JPH08256018A - Power consumption control circuit for high-frequency linear amplifier - Google Patents

Abstract

PURPOSE: To provide the power consumption control circuit for high-frequency linear amplifier having satisfactory amplification efficiency. CONSTITUTION: Mutual modulation distortion is detected from the input/output signal of a high-frequency linear amplifier part 3 by a mutual modulation distortion detection circuit composed of couplers 2 and 4, distributors 7 and 10, detectors 6 and 10, delay line 8, synthesizer 13 and control part 16 or the like. Corresponding to a signal based on the state of mutual modulation distortion outputted from the control part 16, a bias circuit part 9 controls the level of a drain current at the high-frequency linear amplifier part 3. Since bias setting is performed to the high-frequency linear amplifier part 3 corresponding to the level of mutual modulation distortion, reactive power is reduced and high- efficiency high-frequency linear amplification can be loaded. Besides, the temperature increase of the amplifier can be managed/suppressed without subordinately providing any temperature detector.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a power consumption control circuit for a high frequency linear amplifier, and more particularly to a power consumption control circuit for a high frequency linear amplifier for reducing the power consumption of a common amplifier for simultaneously amplifying a plurality of carriers.

[0002]

2. Description of the Related Art Conventionally, there is JP-A-56-69907 as a general device for the purpose of reducing this kind of power consumption. The conventional example 1 is configured to detect the output of the linear amplifier and control the bias of the amplifier. This device is shown in Figure 1.
As shown in FIG. 1, the radio wave is received by the antenna 31, amplified by the linear amplifier 32 with a constant gain, and then supplied to the output antenna 33. On the other hand, a part of the output is detected by a detection circuit 34 formed of a diode or the like, and this output is added to a comparison circuit 35 formed of a differential amplifier circuit or the like and compared with a reference level, and a linear output is obtained by the output. The bias value of the bias circuit 36 connected between the emitter and base of the transistor of the amplifier 32 is continuously changed, and the collector current of the transistor is controlled so that the intermodulation distortion does not become large.

This is to control the current consumption within a range in which the gain does not change depending on the number of multi-wave inputs and the size thereof. In the device for reducing the power consumption, only the output level is detected, and the bias of the amplifier is set according to the output level.

As another conventional example 2, Japanese Patent Laid-Open No. 9830/1989
There is No. 4 publication. The conventional example 2 includes a power amplifier circuit for power-amplifying an input signal, a power supply circuit for supplying a DC bias voltage to the power amplifier circuit, and a control means, and the power amplifier circuit linearizes the input signal at the best operating point. The DC bias voltage output from the power supply circuit is controlled so that the power is amplified. In this configuration, a temperature detecting thermistor is provided for temperature compensation of the power transistor.

Still another conventional example 2 is Japanese Patent Laid-Open No. 3-3.
There is a 962 publication. In the "operating point compensation circuit of the transistor linear amplifier" of the conventional example 3, a radiator temperature sensor diode is provided for temperature compensation of the transistor.

[0006]

However, the above-mentioned conventional example 1 has the following problems. The high-frequency linear amplifier 32 used as the common amplifier is often used in class A or class AB operation for improving the intermodulation distortion characteristics. Moreover, since the allowable spurious standard is determined by the Radio Law, the intermodulation distortion is often set to satisfy the spurious standard at the maximum number of carriers. For this reason, a large amount of current flows and is wasteful even when the number of carriers is small, the carrier level is low, or during idle.

Further, in each of the above-described conventional devices for reducing the power consumption and compensating the operating point of the amplifier, only the output level is detected, and the bias setting of the amplifier is set according to the output level. Is to do. For example, in Conventional Example 1, it is not possible to sufficiently cope with deterioration of intermodulation distortion due to temperature change which does not depend on the output level. Further, in order to achieve sufficient compensation including temperature change, there is a problem that a temperature detector is required as in the conventional examples 2 and 3.

It is an object of the present invention to provide a power consumption control circuit for a high frequency linear amplifier having good amplification efficiency.

[0009]

To achieve the above object, a power consumption control circuit for a high frequency linear amplifier according to the present invention comprises:
High frequency linear amplification means, intermodulation distortion detection means for detecting the level of intermodulation distortion generated by this high frequency linear amplification means, and adjusting the bias of the high frequency linear amplification means according to the level of intermodulation distortion. , And bias control means for controlling the value of the current flowing through the high frequency linear amplification means.

Further, the above intermodulation distortion detecting means has a synthesizing means for extracting a differential signal of the input / output signals of the high frequency linear amplifying means, and controls the bias control means on the basis of the magnitude of the extracted differential signal. Good to do.

Further, the power consumption control circuit for a high frequency linear amplifier of the present invention includes a high frequency linear amplifying means, a differential signal extracting means for extracting a differential signal between an input signal and an output signal of the high frequency linear amplifying means, and a differential signal. Bias control based on the control signal output by the control means, which has a control means for outputting a control signal based on the control signal and a bias control means for adjusting the bias of the high frequency linear amplification means to control the value of the current flowing through the high frequency linear amplification means. The means controls the operation of the high frequency linear amplification means.

The differential signal extracting means has two distributing means for distributing the signals, a delay line for delaying the signals and a combining means for combining the signals, and two input signals and two output signals are provided. It is preferable that each of the distribution means distributes the distributed input signal, the delayed input signal is delayed by the delay line, and the synthesizing means detects a differential signal between the delayed input signal and the distributed output signal.

[0013]

Therefore, according to the power consumption control circuit of the high frequency linear amplifier of the present invention, the level of the intermodulation distortion generated by the high frequency linear amplification is detected, and the high frequency is detected according to the level of the intermodulation distortion. The bias in the linear amplification is adjusted to control the current value flowing in the high frequency linear amplification means. Therefore, the bias amount for high frequency linear amplification is maintained optimally,
Intermodulation distortion and reactive power consumption are reduced.

[0014]

Embodiments of the power consumption control circuit for a high frequency linear amplifier according to the present invention will now be described in detail with reference to the accompanying drawings. 1 to 10, there is shown an embodiment of a power consumption control circuit for a high frequency linear amplifier according to the present invention. 1 is a block diagram showing an embodiment, FIGS. 2 to 6 are vectors in the main components of FIG. 1, FIG. 7 is an example of input / output characteristics of GaAs-FET, and FIGS. 8 to 10 are intermodulation distortion of GaAs-FET. It is a figure showing each characteristic example.

The power consumption control circuit of the high frequency linear amplifier shown in FIG. 1 has an RF input terminal 1 which is an input / output terminal for an RF signal.
Further, it has an RF output terminal 5, a first coupler 2 and a second coupler 4 for extracting an RF carrier connected between these input / output terminals, and a high frequency linear amplification section 3 for amplifying a signal. Further, a first distributor 7 for separating / dividing a signal,
Second distributor 10 and combiner 13, R for combining signals
A first detector 6, which detects the signal by detecting the F carrier,
The second detector 15 and the third detector 14, the attenuator 11 for attenuating the signal, the phase shifter 12 for rotating the phase of the RF signal by 180 degrees, the delay line 8 for delaying the signal, and the desired operating point are set. The bias circuit 9 and the control unit 16 are included in the configuration.

The operation of the power consumption control circuit of the high frequency linear amplifier configured as described above will be described with reference to FIG.
The RF signal input from the RF input terminal 1 passes through the first coupler 2, is amplified by the high frequency linear amplification unit 3, passes through the second coupler 4, and is then output from the RF output terminal 5. In the process of amplifying the RF signal, the gain of the high frequency linear amplification unit 3 is obtained by the following procedure.

The RF carrier entering the high-frequency linear amplification unit 3 is taken out by the first coupler 2, distributed by the first distributor 7, and then detected by the first detector 6, and the input level of the amplification unit is detected. Is input to the control unit 16. Similarly, the RF carrier amplified by the high-frequency linear amplification unit 3 is taken out from the second coupler 4 and distributed by the second distributor 10, and then the second carrier
The signal is detected by the detector 15 and input to the control unit 16 as the output level of the amplification unit. The control unit 16 compares the input level entering the amplification unit with the output level amplified by the amplification unit to obtain the gain of the high frequency linear amplification unit 3.

The process of extracting only the intermodulation distortion generated in the amplification in the high frequency linear amplification section 3 will be described with reference to FIG.
Also, description will be made below with reference to FIGS. 2 to 6
Shows a vector diagram in which the RF carrier has two waves.
The length of the vector in these figures indicates the RF level, and the direction indicates the phase.

The signal shown in FIG. 2 is another RF signal distributed by the aforementioned first distributor 7, and this signal is input to one input of the combiner 13 through the delay line 8. Further, to the other input of the synthesizer 13, the RF signal distributed by the second distributor 10 shown in FIG. 3 is leveled by the attenuator 11 to be in the state of FIG. The phase of the RF signal is rotated by 180 degrees by the device 12 to be in the state shown in FIG.

Generally, in the amplifier, the phase of the RF signal is rotated and a time delay is caused. Therefore, in order to match the phase and delay time of the two inputs of the combiner 13, correction is performed by the delay line 8. The difference signal between these two input signals is extracted in the combiner 13. This difference signal is
It is a distortion signal generated in the amplification process in the high frequency linear amplification unit 3. From the output from the combiner 13, only the intermodulation distortion component shown in FIG. 6 is extracted. The intermodulation distortion component is detected by the third detector 14 and input to the controller 16. The control unit 16 monitors the intermodulation distortion level and sets the bias of the amplifier according to the state of the intermodulation distortion level.

The following characteristics are used to set the bias.
FIG. 7 shows the input / output characteristics of a given GaAs-FET. Generally, transistors and FETs have the input / output characteristics as shown in FIG. 7 depending on the difference in the current flowing through the device. In the figure, symbols a and b indicate input / output characteristics, symbols c and d indicate intermodulation distortion characteristics, and symbols e and f indicate intercept points. Furthermore, the symbols a, c, e
Indicates the case of drain current 5A, and b, d, f indicate the case of drain current 3A. From this, it is understood that the input / output gain does not change even if the drain current is changed, but the saturation level and the intermodulation distortion are improved as the drain current is increased.

As an example, FIGS. 8 to 10 show how intermodulation distortion occurs when the number of carriers is increased or decreased. For example, FIG. 8 shows a case where the drain current has a spectrum of 2 carriers at 3 A, and FIG. 9 shows a case where the carrier current is increased to 4 carriers. As shown in FIG. 9, the intermodulation distortion deteriorates. Therefore, when the drain current is increased to 5 A and the saturation power is increased, the intermodulation distortion characteristic is improved as shown in FIG.

By utilizing this characteristic, when there is a large amount of distortion, the bias circuit section 9 is controlled so that a large amount of current flows.
Further, when the distortion is small, control is performed to reduce the current.

As described above, in the power consumption control circuit of the high frequency linear amplification circuit according to the present embodiment, the current flowing through the transistor or FET is not controlled only by looking at the output level, but the actual intermodulation distortion amount is used. To control,
It is possible to cope with fluctuations in the intermodulation distortion amount that do not depend on the output level. When this is used in the common amplifier, the current consumption can be suppressed when the number of carriers is small or when the output power is low. Therefore, downsizing of equipment and installation space, reduction of capacity of uninterruptible equipment, extension of life of equipment,
It has advantages such as low heat generation.

Although the above-mentioned embodiment is a preferred embodiment of the present invention, the present invention is not limited to this, and various modifications can be made without departing from the gist of the present invention.

[0026]

As is apparent from the above description, the power consumption control circuit of the high frequency linear amplifier of the present invention detects the level of the intermodulation distortion generated by the high frequency linear amplification and detects the level of the intermodulation distortion. The bias in the high-frequency linear amplification is adjusted according to the frequency, and the current value flowing through the high-frequency linear amplification means is controlled. Therefore, the bias amount of the high frequency linear amplification is optimally maintained, the amount of reactive power consumption is reduced, and the power consumption of the high frequency linear amplifier is optimally controlled. By controlling / suppressing the power consumption, it becomes possible to perform secondary monitoring of the temperature rise of the amplifier without providing a temperature detecting means.

[Brief description of drawings]

FIG. 1 is a block diagram showing an embodiment of a power consumption control circuit of a high frequency linear amplifier according to the present invention.

FIG. 2 is a vector diagram showing an RF carrier after passing through a delay line 8 in FIG.

3 is a vector diagram showing the RF carrier after passing through the distributor 10 of FIG. 1. FIG.

4 is a vector diagram showing the RF carrier after passing through the attenuator 11 of FIG. 1. FIG.

5 is a vector diagram showing the RF carrier after passing through the phase shifter 12 of FIG. 1. FIG.

6 is a vector diagram showing the RF carrier after passing through the combiner 13 of FIG. 1. FIG.

FIG. 7 is a diagram showing input / output characteristics of a predetermined GaAs-FET.

FIG. 8: Intermodulation distortion characteristics of a given GaAs-FET (2
It is a figure showing the case of drain current 3A with a carrier.

FIG. 9: Intermodulation distortion characteristics (4 of a given GaAs-FET)
It is a figure showing the case of drain current 3A with a carrier.

FIG. 10 is a diagram showing the intermodulation distortion characteristics of a predetermined GaAs-FET (when the carrier current is 4 A and the drain current is 5 A).

FIG. 11 is a block diagram showing a configuration example of a power consumption control circuit of a conventional high frequency linear amplifier.

[Explanation of symbols]

 1 RF input terminal 2 Coupler 3 High frequency linear amplification section 4 Coupler 5 RF output terminal 6 Detector 7 Distributor 8 Delay line 9 Bias circuit section 10 Distributor 11 Attenuator 12 Phaser 13 Combiner 14, 15 Detector 16 Control group

Claims (4)

[Claims] 1. A high-frequency linear amplification means, an intermodulation distortion detection means for detecting a level of intermodulation distortion generated by the high-frequency linear amplification means, and the high-frequency straight line according to the level of the intermodulation distortion. A power consumption control circuit for a high-frequency linear amplifier, comprising: a bias control unit that adjusts a bias of the amplification unit and controls a current value flowing in the high-frequency linear amplification unit. 2. The intermodulation distortion detecting means has a synthesizing means for extracting a differential signal between input and output signals of the high frequency linear amplifying means, and the bias control means is controlled based on the magnitude of the extracted differential signal. It controls, It is characterized by the above-mentioned.
A power consumption control circuit for the high-frequency linear amplifier described. 3. A high frequency linear amplification means, a differential signal extraction means for extracting a differential signal between an input signal and an output signal of the high frequency linear amplification means, a control means for outputting a control signal based on the differential signal, and the high frequency. A bias control means for adjusting the bias of the linear amplification means and controlling the value of the current flowing through the high frequency linear amplification means, wherein the bias control means controls the high frequency linear amplification means based on a control signal output from the control means. A power consumption control circuit for a high-frequency linear amplifier characterized by controlling operation. 4. The differential signal extracting means has two distributing means for distributing signals, a delay line for delaying the signals, and a combining means for combining the signals, and the input signal and the output signal are The two distributing means respectively distribute, the distributed input signal is delayed by the delay line, and the combining means calculates the difference signal between the delayed input signal and the distributed output signal. The power consumption control circuit for a high frequency linear amplifier according to claim 3, wherein the power consumption control circuit detects the power consumption.