JP2000101663A - Device and method for amplifying high frequency power and high frequency transmitter - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a high frequency power amplifying device with a linear compensation function with circuit constitution for stably operating by reducing a DC offset error required for increasing a linearity compensation improving quantity. SOLUTION: The device is provided with base band adders 1, 2 adding input I, Q signals and feedback I, Q signals, quadrature modulator 3 modulating output I, Q signals from the base band adder to RF signals, a high frequency power amplifier 4 amplifying the RF signal, a coupler 5 fetching a part of the RF signal obtained by amplifying, a quadrature demodulator 6 demodulating the partial signal to output the feedback I, Q signals, variable shifters 7, 8 optionally shifting the phases of the feedback I, Q signals, opening/closing switches 9, 10 for open/close-connecting the output of the variable shifter and the input of the base band adder and a phase detector 11 detecting a phase difference between the input I, Q signals and the output of a variable phase shifter to adjust the variable phase shifter. The phase detector adjusts the variable phase shifter by inverting a phase between the input I, Q signals and the feedback I, Q signals by 180 deg. when the opening/closing switch is open.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a high-frequency power amplifier, amplifying method, and a high-frequency transmitter having a function of compensating for nonlinear distortion of a high-frequency power amplifier used for a linear transmitter using, for example, multilevel quadrature modulation.

[0002]

2. Description of the Related Art In a linear transmitter for amplifying a multilevel quadrature modulated signal to a constant power, a negative feedback compensation circuit is used to compensate for non-linear distortion generated in a power amplifier.
The circuit shown in FIG. 6 is a linear compensation circuit called a Cartesian loop in one example.

This Cartesian loop linear compensation circuit decomposes a high-frequency signal into orthogonal I and Q baseband signals, and converts the obtained feedback I and Q signals to a phase of 180 degrees with respect to the input I and Q signals. This is a circuit that obtains linear compensation by inverting each other and independently adding the I signal and the Q signal. This circuit is frequently used because its circuit configuration is easy.

In FIG. 6, orthogonal I and Q signals are input to baseband adders 71 and 72, respectively. Each baseband signal output from the baseband adders 71 and 72 is input to a quadrature modulator 73. And is modulated into an RF signal.

After this RF signal is amplified by a power amplifier (PA) 74, a part of the output signal is taken out by a combiner 75, demodulated by a quadrature demodulator 76, and the I signal and Q which are feedback baseband signals are output. The signal is input to the baseband adders 71 and 72.

As described above, the feedback baseband signal is phase-inverted by 180 degrees with respect to the input baseband signal and added, so that the nonlinear distortion of the power amplifier 74 can be reduced.

[0007]

In a high frequency power amplifier having a linear compensation function, a transmission output signal is quadrature-demodulated by a feedback circuit in order to linearly compensate nonlinear distortion of a power amplifier or the like in a transmission circuit. It is required to obtain an I signal and a Q signal containing a distortion component to an adjacent channel, and to realize a linear compensation that has a large improvement and operates stably.

SUMMARY OF THE INVENTION The present invention has been made to solve such a conventional problem. A circuit for linearly compensating for nonlinear distortion generated in a transmission system is compatible with a recent complicated communication protocol and has a linear compensation function. It is an object of the present invention to provide a high-frequency power amplifying device, amplifying method, and a high-frequency transmitting device having a linear compensation function having a circuit configuration for stably operating by reducing a DC offset error necessary for increasing an improvement amount. .

[0009]

A high frequency power amplifier according to the present invention comprises a baseband adder to which orthogonal input I and Q signals are respectively inputted, and an I signal and a Q signal outputted from the baseband adder. A quadrature modulator that modulates an RF signal, a high-frequency power amplifier that amplifies the RF signal, and a coupler that extracts a part of the amplified RF signal,
A quadrature demodulator for demodulating a part of the extracted signals and outputting orthogonal feedback I and Q signals;
A variable phase shifter for arbitrarily shifting the phase of a signal; an open / close switch for opening and closing the output of the variable phase shifter and the input of the baseband adder; and a phase difference between the input I and Q signals and the output of the variable phase shifter And a phase detector for adjusting the variable phase shifter, wherein the phase between the input I signal and the Q signal and the feedback I signal and the Q signal is inverted by 180 degrees when the open / close switch is open. The variable phase shifter is adjusted as described above.

According to the present invention, a circuit for linearly compensating for non-linear distortion generated in a transmission system is made compatible with a recent complicated communication protocol, and a DC offset error required for increasing a linear compensation improvement amount is reduced. As a result, a high-frequency power amplifying device having a linear compensation function and a circuit configuration for operating stably can be obtained.

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS A high-frequency power amplifier according to a first aspect of the present invention comprises a baseband adder to which orthogonal input I and Q signals are respectively input, and an I-output from the baseband adder. A quadrature modulator that modulates a signal and a Q signal into an RF signal, a high-frequency power amplifier that amplifies the RF signal, a coupler that extracts a part of the amplified RF signal, and a demodulator that demodulates a part of the extracted signal. A quadrature demodulator that outputs orthogonal feedback I and Q signals, a variable phase shifter that arbitrarily shifts the phases of the feedback I and Q signals, and an open / close connection between the output of the variable phase shifter and the input of the baseband adder And a phase detector for detecting a phase difference between the input I signal and the Q signal and the output of the variable phase shifter and adjusting the variable phase shifter. The phase detector detects the input I signal when the open / close switch is open. Signal Phase between the fine Q signal and the feedback I and Q signals is to adjust the variable phase shifter to invert 180 degrees.

According to the present invention, by opening and closing the open / close switch, it is possible to suppress the phase error between the input I and Q signals and the feedback I and Q signals in the baseband adder.

[0013] The high-frequency power amplifier according to claim 2 is
According to the first aspect of the present invention, the input I signal and Q signal and the feedback I signal and Q signal input to the phase detector are converted into digital signals, respectively, and the phase detector converts the variable phase shifter by digital processing. The high-frequency power amplifier according to claim 1, wherein adjustment is performed.

According to the present invention, the open / close switch is opened and closed by digital processing using an A / D converter, so that the phase error between the input I signal and Q signal and the feedback I signal and Q signal in the baseband adder is obtained. Can be suppressed.

[0015] The high-frequency power amplifying device according to claim 3 is
2. A temperature detecting circuit for detecting a temperature of a high-frequency power amplifier, a voltage detecting circuit for detecting one or both of a power supply voltage and a non-operating time of the high-frequency power amplifier, and a temperature detecting circuit. And an initial table for determining an initial value of the variable phase shifter based on the temperature data from the controller and the voltage data from the voltage detection circuit.

According to the present invention, the temperature and voltage are detected by using the temperature detection circuit and the voltage detection circuit, and an initial table corresponding to the detected values is provided. This has the effect that the initial variable amount of the phase shifter can be determined.

A high-frequency power amplifier according to claim 4 is
According to the third aspect of the present invention, a representative characteristic of the high-frequency power amplifier is obtained, and an approximate function is obtained by representing the representative characteristic by temperature data detected by the temperature detection circuit and voltage data detected by the voltage detection circuit. The initial table is configured by using this.

According to the present invention, the temperature and the voltage are detected by using the temperature detection circuit and the voltage detection circuit, and the initial table represented by the approximate function corresponding to the detected value is provided, so that the feedback at the time of power-on or the like is provided. This has the effect that the initial variable amount of the variable phase shifter can be determined by calculation when there is no data.

A high-frequency power amplifier according to claim 5 is
According to a fourth aspect of the present invention, the coefficient of the approximate function is updated using a forgetting coefficient based on the actually measured data.

According to the present invention, since the approximate function for calculating the initial variable amount of the variable phase shifter can be updated, it has an effect that it can cope with aging of the high frequency power amplifier and the like.

According to a sixth aspect of the present invention, there is provided a high-frequency power amplifying apparatus,
A linearizer that generates an inverse characteristic that cancels nonlinear distortion of a high-frequency power amplifier with respect to orthogonal input I and Q signals; a quadrature modulator that modulates I and Q signals output from the linearizer into an RF signal; A high-frequency power amplifier that amplifies signals, a coupler that extracts some of the signals obtained by amplification, a high-frequency switch that controls conduction or non-conduction of some signals, and a signal that demodulates signals that have passed through the high-frequency switches A quadrature demodulator that outputs orthogonal feedback I and Q signals, compares the input I and Q signals with the feedback I and Q signals, and feeds back error information to the linearizer so that the feedback signal is the same as the input signal. And a baseband signal comparator.

According to the present invention, the input I signal and the Q signal are compared with the feedback I signal and the Q signal, and the error information is fed back to the linearizer so that the feedback signal becomes the same as the input signal.

[0023] The high-frequency power amplifying device according to claim 7 is
In the invention according to claim 6, the baseband signal comparator detects the DC offset of the feedback system by opening the high-frequency on / off switch at times other than the burst transmission, and detects the known signal included in the burst frame during the burst transmission. To detect the entire DC offset from the input I signal and Q signal and the feedback I signal and Q signal,
The offset is obtained and fed back to the linearizer as an error.

According to the present invention, the DC offset of the transmission system is obtained by calculation by detecting the entire DC offset by the baseband signal comparator, and the operation is fed back to the linearizer as an error.

The high-frequency power amplifier according to claim 8 is
In the invention according to claim 6, the baseband signal comparator replaces a frame composed of a fixed bit interval with a burst frame during continuous transmission, and when measuring a DC offset of a receiving system, an error to the linearizer during transmission is measured. The feedback of information is temporarily stopped, and the measurement is performed with the high-frequency open / close switch opened.

According to the present invention, the DC offset of the transmission system is obtained by calculation by detecting the entire DC offset by the baseband signal comparator, and the operation is fed back to the linearizer as an error.

The high-frequency power amplifier according to claim 9 is
A linearizer that generates an inverse characteristic that cancels nonlinear distortion of a high-frequency power amplifier with respect to orthogonal input I and Q signals; a quadrature modulator that modulates I and Q signals output from the linearizer into an RF signal; A high-frequency gain variable device and a high-frequency power amplifier for amplifying the signal, and a coupler for extracting a part of the amplified output signal;
A quadrature demodulator that demodulates some of the extracted signals to output orthogonal feedback I and Q signals and feeds them back to the linearizer, a power detector that measures output power from the extracted signals, and a high-frequency power A voltage detection circuit that detects the power supply voltage of the amplifier, a temperature detection circuit that detects the temperature of the high-frequency power amplifier, and a gain control circuit that controls the gain of the high-frequency gain variable device based on each information of the output power, the power supply voltage, and the temperature. The gain control circuit is configured such that the output power becomes a set value of the power detector within a control range of the high-frequency gain variable device set in advance based on the information of the power supply voltage and the temperature. Is controlled to be optimal within the control range.

According to the present invention, the output saturation power of the high-frequency power amplifier is reduced when the power supply of the high-frequency power amplifier is lowered or becomes high temperature. This has the effect that compensation can be prevented from becoming unstable.

According to a tenth aspect of the present invention, there is provided a method for amplifying a high-frequency power, wherein an I signal and a Q signal obtained by adding orthogonal input I and Q signals and a feedback I signal and a Q signal by a baseband adder. Is modulated into an RF signal by a quadrature modulator, the RF signal is amplified by a high-frequency power amplifier and output as an output signal, a part of the output signal is taken out, and demodulated into a quadrature feedback I signal and Q signal by a quadrature demodulator, The phase of the feedback I signal and Q signal is 1 with respect to the input I signal and Q signal.
The open / close switch provided between the baseband adder and the variable phase shifter is opened so that the variable phase shifter is inverted by 80 degrees to adjust the variable phase shifter, thereby reducing the nonlinear distortion of the high frequency power amplifier.

According to the present invention, by opening and closing the open / close switch, it is possible to suppress the phase error between the input I signal and Q signal and the feedback I signal and Q signal in the baseband adder.

In the high frequency power amplifying method according to the present invention, a linearizer generates an inverse characteristic for canceling the nonlinear distortion of the high frequency power amplifier with respect to the orthogonal input I signal and Q signal, and outputs the I signal output from the linearizer.
The signal and the Q signal are modulated into an RF signal by a quadrature modulator, and R
The F signal is amplified by a high-frequency power amplifier and output as an output signal. A part of the output signal is extracted and demodulated by a quadrature demodulator into orthogonal I and Q signals, and the input I signal, Q signal and feedback I signal And the Q signal are compared by a baseband signal comparator, and error information is fed back to the linearizer so that the feedback signal becomes the same as the input signal, thereby reducing nonlinear distortion of the high-frequency power amplifier.

According to the present invention, the input I signal and the Q signal are compared with the feedback I signal and the Q signal, and the error information is fed back to the linearizer so that the feedback signal becomes the same as the input signal.

According to a twelfth aspect of the present invention, a linearizer generates inverse characteristics such that the nonlinear distortion of the high-frequency power amplifier is canceled with respect to the orthogonal input I signal and Q signal, and outputs the I signal output from the linearizer.
The signal and the Q signal are modulated into an RF signal by a quadrature modulator, and R
The F signal is amplified by the high-frequency gain variable device and the high-frequency power amplifier, and a part of the amplified output signal is demodulated into orthogonal I and Q signals by the quadrature demodulator and fed back to the linearizer. Measure the output power with a power detector,
The power supply voltage of the high-frequency power amplifier is detected by a voltage detection circuit,
The temperature of the high-frequency power amplifier is detected by the temperature detection circuit, and the output power becomes the set value of the power detector within the control range of the high-frequency gain variable device set in advance based on the information of the power supply voltage and the temperature. In this manner, the high-frequency gain variable device is controlled so as to be optimal within the control range, and the nonlinear distortion of the high-frequency power amplifier is reduced.

According to the present invention, the output saturation power of the high-frequency power amplifier is reduced when the power supply of the high-frequency power amplifier is lowered or the temperature becomes high. This has the effect of preventing the compensation from becoming unstable.

A high-frequency transmitting apparatus according to a thirteenth aspect includes the high-frequency power amplifying apparatus according to any one of the first to ninth aspects.

According to the present invention, the linear compensation improvement amount of a circuit for linearly compensating for nonlinear distortion generated in a transmission system is increased,
A high-frequency transmitter including a high-frequency power amplifier capable of performing a stable operation is obtained.

Hereinafter, an embodiment of the present invention will be described with reference to FIG.
This will be described with reference to FIG.

(First Embodiment) FIG. 1 is a block diagram showing a configuration of a high-frequency power amplifier according to a first embodiment of the present invention.

In the present embodiment, baseband adders 1 and 2 to which orthogonal input I baseband signals and Q baseband signals are input, and I and Q signals output from baseband adders 1 and 2 Modulator 3 that modulates the RF signal into an RF signal, a high-frequency power amplifier (PA) 4 that amplifies the RF signal, a coupler 5 that extracts a part of the amplified output signal, and a part of the extracted signal. A quadrature demodulator 6 for demodulating and outputting orthogonal feedback I and Q signals; variable phase shifters 7 and 8 for arbitrarily shifting the phases of the feedback I and Q signals; and variable phase shifters 7 and 8 Open / close switches 9 and 10 for opening and closing the connection between the output and the baseband adders 1 and 2, and detecting the phase difference between the input I and Q signals and the outputs of the variable phase shifters 7 and 8 to detect 8 for adjusting phase detector 1 Provided with a door.

In this configuration, the input I baseband signal and the Q baseband signal are input to baseband adders 1 and 2 and phase detector 11, respectively, and both signals output from baseband adders 1 and 2 are orthogonal. Modulator 3 uses R
Modulated to F signal.

The RF signal is amplified by a high-frequency power amplifier (PA) 4, a part of the output signal is taken out by a coupler 5, and demodulated by a quadrature demodulator 6 into orthogonal feedback I and Q signals. The signals pass through independent variable phase shifters 7 and 8 and are input to open / close switches 9 and 10 and a phase detector 11.

At this time, the phase detector 11 opens (turns off) the two open / close switches 9 and 10 and outputs the input I signal and the Q signal.
The variable phase shifters 7 and 8 are adjusted so that the phase of the signal and the feedback I signal and the Q signal are inverted by 180 degrees.

As described above, according to the present embodiment, by opening and closing the open / close switches 9 and 10, the input I signal and the Q signal in the baseband adders 1 and 2 and the feedback I
The phase error between the signal and the Q signal can be suppressed.

(Embodiment 2) FIG. 2 is a block diagram showing a configuration of an embodiment 2 of a high frequency power amplifier according to the present invention. In the figure, the same components as those in the first embodiment are denoted by the same reference numerals and described.

In this embodiment, A / D converters 21 and 22 for converting input I and Q signals, which are analog signals, into digital signals and inputting them to the phase detector 11, respectively.
A / D converters 23 and 2 which convert the feedback I signal and Q signal into digital signals and input to digital phase detector 11, respectively
4 has the same configuration as that of the above-described first embodiment, except that the fourth embodiment is newly provided.

In this configuration, orthogonal input I and Q signals are input to baseband adders 1 and 2, respectively, and are simultaneously converted into digital signals by A / D converters 21 and 22, and output to phase detector 11. Is entered.

Each signal output from the baseband adders 1 and 2 is modulated into an RF signal by the quadrature modulator 3, amplified by the high-frequency power amplifier (PA) 4, and partially output by the coupler 5. Are taken out, and the orthogonal feedback I
The signal is demodulated into a signal and a Q signal, passes through independent variable phase shifters 7 and 8, one is input to baseband adders 1 and 2 through on / off switches 9 and 10, and the other is A / A
The signals are converted into digital signals by the D converters 23 and 24 and input to the phase detector 11.

At this time, the phase detector 11 opens (turns off) the two open / close switches 9 and 10 and outputs the input I signal and the Q signal.
The variable phase shifters 7 and 8 are adjusted by digital processing so that the phase of the signal, the feedback I signal, and the Q signal are inverted by 180 degrees.

As described above, according to the present embodiment, A
By digital processing using the / D converters 21 to 24,
By opening and closing the open / close switches 9, 10, the input I signal and the Q signal in the baseband adders 1, 2 and the feedback I
The phase error between the signal and the Q signal can be suppressed.

(Embodiment 3) FIG. 3 is a block diagram showing a configuration of an embodiment 3 of a high frequency power amplifier according to the present invention. In the figure, the same components as those in the first embodiment are denoted by the same reference numerals and described.

In this embodiment, a high-frequency power amplifier (P
A) Except that a voltage detection circuit 31 for detecting a power supply voltage, a temperature detection circuit 32 for detecting a temperature, and an initial table 33 for determining an initial variable amount of the variable phase shifters 7 and 8 are newly provided. It has the same configuration as the first embodiment.

In this configuration, the voltage detection circuit 31 detects the power supply voltage of the high-frequency power amplifier 4 during operation and non-operation, and the temperature detection circuit 32 detects the temperature of the high-frequency power amplifier 5 side. 5 is grasped. Then, when there is no feedback data such as when the power is turned on, the initial variable amount of the variable phase shifters 7 and 8 is determined by the initial table 33.

The initial table 33 has an approximate function using the power supply voltage obtained by the voltage detection circuit 31 and the temperature obtained by the temperature detection circuit 32 as parameters, and determines the initial variable amount of the variable phase shifters 7 and 8. You may. In this way, when there is no feedback data such as when the power is turned on, the initial variable amounts of the variable phase shifters 7 and 8 can be determined by calculation.

The initial table 33 has an approximate function using the power supply voltage obtained by the voltage detection circuit 31 and the temperature obtained by the temperature detection circuit 32 as parameters, and determines the initial variable amount of the variable phase shifters 7 and 8. At the same time, when the feedback data is obtained, the approximation function coefficient may be gradually corrected using the forgetting coefficient. By doing so, the approximate function for calculating the initial variable amount of the variable phase shifters 7 and 8 can be updated.
And so on.

(Embodiment 4) FIG. 4 is a block diagram showing a configuration of an embodiment 4 of a high frequency power amplifier according to the present invention.

In the present embodiment, a linearizer 41 to which orthogonal input I baseband signals and Q baseband signals are input, and a quadrature modulator 42 for modulating I and Q signals output from the linearizer 41 to RF signals. When,
A high frequency power amplifier (PA) 43 for amplifying an RF signal;
A coupler 44 for extracting a part of the amplified output signal;
High-frequency open / close switch 4 that opens and closes some of the extracted signals
5, a quadrature demodulator 46 that demodulates a signal passed through the high-frequency on / off switch 45 and outputs orthogonal feedback I and Q signals, compares the input I and Q signals with the feedback I and Q signals, and performs feedback. A baseband signal comparator 47 that feeds back error information to the linearizer 41 so that the signal becomes the same as the input signal is provided.

In this configuration, the input I baseband signal and the Q baseband signal are input to the linearizer 41 and the baseband signal comparator 47, respectively. Each signal output from the linearizer 41 is converted by the quadrature modulator 42 into R
Modulated to F signal.

The RF signal is supplied to a high frequency power amplifier (PA) 43
After amplifying the output signal, a part of the output signal is taken out by a coupler 44, passed through a high-frequency switch 45, and passed through a quadrature demodulator 46
Are demodulated into feedback I and Q signals orthogonal to each other, and input to the baseband signal comparator 47, respectively.

The baseband signal comparator 47 compares the input I signal and Q signal with the feedback I signal and Q signal, and adjusts the linearizer 41 so that the feedback signal becomes the same as the input signal.
To the error information.

In this case, the high-frequency on / off switch 46 is opened at times other than the burst transmission, a DC offset of the feedback system is detected, and a known signal included in a burst frame during the burst transmission is used to input the I signal. And the baseband signal comparator 47 detects the entire DC offset from the Q signal, the feedback I signal and the Q signal. Thus, the DC offset of the transmission system is obtained by calculation, and the linearizer 4
1 is fed back as error information.

Alternatively, during continuous transmission, a frame composed of a fixed bit interval is replaced with a burst frame, and when measuring the DC offset of the receiving system, feedback of error information to the linearizer 41 is temporarily stopped during transmission. The high-frequency on / off switch 45 is opened, and the input I signal and the Q signal and the feedback I signal and the Q signal are measured by using a known signal contained in the frame being transmitted.
The baseband signal comparator 47 detects the entire DC offset from the signal and calculates the DC of the transmission system by calculation.
The offset may be obtained and fed back to the linearizer 41 as error information.

As described above, according to the present embodiment, the DC of the feedback system and the transmission system can be used even during burst or continuous transmission.
An offset can be determined.

(Fifth Embodiment) FIG. 5 is a block diagram showing a configuration of a high-frequency power amplifier according to a fifth embodiment of the present invention.

In this embodiment, a linearizer 51 to which orthogonal input I baseband signals and Q baseband signals are input, and a quadrature modulator 52 for modulating I and Q signals output from linearizer 51 to RF signals. When,
A high-frequency gain varying device 53 for varying the gain of the RF signal;
A high frequency power amplifier (PA) 54 for amplifying the RF signal;
A coupler 55 for extracting a part of the amplified output signal;
A quadrature demodulator 56 that demodulates part of the extracted signal to output orthogonal feedback I and Q signals and feeds it back to the linearizer 51; and a power detector 57 that measures output power from the extracted part of the signal. A voltage detection circuit 58 for detecting the power supply voltage of the high-frequency power amplifier 54, a temperature detection circuit 59 for detecting the temperature of the high-frequency power amplifier 54,
It comprises a gain control circuit 60 for controlling the gain of the high-frequency gain variable device 53 from three pieces of information of the power supply voltage and the temperature.

In this configuration, the input I baseband signal and the Q baseband signal are input to the linearizer 51, respectively. Each signal output from the linearizer 51 is modulated by the quadrature modulator 52 into an RF signal.

The RF signal passes through a high frequency gain variable device 53 and is amplified by a high frequency power amplifier
, A part of the output signal is taken out.
Are demodulated into feedback I and Q signals orthogonal to each other and input to the linearizer 51, and the other enters the power detector 57.
The power detector 57 measures the output power and sends the measured power value to the gain control circuit 60.

The power supply voltage of the high-frequency power amplifier 54 is detected by a voltage detection circuit 58, and the temperature of the high-frequency power amplifier 54 is detected by a temperature detection circuit 59. Each value is passed to the gain control circuit 60. The gain control circuit 60 controls the gain of the high-frequency gain variable device 53 based on three pieces of information: output power, power supply voltage, and temperature.

The gain control circuit 60 adjusts the output power to the value of the power detector 57 within a preset control range of the high-frequency gain varying device 53 based on the values obtained from the voltage detection circuit 58 and the temperature detection circuit 59. Is controlled so that the high-frequency gain variable device 53 becomes optimum within the control range so that the set value becomes the set value.

As described above, according to the present embodiment, when the power of the high-frequency power amplifier 54 decreases or the temperature of the high-frequency power amplifier 54 increases, the output saturation power of the high-frequency power amplifier 54 decreases. Is controlled so that the linear compensation does not become unstable.

In the above embodiment, the input I signal and Q signal and the feedback I signal and Q signal are matched with respect to the phase. However, the same applies to the amplitude.
Further, it is more effective to perform both the phase and the amplitude simultaneously.

Further, in the above-described embodiment, direct conversion is described in RF signal processing.
Up-conversion and down-conversion may be used.

Further, if the high-frequency power amplifier according to the present invention is provided in the high-frequency transmission device, the amount of linear compensation improvement of the circuit for linearly compensating for nonlinear distortion generated in the transmission system can be increased, and stable operation can be achieved. A high-frequency transmission device is obtained.

[0073]

According to the present invention, a circuit for linearly compensating for non-linear distortion generated in a transmission system is adapted to a recent complicated communication protocol, and the linear compensation improvement amount is increased.
A high-frequency power amplifying device, an amplifying method, and a high-frequency transmitting device capable of performing a stable operation are obtained.

[Brief description of the drawings]

FIG. 1 is a block diagram showing Embodiment 1 of a high-frequency power amplifier according to the present invention.

FIG. 2 is a block diagram showing a high-frequency power amplifier according to a second embodiment of the present invention;

FIG. 3 is a block diagram showing a high-frequency power amplifier according to a third embodiment of the present invention;

FIG. 4 is a block diagram showing a high-frequency power amplifier according to a fourth embodiment of the present invention;

FIG. 5 is a block diagram showing a fifth embodiment of the high-frequency power amplifier according to the present invention;

FIG. 6 is a block diagram of a conventional high-frequency power amplifier.

[Explanation of symbols]

 1, 2 Baseband adder 3, 42, 52 Quadrature modulator 4, 43, 54 High frequency power amplifier (PA) 5, 44, 55 Combiner 6, 46, 56 Quadrature demodulator 7, 8 Variable phase shifter 9, 10 On / off switch 11 Phase detector 21, 22, 23, 24 A / D converter 31, 58 Voltage detection circuit 32, 59 Temperature detection circuit 33 Initial table 41, 51 Linearizer 45 High frequency on / off switch 47 Baseband signal comparator 53 High frequency gain Variable device 57 Power detector 60 Gain control circuit

Claims (13)

[Claims] 1. A baseband adder to which orthogonal input I and Q signals are respectively input, and an I signal and a Q output from the baseband adder
A quadrature modulator for modulating a signal into an RF signal; a high-frequency power amplifier for amplifying the RF signal; a coupler for extracting a part of the amplified RF signal; and a demodulator for demodulating the extracted part of the signal A quadrature demodulator for outputting orthogonal feedback I and Q signals; a variable phase shifter for arbitrarily shifting the phases of the feedback I and Q signals; an output of the variable phase shifter and an input of the baseband adder An open / close switch that opens and closes a connection, and a phase detector that detects a phase difference between the input I signal and Q signal and the output of the variable phase shifter and adjusts the variable phase shifter. A variable phase shifter that adjusts the phase between the input I signal and the Q signal and the feedback I signal and the Q signal by 180 degrees when the open / close switch is opened. Place. 2. The method according to claim 1, wherein the input I signal and Q signal and the feedback I signal and Q signal input to the phase detector are converted into digital signals, respectively, and the phase detector adjusts the variable phase shifter by digital processing. The high-frequency power amplifier according to claim 1, wherein: A temperature detection circuit for detecting a temperature of the high-frequency power amplifier; a voltage detection circuit for detecting one or both of a power supply voltage when the high-frequency power amplifier is operating and a non-operational time; 2. The high frequency power amplifier according to claim 1, further comprising: an initial table for determining an initial value of the variable phase shifter based on the temperature data and the voltage data from the voltage detection circuit. 4. Calculating a representative characteristic of the high-frequency power amplifier, obtaining an approximate function representing the representative characteristic by temperature data detected by a temperature detecting circuit and voltage data detected by the voltage detecting circuit, and using the approximate function. 4. The high-frequency power amplifier according to claim 3, wherein the initial table is configured by: 5. The high-frequency power amplifier according to claim 4, wherein a coefficient of the approximation function is updated using a forgetting coefficient based on the actually measured data. 6. A linearizer for generating an inverse characteristic for canceling non-linear distortion of a high-frequency power amplifier with respect to orthogonal input I and Q signals, and modulating the I and Q signals output from the linearizer into an RF signal. A quadrature modulator; a high-frequency power amplifier for amplifying the RF signal; a coupler for extracting a part of the signal obtained by the amplification; a high-frequency on / off switch for controlling conduction or non-conduction of the part of the signal; A quadrature demodulator for demodulating a signal passed through a high-frequency on / off switch and outputting orthogonal feedback I and Q signals; the input I and Q signals, and the feedback I and Q signals
And a baseband signal comparator for feeding back error information to the linearizer so that a feedback signal becomes the same as the input signal. 7. The baseband signal comparator opens a high-frequency on / off switch during a period other than burst transmission and sets a feedback D
The C offset is detected, and the entire D signal is obtained from the input I signal and the Q signal and the feedback I signal and the Q signal by using a known signal included in a burst frame during burst transmission.
7. The high-frequency power amplifier according to claim 6, wherein a C offset is detected, a DC offset of a transmission system is obtained, and the error is fed back to a linearizer as an error. 8. A baseband signal comparator replaces a frame composed of a fixed bit interval with a burst frame during continuous transmission, and feeds back error information to a linearizer during transmission when measuring a DC offset of a receiving system. 7. The high-frequency power amplifier according to claim 6, wherein the measurement is temporarily stopped and the high-frequency on / off switch is opened for measurement. 9. A linearizer for generating an inverse characteristic for canceling non-linear distortion of a high frequency power amplifier with respect to orthogonal input I and Q signals, and modulating the I and Q signals output from the linearizer into an RF signal. A quadrature modulator; a high-frequency gain variable device and a high-frequency power amplifier for amplifying the RF signal; a coupler for extracting a part of the amplified output signal; and a quadrature for demodulating the extracted part of the signal. A quadrature demodulator that outputs feedback I and Q signals to be fed back to the linearizer, a power detector that measures output power from the extracted partial signal, and a voltage that detects a power supply voltage of the high-frequency power amplifier A detection circuit, a temperature detection circuit for detecting the temperature of the high-frequency power amplifier, and the information from the output power, the power supply voltage, and the temperature. A gain control circuit for controlling the gain of the variable frequency gain device, wherein the gain control circuit outputs the output within a control range of the high frequency gain variable device set in advance based on the information of the power supply voltage and the temperature. A high-frequency power amplifying device characterized in that the high-frequency gain variable device is controlled so that power becomes an optimum value within a control range so that a value of the power detector becomes a set value. 10. An orthogonal input I signal and Q signal, a feedback I signal and a Q signal are added by a baseband adder, and the I and Q signals obtained by the addition are added to a quadrature modulator by an R modulator.
The RF signal is amplified by a high-frequency power amplifier and output as an output signal. A part of the output signal is taken out and demodulated by a quadrature demodulator into orthogonal I and Q signals. Adjusting the variable phase shifter by opening an open / close switch provided between the baseband adder and the variable phase shifter so that the phases of the signal and the Q signal are inverted by 180 degrees with respect to the input I signal and the Q signal. And a non-linear distortion of the high-frequency power amplifier is reduced. 11. A linearizer that generates an inverse characteristic for canceling nonlinear distortion of a high-frequency power amplifier with respect to orthogonal input I and Q signals, and outputs an I signal and a Q signal output from the linearizer using a quadrature modulator. The RF signal is amplified by a high-frequency power amplifier and output as an output signal. A part of the output signal is extracted and demodulated by a quadrature demodulator into orthogonal I and Q signals. Signal and Q signal and the feedback I signal and Q
A high frequency power amplification method comprising: comparing a signal with a baseband signal comparator; feeding back error information to the linearizer so that a feedback signal is the same as an input signal; and reducing nonlinear distortion of the high frequency power amplifier. . 12. A linearizer generates inverse characteristics for canceling nonlinear distortion of a high-frequency power amplifier with respect to orthogonal input I and Q signals, and outputs an I signal and a Q signal output from the linearizer to a quadrature modulator. The RF signal is amplified by a high-frequency gain variable device and a high-frequency power amplifier, and a part of the amplified output signal is demodulated into a quadrature feedback I signal and Q signal by a quadrature demodulator. Returning to the linearizer, measuring the output power of the output signal with a power detector, detecting the power supply voltage of the high-frequency power amplifier with a voltage detection circuit, detecting the temperature of the high-frequency power amplifier with a temperature detection circuit, The output power is the value of the power detector within the control range of the high-frequency gain variable device set in advance based on the information of the voltage and the temperature. RF power amplifier method characterized by controlling so as to optimize the high frequency variable gain device such that the value in the control range, thereby reducing non-linear distortion of the high frequency power amplifier. 13. A high-frequency transmitting device comprising the high-frequency power amplifying device according to claim 1. Description: