KR101002834B1 - Method and apparatus for controlling power amplifier in a mobile communication system - Google Patents

Abstract

Disclosed are an apparatus and method for controlling a power amplifier of a mobile communication system.

The present invention as described above is a converter for outputting a variable DC voltage according to the envelope of the input signal, supply voltage fluctuation compensation unit for controlling the maximum output voltage of the converter in accordance with the variation of the supply voltage output from the power supply, And a combiner for providing a sum of the maximum output voltage of the converter and the supply voltage as a bias voltage of a power amplifier.

Power amplifier, bias control,

Description

METHOD AND APPARATUS FOR CONTROLLING POWER AMPLIFIER IN A MOBILE COMMUNICATION SYSTEM}             

1 is a view showing a power amplifier according to a general bias control method,

2 is a view showing an improved bias control type amplification device;

3 is a view showing a voltage relationship in the apparatus shown in FIG.

4 is a view showing a power amplifier according to an embodiment of the present invention;

5 is a flowchart showing a power amplifier control process according to the principles of the present invention;

6 is a flowchart illustrating a power amplifier control process according to an embodiment of the present invention;

7 is a diagram showing a voltage relationship in the apparatus shown in FIG. 4;

FIG. 8 is another diagram illustrating the voltage relationship in the apparatus shown in FIG. 4.

The present invention relates to a mobile communication system, and more particularly, to a method and apparatus for controlling a power amplifier.

The power amplifier of the base station and the terminal of the mobile communication system uses a bias control method of the power amplifier for high efficiency characteristics. The bias control method adjusts the DC bias according to the envelope of the input signal of the transistor to reduce power consumed in the transistor.

1 is a view showing a power amplifier according to a general bias control method.

)을 상향 변환하는 직류-직류 변환기(controllable DC-DC converter)(102)와, 상기 직류-직류 변환기(102)의 출력전압을 바이어스 전압으로 입력받는 고주파 전력증폭기(RF power amplifier :RFPA)(104)로 구성된다.Referring to FIG. 1, the bias control type amplifying apparatus includes an envelope detector 101 that detects an envelope of an input signal, and a DC voltage supply that is a system supply power according to an output of the envelope detector 101. DC output voltage from (103)

Control DC-DC converter 102 for up-converting the input power, and a high frequency power amplifier (RFPA) 104 that receives the output voltage of the DC-DC converter 102 as a bias voltage. It is composed of

Unlike a terminal, a power amplifier for a base station consumes several hundred watts of power, and therefore, a real hundreds of watts DC-DC converter must be manufactured. However, manufacturing costs and technical problems make it difficult to manufacture hundreds of watts of DC-DC converters. In order to improve this problem, the amplifying apparatus shown in FIG. 2 has been proposed.

2 is a view showing an improved bias control type amplification device. The improved bias control method uses two DC voltages, unlike one DC voltage.                         

Referring to FIG. 2, the improved bias control method includes a first power supply (DC Supply, Vc) 203 for supplying Vc and a second power supply (DC Supply) for supplying an input voltage Vv to the converter 202. , Max Vv) 206 and by combining the output voltages of the first power supply 203 and the converter 202.

The first power supply 203 supplies a constant DC output voltage Vc to the power amplifier, and the DC-DC converter 202 adjusts the output voltage Vv between 0V and MaxVv according to the envelope of the signal input to the amplifier 204. Output by voltage. Here, Max Vv is the maximum value of the power supplied by the second power supply 206.

The operation of the power amplification apparatus shown in FIG. 2 is as follows. When the envelope of the input signal is below the predetermined reference value, Vc is supplied to the power amplifier. When the envelope of the input signal is above the reference value, the DC-DC converter 202 operates to bias voltage Vp plus Vv. + Vv is supplied to the power amplifier. In order to supply Vc, a power source of several hundred watts is used. The DC-DC converter 202 supplying a value Vv that varies according to the envelope of the input signal can be implemented in the tens of watts.

The relationship between the supply voltage Vc, the breakdown voltage Vb of the transistor, the converter output voltage Vv, the bias voltage Vp, and the envelope of the input signal is shown in FIG.

In the power amplifier shown in Fig. 2, when the breakdown voltage of the transistor is Vb, the maximum value of Vv should be Max Vv = Vb-Vc for the protection of the transistor. That is, the maximum value of Vv is determined according to the value of Vb. However, in the base station, a change in supply voltage Vc occurs due to the use of an auxiliary power supply due to a power failure, and in the case of a terminal, a discharge of the power supply. Therefore, when the maximum value of Vv is fixed to Vv = Vb-Vc, when Vc rises by ΔVc, the voltage supplied to the power amplifier Vp = Vc + ΔVc + Vv> Vb, which can cause deterioration and destruction of the characteristics of the transistor. have. In addition, when Vc falls by ΔVc, the bias voltage Vp = Vc-ΔVc + Vv <Vb supplied to the power amplifier becomes distorted, resulting in deterioration of spurious characteristics.

It is therefore an object of the present invention to provide an apparatus and method in which the characteristics of a power amplifier are maintained even with a change in supply voltage.

Another object of the present invention is to provide a power amplification apparatus and method capable of protecting a transistor even when a supply voltage changes.

The present invention to achieve these objects

In the bias adaptive based power amplification control device,

A converter for outputting a variable DC voltage according to an envelope of the input signal, a supply voltage variation compensator for controlling a maximum output voltage of the converter according to a change in a supply voltage output from a power supply, and a maximum output voltage of the converter And a combiner for providing a sum of the supply voltage and the bias voltage of the power amplifier.

In addition, in the embodiment of the present invention, the supply voltage variation compensation unit includes a voltage detector for detecting a change in the supply voltage, and a control unit for controlling the maximum output voltage of the converter in accordance with the voltage detector output.

In another embodiment of the present invention, the supply voltage fluctuation compensator reduces the output voltage of the converter by a preset level when the supply voltage is greater than or equal to a threshold.

In another embodiment of the present invention, the supply voltage variation compensation unit, when the supply voltage is less than the threshold, increases the output voltage of the converter by a predetermined level.

DETAILED DESCRIPTION A detailed description of preferred embodiments of the present invention will now be described with reference to the accompanying drawings. It should be noted that reference numerals and like elements among the drawings are denoted by the same reference numerals and symbols as much as possible even though they are shown in different drawings. In the following description of the present invention, if it is determined that a detailed description of a related known function or configuration may unnecessarily obscure the subject matter of the present invention, the detailed description thereof will be omitted.

The present invention relates to a high frequency signal power amplifying apparatus and method for a mobile communication system.

4 is a view showing a power amplifier according to an embodiment of the present invention.

)으로 제공한다.Referring to FIG. 4, the envelope detector 410 detects an envelope of an input high frequency signal. The DC-DC converter 420 outputs the voltage supplied from the power supply 460 as a variable DC voltage Vv according to the envelope of the input signal detected by the envelope detector 410. The supply voltage variation compensator 470 controls the maximum output voltage Max Vv of the converter 420 according to the variation of the output voltage Vc of the power supply 450. The voltage combiner 430 may add the sum of the output voltage Vv of the converter 420 and the output voltage Vc of the power supply 450 to the bias voltage of the power amplifier 440.

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The supply voltage fluctuation compensator 470 may determine the maximum of the converter 420 according to the output of the voltage detector 473 and the voltage detector 473 for detecting the fluctuation of the output voltage Vc of the power supply 450. A control unit (Max Vv Controller) 471 for controlling the output voltage is provided.

5 is a flowchart illustrating a power amplifier control process according to the principles of the present invention.

The process illustrated in FIG. 5 includes an envelope detector 410 for detecting an envelope of an input high frequency signal, a first power supply 450 for supplying a predetermined voltage, and the like shown in FIG. 4. In the power amplification device of the mobile communication system having a converter 420 is supplied from a second power supply 460 other than the first power supply and changes the second power supply output in accordance with the envelope detector output, bias Show how to control the voltage.

Referring to FIG. 5, in step 510, the supply voltage variation compensator 470 detects a supply voltage variation of the first power supply. When the supply voltage variation is detected, in step 530, the supply voltage variation compensator 470 controls the maximum output voltage of the converter according to the detected variation amount.                     

The combiner 430 then provides the sum of the converter output voltage and the varied output voltage of the power supply as the bias voltage of the power amplifier.

Hereinafter, a power amplifier control process according to an embodiment of the present invention will be described in detail.

6 is a flowchart illustrating a power amplifier control process according to an embodiment of the present invention.

In operation 600, when the supply voltage Vc is changed to Vc ′ due to a power failure or a rectifier problem, and the signal having the maximum envelope is input, the voltage detector 473 detects the amount of change in the supply voltage.

In step 610, the controller 471 determines whether the change in the supply voltage is a voltage drop -ΔVc or a voltage rise + ΔVc.

When the voltage drop of the supply voltage occurs, in step 620, the controller 473 changes the converter maximum output voltage Max Vv to Max Vv '= Vb-Vc' = Vb-(Vc-ΔVc) = Vb-Vc + ΔVc. Adjust The output voltage Vp of the combiner 420 becomes Vp '= Vc' + Vv '= Vc-DELTA Vc + Vv + DELTA Vc = Vc + Vv in step 630 and the combiner output voltage Vp' = Vc + Vv in step 660. It is supplied with the bias voltage of the power amplifier. Therefore, the same characteristics of the power amplifier are maintained even with the fluctuation of the supply voltage.

When the voltage rise of the supply voltage occurs, in step 640, the controller 473 sets the converter maximum output voltage Max Vv to Max Vv '= Vb-Vc' = Vb-(Vc + ΔVc) = Vb-Vc-ΔVc = Adjust to Vv-ΔVc. In step 650, the output voltage Vp of the combiner 420 becomes Vp '= Vc' + Vv '= Vc + DELTA Vc + Vv-DELTA Vc = Vc + Vv. In step 660, the combiner output voltage Vp' = Vc + Vv is It is supplied with the bias voltage of the power amplifier. Therefore, the transistor can be protected by preventing the bias voltage Vp from becoming larger than the breakdown voltage Vb in advance.

FIG. 7 is a diagram illustrating a relationship between a supply voltage Vc at a supply voltage drop, a breakdown voltage Vb of a transistor, a converter output voltage Vv, a bias voltage Vp, and an envelope of an input signal.

Referring to FIG. 7, when a voltage drop of the supply voltage Vc occurs and a high frequency signal having a maximum envelope is input, the power amplification device according to the prior art is clipped by Vp = Vc−ΔVc + Vv <Vb. ) Is generated. However, as described above, the power amplifier according to the present invention solves the problems of the prior art by Vp '= Vv + Vc.

FIG. 8 is a diagram illustrating a relationship between a supply voltage Vc when a supply voltage rises, a breakdown voltage Vb of a transistor, a converter output voltage Vv, a bias voltage Vp, and an envelope of an input signal.

Referring to FIG. 8, when a voltage rise of the supply voltage Vc occurs and a high frequency signal having a maximum envelope is input, the power amplifier according to the prior art deteriorates a transistor by Vp = Vc + ΔVc + Vv> Vb. And destruction. However, as described above, the power amplifier according to the present invention solves the problems of the prior art by Vp '= Vv + Vc.                     

Meanwhile, in the detailed description of the present invention, specific embodiments have been described, but various modifications may be made without departing from the scope of the present invention. Therefore, the scope of the present invention should not be limited to the described embodiments, but should be determined not only by the scope of the following claims, but also by the equivalents of the claims.

As described above, the present invention has the advantage that the characteristics of the power amplifier are maintained even when the supply voltage is changed. In addition, there is an advantage that the transistor can be protected even when the supply voltage changes.

Claims (25)

In the bias adaptive based power amplification control device, A converter for outputting a variable DC voltage according to the envelope of the input signal; Supply voltage fluctuation compensation unit for controlling the maximum output voltage of the converter in accordance with the change in the supply voltage output from the power supply, And a combiner for providing a sum of the maximum output voltage of the converter and the supply voltage as a bias voltage of a power amplifier. The method of claim 1, wherein the supply voltage variation compensation unit, A voltage detector for detecting a change in the supply voltage; And a controller for controlling the maximum output voltage of the converter according to the voltage detector output. The method of claim 1, wherein the supply voltage variation compensation unit, And when the supply voltage is greater than or equal to a threshold, reducing the output voltage of the converter by a predetermined level. The method of claim 1, wherein the supply voltage variation compensation unit, And when the supply voltage is less than or equal to the threshold, increasing the output voltage of the converter by a predetermined level. In the bias adaptive based power amplification control method, Detecting a change in the supply voltage output from the power supply; If the change in the supply voltage is detected, controlling an output voltage changed according to an envelope voltage of an input signal according to the detected change amount; And providing a sum of the controlled output voltage and the supply voltage as a bias voltage of a power amplifier. The method of claim 5, And reducing the output voltage by a predetermined level when the supply voltage is greater than or equal to a threshold value. The method of claim 5, And increasing the output voltage by a predetermined level when the supply voltage is less than or equal to a threshold value. delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete

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