JP5523210B2 - High frequency amplifier - Google Patents

Description

  The present invention relates to a high frequency amplification device.

  For example, in the conventional high-frequency amplifier disclosed in Patent Document 1 below, the modulated wave input signal to the high-frequency power amplifier is branched and the envelope component of the modulated wave input signal is detected by the detection circuit, and the voltage control means detects the envelope component. A power supply voltage substantially proportional to the detected envelope component is applied to the high frequency power amplifier. The high frequency power amplifier amplifies the modulated wave input signal based on the power supply voltage applied from the voltage control means, and outputs it as a modulated wave output signal. In such a high-frequency amplifier, since the power supply voltage of the high-frequency power amplifier is adjusted according to the envelope component of the modulated wave input signal, high-efficiency operation is possible particularly in a region with a large back-off.

JP 62-274906 A

  However, in the conventional high-frequency amplifier, the dynamic gain characteristic and dynamic phase characteristic of the instantaneous output signal with respect to the instantaneous input signal (hereinafter referred to as the dynamic gain characteristic and dynamic phase characteristic, respectively) are not constant, so that distortion is deteriorated. There are challenges.

  The present invention has been made in order to solve the above-described problems, and by making the dynamic gain characteristic or the dynamic phase characteristic of the high-frequency amplifier device constant, it can be operated with high efficiency and An object of the present invention is to obtain a high-frequency amplifier that can reduce nonlinear distortion of the amplifier.

The present invention is a high-frequency amplifier that amplifies and outputs an input high-frequency input signal, and a source-grounded or emitter-grounded high-frequency power amplifier that amplifies the input signal based on an applied power supply voltage, A first envelope detector for detecting an envelope component of the input signal; and a power supply voltage according to the envelope component detected by the first envelope detector to generate a drain voltage of the high-frequency power amplifier or The high-frequency power according to the envelope component of the input signal so that the dynamic phase characteristic of the instantaneous output signal with respect to the instantaneous input signal of the high-frequency amplifier is constant and the drain voltage or collector voltage generating means applied to the collector voltage supply terminal A gate voltage to which a gate voltage or a base voltage for the amplifier is generated and the input signal of the high-frequency power amplifier is also input Others are in the high frequency amplifying apparatus comprising: the gate voltage or the base voltage adjusting means for applying a base voltage supply terminal.

  According to the present invention, it is possible to provide a high-frequency amplifying device that can be operated with high efficiency by reducing the non-linear distortion of the high-frequency amplifying device by making the dynamic gain characteristic or dynamic phase characteristic of the high-frequency amplifying device constant.

It is a block diagram which shows the structure of the high frequency amplifier by Embodiment 1 of this invention. It is a circuit diagram which shows an example of the drain voltage control circuit and gate voltage control circuit of the high frequency amplifier by Embodiment 1 of this invention. It is a figure for demonstrating operation | movement of the high frequency amplifier by Embodiment 1 of this invention. It is a figure for demonstrating operation | movement of the high frequency amplifier by Embodiment 1 of this invention. It is a block diagram which shows the structure of the high frequency amplifier by Embodiment 2 of this invention. It is a figure for demonstrating operation | movement of the high frequency amplifier by Embodiment 2 of this invention. It is a block diagram which shows the structure of the high frequency amplifier by Embodiment 3 of this invention. It is a circuit diagram which shows an example of the drain voltage control circuit of the high frequency amplifier by Embodiment 3 of this invention. It is a figure for demonstrating operation | movement of the high frequency amplifier by Embodiment 3 of this invention. It is a figure for demonstrating operation | movement of the high frequency amplifier by Embodiment 3 of this invention. It is a figure for demonstrating operation | movement of the high frequency amplifier by Embodiment 3 of this invention.

Hereinafter, a high-frequency amplifier according to the present invention will be described with reference to the drawings according to each embodiment. In each embodiment, the same or corresponding parts are denoted by the same reference numerals, and redundant description is omitted.
In the following description, the high-frequency power amplifier is composed of a field effect transistor or the like. The present invention is also applicable to a high-frequency power amplifier composed of a junction transistor or the like. The gate voltage and drain voltage in the source grounded high frequency power amplifier (field effect transistor) correspond to the base voltage and collector voltage in the emitter grounded high frequency power amplifier (junction transistor).

Embodiment 1 FIG.
1 is a block diagram showing a configuration of a high-frequency amplifier according to Embodiment 1 of the present invention. The high frequency amplifier of FIG. 1 is a device that amplifies an input signal and outputs it. An input terminal 1 is connected to the input of the high frequency power amplifier 7 and an output terminal 2 is connected to the output. The input terminal 1 further passes through a drain voltage control circuit 3, a first pulse width modulator 4, a first switching amplifier 5, and a first low-pass filter 6 (hereinafter referred to as LPF (Low Pass Filter)). The high-frequency power amplifier 7 is connected to a drain voltage supply terminal (drain voltage or collector voltage supply terminal) 100, and further includes a gate voltage control circuit 8, a second pulse width modulator 9, a second switching amplifier 10, and a second switching amplifier 10. A gate voltage supply terminal (gate voltage or base voltage supply terminal) 101 to which an input signal of the high frequency power amplifier 7 is also input through the LPF 11 is connected.

Next, the operation will be described. Modulated wave input signal P _in the high-frequency input from the input terminal 1 is branched and the drain voltage control circuit 3, the gate voltage control circuit 8, and are input to the RF power amplifier 7. Drain voltage control circuit 3 and the gate voltage control circuit 8 is composed of a circuit for detecting the envelope of the input signal shown together in FIG. 2, for example, the output voltage signal V _{Outdet_d} and corresponding to the envelope component of the modulated wave input signal P _in V _{outdet_g} is _output to the first pulse width modulator 4 and the second pulse width modulator 9, respectively.

The output voltage signals V _{outdet_d} and V _{outdet_g} are pulse width modulated by the first pulse width modulator 4 and the second pulse width modulator 9 and output to the first switching amplifier 5 and the second switching amplifier 10. . The output voltage signals V _{outdet_d} and V _{outdet_g subjected} to pulse width modulation are amplified by the first switching amplifier 5 and the second switching amplifier 10 and output to the first LPF 6 and the second LPF 11. The amplified and pulse width modulated output voltage signals V _{outdet_d} , V _{outdet_g} are removed from the high frequency components by the first LPF 6 and the second LPF ₁₁ and applied to the high frequency power amplifier 7 as the drain voltage V _{out_d} and the gate voltage V _{out_g.} The RF power amplifier 7 on the basis of the voltage applied from the first LPF6 and second LPF 11, amplifies the modulated wave input signal P _in. Amplified modulated wave input signal P _in is output from the output terminal 2 as a modulated wave output signal P _out.

The conventional problem and the effect of the gate voltage control circuit 8 will be described below with reference to FIGS. The drain voltage control circuit 3 and the gate voltage control circuit 8 are configured as shown in FIG. 2, for example. In the drain voltage control circuit 3 and the gate voltage control circuit 8, the diode D _det is connected in the forward direction between the input terminal 50 and the output terminal 51, and further, between the connection point between the input terminal 50 and the anode of the diode D _det and the ground. An inductor L _det is connected, and a resistor R _det and a capacitor C _det are connected in parallel between the connection point between the cathode of the diode D _det and the output terminal 51 and the ground (that is, between the input terminal 50 and the output terminal 51). and a diode connected D _det the serial forward, and a diode D _det parallel-connected reactance L _det, a resistor R _det and capacitance C _det) to. Drain voltage control circuit 3 and the gate voltage control circuit 8 detects an envelope component of the modulated wave input signal P _in, respectively as an envelope signal a first pulse width modulator 4, a second pulse width modulator 9 Output.

FIG. 3 is a diagram for explaining the problem of the drain voltage control circuit 3 according to the first embodiment of the present invention. FIG. 3A shows the relationship (input / output characteristics) between the instantaneous input signal and the instantaneous output signal in the drain voltage control circuit 3. In (a) of FIG. 3, the horizontal axis represents the modulation wave instantaneous input signal P _in, the vertical axis represents the instantaneous output voltage signal _V outdet_d. The broken line is an input / output characteristic necessary for linearizing the dynamic gain characteristic of the high-frequency amplifier, and the solid line is an input / output characteristic when the drain voltage control circuit 3 is configured by a circuit as shown in FIG. ing. Incidentally, (a) of FIG. 3 shows the case where the lower limit voltage V _min and upper limit voltage V _max is set.

FIG. 3B shows a case in which the drain voltage control circuit 3 and the gate voltage control circuit 8 are configured in the circuit as shown in FIG. 2, for example, and the drain voltage or both the drain voltage and the gate voltage of the high frequency power amplifier 7 are controlled. The relationship (dynamic gain characteristic) between the modulated wave instantaneous output signal _Pout and the dynamic gain G of the high-frequency amplifier is shown. In FIG. 3B, the horizontal axis represents the modulated wave instantaneous output signal _Pout , and the vertical axis represents the dynamic gain G. The broken line is the dynamic gain characteristic when the drain voltage is controlled with the input / output characteristic necessary for linearizing the dynamic gain characteristic of the high-frequency amplifier, and the solid line is the drain voltage control circuit shown in FIG. 3 shows a dynamic gain characteristic when 3 is configured.

Output characteristics necessary to linearize the dynamic gain characteristic of the high frequency amplifying device, in a region modulated wave input signal P _in is large, due to the influence of the saturation of the high-frequency power amplifier 7, in FIG. 3 dashed line of (a) So that it deviates from the straight line. However, the input-output characteristic obtained by the actual drain voltage control circuit 3 is almost linear as a solid line, in the region modulated wave input signal P _in is large, the drain voltage is excessively supplied. As a result, as shown by the solid line in FIG. 3B, the gain increases in the modulated wave output signal _Pout when the drain voltage is excessively supplied, and the dynamic gain characteristic of the high-frequency amplifier cannot be linearized. As a result, there is a problem that amplitude distortion occurs.

  On the other hand, the gate voltage control circuit 8 according to the first embodiment of the present invention controls the gate voltage in order to reduce the gain deviation caused by the solid line in FIG.

In FIG. 4 (a), the modulated wave instants when the same fixed drain voltage (V _d1 ) and different fixed gate voltages (V _g1 , V _g2 , V _g3 ) (where V _g1 <V _g2 <V _g3 ) are supplied. The relationship (dynamic gain characteristic) between the output signal _Pout and the dynamic gain G is shown. FIG. 4B shows a case where only the modulated wave instantaneous output signal _Pout and the drain voltage of the high-frequency power amplifier 7 are controlled (conventional technology), and a case where both the drain voltage and the gate voltage are controlled (this embodiment). ) Shows the relationship (dynamic gain characteristics) with the dynamic gain G of the high-frequency amplifier. 4A and 4B, the horizontal axis indicates the modulated wave instantaneous output signal _Pout , and the vertical axis indicates the dynamic gain G. In FIG. 4B, the broken line shows the dynamic gain characteristic of the prior art, and the solid line shows the dynamic gain characteristic of this embodiment.

In the high-frequency power amplifier as shown in FIG. 4A, when the drain voltage is a fixed voltage, the dynamic gain characteristic changes when the gate voltage is changed. Therefore, in the broken line in FIG. 4 (b), a dynamic gain greater modulated wave output signal P _out, controls the gate voltage to reduce the gain. As a result, it is possible to reduce a dynamic gain deviation that has conventionally occurred.

  As described above, according to the first embodiment, the drain voltage control circuit controls the drain voltage so that the dynamic gain characteristic of the high-frequency amplification device is constant, and the gate voltage control circuit only performs drain voltage control. The gate voltage of the high frequency power amplifier is controlled so as to reduce dynamic gain characteristics that cannot be made constant. In the first embodiment, the drain voltage control circuit and the gate voltage control circuit are configured as separate circuits, so that the effect of reducing dynamic gain characteristics can be obtained with higher accuracy. Therefore, the dynamic gain characteristic of the high frequency amplifying device can be linearized to operate with high efficiency, and the nonlinear distortion of the high frequency amplifying device can be reduced.

  In the first embodiment, the drain voltage control circuit and the gate voltage control circuit control the drain voltage and the gate voltage so as to make the dynamic gain characteristics of the high frequency amplifier constant, but the present invention is not limited to this, and the high frequency The drain voltage and the gate voltage may be controlled so that the dynamic phase characteristic of the amplifying device is constant. Note that the above-described high-frequency power amplifier may be configured by, for example, a class A amplifier, a class AB amplifier, a B amplifier, or a Doherty amplifier. Further, the above-described pulse width modulator may be constituted by, for example, a delta sigma modulator or a delta modulator.

Embodiment 2. FIG.
FIG. 5 is a block diagram showing a configuration of a high-frequency amplifier according to Embodiment 2 of the present invention. In the high frequency amplifier of FIG. 5, the gate voltage supply terminal 101 of the high frequency power amplifier 7 is not provided with a circuit similar to the drain voltage supply terminal 100, but the output voltage signal V _{outdet_d} of the drain voltage control circuit 3 is used. A gate voltage control circuit 20 including a comparator 21 and a reference voltage source 22 as inputs is provided.

Hereinafter, the problems of the prior art and the effects of the gate voltage control circuit 20 will be described with reference to FIG. FIG. 6A shows the relationship (input / output characteristics) between the instantaneous input signal and the instantaneous output signal in the drain voltage control circuit 3. (A) in FIG. 6 is similar to FIG. 3 (a), the horizontal axis represents the modulation wave instantaneous input signal P _in, the vertical axis represents the instantaneous output voltage signal _V outdet_d. The broken line is an input / output characteristic necessary for linearizing the dynamic gain characteristic of the high-frequency amplifier, and the solid line is an input / output characteristic when the drain voltage control circuit is configured by a circuit as shown in FIG. Yes. FIG. _6A shows the case where the lower limit voltage V _min and the upper limit voltage V _max are set.

In (b) of FIG. 6, the same drain voltage (V _d1), and different gate voltages (V _g1, V _g2) (where V _g1 <V _g2) modulated wave instantaneous output signal P _out in the case of supply, dynamic The relationship with the gain G (dynamic gain characteristics) is shown.

In FIG. _6A , when the modulated wave input signal is larger than P _in1 , the output voltage of the drain voltage control circuit 3 becomes larger than V _out1 . At this time, V _out1 is increased in gain by supplying an excessive drain voltage with respect to the output voltage necessary for linearizing the dynamic gain characteristic of the high-frequency amplifier of the wavy line. There is a problem that the gain characteristic cannot be linearized, resulting in amplitude distortion. For this reason, when the drain voltage is _Vout1 , the gain can be reduced and the gain deviation can be reduced by changing the gate voltage from _Vg1 to _Vg2 .

Next, the operation of the high frequency amplification device having the above configuration will be described. Modulated wave input signal P _in the high-frequency input from the input terminal 1 is inputted to the drain voltage control circuit 3 and the high-frequency power amplifier 7 branches. The drain voltage control circuit 3, the circuit of Figure 2 described above, and outputs an output voltage signal V _{Outdet_d} corresponding to the modulation wave input signal P _in the pulse width modulator 4 and the gate voltage control circuit 20. The output voltage signal V _{outdet_d} is branched and input to the pulse width modulator 4 and the gate voltage control circuit 20, one of which is pulse width modulated by the pulse width modulator 4 and output to the switching amplifier 5. The pulse width modulated output voltage signal V _{outdet_d} is amplified by the switching amplifier 5 and output to the _{LPF 6} . The amplified and pulse width modulated output voltage signal V _{outdet_d} is removed of the high frequency component by the _{LPF 6} and applied to the drain voltage supply terminal 100 of the high frequency power amplifier 7 as the drain voltage V _{out_d} .

The other of the output voltage signal V _{outdet_d} is input to a comparator 21 constituting the gate voltage control circuit 20 and is compared with a reference voltage V _s of a reference voltage source 22 set in advance. For example, the reference voltage V _s is set to V _out1 in FIG.

If V _{outdet_d} ≥ V _s (V _out1 ),
V _{out_com} = V _g2
If V _{outdet_d} <V _s (V _out1 ),
V _{out_com} = V _g1

And works. That is, when the output voltage signal V _{Outdet_d} is equal to or higher than the reference voltage V _s, in order to reduce the increase in the gain of the high frequency power amplifier 7, the output voltage V _{Out_com} is V _g2 becomes reverse to the output voltage signal of the gate voltage control circuit 20 When V _{outdet_d} is smaller than the reference voltage V _s , the output voltage V _{out_com} of the gate voltage control circuit 20 becomes V _g1 in order to maintain the gain of the high frequency power amplifier 7.

Note that the output voltage V _{out_com} may be switched between two values, an arbitrary fixed voltage, and a drain voltage V _{out_d} that is an output of the _{LPF 6} applied to the drain voltage supply terminal 100 of the high-frequency power amplifier 7 described above. It may be continuously controlled with the voltage based on it. In this case, the comparator 21 inputs and outputs the drain voltage _{Vout_d} output from the _{LPF 6} (not shown).

The output voltage V _{out_com} of the gate voltage control circuit 20 is applied to the gate voltage supply terminal 101 of the high frequency power amplifier 7 as the gate voltage V _{out_g} . RF power amplifier 7, based on the gate voltage V _{Out_g} applied drain voltage V _{OUT_D} applied from LPF 6, and the gate voltage control circuit 20, amplifies the modulated wave input signal P _in. Amplified modulated wave input signal P _in is output from the output terminal 2 as a modulated wave output signal P _out.

  As described above, according to the second embodiment, the drain voltage control circuit controls the drain voltage so that the dynamic gain characteristic of the high-frequency amplification device is constant, and the gate voltage control circuit only performs drain voltage control. The gate voltage of the high frequency power amplifier is controlled so as to reduce the gain deviation that cannot be made constant. Furthermore, in the second embodiment, the gate voltage control circuit is composed of a comparator and a reference voltage, thereby linearizing the dynamic gain characteristics of the high-frequency amplifier with a simple configuration and reducing nonlinear distortion of the high-frequency amplifier. can do.

  In the second embodiment, the drain voltage control circuit and the gate voltage control circuit control the drain voltage and the gate voltage so as to make the dynamic gain characteristic of the high frequency amplifier constant, but the present invention is not limited to this, and the high frequency The drain voltage and the gate voltage may be controlled so that the dynamic phase characteristic of the amplifying device is constant. Note that the above-described high-frequency power amplifier may be configured by, for example, a class A amplifier, a class AB amplifier, a B amplifier, or a Doherty amplifier. Further, the above-described pulse width modulator may be constituted by, for example, a delta sigma modulator or a delta modulator.

Embodiment 3 FIG.
FIG. 7 is a block diagram showing the structure of the high frequency amplifier according to Embodiment 3 of the present invention. In the high frequency amplification device of FIG. 7, a variable attenuator 70 is inserted in series between the input terminal 1 and the high frequency power amplifier 7. Further, there is no voltage control circuit for the gate voltage supply terminal of the high-frequency power amplifier 7, and a drain voltage control circuit 40 having a configuration different from that of the above-described embodiment is provided for the drain voltage supply terminal 100 of the high-frequency power amplifier 7. In addition, a variable gain device 71 is inserted in series between the input terminal 1 and the drain voltage control circuit 40.

Next, the operation of the high frequency amplification device having the above configuration will be described. The modulated wave input signal P _in input from the input terminal 1 is branched and input to the variable gain device 71 and the variable attenuator 70. The amplitude of the input signal input to the variable gain device 71 is adjusted by the gain (amplification factor) of the variable gain device 71 and then input to the drain voltage control circuit 40. For example, the drain voltage control circuit 40 is configured as shown in FIG. 8, and outputs an output voltage signal V _{outdet_d} corresponding to the output signal from the variable gain device 71 to the pulse width modulator 4. The output voltage signal V _{outdet_d} is pulse width modulated by the pulse width modulator 4 and output to the switching amplifier 5. The pulse width modulated output voltage signal V _{outdet_d} is amplified by the switching amplifier 5 and output to the _{LPF 6} . The amplified and pulse width modulated output voltage signal V _{outdet_d} is removed of the high frequency component by the _{LPF 6} and applied to the drain voltage supply terminal 100 of the high frequency power amplifier 7 as the drain voltage. The high frequency power amplifier 7 amplifies the modulated wave input signal P _{in_PA} after passing through the variable attenuator 70 based on the voltage applied from the _{LPF 6} . The amplified modulated wave input signal P _{in_PA} is output from the output terminal 2 as the modulated wave output signal P _out .

Hereinafter, the problems of the prior art and the effects of the variable gain device 71, the variable attenuator 70, and the drain voltage control circuit 40 will be described with reference to FIGS. FIG. 9A shows the relationship (input / output characteristics) between the modulated wave instantaneous input signal P in — _PA to the high frequency power amplifier 7 and the output voltage signal V _{outdet — d} of the drain voltage control circuit 40. In FIG. 9A, the horizontal axis represents the modulated wave instantaneous input signal P _{in_PA} , and the vertical axis represents the output voltage signal V _{outdet_d} . A broken line indicates input / output characteristics necessary for linearizing the dynamic gain characteristics of the high-frequency amplifier, and a solid line indicates input / output characteristics when the drain voltage control circuit 40 is configured by a circuit as shown in FIG. ing. FIG. 9A shows the case where the lower limit voltage V _min and the upper limit voltage V _max are set.

FIG. 9B shows the relationship (dynamic gain characteristics) between the modulated wave instantaneous output signal _Pout and the dynamic gain G of the high-frequency amplifier. In FIG. 9B, the horizontal axis represents the modulated wave instantaneous output signal _Pout , and the vertical axis represents the dynamic gain G. The broken line is the dynamic gain characteristic when the drain voltage is controlled by the input / output characteristic (broken line in FIG. 9A) necessary for linearizing the dynamic gain characteristic of the high-frequency amplifier, and the solid line is, for example, The dynamic gain characteristics when the drain voltage control circuit 40 is configured with the input / output characteristics (solid line in FIG. 9A) by the circuit as shown in FIG. In FIG. 9A, the solid line input / output characteristics deviate significantly from the input / output characteristics necessary for linearizing the broken line dynamic gain characteristics. For this reason, in FIG. 9B, there is a problem that the deviation of the dynamic gain characteristic becomes large, and as a result, the amplitude distortion deteriorates.

  On the other hand, in the third embodiment of the present invention, the variable gain device 71 and the variable attenuator 70 are provided, and the drain voltage control circuit is configured as shown in FIG. 8, whereby the solid line in FIG. The gate voltage is controlled in order to reduce the gain deviation caused by.

First, FIG. 10 shows the relationship between the modulated wave instantaneous input signal P _{in_PA} to the high frequency power amplifier 7 and the output voltage signal V _{outdet_d} of the drain voltage control circuit 40 when the variable gain device 71 and the variable attenuator 70 are controlled ( Input / output characteristics). In FIG. 10, the horizontal axis indicates the modulated wave instantaneous input signal P _{in_PA} , and the vertical axis indicates the output voltage signal V _{outdet_d} . The broken line has the same input / output characteristics as the solid line in FIG. 9A. The solid line indicates that the gain (amplification factor) of the variable gain device 71 is increased by ΔG (P _in2 −P _in1 ) or is variable. This is an input / output characteristic when the attenuation amount of the attenuator 70 is increased by ΔL (P _in2 −P _in1 ). As shown in FIG. 10, by controlling the variable gain device 71 in the drain voltage control path or the variable attenuator 70 in the input signal path, the slope of the input / output characteristics can be changed. Accordingly, for example, in FIG. 9, the solid line input / output characteristics can be made closer to the broken line input / output characteristics, and as a result, the dynamic gain characteristic deviation can be reduced in FIG. 9B.

  Depending on the desired input / output characteristics, the variable gain unit 71 may be configured with a variable attenuator, and the variable attenuator 70 may be configured with a variable gain unit.

  Next, the effect when the drain voltage control circuit 40 is configured as shown in FIG. 8, for example, will be described. The drain voltage control circuit 40 includes an envelope detector 31 and a polygonal line generator 32.

The envelope detector 31 connected to the input terminal 60 side of the drain voltage control circuit 40 has the same configuration as the circuit shown in FIG. Envelope detector 31 detects the envelope component of the modulated wave input signal P _in, and outputs the polygonal line generating unit 32 as the envelope signal.

Polygonal line generating unit 32, to the other end of the resistor R _S connected to be in series with one end of the envelope signal at the output of the envelope detector 31, the DC input terminal of the operational amplifier OP, a resistor R _A1 One end of a series circuit of a diode D ₁ that conducts at a voltage V ₁ or higher, one end of a series circuit of a resistor D _A2 and a diode D ₂ that conducts at a DC voltage V ₂ or higher, and one end of a resistor R _A0 are connected to each other. ing. The output terminal of the operational amplifier OP is connected to the output terminal 61 of the drain voltage control circuit 40, and the other end of the resistor R _A0 is connected to the ground. Also, a resistor R _B0 , a resistor R _B1 , and a resistor R _B2 are connected in series so as to divide the voltage of the constant voltage source V _c between the constant voltage source V _c and the ground, and the anode of the diode D ₁ is connected to the resistor R _B0. a connection point between the resistor R _B1, the anode of the diode D ₂ is connected to a connection point between the resistance R _B1 and the resistor R _B2.

The broken line generating unit 32 outputs an output voltage signal V _{outdet_d} having a broken line characteristic by switching a diode that is turned on according to the magnitude of the envelope signal. Here, the output voltage signal V _{outdet_d} is arbitrarily set.

For example, in a polygonal line generating unit 32 shown in FIG. 8, when the size of the envelope signal is less than P _1, the diode D _1, since the D ₂ are non-conductive, the output voltage signal V _{Outdet_d} This envelope signal resistor R _s And a value divided by the resistor R _A0 .
Further, when the magnitude of the envelope signal is greater than or equal to P _{1 and} less than P ₂ , only the diode D ₁ is turned on. Therefore, the output voltage signal V _{outdet_d} has a magnitude of the envelope signal of the resistance R _s and the resistance R _A0. And a combined resistance of the resistor R _A1 (R _A0 // R _A1 ).
In addition, when the magnitude of the envelope signal is P ₂ or more, the diodes D ₁ and D ₂ are both conducted. Therefore, the output voltage signal V _{outdet_d} has the magnitude of the envelope signal of the resistance R _s and the resistance R _A0. And a combined resistance of the resistor R _A1 and the resistor R _A2 (R _A0 // R _A1 // R _A2 ).

FIG. 11A shows the relationship (input / output characteristics) between the modulated wave instantaneous input signal P in — _PA to the high frequency power amplifier and the output voltage signal V _{outdet — d} of the drain voltage control circuit 40. In FIG. 11A, the horizontal axis represents the modulated wave instantaneous input signal P _{in_PA} , and the vertical axis represents the output voltage signal V _{outdet_d} . The broken line shows the input / output characteristics when the drain voltage control circuit 40 is configured with the circuit shown in FIG. 2, and the solid line shows the input / output characteristics when the drain voltage control circuit is configured with the circuit shown in FIG. Yes. FIG. 11A shows a case where the lower limit voltage V _min and the upper limit voltage V _max are set.

FIG. 11B shows the relationship (dynamic gain characteristics) between the modulated wave instantaneous output signal _Pout and the dynamic gain G of the high-frequency amplifier. In FIG. 11B, the horizontal axis indicates the modulated wave instantaneous output signal _Pout , and the vertical axis indicates the dynamic gain G. The solid line is the dynamic gain characteristic when the drain voltage is controlled by the input / output characteristic (solid line in FIG. 11A) obtained when the drain voltage control circuit 40 is configured as shown in FIG. The dynamic gain characteristic when the drain voltage is controlled by the input / output characteristic (broken line in FIG. 11A) obtained when the drain voltage control circuit 40 is configured as shown in FIG. 2 is shown.

When the drain voltage control circuit 40 is configured as shown in FIG. 8, the broken line characteristic (different from the output voltage signal V _{outdet_d} ) according to the input power (modulated wave instantaneous input signal P _{in_PA} ) as shown by the solid line in FIG. A ₁ , A ₂ , A ₃ ) can be given. As a result, it is possible to reduce the dynamic gain deviation that occurs when the drain voltage control circuit 40 is configured by a circuit (for example, FIG. 2) that does not include a polygonal line generator as shown by the broken line in FIG. .

  In the above description, the variable attenuator 70 is disposed in front of the high frequency power amplifier 7 and the variable gain device 71 is disposed in front of the drain voltage control circuit 40, or vice versa. However, the high frequency power amplifier 7 and the drain voltage control circuit 40 are reversed. Any one of the variable attenuator 70 and the variable gain device 71 may be provided in front of any one of the above. In addition, for the drain voltage control circuit 40, one of the variable attenuator 70 and the variable gain device 71 may be provided in the subsequent stage instead of the previous stage.

The control of the gain and attenuation of the variable gain device 71 and the variable attenuator 70 receives the modulated wave input signal P _in to the high-frequency amplifying device that is input for example to the input terminal 1, according to the modulation wave input signal P _in A variable amplification / attenuation control unit (not shown) for controlling the gain and attenuation amount according to the input signal-gain / attenuation characteristics stored in advance may be provided.

  As described above, according to the third embodiment, the variable gain device or the variable attenuator provided in the drain voltage control path, the input signal path, or both are provided in order to keep the dynamic gain characteristic of the high frequency amplifier constant. Control. Further, in the third embodiment, the drain voltage control circuit controls the power supply voltage of the high-frequency power amplifier by outputting an output voltage signal so that the input / output characteristic has a broken line characteristic. Therefore, the dynamic gain characteristic of the high frequency amplifying device can be linearized to operate with high efficiency, and the nonlinear distortion of the high frequency amplifying device can be reduced.

  In the third embodiment, the variable gain device, the variable attenuator, and the drain voltage control circuit are controlled so as to make the dynamic gain characteristic of the high frequency amplification device constant. However, the present invention is not limited to this, and the high frequency amplification device. The dynamic phase characteristics may be controlled to be constant. Note that the above-described high-frequency power amplifier may be configured by, for example, a class A amplifier, a class AB amplifier, a B amplifier, or a Doherty amplifier. Further, the above-described pulse width modulator may be constituted by, for example, a delta sigma modulator or a delta modulator.

  In each embodiment, the lower limit voltage and the upper limit voltage are set for the drain voltage or the collector voltage. However, the lower limit voltage and the upper limit voltage may be set for the gate voltage or the base voltage. Alternatively, at least one of the lower limit voltage and the upper limit voltage may be set.

  Further, in the control for making the dynamic phase characteristic of the instantaneous output signal constant with respect to the instantaneous input signal of the high frequency amplifier instead of the dynamic gain characteristic of the high frequency amplifier in each embodiment, FIG. The circuit configurations of FIGS. 1, 2, 5, 7, and 8 are obtained only by changing the gain G including the gain G and the like of FIG. 6B, FIG. 9B, and FIG. Their operation and control are exactly the same.

  The drain voltage control circuit 3 constitutes a first envelope detection means, the pulse width modulator 4, the switching amplifier 5 and the LPF 6 constitute a drain voltage or collector voltage generation means, a gate voltage control circuit 8, a pulse width. The modulator 9, the switching amplifier 10, the LPF 11, or the gate voltage control circuit 20 (the gate voltage or base voltage generating means including the comparator 21 and the reference voltage source 22) constitutes the gate voltage or base voltage adjusting means, and the gate voltage control. The circuit 8 constitutes a second envelope detection means, the pulse width modulator 9, the switching amplifier 10 and the LPF 11 constitute a gate voltage or base voltage generation means, and the variable gain device 71 and the variable attenuator 70 amplify and attenuate. The drain voltage control circuit 40 that constitutes the means and includes the envelope detector 31 and the polygon generator 32 is a polygon envelope. Configure formed unit, a variable gain and attenuation control means not shown.

  Further, the present invention is not limited to the above-described embodiments, and it goes without saying that all possible combinations thereof are included.

  1, 50, 60 input terminal, 2, 51, 61 output terminal, 3, 40 drain voltage control circuit, 4, 9 pulse width modulator, 5, 10 switching amplifier, 6, 11 LPF, 7 high frequency power amplifier, 8, 20 gate voltage control circuit, 9 pulse width modulator, 21 comparator, 22 reference voltage source, 31 envelope detector, 32 broken line generator, 70 variable attenuator, 71 variable gain, 100 drain voltage or collector voltage supply terminal , 101 Gate voltage or base voltage supply terminal.

Claims (12)

A high frequency amplification device that amplifies and outputs an input high frequency input signal,
A source-grounded or emitter-grounded high-frequency power amplifier that amplifies the input signal based on an applied power supply voltage;
First envelope detection means for detecting an envelope component of the input signal;
A drain voltage or collector voltage generating means for generating a power supply voltage according to the envelope component detected by the first envelope detecting means and applying it to the drain voltage or collector voltage supply terminal of the high frequency power amplifier;
The high frequency power amplifier is configured to generate a gate voltage or a base voltage to the high frequency power amplifier according to an envelope component of the input signal so that a dynamic phase characteristic of the instantaneous output signal with respect to the instantaneous input signal of the high frequency amplifier is constant. A gate voltage or base voltage adjusting means applied to a gate voltage or base voltage supply terminal to which the input signal is also input,
A high frequency amplifying apparatus comprising: The gate voltage or base voltage adjusting means is
Second envelope detection means for detecting an envelope component of the input signal;
Gate voltage or base voltage generating means for generating and applying a gate voltage or base voltage according to the envelope component detected by the second envelope detecting means;
The high-frequency amplification device according to claim 1, comprising: The gate voltage or base voltage adjusting means is
According to the comparison between the envelope component detected by the first envelope detection means in the comparator and the predetermined reference signal, the voltage value of the gate voltage or the base voltage is calculated when the envelope component is equal to or higher than the predetermined reference signal. 2. The high frequency amplifier according to claim 1, further comprising a gate voltage or base voltage generating means that generates and applies the voltage by lowering.   The gate voltage or base voltage generating means generates a relatively low gate voltage or base voltage when the envelope component is greater than or equal to the predetermined reference signal, and relatively when the envelope component is smaller than the predetermined reference signal. 4. The high frequency amplifier according to claim 3, wherein a high gate voltage or base voltage is generated.   A gate voltage or base voltage generating means generates a gate voltage or base voltage having a relatively low predetermined voltage when the envelope component is equal to or higher than the predetermined reference signal, and detects when the gate voltage or base voltage is smaller than the predetermined reference signal. 4. The high frequency amplification device according to claim 3, wherein a gate voltage or a base voltage is generated in accordance with the envelope component thus generated. A high frequency amplification device that amplifies and outputs an input high frequency input signal,
A source-grounded or emitter-grounded high-frequency power amplifier that amplifies the input signal based on an applied power supply voltage;
The input signal and the drain voltage or the collector voltage input as the gate voltage or the base voltage to the high frequency power amplifier so that the dynamic gain characteristic of the instantaneous output signal with respect to the instantaneous input signal of the high frequency amplifier is constant. Variable for amplifying or attenuating the provided signal with variable gain and attenuation so that at least one of the branched input signals branched from the input signal and both are amplified and one is attenuated Amplifying / attenuating means;
An envelope detector that detects an envelope component of the branch input signal or a branch input signal amplified or attenuated by the amplifying / attenuating means, and an envelope component detected so that the dynamic gain characteristic is constant. A polygonal envelope generating means including a polygonal line generating unit that reduces in steps according to the value of the envelope component;
A drain voltage or collector voltage generating means for generating a power supply voltage according to the envelope component generated by the broken line envelope generating means and applying it to the drain voltage or collector voltage supply terminal of the high frequency power amplifier;
A high frequency amplifying apparatus comprising: 7. The high frequency amplification according to claim 6, wherein the polygonal line generating unit of the polygonal envelope generating means includes a plurality of diodes each having a series resistance and having different conduction voltages connected in parallel to an input indicating the envelope component. apparatus.   8. The high frequency amplifying apparatus according to claim 6, wherein the variable amplifying / attenuating means is provided in front of the high frequency power amplifier.   9. The high frequency amplifying apparatus according to claim 6, wherein the variable amplifying / attenuating means is provided before or after the polygonal envelope generating means.   10. The high frequency device according to claim 6, further comprising variable gain / attenuation control means for controlling the gain and attenuation amount of the variable amplification / attenuation means in accordance with an input signal to the high frequency amplification device. Amplification equipment. Control the drain voltage or collector voltage, or the drain voltage or collector voltage and the gate voltage or base voltage so that the dynamic phase characteristics of the instantaneous output signal with respect to the instantaneous input signal of the high-frequency amplifier are constant instead of the dynamic gain characteristics. The high frequency amplification device according to any one of claims 6 to 10, wherein At least one of drain voltage or collector voltage generation means and gate voltage or base voltage adjustment means, or at drain voltage or collector voltage generation means, at least one of a lower limit voltage and an upper limit voltage with respect to the drain voltage or collector voltage, gate voltage or base The high-frequency amplifier according to any one of claims 1 to 11, wherein at least one of a lower limit voltage and an upper limit voltage is set for the voltage.

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