected high-frequency power is:
Since the positive voltage is input from the positive voltage generation circuit to the input terminals of the high-frequency power transistor in the preceding stage and the high-frequency power transistor in the subsequent stage, the current consumption when the input high-frequency power is small is greatly reduced.

Similarly to the first high-frequency power amplifier, the first and second high-frequency power transistors, which operate when a positive voltage is applied to the input terminal and whose current-voltage characteristics change greatly, A positive voltage generation circuit that outputs a positive voltage that increases or decreases in accordance with an increase or a decrease in the high-frequency power to input terminals of a high-frequency power transistor in a preceding stage and a subsequent-stage high-frequency power transistor via an input bias circuit without a DC power supply. Unlike the second conventional example, there is no need to provide a negative DC bias power supply in the bias voltage generation circuit, so that a negative voltage generation circuit for generating a negative voltage in the negative DC bias power supply becomes unnecessary. .

In the second high-frequency power amplifier, it is preferable that the rectifier circuit includes a pair of diodes connected in parallel with each other in opposite directions and outputs a double pulsating positive voltage.

In the second high-frequency power amplifier, the smoothing circuit divides the positive voltage into a first positive voltage and a second positive voltage that are different from each other, and divides the first positive voltage into an input of the first input bias circuit. It is preferable to have a voltage dividing circuit that outputs the second positive voltage to the input terminal of the second input bias circuit while outputting the voltage to the terminal.

In the second high-frequency power amplifier, the voltage dividing circuit includes a plurality of divided resistors including at least one variable resistor, and the first positive voltage or the first positive voltage or the first variable voltage that changes according to a change in the resistance value of one variable resistor. It is preferable to output the second positive voltage.

In the second high-frequency power amplifier, the first-stage high-frequency power transistor and the second-stage high-frequency power transistor are N-channel MOSFETs, NPN-type bipolar transistors, N-channel MESFETs, or N-channel heterojunction FETs. -It is preferable to have a current-voltage characteristic of an off type, an enhancement mode type, or similar.

In the second high-frequency power amplifier, a high-frequency power transistor, a first input bias circuit, a first output bias circuit, a first input impedance matching circuit, a first output impedance matching circuit, The high-frequency power transistor, the second input bias circuit, the second output bias circuit, the second input impedance matching circuit, the second output impedance matching circuit, and the positive voltage generating circuit are formed on the same semiconductor substrate. Is preferred.

In the second high-frequency power amplifier, a high-frequency power transistor at the preceding stage, a first input bias circuit,
A first output bias circuit, a first input impedance matching circuit, a first output impedance matching circuit, a high-frequency power transistor in a subsequent stage, a second input bias circuit, a second output bias circuit, and a second input impedance matching Preferably, the circuit and the second output impedance matching circuit are formed on the same semiconductor substrate.

[0045]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a high-frequency power amplifier according to each embodiment of the present invention will be described with reference to the drawings.

(First Embodiment) Hereinafter, a high-frequency power amplifier according to a first embodiment of the present invention will be described with reference to FIGS.
13 (a) and 13 (b). 1 and 2 show a circuit configuration of the high-frequency power amplifier according to the first embodiment. FIG. 1 is a circuit diagram including details of the positive voltage generation circuit 4, and FIG. It is a circuit diagram shown by a block. FIG. 13A is a diagram illustrating current-voltage characteristics of the high-frequency power transistors at the front and rear stages in the high-frequency power amplifier according to the first embodiment.
FIG. 13B illustrates the power consumption of the high-frequency power amplifier according to the first embodiment. In FIGS. 1 and 2, the same members as those of the first conventional example shown in FIG.

The first stage high-frequency power transistor Tr ₁ and the second stage high-frequency power transistor Tr ₂ in the first embodiment operate when a positive voltage is applied to the input terminal, as shown in FIG. In addition, it has a characteristic in which the current-voltage characteristic changes greatly, that is, a normally-off type, an enhancement mode type, or a similar characteristic. Note that characteristics similar to these are that, when the voltage applied to the input terminal is near 0 V, only a small current flows, and when the voltage applied to the input terminal goes from near 0 V to the positive voltage side. It refers to the characteristic that the flowing current increases. Specifically, the first stage high-frequency power transistor Tr ₁ and the second stage high-frequency power transistor Tr ₂
Is constituted by an N-channel MOSFET, an NPN-type bipolar transistor, an N-channel MESFET, or an N-channel heterojunction FET.

As shown in FIG. 1, the high-frequency power amplifier according to the first embodiment includes a high-frequency power transistor Tr _{1 in the first} stage, a high-frequency power transistor Tr _{2 in the second} stage, and a high-frequency power transistor Tr _{1 in} the _first stage. A first microstrip line S ₁ having a length of 波長 wavelength as a first input bias circuit connected to the terminal, a _first output connected to the output terminal of the high-frequency power transistor Tr _{1 in} the preceding stage; A second microstrip line S ₂ having a length of １ ／ wavelength as a bias circuit, and a マ イ ク ロ wavelength as a second input bias circuit connected to the input terminal of the high-frequency power transistor Tr _{2 at} the subsequent stage. 1 as the third microstrip line S _3, a second output bias circuit connected downstream of the output terminal of the high-frequency power transistor Tr ₂ having a length 4 a fourth microstrip line S ₄ having a length of wavelength, preceding the input impedance matching circuit 1 connected to the input terminal of the RF power transistor Tr _1, the output terminal and the rear stage of the front stage of the high frequency power transistor Tr ₁ It has connected interstage impedance matching circuit 2, and the subsequent stage of the output impedance matching circuit 3 connected to an output terminal of the RF power transistor Tr ₂ between the output terminal of the RF power transistor Tr ₂ of . Incidentally, interstage impedance matching circuit 2, in the high-frequency power amplifier of the multi-stage configuration consisting of a plurality of high-frequency power transistor, performing the preceding impedance matching between the high frequency power transistor Tr ₁ and the rear stage of the RF power transistor Tr ₂ but for front of the high-frequency power transistor Tr ₁ with has a function of the output impedance matching circuit, for subsequent RF power transistor Tr ₂ has a function of the input impedance matching circuit.

As a feature of the first embodiment, a positive voltage generating circuit 4 for generating a positive voltage that increases or decreases according to an increase or decrease of the input high-frequency power is provided. A detection point A is provided, and a positive voltage output point B is provided at the output of the positive voltage generation circuit 4. As shown in FIG. 1, the positive voltage generation circuit 4 includes a resistor R ₁₁ for detecting a part of high frequency power from the input high frequency power.
And (detection circuit), a condenser C ₁₂ for outputting a small high-frequency power to remove a DC component from a portion of the high-frequency power detected by the resistor R _11, and rectifies micro high-frequency power output from the capacitor C ₁₂ A diode D ₁₁ (rectifying circuit) for outputting a pulsating positive voltage, a capacitor C ₁₁ for smoothing the pulsating positive voltage output from the diode D ₁₁ and outputting a positive voltage, and a resistor R ₁₂ (smoothing circuit). I have. As is clear from FIG. 1, the positive voltage generating circuit 4 does not have a negative DC bias power supply.

[0050] The detection circuit for detecting a portion of the high frequency power from the high frequency power input has been a resistor R ₁₁ in the first embodiment, instead of this, connected diode only or in series Or a resistor and a diode. Further, the capacitor C ₁₃ is added to reduce the high frequency noise of the positive voltage.

As a feature of the first embodiment, the power detection point A of the positive voltage generating circuit 4 is connected to the output terminal of the output impedance matching circuit 3 and the positive voltage output point of the positive voltage generating circuit 4 B is connected to the input terminal of the _third microstrip line S ₃ (first input bias circuit). As a result, the positive voltage generation circuit 4 detects a part of the high-frequency power from the high-frequency power output from the output impedance matching circuit 3 and generates a third positive voltage that increases or decreases in accordance with the detected part of the high-frequency power. High-frequency power transistor T via the microstrip line S ₃ of FIG.
to output to the input terminal of the r _2.

Therefore, according to the first embodiment, when the high-frequency power output from the output impedance matching circuit 3 is large, a high positive voltage is applied to the input terminal of the high-frequency power transistor Tr _{2 at} the subsequent stage, and the output impedance is high. When the high frequency power output from the matching circuit 3 is small, a low positive voltage is applied.

[0053] Also, since the positive voltage generation circuit 4 does not have a negative DC bias power source, the negative voltage generating circuit for generating a negative voltage based on the positive voltage output from the positive supply + VDD ₂ is not necessary.

FIG. 13B shows the input / output characteristics (P _out ) of the high-frequency power of the high-frequency power amplifier and the operating current of the high-frequency power transistor Tr _{2 at} the subsequent stage.
As shown in (b), the operating current when the output high-frequency power is small is reduced.

Further, according to the first embodiment, since the power detection point A of the positive voltage generation circuit 4 is connected to the output terminal of the output impedance matching circuit 3, the circuit configuration is simplified, Since the impedance is raised to about 50Ω by the output impedance matching circuit 3, a comprehensive design that takes into account the effect of adding the positive voltage generation circuit 4 is required.

(Second Embodiment) A high-frequency power amplifier according to a second embodiment of the present invention will be described below with reference to FIG. FIG. 3 shows a circuit configuration of the high-frequency power amplifier according to the second embodiment. The same members as those in the first conventional example shown in FIG. 15 or the first embodiment shown in FIG. The description will be omitted by attaching.

[0057] As a feature of the second embodiment, the power detection point A of the positive voltage generation circuit 4, together with being connected to the subsequent stage of the output terminal of the high-frequency power transistor Tr _2, a positive voltage output of the positive voltage generation circuit 4 Point B is connected to the input terminal of the _third microstrip line S3. Thereby, the positive voltage generation circuit 4 is connected to the high-frequency power transistor T
A part of high-frequency power is detected from the high-frequency power output from r _1, and a positive voltage that increases or decreases according to an increase or decrease of the detected part of high-frequency power is supplied to the subsequent high-frequency power via the _third microstrip line S _3. output to the input terminal of the use transistor Tr _2.

[0058] Therefore, according to the second embodiment, the latter stage of the input terminal of the RF power transistor Tr _2, a high positive voltage is applied when the high-frequency power outputted from the high frequency power transistor Tr ₂ of the rear stage is large is a low positive voltage is applied when the high-frequency power outputted from the later stage of the RF power transistor Tr ₂ is small.

[0059] According to the second embodiment, since the power detection point A of the positive voltage generation circuit 4 is connected to the subsequent stage of the output terminal of the high-frequency power transistor Tr _2, as compared with the first embodiment Since the impedance of the input high-frequency power is low, it is not necessary to consider the influence of the impedance when designing the high-frequency amplifier circuit.

(Third Embodiment) A high-frequency power amplifier according to a third embodiment of the present invention will be described below with reference to FIG. FIG. 4 shows a circuit configuration of a high-frequency power amplifier according to the third embodiment. The same members as those in the first conventional example shown in FIG. 15 or the first embodiment shown in FIG. The description will be omitted by attaching.

As a feature of the third embodiment, the power detection point A of the positive voltage generation circuit 4 is defined by the output terminal of the interstage impedance matching circuit 2 and the high-frequency power transistor Tr _{2 in the} subsequent stage.
And the positive voltage output point B of the positive voltage generating circuit 4 is connected to the input terminal of the _third microstrip line S3. As a result, the positive voltage generation circuit 4 is connected to the subsequent high-frequency power transistor Tr.
_A part of the high-frequency power is detected from the high-frequency power input to _2, and a positive voltage that increases or decreases in accordance with the increase or decrease of the detected part of the high-frequency power is supplied to the subsequent high-frequency power via the _third microstrip line S3. output to the input terminal of the transistor Tr _2. In FIG. 4, _Cb5 is a capacitor for removing a DC component from the high-frequency power output from the interstage impedance matching circuit 2.

[0062] Therefore, according to the third embodiment, the subsequent stage of the input terminal of the RF power transistor Tr _2, a high positive voltage is applied when the high-frequency power input to the high frequency power transistor Tr ₂ of the rear stage is large is a low positive voltage is applied when high frequency power is input to the transistor Tr ₂ subsequent RF power is low.

(Fourth Embodiment) Hereinafter, a high-frequency power amplifier according to a fourth embodiment of the present invention will be described with reference to FIG. FIG. 5 shows a circuit configuration of the high-frequency power amplifier according to the fourth embodiment. The same members as those in the first conventional example shown in FIG. 15 or the first embodiment shown in FIG. The description will be omitted by attaching.

As a feature of the fourth embodiment, the power detection point A of the positive voltage generation circuit 4 is set between the output terminal of the preceding high-frequency power transistor Tr ₁ and the interstage impedance matching circuit 2.
And the positive voltage output point B of the positive voltage generating circuit 4 is connected to the input terminal of the _third microstrip line S3. As a result, the positive voltage generation circuit 4 is connected to the subsequent high-frequency power transistor Tr.
_A part of the high-frequency power is detected from the high-frequency power input to _2, and a positive voltage that increases or decreases in accordance with the increase or decrease of the detected part of the high-frequency power is supplied to the subsequent high-frequency power via the _third microstrip line S3. output to the input terminal of the transistor Tr _2.

[0065] Thus, according to the fourth embodiment, the subsequent stage of the input terminal of the RF power transistor Tr _2, a high positive voltage is applied when the high-frequency power input to the high frequency power transistor Tr ₂ of the rear stage is large is a low positive voltage is applied when high frequency power is input to the transistor Tr ₂ subsequent RF power is low.

(Fifth Embodiment) A high frequency power amplifier according to a fifth embodiment of the present invention will be described below with reference to FIG. FIG. 6 shows a circuit configuration of the high-frequency power amplifier according to the fifth embodiment. The same members as those of the first conventional example shown in FIG. 15 or the first embodiment shown in FIG. The description will be omitted by attaching.

[0067] As a feature of the fifth embodiment, the power detection point A of the positive voltage generation circuit 4, as the fourth output bias circuit connected downstream of the output terminal of the high-frequency power transistor Tr _2, the two Split microstrip line S
_4a , S _4b , a fourth microstrip line S ₄
And the positive voltage output point B of the positive voltage generating circuit 4 is connected to the input terminal of the _third microstrip line S3. Thus, the positive voltage generation circuit 4 detects a part of the high frequency power from the high frequency power output from the subsequent stage of the high frequency power transistor Tr _2, a positive voltage which increases or decreases according to the increase or decrease of the part detected high-frequency power the through third microstrip line S ₃ to the subsequent stage of the input terminal of the RF power transistor Tr _2.

[0068] Thus, according to the fifth embodiment, the subsequent stage of the input terminal of the RF power transistor Tr _2, a high positive voltage is applied when the high-frequency power outputted from the high frequency power transistor Tr ₂ of the rear stage is large is a low positive voltage is applied when the high-frequency power outputted from the later stage of the RF power transistor Tr ₂ is small.

In the fifth embodiment, the power detection point A is connected in the middle of the _fourth microstrip line S ₄ as the fourth output bias circuit, that is, the fourth output bias Since part of the high-frequency power leaking into the circuit is detected, it is not necessary to consider the amount by which the basic high-frequency power is reduced by the detection, so that the design of the basic amplifier circuit can be simplified.

(Sixth Embodiment) Hereinafter, a high frequency power amplifier according to a sixth embodiment of the present invention will be described with reference to FIG. FIG. 7 shows a circuit configuration of a high-frequency power amplifier according to the sixth embodiment. The same members as those in the first conventional example shown in FIG. 15 or the first embodiment shown in FIG. The description will be omitted by attaching.

As a feature of the sixth embodiment, the power detection point A of the positive voltage generation circuit 4 is
Of the positive voltage generating circuit 4
Is a positive voltage output point B of the first microstrip line S ₁
Is connected to each of the input terminals and second microstrip lines S _3. Thereby, the positive voltage generation circuit 4 detects a part of the high-frequency power from the high-frequency power output from the output impedance matching circuit 3, and generates a positive voltage that increases or decreases in accordance with the increase or decrease of the detected part of the high-frequency power. The signal is output to the input terminal of the high-frequency power transistor Tr ₁ of the preceding stage via the _first microstrip line S _{1 and} to the input terminal of the high-frequency power transistor Tr ₂ of the subsequent stage via the _third microstrip line S _3. I do.

Therefore, according to the sixth embodiment, the high-frequency power output from the output impedance matching circuit 3 is large at each input terminal of the _first- stage high-frequency power transistor Tr ₁ and the second-stage high-frequency power transistor Tr _2. Sometimes, a high positive voltage is applied, and when the high-frequency power output from the output impedance matching circuit 3 is low, a low positive voltage is applied. Therefore, the front-stage high-frequency power transistor Tr ₁ and the rear-stage high-frequency power transistor Tr ₂
, Respectively.

FIG. 14 shows the input / output characteristic (P _out ) of the high-frequency power of the high-frequency power amplifier according to the sixth embodiment, and the total operation of the preceding high-frequency power transistor Tr ₁ and the subsequent high-frequency power transistor Tr ₂ . As shown in FIG. 14, when the output high-frequency power is small, the total operating current is greatly reduced.

(Seventh Embodiment) Hereinafter, a high-frequency power amplifier according to a seventh embodiment of the present invention will be described with reference to FIG. FIG. 8 shows a circuit configuration of the high-frequency power amplifier according to the seventh embodiment. The same members as those in the first conventional example shown in FIG. 15 or the first embodiment shown in FIG. The description will be omitted by attaching.

A feature of the seventh embodiment is that a positive voltage that increases or decreases according to an increase or decrease of the input high-frequency power is generated.
An output positive voltage generation circuit 5 is provided, a power detection point A is provided at an input portion of the two-output positive voltage generation circuit 5, and a first positive voltage is provided at an output portion of the two-output positive voltage generation circuit 5. output point B ₁ and the second positive voltage output point B ₂ is provided.
As shown in FIG. 8, the two-output positive voltage generation circuit 5 includes a resistor R for detecting a part of high-frequency power from the input high-frequency power.
₁₁ (detection circuit), a condenser C ₁₂ for outputting a small high-frequency power to remove a DC component from a portion of the high-frequency power detected by the resistor R _11, rectifies the minute high-frequency power outputted from the condenser C ₁₂ D ₁₁ (rectifier circuit) that outputs a positive pulsating voltage, a capacitor C ₁₁ that smoothes the pulsating positive voltage output from the diode D ₁₁ and outputs a positive voltage, a first split resistor R _13, and a second split resistor. R ₁₄ (smoothing circuit). The two-output positive voltage generation circuit 5
As is clear from FIG. 8, no negative DC bias power supply is provided.

Further, as a feature of the seventh embodiment, the power detection point A of the two-output positive voltage generation circuit 5 is connected to the output terminal of the output impedance matching circuit 3, and the first positive voltage output point B ₁ represents is connected to a first input terminal of the microstrip line S _1, the second output second positive voltage output point B ₂ of the positive voltage generation circuit 5 of the third microstrip line S ₃ Connected to input terminal. Thereby, the two-output positive voltage generation circuit 5 detects a part of the high-frequency power from the high-frequency power output from the output impedance matching circuit 3, and generates a positive voltage that increases or decreases in accordance with the increase or decrease of the detected part of the high-frequency power. Is output to the input terminal of the high-frequency power transistor Tr ₁ of the preceding stage via the _first microstrip line S _1, and is input to the input terminal of the high-frequency power transistor Tr ₂ of the following stage via the _third microstrip line S _3. Output to In this case, the resistance of the smoothing circuit, because it is composed of a first dividing resistor R ₁₃ and the second dividing resistor R _14, outputs a relatively small positive voltage in the front stage of the input terminal of the RF power transistor Tr ₁ And
The subsequent stage of the input terminal of the RF power transistor Tr ₂ can output a relatively large positive voltage.

Therefore, according to the seventh embodiment, even if there is a difference between the current-voltage characteristic of the high-frequency power transistor Tr _{1 in} the preceding stage and the current-voltage characteristic of the high-frequency power transistor Tr _{2 in} the subsequent stage, the output is performed. The operating current when the high-frequency power is small can be reliably reduced.

(Eighth Embodiment) Hereinafter, a high-frequency power amplifier according to an eighth embodiment of the present invention will be described with reference to FIG. FIG. 9 shows a circuit configuration of a high-frequency power amplifier according to the eighth embodiment. The same members as those in the first conventional example shown in FIG. 15 or the first embodiment shown in FIG. The description will be omitted by attaching.

The feature of the eighth embodiment is that a positive voltage that increases or decreases according to an increase or decrease in the input high-frequency power is generated.
A double positive voltage generation circuit 6 is provided, and a power detection point A is provided at an input portion of the double positive voltage generation circuit 6,
A positive voltage output point B is provided at the output of the double positive voltage generation circuit 6. As shown in FIG. 9, two times the positive voltage generating circuit 6 includes a resistor R ₁₁ for detecting a portion of the high frequency power from the high frequency input power (detection circuit), a part detected by the resistor R ₁₁ RF a condenser C ₁₂ for outputting a small high-frequency power to remove the DC component from the power, the capacitor C
_A first diode D ₁₁ and a second diode D ₁₂ that rectify the minute high-frequency power output from ₁₂ and output a pulsating positive voltage.
And (voltage doubler rectification circuit), a first diode D ₁₁ and a second
Rang pulsating positive voltage outputted from the diode D ₁₂ 2
Condenser C ₁₁ and resistor R ₁₂ and outputs the multiplied positive voltage has the (smoothing circuit) and. As is apparent from FIG. 9, the double positive voltage generating circuit 6 does not have a negative DC bias power supply.

While the rectifying circuits of the positive voltage generating circuit 4 and the two-output positive voltage generating circuit 5 perform half-wave rectification, in the eighth embodiment, the double voltage rectifying circuit performs full-wave rectification. performed for, since the voltage generated across the resistor R ₁₂ can be increased to double, it is possible to halve the absolute value of the high-frequency power required to generate a predetermined positive voltage. Therefore, the high-frequency power extracted at the power detection point A can be reduced, so that the loss of the high-frequency power can be reduced. For example, as for the input high-frequency power at the power detection point A, 10 dBm is required in the positive voltage generation circuit 4 and the two-output positive voltage generation circuit 5 described above, but only 7 dBm which is half in the double positive voltage conversion circuit 6. .

(Ninth Embodiment) Hereinafter, a high-frequency power amplifier according to a ninth embodiment of the present invention will be described with reference to FIG. FIG. 10 shows a circuit configuration of the high-frequency power amplifier according to the ninth embodiment. The same members as those in the first conventional example shown in FIG. 15 or the first embodiment shown in FIG. The description will be omitted by attaching.

As a feature of the ninth embodiment, there is provided a variable positive voltage generation circuit 7 for generating a positive voltage that increases or decreases in accordance with an increase or decrease in the input high-frequency power. Is provided with a power detection point A,
A positive voltage output point B is provided at the output section of the variable positive voltage generation circuit 7. As shown in FIG. 10, the variable positive voltage generation circuit 7 includes a resistor R ₁₁ for detecting a portion of the high frequency power from the high frequency power input (detection circuit), a part of the high-frequency power detected by the resistor R ₁₁ and a capacitor C ₁₂ which outputs the micro-frequency power to remove the DC component, diode D ₁₁ for outputting a pulsating positive voltage by rectifying a small high-frequency power outputted from the condenser C ₁₂ (the rectifier circuit), diodes D ₁₁ It has been capacitor C ₁₁ to pulsation leveling a positive voltage and outputs a positive voltage, invariant dividing resistor R ₁₃ and a variable divider resistor R ₁₅ and a (smoothing circuit) outputted from. The variable positive voltage generator 7 does not have a negative DC bias power supply, as is apparent from FIG.

According to the ninth embodiment, the positive voltage output to the input terminal of the subsequent high-frequency power transistor Tr ₂ via the _third microstrip line S ₃ as the second input bias circuit is supplied to the variable dividing resistor. it can be adjusted by R _15. Therefore, even when the current-voltage characteristic largely changes when the current starts to flow in the later stage of the RF power transistor Tr _2, by adjusting the resistance value of the variable dividing resistor R ₁₅ in accordance with a change of the current-voltage characteristics, A high-frequency power amplifier whose gain and output do not change can be realized.

(Tenth Embodiment) Hereinafter, the first embodiment of the present invention will be described.
A high-frequency power amplifier according to Embodiment 0 will be described with reference to FIG. FIG. 11 shows a semiconductor substrate 8 in which the high-frequency power amplifier according to the sixth embodiment shown in FIG.
A microwave integrated circuit (MMIC: Microwave Monolithic IC) formed on the
The same members as those in the first conventional example shown in FIG. 15, the first embodiment shown in FIG. 1, and the sixth embodiment shown in FIG.

The features of the tenth embodiment are that a high-frequency power transistor Tr _{1 in the first} stage, a high-frequency power transistor Tr ₂ in the _second stage, a first microstrip line S ₁ , a second microstrip line S ₂ , a third Microstrip line S ₃ , fourth microstrip line S ₄ , input impedance matching circuit 1, interstage impedance matching circuit 2, output impedance matching circuit 3, and positive voltage generation circuit 4 are formed on the same semiconductor substrate 8. Have been.

In the tenth embodiment, the semiconductor substrate 8
When a compound semiconductor substrate made of gallium arsenide (GaAs) is used, a microwave circuit integrated type integrated circuit can be realized with a chip size of several mm square.

According to the tenth embodiment, the input bias circuit of the high-frequency power transistor used in the high-frequency power amplifier does not need to be drawn out, and a positive voltage can be generated on the semiconductor substrate 8. Therefore, when a microwave circuit integrated type integrated circuit is mounted on a resin package, the number of lead terminals can be reduced, so that a high-frequency power amplifier which is small and does not require setting of an input bias circuit can be realized.

In the tenth embodiment, the case where the high-frequency power amplifier according to the sixth embodiment is formed on the semiconductor substrate 8 has been described, but the first to fifth and seventh to fifth embodiments are described.
It goes without saying that any of the high-frequency power amplifiers of the ninth embodiment may be formed on the semiconductor substrate 8.

(Eleventh Embodiment) Hereinafter, the first embodiment of the present invention will be described.
A high-frequency power amplifier according to one embodiment will be described with reference to FIG. FIG. 12 is a microwave circuit-integrated integrated circuit in which components other than the positive voltage generation circuit 4 in the high frequency power amplifier according to the sixth embodiment shown in FIG. 7 are formed on the same semiconductor substrate 8. Circuit (MMI
C), and the same members as those of the first conventional example shown in FIG. 15, the first embodiment shown in FIG. 1, and the sixth embodiment shown in FIG. 7 are denoted by the same reference numerals. Is omitted.

As a feature of the eleventh embodiment, the first stage high-frequency power transistor Tr ₁ , the second stage high-frequency power transistor Tr ₂ , the first microstrip line S ₁ , the second microstrip line S ₂ , the third microstrip line S _3, a fourth microstrip line S _4, the input impedance matching circuit 1, an interstage impedance matching circuit 2 and the output impedance matching circuit 3 are formed on the same semiconductor substrate 8, a positive voltage The generation circuit 4 is formed on another semiconductor substrate.

According to the eleventh embodiment, the input bias circuit of the high-frequency power amplifier can be simplified by adding the positive voltage generating circuit 4 from the outside to the microwave circuit integrated type integrated circuit having the conventional configuration, The miniaturization of the high-frequency power amplifier can be realized at the same time.

In the eleventh embodiment, a case has been shown in which the components other than the positive voltage generating circuit 4 in the high frequency power amplifier according to the sixth embodiment are formed on the semiconductor substrate 8. Are the positive voltage generator 4, the two-output positive voltage generator 5, the double positive voltage generator 6, or the variable positive voltage generator 6 in the high-frequency power amplifier according to any of the first to fifth and seventh to ninth embodiments. It goes without saying that the circuit 7 may be formed on the semiconductor substrate 8.

[0093]

According to the first high-frequency power amplifier, it is not necessary to provide a negative DC bias power supply in the positive voltage generation circuit. Therefore, a negative voltage generation circuit for generating a negative voltage in the negative DC bias power supply is provided. Since it becomes unnecessary, current consumption when the input high-frequency power is small can be further reduced.

Further, since a negative DC bias power supply and a negative voltage generation circuit are not required, the circuit configuration of the bias voltage generation circuit and the circuit configuration as a whole are simplified, and the circuit is led to a high frequency power amplifier. Since the number of wirings is reduced, the size of the high-frequency power amplifier can be reduced.

In the first high-frequency power amplifier, when the input terminal of the detection circuit is connected to the input terminal of the input impedance matching circuit or the output terminal of the output impedance matching circuit, the input terminal of the detection circuit is connected to the high-frequency power amplifier. Since it can be arranged near the external input terminal or the external output terminal, a high-frequency power transistor, an input bias circuit, an output bias circuit, an input impedance matching circuit, an output impedance matching circuit, and a positive voltage generating circuit are separated from each other by a semiconductor. Connection when mounting on a substrate is facilitated.

In the first high-frequency power amplifier, when the input terminal of the detection circuit is connected to the output terminal of the input impedance matching circuit or the input terminal of the output impedance matching circuit, the basic operation is performed by adding a positive voltage generating circuit. The effect on the amplifying circuit can be reduced.
That is, while the input impedance and the output impedance of the high-frequency power transistor are usually much lower than 50Ω, the input impedance and the output impedance of the
Even if a resistor having an impedance much larger than Ω is used, it is possible to avoid a situation in which the high-frequency power transistor is adversely affected by the difference in impedance. Therefore, when designing the input impedance matching circuit or the output impedance matching circuit, it is not necessary to consider the influence of the positive voltage generation circuit, so that the design of the matching circuit is facilitated.

In the first high-frequency power amplifier, when the input terminal of the detection circuit is connected to the output bias circuit, the influence on the basic amplification circuit due to the addition of the positive voltage generation circuit can be ignored. That is, usually, a certain amount of high-frequency power is leaking to the output bias circuit, and the leaking high-frequency power can be detected by the detection circuit, that is, the basic high-frequency power flowing through the amplifier circuit is not detected. There is no need to consider the loss associated with the detection of high frequency power.

In the first high-frequency power amplifier, when the rectifier circuit includes a pair of diodes connected in parallel in opposite directions and outputs a double pulsating voltage, the voltage input to the smoothing circuit is doubled. Can be increased to
Even if the absolute value of the detected high-frequency power is reduced by half, a predetermined positive voltage can be generated. Therefore, the high frequency power extracted from the basic amplifier circuit can be halved,
The loss of high frequency power flowing through the basic amplifier circuit can be reduced.

In the first high-frequency power amplifier, when the smoothing circuit has a capacitor and a variable resistor and outputs a positive voltage that changes according to a change in the resistance value of the variable resistor,
Even if the current-voltage characteristics of the high-frequency power transistor greatly change when a current starts flowing through the high-frequency power transistor, a high-frequency power amplifier having an equivalent gain and output can be realized by adjusting the resistance value of the variable resistor. .

In the first high-frequency power amplifier, the high-frequency power transistor is an N-channel MOSFET, NP
N-type bipolar transistor, N-channel MESFET
Or an N-channel heterojunction FET having a normally-off type, an enhancement mode type, or a current-voltage characteristic similar thereto, by applying a positive voltage to the control terminals of these transistors, Characteristics can be greatly changed. Therefore, while the idle current when the high-frequency power is small can be reduced, when the high-frequency power is large, the idle current greatly increases with an increase in the positive voltage input to the control terminals of these transistors. The output high-frequency power increases. Therefore, while the operating current when the high frequency power input to the high frequency power amplifier circuit is small can be reduced, when the high frequency power input to the high frequency power amplifier circuit is large, the high frequency power output from the high frequency power amplifier increases. Can be done.

In the first high-frequency power amplifier, it is assumed that a high-frequency power transistor, an input bias circuit, an output bias circuit, an input impedance matching circuit, an output impedance matching circuit, and a positive voltage generation circuit are formed on the same semiconductor substrate. Gallium arsenide (G)
By using an aAs) substrate, a microwave circuit integrated type integrated circuit (MMIC) can be realized with a chip size of several mm square. Therefore, a positive voltage can be generated on the semiconductor substrate without drawing out the input bias circuit of the high-frequency power transistor to the outside of the chip. Further, when the semiconductor substrate is mounted on the resin package, it is not necessary to lead the lead terminals of the input bias circuit to the outside, so that the number of lead terminals can be reduced. Therefore, it is possible to realize a high-frequency power amplifier that is small and does not require setting of an input bias circuit.

In the first high-frequency power amplifier, if the high-frequency power transistor, input bias circuit, output bias circuit, input impedance matching circuit and output impedance matching circuit are formed on the same semiconductor substrate, the existing microwave Circuit integrated circuit (MMIC)
Since a positive voltage generating circuit can be externally added to the high-frequency power amplifier having the above configuration, the input bias circuit can be simplified, and the whole high-frequency power amplifier can be downsized.

According to the second high-frequency power amplifier, the positive voltage that increases or decreases according to the increase or decrease of the detected high-frequency power is:
Since the input from the positive voltage generation circuit to each input terminal of the high-frequency power transistor in the preceding stage and the high-frequency power transistor in the subsequent stage, the total current consumption when the high-frequency power input to the high-frequency power amplifier is small can be greatly reduced. it can.

Further, similarly to the first high-frequency power amplifier, there is no need to provide a negative DC bias power supply in the positive voltage generation circuit, so that a negative voltage generation circuit for generating a negative voltage in the negative DC bias power supply is provided. Since it becomes unnecessary, current consumption when the input of high frequency power is small can be further reduced.

Further, similar to the first high frequency power amplifier,
Since a negative DC bias power supply and a negative voltage generating circuit are not required, the circuit configuration of the bias generating circuit and the overall circuit configuration are both simplified, and the number of wirings routed to the high-frequency power amplifier is reduced. The size of the power amplifier can be reduced.

In the second high-frequency power amplifier, when the rectifier circuit comprises a pair of diodes connected in parallel in opposite directions and outputs a double pulsating voltage, the voltage input to the smoothing circuit is doubled. Can be increased to
Even if the absolute value of the detected high-frequency power is reduced by half, a predetermined positive voltage can be generated. Therefore, the high frequency power extracted from the basic amplifier circuit can be halved,
The loss of high frequency power flowing through the basic amplifier circuit can be reduced.

In the second high-frequency power amplifier, the smoothing circuit divides the positive voltage into a first positive voltage and a second positive voltage that are different from each other, and divides the first positive voltage into the first input impedance matching circuit. When a voltage dividing circuit for outputting to the input terminal and outputting the second positive voltage to the input terminal of the second input impedance matching circuit is provided, the former high-frequency power transistor and the latter high-frequency power transistor Different input bias voltages can be supplied even if there is a difference in current-voltage characteristics between them. Therefore, the idle current of the high-frequency power transistor at the front stage and the idle current of the high-frequency power transistor at the rear stage can be individually adjusted according to the high-frequency power, so that the idle current can be further reduced.

In the second high-frequency power amplifier, the voltage dividing circuit includes a plurality of divided resistors including at least one variable resistor, and the first positive voltage changes according to a change in the resistance value of at least one variable resistor. Or, when the second positive voltage is output, the resistance value of the variable resistor is adjusted even when the current-voltage characteristics of the high-frequency power transistor at the preceding or subsequent stage start flowing. Accordingly, a high-frequency power amplifier having an equivalent gain and output can be realized.

In the second high-frequency power amplifier, the front-stage high-frequency power transistor and the rear-stage high-frequency power transistor are N-channel MOSFETs, NPN-type bipolar transistors, N-channel MESFETs, or N-channel heterojunction FETs,・ If the device has an off-type, an enhancement-mode type, or a current-voltage characteristic similar to these, the operating current when the high-frequency power input to the high-frequency power amplifier is small is reduced, as in the first high-frequency power amplifier. On the other hand, when the high frequency power input to the high frequency power amplifier circuit is large, the high frequency power output from the high frequency power amplifier can be increased.

In the second high-frequency power amplifier, the first-stage high-frequency power transistor, the first input bias circuit, the first output bias circuit, the first input impedance matching circuit, the first output impedance matching circuit, High-frequency power transistor, a second input bias circuit, a second output bias circuit, a second input impedance matching circuit, a second output impedance matching circuit, and a positive voltage generation circuit are formed on the same semiconductor substrate. In this case, similarly to the first high-frequency power amplifier, a positive voltage can be generated on the semiconductor substrate without drawing out the input bias circuit of the high-frequency power transistor to the outside of the chip. Further, when the semiconductor substrate is mounted on the resin package, it is not necessary to lead the lead terminals of the input bias circuit to the outside, so that the number of lead terminals can be reduced. Therefore, it is possible to realize a high-frequency power amplifier that is small and does not require setting of an input bias circuit.

In the second high-frequency power amplifier, a high-frequency power transistor in the preceding stage, a first input bias circuit,
A first output bias circuit, a first input impedance matching circuit, a first output impedance matching circuit, a high-frequency power transistor in a subsequent stage, a second input bias circuit, a second output bias circuit, and a second input impedance matching When the circuit and the second output impedance matching circuit are formed on the same semiconductor substrate, the input bias circuit can be simplified and the whole high-frequency power amplifier can be reduced in size as in the case of the first high-frequency power amplifier. it can.

[Brief description of the drawings]

FIG. 1 is a circuit diagram of a high-frequency power amplifier according to a first embodiment of the present invention, showing details of a positive voltage generation circuit.

FIG. 2 is a circuit diagram of the high-frequency power amplifier according to the first embodiment of the present invention, in which a positive voltage generation circuit is shown by blocks.

FIG. 3 is a circuit diagram of a high-frequency power amplifier according to a second embodiment of the present invention.

FIG. 4 is a circuit diagram of a high-frequency power amplifier according to a third embodiment of the present invention.

FIG. 5 is a circuit diagram of a high-frequency power amplifier according to a fourth embodiment of the present invention.

FIG. 6 is a circuit diagram of a high-frequency power amplifier according to a fifth embodiment of the present invention.

FIG. 7 is a circuit diagram of a high-frequency power amplifier according to a sixth embodiment of the present invention.

FIG. 8 is a circuit diagram of a high-frequency power amplifier according to a seventh embodiment of the present invention.

FIG. 9 is a circuit diagram of a high-frequency power amplifier according to an eighth embodiment of the present invention.

FIG. 10 is a circuit diagram of a high-frequency power amplifier according to a ninth embodiment of the present invention.

FIG. 11 is a circuit diagram of a high-frequency power amplifier including an MMIC according to a tenth embodiment of the present invention.

FIG. 12 is a circuit diagram of a high-frequency power amplifier including an MMIC according to an eleventh embodiment of the present invention.

13A is a diagram illustrating current-voltage characteristics of a high-frequency power transistor of the high-frequency power amplifier according to each embodiment of the present invention, and FIG. 13B is a diagram illustrating high-frequency power according to the first embodiment of the present invention; FIG. 9 is a characteristic diagram illustrating input / output characteristics of high-frequency power and operating current of a high-frequency power transistor at a subsequent stage in the amplifier.

FIG. 14 is a characteristic diagram showing input / output characteristics of high-frequency power and a total operating current of a preceding high-frequency power transistor and a following high-frequency power transistor in the high-frequency power amplifier according to the sixth embodiment of the present invention. .

FIG. 15 is a circuit diagram of a high-frequency power amplifier according to a first conventional example.

16A is a diagram illustrating current-voltage characteristics of a high-frequency power transistor of the high-frequency power amplifier according to the first conventional example, and FIG. 16B is a diagram illustrating high-frequency power in the high-frequency power amplifier according to the first conventional example; FIG. 4 is a characteristic diagram showing power input / output characteristics and an operating current of a high-frequency power transistor at a subsequent stage.

FIG. 17 is a circuit diagram of a high-frequency power amplifier according to a second conventional example.

FIG. 18 is a characteristic diagram showing the input / output characteristics of high-frequency power and the operating current of a high-frequency power transistor at a subsequent stage in the high-frequency power amplifier according to the second conventional example.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Input impedance matching circuit 2 Interstage impedance matching circuit 3 Output impedance matching circuit 4 Positive voltage generating circuit 5 2 Output positive voltage generating circuit 6 Double positive voltage generating circuit 7 Variable positive voltage generating circuit 8 Semiconductor substrate

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Junji Ito 1006 Kazuma Kadoma, Osaka Prefecture Matsushita Electric Industrial Co., Ltd. (72) Inventor Shinji Yamamoto 1006 Kadoma, Kadoma, Osaka Prefecture Matsushita Electric Industrial Co., Ltd.

Claims (16)

[Claims] 1. A high-frequency power transistor that operates when a positive voltage is applied to an input terminal and has a large change in current-voltage characteristics; an input bias circuit connected to an input terminal of the high-frequency power transistor; An output bias circuit connected to the output terminal of the high-frequency power transistor; an input impedance matching circuit connected to the input terminal of the high-frequency power transistor; and an output impedance matching circuit connected to the output terminal of the high-frequency power transistor. An input terminal is connected to an input side or an output side of the high-frequency power transistor, and converts a part of high-frequency power from high-frequency power input to the high-frequency power transistor or high-frequency power output from the high-frequency power transistor A detection circuit for detecting and outputting, and an input terminal connected to the output of the detection circuit. Connected to an end, a rectifying circuit for outputting a pulsating positive voltage by rectifying the part of the high-frequency power outputted from said detection circuit,
An input terminal connected to the output terminal of the rectifier circuit, an output terminal connected to the input terminal of the input bias circuit, and a smoothing circuit that smoothes the pulsating positive voltage output from the rectifier circuit and outputs a positive voltage. A positive voltage generation circuit that outputs a positive voltage that increases or decreases in accordance with an increase or decrease in the detected high-frequency power without inputting a DC power supply to an input terminal of the input bias circuit. A high frequency power amplifier characterized in that: 2. The high-frequency power amplifier according to claim 1, wherein an input terminal of the detection circuit is connected to an input terminal of the input impedance matching circuit or an output terminal of the output impedance matching circuit. 3. The high-frequency power amplifier according to claim 1, wherein an input terminal of the detection circuit is connected to an output terminal of the input impedance matching circuit or an input terminal of the output impedance matching circuit. 4. The high-frequency power amplifier according to claim 1, wherein an input terminal of the detection circuit is connected to the output bias circuit. 5. The high-frequency power amplifier according to claim 1, wherein the rectifier circuit includes a pair of diodes connected in parallel with each other in opposite directions and outputs a double pulsating positive voltage. 6. The smoothing circuit according to claim 1, wherein the smoothing circuit has a capacitor and a variable resistor, and outputs a positive voltage that changes according to a change in the resistance value of the variable resistor.
3. The high-frequency power amplifier according to 1. 7. The high-frequency power transistor is an N-channel MOSFET, an NPN-type bipolar transistor, an N-channel MESFET or an N-channel heterojunction FET, and has a normally-off type, an enhancement mode type or a current voltage similar thereto. The high-frequency power amplifier according to claim 1, wherein the high-frequency power amplifier has characteristics. 8. The high frequency power transistor, the input bias circuit, the output bias circuit, the input impedance matching circuit, the output impedance matching circuit, and the positive voltage generating circuit are formed on the same semiconductor substrate. The high-frequency power amplifier according to claim 1. 9. The high frequency power transistor, input bias circuit, output bias circuit, input impedance matching circuit, and output impedance matching circuit are formed on the same semiconductor substrate. High frequency power amplifier. 10. A high-frequency power transistor in a preceding stage, which operates when a positive voltage is applied to an input terminal and whose current-voltage characteristics change greatly, and a first terminal connected to an input terminal of the high-frequency power transistor in the preceding stage. An input bias circuit, a first output bias circuit connected to the output terminal of the preceding high-frequency power transistor, and a first input impedance matching circuit connected to the input terminal of the preceding high-frequency power transistor. A first output impedance matching circuit connected to an output terminal of the preceding high-frequency power transistor; and a second-stage high-frequency power transistor that operates when a positive voltage is applied to an input terminal and has a large change in current-voltage characteristics. A transistor, a second input bias circuit connected to an input terminal of the subsequent high-frequency power transistor, A second output bias circuit connected to the output terminal of the subsequent high-frequency power transistor; a second input impedance matching circuit connected to the input terminal of the subsequent high-frequency power transistor; A second output impedance matching circuit connected to the output terminal of the power transistor; and an input terminal connected to the input side or output side of the subsequent high-frequency power transistor, and input to the second high-frequency power transistor. A detection circuit that detects and outputs a portion of high-frequency power from high-frequency power or high-frequency power output from the high-frequency power transistor at the subsequent stage, and an input terminal connected to an output terminal of the detection circuit, and an output from the detection circuit A rectifying circuit for rectifying the part of the high-frequency power to output a pulsating positive voltage, and an input terminal connected to an output terminal of the rectifying circuit. , And an output terminal connected to each input terminal of the first input bias circuit and the second input bias circuit, and smoothing a pulsating positive voltage output from the rectifier circuit to output a positive voltage. Having a DC power supply interposed between input terminals of the first input bias circuit and the second input bias circuit with a positive voltage that increases or decreases according to an increase or decrease in the detected high-frequency power of the part. A high-frequency power amplifier comprising: 11. The high-frequency power amplifier according to claim 10, wherein the rectifier circuit includes a pair of diodes connected in parallel with each other in opposite directions and outputs a double pulsating positive voltage. 12. The smoothing circuit divides a positive voltage into a first positive voltage and a second positive voltage that are different from each other, and outputs the first positive voltage to an input terminal of the first input bias circuit. 11. The high frequency power amplifier circuit according to claim 10, further comprising a voltage dividing circuit for outputting the second positive voltage to an input terminal of the second input bias circuit. 13. The voltage dividing circuit includes a plurality of divided resistors including at least one variable resistor, wherein the first positive voltage or the second positive voltage changes according to a change in a resistance value of the one variable resistor. The high-frequency power amplifier according to claim 12, which outputs a positive voltage. 14. The high-frequency power transistor of the preceding stage and the high-frequency power transistor of the following stage are an N-channel MOSFET, an NPN-type bipolar transistor, an N-channel MESFET or an N-channel heterojunction FET.
The high-frequency power amplifier according to claim 10, wherein the high-frequency power amplifier has a normally-off type, an enhancement mode type, or a current-voltage characteristic similar thereto. 15. The high-frequency power transistor of the preceding stage, a first input bias circuit, a first output bias circuit, a first input impedance matching circuit, a first output impedance matching circuit, and a high-frequency power transistor of the following stage. The transistor, the second input bias circuit, the second output bias circuit, the second input impedance matching circuit, the second output impedance matching circuit, and the positive voltage generating circuit are formed on the same semiconductor substrate. Claim 10
3. The high-frequency power amplifier according to 1. 16. A high-frequency power transistor, a first input bias circuit, a first output bias circuit, a first input impedance matching circuit, a first output impedance matching circuit, and a high-frequency power transistor at the preceding stage. 11. The device according to claim 10, wherein the second input bias circuit, the second output bias circuit, the second input impedance matching circuit, and the second output impedance matching circuit are formed on the same semiconductor substrate. The high-frequency power amplifier according to any one of the preceding claims.