KR20010049027A - Apparatus for adaptive controlling of feed forward linear device - Google Patents

Abstract

PURPOSE: An adaptive control system of a feed-forward linear device is provided which adjusts a variable attenuator by with power detection comparison and controls a phase changer by phase detection comparison. CONSTITUTION: A feed-forward linear device includes a main amplifier(120) for amplifying the power of a signal received from the first coupler, a signal amplifier(130) for amplifying a low-power signal distributed by the first coupler without giving distortion to the signal, the first phase changer(140) for changing the phase of the signal output from the signal amplifier, and the first variable attenuator(150) for changing the magnitude of the power of the signal whose phase is changed by the first phase changer. An adaptive control system of the feed-forward linear device has a 3dB coupler and power detector(220) for detecting the power magnitude and phase information of the signals from the main amplifier and the signal amplifier to combine the detected signals with each other, and detecting the power magnitude and phase information of the signals from the main amplifier and the signal amplifier to combine the detected signals with each other again. The adaptive control system further has a power comparison adaptive controller(160) for receiving a plurality of detection signals from the 3dB coupler and power detector to control the degree of the phase change of the phase changer and the degree of the power variation of the variable attenuator, to eliminate error components in the combined signal output from the 3dB coupler and power detector.

Description

Apparatus for adaptive controlling of feed forward linear device

The present invention relates to an adaptive control device of a feedforward linearization device for reducing the nonlinearity of a high output power amplifier, and in particular, a one-to-one control of adjusting a variable attenuator by a power detection comparison and a phase shifter by a phase detection comparison is possible. The present invention relates to an adaptive control device of a feedforward linearization device suitable for the following.

1 is a block diagram of an adaptive control apparatus of a conventional feedforward linearization apparatus.

As shown therein, the first coupler 11 distributes the input signal at a constant ratio; A main amplifier 12 which amplifies the power of the signal output from the first coupler 11; A signal amplifier 13 for amplifying the low power signal distributed by the first coupler 11 without distortion; A first phase shifter (14) for changing the phase of the signal output from the signal amplifier (13); A first variable attenuator (15) for changing the power magnitude of the signal phase shifted in the first phase shifter (14); A second coupler 21 for distributing the signal output from the main amplifier 12; The power magnitude and phase information of the signal of the main amplifier 12 distributed by the second coupler 21 is detected, and the power of the signal of the signal amplifier 13 input through the variable attenuator 15. A combining and detecting section (22) for detecting magnitude and phase information; A signal removal loop adaptive control unit 16 for controlling the degree of phase change of the phase shift unit 14 and the degree of power change of the variable attenuation unit 15 according to the signal detected by the coupling and detection unit 22; A delay unit 31 for delaying the transmission time of the signal distributed by the second signal distributor 21; A distortion signal amplifying unit (32) for amplifying distortion components of the signal output from the combining and detecting unit (22); A second phase shifter 33 for changing a phase of a signal output from the distortion signal amplifier 32; A second variable attenuator (34) for changing the power of the phase shifted signal in the second phase shifter (33); The third coupler 35 outputs a signal from which the distortion component is removed by combining the signal delayed through the delay unit 31 and the signal of the variable attenuation unit 34.

Here, the signal removing loop 10 includes a first coupler 11, a main amplifier 12, a signal amplifier 13, a first phase shifter 14, and a first variable attenuator 15. And a second coupler 21, a coupling and detection unit 22, and a signal removal loop adaptive control unit 16. The distortion control loop 30 includes a second coupler 21, a coupling and detection unit 22, a delay unit 31, a distortion signal amplifier 32, a second phase shift unit 33, It consists of a 2nd variable damping part 34 and the 3rd coupler 35. As shown in FIG.

FIG. 2 is a detailed block diagram of the coupling and detection unit of FIG. 1.

As shown in the drawing, the combined signal is obtained by combining the signal of the main amplifier 12 distributed by the second coupler 21 with the signal of the signal amplifier 13 input through the variable attenuator 15. A signal combiner 23 for transmitting the distortion signal amplifier 32 to the distortion signal amplifier 32; The power combiner 23 detects power and transmits a detection signal to the signal removing loop adaptive controller 16.

FIG. 3 is a detailed block diagram of the signal rejection loop adaptive control unit in FIG. 1.

As shown therein, an A / D converter 17 for converting an analog detection signal input from the combining and detecting unit 22 into digital; A CPU 18 which receives the detection signal of the A / D converter 17 and outputs control signals for the phase shifter 14 and the variable attenuator 15; A D / A converter 19 for receiving a digital control signal from the CPU 18 and converting it into an analog signal; The memory unit 20 stores data processed by the CPU 18.

Referring to the operation of the conventional device configured as described above in detail.

First, the conventional apparatus is largely composed of a signal removal loop 10 and a distortion control loop 30.

Thus, a signal input from the signal removal loop 10 to the main amplifier 12 is partially coupled by the first coupler 11 and input to the signal amplifier 13 to be amplified.

The signal amplified by the signal amplifier 13 has the same power level as the signal coupled to the output of the main amplifier 12 by the second coupler 21, and has a first phase so as to have an opposite phase value. It is adjusted by the displacement unit 14 and the first variable attenuation unit 15 and coupled by the coupling and detection unit 22.

In addition, only the distortion component generated by the nonlinear characteristics of the main amplifier 12 is output from the coupling and detection unit 22.

In addition, the coupling and detection unit 22 detects the signal coupled from the second coupler 21 and the output signal of the signal amplifier 13 and sends the detected signal to the signal removal loop adaptation controller 16.

Then, the signal removing loop adaptive controller 16 receives the detected signal, compares the power level with the phase, and continues the first phase shifter 14 and the first variable attenuator 15 so as to have the same power level and opposite phase characteristics. Readjust.

On the other hand, the distortion control loop 30 combines the pure distortion components generated by the signal removal loop 10 to the output of the main amplifier 12 to remove the distortion components of the third coupler 35, which is the final output stage. to be.

Thus, the distortion component generated by the signal removal loop 10 is amplified by the distortion signal amplifier 32 to an amplification degree that compensates the amount of signal attenuation caused by the second and third couplers 21 and 35.

The distortion signal amplified by the distortion signal amplifier 32 is passed through the second phase shifter 33 and the second variable attenuator 34 to adjust the phase and power level.

The distortion signal whose phase and power levels are adjusted is coupled to the main amplification path by the third coupler 35 so that the signal from which the distortion component is removed appears as the final output.

However, the distortion characteristics of the power amplifier using the conventional feedforward linearization scheme play a more decisive role in the signal cancellation loop than the distortion cancellation loop, so that the accuracy of the coupling and detection unit 22 and the signal cancellation loop adaptive control unit 16 connected thereto are reduced. In the conventional coupling and detection unit 22, the phase of the signal coupled to the second coupler 21 and the distortion-free signal amplified through the signal amplifier 13 are detected. Since it is impossible to compare exactly 180 degrees of difference, the performance of the signal rejection loop is degraded. When the distortion components are combined in the third coupler 35, not only the distortion components are removed but also the signal components are affected. There was a problem that the power level of the decrease.

In addition, since the variable attenuator and phase shifter must be adjusted so that the detection value is minimized by only one power detection, the algorithm inside the processor is not only complicated, but also needs to be adjusted in real time for power detection. there was.

Accordingly, the present invention has been proposed to solve the above-mentioned conventional problems, and an object of the present invention is to control the variable attenuator by the power detection comparison and the feed forward capable of one-to-one control of the phase shift by the phase detection comparison. It is to provide an adaptive control device of the linearization device.

In order to achieve the above object, the adaptive control apparatus of the feedforward linearization apparatus according to the present invention,

A main amplifier for amplifying the power of the signal input from the first coupler, a signal amplifier for amplifying the low power signal distributed by the first coupler without distortion, and a second amplifier for changing the phase of the signal output from the signal amplifier 1. A feedforward linearization device having a first phase shifter and a first variable attenuator for varying a power magnitude of a signal phase shifted in the first phase shifter, the power amplitude of the signal of the main amplifier and the signal amplifier. And a 3 dB coupler and a power detector for detecting phase information, combining the detected signals, and then detecting and combining power magnitude and phase information of the main amplifier and the signal amplifier. The plurality of detection signals detected by the 3dB coupler and the power detector are input to control the degree of phase change of the phase shifter and the power change of the variable attenuator to remove error components of the combined signal output from the 3dB coupler and the power detector. It is characterized by the technical configuration of the power comparison adaptive control unit to control as possible.

1 is a block diagram of an adaptive control apparatus of a conventional feedforward linearization apparatus.

Figure 2 is a detailed block diagram of the coupling and detection unit in Figure 1,

FIG. 3 is a detailed block diagram of the signal removing loop adaptive controller of FIG. 1;

4 is a block diagram of an adaptive control device of a feedforward linearization device according to the present invention;

5 is a detailed block diagram of a 3 dB coupler and a power detector in FIG. 4;

FIG. 6 is a detailed block diagram of the power comparison adaptive controller of FIG.

FIG. 7 is a coordinate diagram when the phases of the third signal detector and the fourth signal detector differ from each other by 180 degrees in FIG. 5;

FIG. 8 is a coordinate diagram when the phases of the third signal detector and the fourth signal detector differ from each other by 150 degrees in FIG. 5.

Explanation of symbols on the main parts of the drawings

100: signal removal loop 110, 210, 350: coupler

120: main amplifier 130: signal amplifier

140, 330: phase shift unit 150, 340: variable attenuation unit

160: power comparison adaptive controller 220: 3dB coupler and power detector

300: distortion control loop 310: delay unit

320: distortion signal amplifier

Hereinafter, an embodiment according to the technical spirit of the adaptive control device of the feed forward linearization device of the present invention as described above is as follows.

4 is a block diagram of an adaptive control apparatus of a feedforward linearization apparatus according to the present invention.

As shown therein, the first coupler 110 distributes the input signal at a constant ratio; A main amplifier 120 for amplifying the power of the signal output from the first coupler 110; A signal amplifier 130 for amplifying the low power signal distributed by the first coupler 110 without distortion; A first phase shifter 140 for changing a phase of a signal output from the signal amplifier 130; A first variable attenuator (150) for changing a power magnitude of the signal phase shifted in the first phase shifter (140); A second coupler 210 for distributing the signal output from the main amplifier 120; Detecting the power magnitude and phase information of the signal of the signal amplifier 130, which is input through the main amplifier 120 and the first variable attenuator 150 distributed by the second coupler 210, respectively, A 3dB coupler and a power detector 220 which combines the detected signals and then detects and combines power magnitude and phase information of the main amplifier 120 and the signal amplifier 130; The plurality of detection signals detected by the 3dB coupler and the power detector 220 are input to control the degree of phase change of the first phase shifter 140 and the degree of power change of the first variable attenuator 150 to the A power comparison adaptive control unit 160 for controlling an error component of the combined signal output from the 3dB coupler and the power detector 220 to be removed; A delay unit (310) for delaying a transmission time of the signal distributed by the second signal distribution unit (210); A distortion signal amplifier 320 for amplifying distortion components of the combined signal output from the 3dB coupler and the power detector 220; A second phase shifter 330 for changing a phase of a signal output from the distortion signal amplifier 320; A second variable attenuator 340 for changing the power of the phase shifted signal in the second phase shifter 330; The third coupler 350 outputs a signal from which the distortion component is removed by combining the signal delayed through the delay unit 310 and the signal of the variable attenuation unit 340.

Here, the signal removing loop 100 includes a first coupler 110, a main amplifier 120, a signal amplifier 130, a first phase shifter 140, and a first variable attenuator 150. And a second coupler 210, a 3dB coupler and a power detector 220, and a power comparison adaptive controller 160. The distortion control loop 300 includes a second coupler 210, a 3dB coupler and a power detector 220, a delay unit 310, a distortion signal amplifier 320, and a second phase shifter 330. And a second variable attenuator 340 and a third coupler 350.

FIG. 5 is a detailed block diagram of a 3 dB coupler and a power detector in FIG. 4.

As shown in FIG. 2, the signal of the main amplifier 120 distributed by the second coupler 210 and the signal of the signal amplifier 130 input through the variable attenuator 150 are respectively received and distributed. First and second distribution unit 221 and; First and second signal detectors 226 and 227 for detecting power magnitude and phase information from the signals respectively distributed by the first and second distributors 221 and outputting first and second detection signals, respectively. Wow; A 3 dB coupler 225 for receiving, combining, and coupling the signals distributed by the first and second distributors 221; Third and fourth distribution units (223) (224) for distributing the signals coupled by the 3dB coupler (225), respectively; Third and fourth signal detectors 228 for detecting power magnitude and phase information from the signals distributed by the third and fourth distributors 223 and 224, respectively, and outputting third and fourth detection signals, respectively. 229; It is composed of a signal combiner 230 for receiving a combined signal received from the third and fourth distribution unit 223 to combine the output signal.

FIG. 6 is a detailed block diagram of the power comparison adaptive controller of FIG. 4.

As shown in the figure, an A / D converter 161 for converting the first to fourth detection signals of the analog input from the combining and detecting unit 220 into digital; Receives the first to fourth detection signals of the A / D converter 161 and uses the 3dB coupler and the power detector 220 to compare and search the power level and the phase difference between the main amplifier signal and the input signal in a one-to-one manner. A CPU 162 for outputting control signals to the phase shifter 140 and the variable attenuator 150; A D / A converter 163 for receiving a digital control signal from the CPU 162 and converting it into an analog signal; The memory unit 164 stores data processed by the CPU 162.

The CPU 162 compares the first detection signal, which is the detection signal of the main amplifier 120, with the second detection signal, which is the detection signal of the signal amplifier 130, and detects the detection value of the second detection signal. Adjust the first variable attenuator 150 to be equal to the value of the first detection signal, and adjust the first phase shifter 140 by comparing the detected value of the third and fourth detection signals. By using the same value to control the error component is removed from the combined signal output from the 3dB coupler and the power detector 220.

The operation of the adaptive control device of the feedforward linearization device according to the present invention configured as described above will be described in detail with reference to the accompanying drawings.

First, the distortion characteristics of the power amplifier using the feedforward linearization method play a more decisive role in the signal cancellation loop than the distortion cancellation loop. Therefore, the accuracy of the signal canceling combiner and the signal detector and the role of the signal cancellation loop adaptive controller connected thereto become important. However, in the conventional coupling and detection unit, it is impossible to accurately detect the phase and compare the phase difference between the signal coupled to the coupler and the distortion-free signal amplified by the signal amplifier 180 degrees. Thus, since the performance of the signal rejection loop is degraded, when the distortion components are combined in the final coupler, not only the distortion components are removed, but also the signal components are affected, resulting in a decrease in the power level of the final output.

Accordingly, in the present invention, the power detector uses the power amplifier so that the power level of the output signal of the main amplifier and the output signal of the signal amplifier have the same identity, and controls the phase difference of 180 degrees to accurately perform adaptive control of the signal removal loop.

Thus, the output signal of the main amplifier 120 is input to the first distribution unit 221 in the 3Db coupler and the power detector 220 through the second coupler 210. Then, the first signal detector 226 receives the signal distributed by the first distributor 221 and detects the power magnitude and phase information of the main amplifier 120 to output the first detection signal. The output signal of the signal amplifier 130 is input to the second divider 222 in the 3dB coupler and the power detector 220 through the first variable attenuator 150. Then, the second signal detector 227 receives the signal distributed by the second distributor 222 to detect power size and phase information of the signal amplifier 130 and output the second detection signal.

In addition, the output signal of the main amplifier 120, which is two signals input to the 3dB coupler 225 through the first and second distribution units 221 and 222, and the output signal of the signal amplifier 130 are 90 degrees out of phase. These leads or racks are coupled at the two terminals, respectively.

At this time, if the phase difference between the output signal of the main amplifier 120 and the output signal of the signal amplifier 130 is exactly 180 degrees, the condition that the signal removal can be maximized, the third and fourth signal detector 228 The voltage value detected at 229 becomes equal. However, if the phase difference between the output signal of the main amplifier 120 and the output signal of the signal amplifier 130 is not exactly 180 degrees, the power level and the fourth signal of the third detection signal detected by the third signal detector 228 A difference occurs in the power level of the fourth detection signal detected by the detector 229, indicating that the phase adjustment of the signal removal loop is not correctly performed.

Here, when the power level of the output signal of the main amplifier 120 is A1 and the phase is P1, and the power level of the output signal of the signal amplifier 130 is A2 and the phase is P2, the power of the signal outputted basically. Levels A1 and A2 are the same and have a phase difference close to 180 degrees between phases P1 and P2, as shown in Equations 1 and 2 below.

A1 = A2

P2 = P1 +/- 180

If A1 and A2 are different from each other, a difference occurs in the detected output voltages of the first and second signal detectors 226 and 227, and the CPU 162 in the power comparison adaptive control unit 160 detects the difference. do. Thus, the CPU 162 adjusts the first variable attenuation unit 150, and A1 and A2 are set to the same level again.

Further, the output signal A3_P3 of the third distribution unit 223 becomes the vector sum of A1_P1 and A2_ (P2-90), and the output signal A4_P4 of the fourth distribution unit 224 is A1_ (P1). -90) and A2∠P2.

Therefore, when the phase difference between P1 and P2 is 180 degrees with respect to the vector sum of the output signal of the main amplifier 120 and the output signal of the signal amplifier 130 in the third and fourth distribution units 223 and 224. 7 and the case where the phase difference is 150 degrees is as shown in FIG.

Thus, by adjusting the first phase shifter 140 such that the power level detected by the third signal detector 228 in the 3dB coupler and the power detector 220 and the power level detected by the fourth signal detector 229 are the same, The phase difference between the phase of the output signal of the main amplifier 120 and the output signal of the signal amplifier 130 is maintained at 180 degrees, and the error component of the combined signal output from the 3dB coupler and the power detector 220 is minimized. Will be done.

As such, the present invention enables one-to-one control of adjusting the variable attenuator by the power detection comparison and adjusting the phase shifter by the phase detection comparison to minimize error components in the final output signal.

Although the preferred embodiment of the present invention has been described above, the present invention may use various changes, modifications, and equivalents. It is clear that the present invention can be applied in the same manner by appropriately modifying the above embodiments. Accordingly, the above description does not limit the scope of the invention as defined by the limitations of the following claims.

As described above, the adaptive control device of the feedforward linearization device according to the present invention enables one-to-one control of adjusting the variable attenuator by the power detection comparison and adjusting the phase shifter by the phase detection comparison. The effect is to minimize the components.

In addition, the present invention has the effect of obtaining an output signal with a much simpler circuit implementation and minimized error components.

Claims (4)

A main amplifier for amplifying the power of the signal input from the first coupler, a signal amplifier for amplifying the low power signal distributed by the first coupler without distortion, and a second amplifier for changing the phase of the signal output from the signal amplifier A feedforward linearization device having a first phase shifter and a first variable attenuator for changing a power magnitude of a signal phase shifted in the first phase shifter, A 3 dB coupler for detecting power magnitude and phase information of the signals of the main amplifier and the signal amplifier, combining the detected signals, and then detecting and combining the power magnitude and phase information of the main amplifier and the signal amplifier; A power detector; The plurality of detection signals detected by the 3dB coupler and the power detector are input to control the degree of phase change of the phase shifter and the power change of the variable attenuator to remove error components of the combined signal output from the 3dB coupler and the power detector. Adaptive control device of the feed forward linearization device, characterized in that consisting of a power comparison adaptive control unit for controlling. The method of claim 1, wherein the 3dB coupler and the power detector, First and second distributors for receiving and distributing the signals of the main amplifier distributed by the second coupler and the signals of the signal amplifier input through the variable attenuator; First and second signal detectors detecting power magnitude and phase information from the signals distributed by the first and second distributors, respectively, and outputting first and second detection signals, respectively; A 3 dB coupler for receiving, combining, and coupling the signals distributed by the first and second distributors; Third and fourth distributors for respectively distributing the signal coupled at the 3dB coupler; Third and fourth signal detectors for detecting power magnitude and phase information from the signals distributed by the third and fourth distributors, respectively, and outputting third and fourth detection signals, respectively; And a signal combiner configured to receive the combined signals from the third and fourth distributors and combine the combined signals to output a combined signal. The method of claim 1, wherein the power comparison adaptive control unit, An A / D conversion unit for converting analog first to fourth detection signals inputted from the combining and detecting unit into digital; The phase shift unit and the variable attenuation are received in a one-to-one manner by receiving the first to fourth detection signals of the A / D converter and comparing the power level and the phase difference between the main amplifier signal and the input signal using the 3dB coupler and the power detector. A CPU for outputting a control signal to the unit; A D / A converter which receives a digital control signal from the CPU and converts it into an analog signal; Adaptive control device of the feed forward linearization device, characterized in that the memory unit for storing the data processed in the CPU. The method of claim 3, wherein the CPU, The first variable attenuation is compared with a first detection signal which is a detection signal of the main amplifier and a second detection signal that is a detection signal of the signal amplifier, so that the detected value of the second detection signal is equal to the value of the first detection signal. Adjust the unit, compare the detected values of the third detection signal and the fourth detection signal, adjust the first phase shift part to equalize the values, and remove the error component from the combined signal output from the 3dB coupler and the power detector. Adaptive control device of the feedforward linearization device, characterized in that for controlling.