WO2010022613A1

WO2010022613A1 - Method and device for power amplification and base station

Info

Publication number: WO2010022613A1
Application number: PCT/CN2009/072349
Authority: WO
Inventors: 张希坤; 孙捷; 殷为民; 张亚文; 吴剑锋; 吴俊�
Original assignee: 深圳华为通信技术有限公司
Priority date: 2008-08-25
Filing date: 2009-06-19
Publication date: 2010-03-04
Also published as: CN101350599B; CN101350599A

Abstract

A method and a device (82) for power amplification and a base station. The device (82) for power amplification includes a first power amplifier module (103), a second power amplifier module (104), a first electric bridge (106), a second electric bridge (107) and a grid voltage module (105). The grid voltage module (105) varies a grid bias voltage provided to the first power amplifier module (103) or the second power amplifier module (104) based on a command or a to-be-amplified signal so as to switch the operating mode of the device (82) for power amplification between a balanced power amplifying mode and a Doherty power amplifying mode.

Description

Power amplification method, device and base station The present application claims priority to Chinese Patent Application entitled "A Power Amplification Method, Apparatus and Base Station" by the Chinese Patent Office on August 25, 2008, Application No. 200810142030.0 The entire contents of which are incorporated herein by reference. Technical field

The present invention relates to the field of communications technologies, and in particular, to a power amplification method, apparatus, and base station. Background technique

In the field of radio frequency communication, Class B (Class AB) and Doherty are two mainstream power amplifier technologies. These two types of power amplifiers are widely used in wireless communication products.

The main characteristic of class AB power amplifier is that the static bias current is greater than zero, the linear index is better, but the efficiency is relatively low. In order to make the power amplifier output higher power, the commonly used method in engineering is to use 3 dB (dB) bridge to two ways. Class AB power amplifiers perform power synthesis to form a balanced power amplifier.

Doherty power amplifiers usually consist of two power amplifiers, one of which is biased in class AB, called a carrier amplifier; the other is biased in class C (class C), called a peak amplifier, whose basic principle is load pulling. Doherty amplifiers have the advantage of significantly improved efficiency compared to Class AB amplifiers, but their linearity is poor.

The inventor has found that at least the following problems exist in the prior art solution: Class AB power amplifiers or balanced power amplifiers are only applicable to scenes with high linearity requirements and low efficiency requirements; Doherty power amplifiers are only suitable for scenes with high efficiency requirements and low linearity requirements; The above two application scenarios respectively produce different power amplifier hardware, which causes the power amplifying devices between the base stations working in different application scenarios to be unusable and interchangeable, thereby improving the cost of network construction and maintenance. Summary of the invention Embodiments of the present invention provide a power amplification method, apparatus, and base station to implement an operation mode of a power amplifying device to switch between a balanced power amplifier mode and a Doherty power amplifier mode.

Embodiments of the present invention provide a power amplifying apparatus, including:

a first power amplifier module, a second power amplifier module, a first bridge, and a second bridge;

The first bridge is configured to split the signal to be amplified, wherein the first input end of the first bridge serves as an isolated end, and the second input end of the first bridge serves as a signal input end for receiving the to be amplified a signal, the first output end and the second output end of the first bridge are used as shunt output ends, respectively, for respectively outputting the signal to be amplified after the shunt;

a first power amplifier module, configured to amplify a signal from the first output end of the first bridge according to a working state thereof, and output the amplified signal to a first input end of the second bridge;

a second power amplifier module, configured to amplify a signal from the second output end of the first bridge according to a working state thereof, and output the amplified signal to a second input end of the second bridge;

a second bridge, configured to combine the amplified signals, wherein the second output end of the second bridge serves as an isolated end, and the first input end and the second input end of the second bridge serve as signal inputs The terminal is configured to receive the amplified signals from the output of the first power amplifier module and the second power amplifier module, respectively, and the first output end of the second bridge is used as a combined output terminal for outputting the combined signal;

a gate voltage module, configured to change a gate bias voltage supplied to the first power amplifier module or the second power amplifier module according to an instruction or a type of the signal to be amplified;

The first power amplifier module or the second power amplifier module is further configured to change the working state of the power amplifying device according to the gate bias voltage, and switch the working mode of the power amplifying device between the balanced power amplifier mode and the Doherty power amplifier mode.

An embodiment of the present invention provides a base station, including a transmitter, further including:

The above power amplifying device;

An input of the power amplifying device is coupled to an output of the transmitter for amplifying a signal output by the transmitter.

An embodiment of the present invention further provides a power amplification method, including: The first bridge receives the signal to be amplified, and divides the signal to be amplified into two outputs; the first power amplifier module and the second power amplifier module respectively amplify the two signals to be amplified outputted by the first bridge according to the working state thereof;

The second bridge combines the two signals to be amplified by the first power amplifier module and the second power amplifier module;

The gate voltage module changes a gate bias voltage supplied to the first power amplifier module or the second power amplifier module according to an instruction or a type of the signal to be amplified;

The first power amplifier module or the second power amplifier module changes its working state according to the gate bias voltage, so that the working mode of the power amplifying device is switched between the balanced power amplifier mode and the Doherty power amplifier mode.

By adjusting the gate bias voltage of the power amplifying module, the embodiment of the present invention can switch between the balanced power amplifier mode and the Doherty power amplifier mode according to specific requirements, thereby improving the versatility of the power amplifying device and reducing the network construction and maintenance cost. DRAWINGS

1 is a schematic diagram of a power amplifying apparatus according to Embodiment 1 of the present invention;

2 is a schematic diagram of a gate voltage module according to Embodiment 1 of the present invention;

3 is a schematic diagram of a power amplifier module according to Embodiment 1 of the present invention;

4 is a schematic diagram of still another power amplifier module according to Embodiment 1 of the present invention;

FIG. 5 is a schematic diagram of another power amplifier module according to Embodiment 1 of the present invention; FIG.

6 is a schematic diagram of a power amplifying device according to Embodiment 2 of the present invention;

7 is a schematic diagram of a power amplifying apparatus according to Embodiment 3 of the present invention;

8 is a schematic diagram of a base station according to Embodiment 4 of the present invention;

FIG. 9 is a schematic flow chart of a power amplification method according to Embodiment 5 of the present invention. detailed description

Embodiments of the present invention provide a power amplification method, apparatus, and base station for power amplification The working mode can be switched between the balanced power amplifier mode and the Doherty power amplifier mode according to specific requirements, which improves the versatility of the power amplifying device and reduces the network construction and maintenance costs. In order to make the technical solutions and advantages of the present invention more clear, the embodiments of the present invention will be further described in detail below with reference to the accompanying drawings.

A first embodiment of the present invention provides a power amplifying device. FIG. 1 is a schematic diagram of a power amplifying device according to Embodiment 1 of the present invention. As shown in FIG. 1, the method includes:

a first power amplifier module 103, a second power amplifier module 104, a gate voltage module 105, a first bridge 106, a second bridge 107;

The first bridge 106 is configured to split the signal to be amplified, wherein the first input end 1 of the first bridge 106 serves as an isolated end, and the second input end 2 of the first bridge 106 serves as a signal input terminal for receiving The signal to be amplified, the first output terminal 3 and the second output terminal 4 of the first bridge 106 serve as shunt output terminals for respectively outputting the signals to be amplified after the shunt;

The first power amplifier module 103 is configured to amplify the signal from the first output end 3 of the first bridge 106 according to the working state thereof, and output the amplified signal to the first input end 7 of the second bridge 107; The power amplifier module 104 is configured to amplify the signal from the second output end 4 of the first bridge 106 according to the working state thereof, and output the amplified signal to the second input end 8 of the second bridge 107; the second bridge 107 is used for combining the amplified signals, wherein the second output end 10 of the second bridge 107 serves as an isolated end, and the first input end 7 and the second input end 8 of the second bridge 107 serve as signal inputs. For receiving the amplified signals from the output of the first power amplifier module 103 and the second power amplifier module 104, respectively, the first output end 9 of the second bridge 107 is used as a combined output terminal for outputting the combined signal;

a gate voltage module 105, configured to change a gate bias voltage provided to the first power amplifier module 103 or the second power amplifier module 104 according to a type of the command or the signal to be amplified; the gate bias voltage is output to the port 5 and the port 6 respectively The gates of the first power amplifier module 103 and the second power amplifier module 104.

The first power amplifier module 103 or the second power amplifier module 104 is further configured to change the working state of the power amplifier according to the gate bias voltage, and the working mode of the power amplifying device is in the balanced power amplifier mode and Doherty. Switch between amplifier modes.

Here, the balanced power amplifier mode means that the two-way power amplification module works in the class (Class A) at the same time, or works in the Class AB, or works in the Class B (Class B) amplification mode.

The power amplifying device may further include a first load 101 and a second load 102;

The first input terminal 1 of the first bridge 106 serves as an isolated terminal and is grounded through the first load 101; the second output terminal 10 of the second bridge 107 serves as an isolated terminal and is electrically coupled to one end of the second load 102.

The first load 101 may be a 50 ohm load, the second load 102 may be a transmission line (a microstrip line, a cable, or the like may be used as the transmission line), and one end of the second load 102 is electrically coupled to the second output of the second bridge 107. 10, the other end can be grounded or open. When the power amplifying device operates in the Doherty power amplifier mode, the second load 102 is used to adjust the load impedance of the first power amplifier module or the second power amplifier module, and the length thereof is determined by the characteristics of the first power amplifier module and the second power amplifier module, or the power amplifying device The output matching characteristics of the two-way power amplifier may be 0 in a certain case. When the length is 0, the second output terminal 10 equivalent to the second bridge 107 is directly open or grounded.

2 is a schematic diagram of a gate voltage module according to Embodiment 1 of the present invention, as shown in FIG.

As explained in detail in Fig. 1, the gate voltage module 105 includes a state control module 1051 and a gate voltage supply module 1052, wherein:

The state control module 1051 is configured to output a mode switching command according to the type of the instruction or the signal to be amplified; the mode switching command is output to the gate voltage providing module 1052 through the port 16; the state control module 1051 may further have multiple output ports for the output mode. Switch commands, such as port 17. The state control module 1051 outputs a mode switching command by detecting a type of the signal to be amplified, for example, when detecting that the signal to be amplified is a signal requiring a higher linearity such as a multimode signal, outputting a mode switching command switched to the balanced power amplifier mode; When it is detected that the signal to be amplified is a signal requiring a low linearity such as a single mode signal, the mode switching command switched to the Doherty power amplifier mode is output. The state control module 1051 can also output a mode switching command according to an instruction such as a system command or an external command, so that the upper module can integrate various factors to determine which mode the power amplifying device should operate, and the power amplifying device The configuration is more flexible and more adaptable to objective situations.

The gate voltage supply module 1052 changes the gate bias voltage supplied to the first power amplifier module 103 or the second power amplifier module 104 according to the mode switching command output by the state control module 1051; the gate bias provided by the gate voltage supply module 1052 The voltage can be one or more ways.

When the power amplifying device is in the balanced power amplifier mode: the first power amplifier module 103 and the second power amplifier module

104 works at the same time in class AB or class A or class B; when the power amplifying device is in the Doherty power amplifier mode: the first power amplifier module 103 operates in class AB or class A or class B, and the second power amplifier module 104 operates in class C; or The first power amplifier module 103 operates in class C, and the second power amplifier module 104 operates in class AB or class A or class B.

The gate voltage module 105 can operate the first power amplifier module 103 or the second power amplifier module 104 in class AB, class A, class B or class C by changing the gate bias voltage of the first power amplifier module 103 or the second power amplifier module 104. When the working state is completed, the working mode of the entire power amplifying device is switched between the balanced power amplifier mode and the Doherty power amplifier mode.

FIG. 3 is a schematic diagram of a power amplifier module according to Embodiment 1 of the present invention. As shown in FIG. 3 and explained in detail in conjunction with the embodiment shown in FIG. 1 and FIG. 2, the first power amplifier module 103 or the second power amplifier module 104 may be configured by one. The power amplifier A1 is constructed. The input terminal a of the power amplifier A1 is for receiving the signal to be amplified from the output of the first bridge 106, and the output terminal b is for outputting the amplified signal to the second bridge 107. The gate c is connected to the gate voltage module 105. According to the different gate bias voltages provided by the gate voltage module 105, the power amplifier A1 can operate in Class AB, Class A, Class B or Class C, respectively.

4 is a schematic diagram of still another power amplifier module according to Embodiment 1 of the present invention. As shown in FIG. 4, the first power amplifier module 103 or the second power amplifier module 104 may be composed of two power amplifiers A2 and a power amplifier A3, and the power amplifier is configured. The input terminal e of A2 is used to receive the signal to be amplified from the output of the first bridge 106, and the output terminal f is used to connect the input terminal h of the power amplifier A3 and the signal for outputting the first stage to the input terminal h. The output terminal i of the power amplifier A3 is used to output the two-stage amplified signal to the second bridge 107. The gate g of the power amplifier A2 and the power amplifier A3 The gates j are both connected to the gate voltage supply module 1052. At this time, the gate voltage module 105 can provide two independent or identical gate bias voltages for the power amplifier A2 and the power amplifier A3. According to the gate bias voltage provided by the gate voltage module 105, the power amplifier A2 and the power amplifier A3 can respectively operate in Class AB, Class A, Class B or Class C, etc., and it should be noted that when the power amplifier A2, power When the working state of amplifier A3 is the same as class AB, class A or class B, the whole power amplifier module is considered to be class AB, class A or class B; when the working states of power amplifier A2 and power amplifier A3 are respectively AB class, A If the class of the class B and the class B are different, the whole power amplifier module is considered to be of class AB. When at least one of the power amplifier A2 and the power amplifier A3 operates in the class C, the entire power amplifier module is considered to be operating in the class C.

FIG. 5 is a schematic diagram of another power amplifier module according to Embodiment 1 of the present invention. As shown in FIG. 5, the first power amplifier module 103 or the second power amplifier module 104 may be formed by cascading N power amplifiers A4...power amplifiers AN. The input k of the power amplifier A4 is used to receive the signal to be amplified from the output of the first bridge 106, the output 1 is used to connect the input of the lower power amplifier, and the output 0 of the power amplifier AN is used to the second bridge. 107 outputs the signal after N-stage amplification. The gates m... of the power amplifier A4...power amplifier AN are both connected to the gate voltage module 105. At this time, the gate voltage module 105 can provide N independent or identical gate bias voltages for A4...AN. . According to the gate bias voltage provided by the gate voltage module 105, the power amplifier A4...power amplifier AN can operate in Class AB, Class A, Class B or Class C, respectively. It should be noted that when the working state of the power amplifier A4...power amplifier AN is the same as class AB, class A or class B, the whole power amplifier module is considered to be class AB, class A or class B; when power amplifier A4. The working state of the power amplifier AN is one of class AB, class A, class B, and is not identical, then the whole power amplifier module is considered to be class AB; and when power amplifier A4... power amplifier AN is at least one When working in class C, the entire power amplifier module is considered to work in class C.

The power amplifier may be a laterally diffused metal oxide semiconductor (LDMOS), a gallium arsenide metal semiconductor field effect transistor (GaAs MESFET), a bipolar transistor (BJT), a junction field effect transistor (JFET) or a potassium nitride transistor ( GAN ); the first bridge 106 and the second bridge 107 can be a 3dB bridge.

The power amplifying device provided in Embodiment 1 of the present invention realizes that the same power amplifier hardware can support balanced power amplifier mode (for scenes with high linearity requirements and low efficiency requirements, such as multi-mode working mode), and can also support Doherty power amplifier mode (for High efficiency, low linearity requirements, such as single-mode operation, and flexible switching between the two modes, which expands the scope of application of the power amplifier hardware, and provides more flexibility and lower mobility for operators' networking and base station upgrades. Cost solution.

FIG. 6 is a schematic diagram of a power amplifying apparatus according to Embodiment 2 of the present invention. As shown in FIG. 6, Embodiment 2 of the present invention provides another power amplifying apparatus, and the power amplifying of Embodiment 1 shown in FIG. 1 to FIG. The device is different in that it further includes a first switch 108 and a third load 109, wherein the first port 11 of the first switch 108 is connected to the second output end 10 of the second bridge 107, and the second port of the first switch 108 12 is connected to one end of the second load 102 (ie, one end of the second load 102 is connected to the second output end 10 of the second bridge 107 through the first switch 108); the third port 13 of the first switch 108 is grounded through the third load 109 . Wherein, one end of the second load 102 is connected to the second port 12 of the first switch 108, and the other end may be grounded or open.

The first switch 108 turns on the first port 11 and the second port 12 of the first switch 108 or turns on the first port 11 and the third port 13 of the first switch 108 in accordance with the mode switching command output from the state control module 1051.

The third load 109 can be a 50 ohm load.

When the mode switching command outputted by the state control module 1051 by the port 16 and the port 17 is a mode switching command for switching to the balanced power amplifier mode (the switching command can be represented by a high level), the first port 11 of the first switch 108 and the first The three ports 13 are turned on (at the same time, the first port 11 and the second port 12 are disconnected); when the mode switching command output by the state control module 1051 is a mode switching command for switching to the Doherty power amplifier mode (the switching command can be used for low power) Flat indicates), the first port 11 and the second port 12 of the first switch 108 are turned on (simultaneously, the first port 11 and the third port 13 are disconnected).

The first switch 108 can be a radio frequency switch or an RF relay.

Compared with the first embodiment shown in FIG. 1 to FIG. 5, the present embodiment is powered by Doherty in the power amplifying device. When the discharge mode is switched to the balanced power amplifier mode, the load connected to the second output terminal 10 of the second bridge 107 is changed from the transmission line to the grounded 50 ohm load by the first switch 108, which is advantageous for absorbing the two-way power amplifier in the power amplifying device. The power generated by the unbalance is amplified to prevent this power from being reflected back to the power amplifier by the second output terminal 10 of the second bridge 107, thereby further improving the performance of the power amplifying device.

FIG. 7 is a schematic diagram of a power amplifying apparatus according to Embodiment 3 of the present invention. As shown in FIG. 7, Embodiment 3 of the present invention provides another power amplifying apparatus, and the power of the first embodiment shown in FIG. 1 to FIG. The amplifying device is further configured to include a third load 109 and a second switch 110, wherein the first port 14 of the second switch 110 is connected to the second output end 10 of the second bridge 107 via the second load 102, the second switch The second port 15 of 110 is grounded through the third load 109;

The second switch 110 turns on the first port 14 and the second port 15 of the second switch 110 or turns off the first port 14 and the second port 15 of the second switch 110 according to the mode switching command output by the state control module 1051.

The third load 109 can be a 50 ohm load.

When the mode switching command output by the state control module 1051 by the port 16 and the port 17 is a mode switching command for switching to the balanced power amplifier mode (the switching command can be represented by a high level), the first port 14 and the second port of the second switch 110 The second port 15 is turned on; when the mode switching command output by the state control module 1051 is a mode switching command for switching to the Doherty power amplifier mode (the switching command can be represented by a low level), the first port 14 and the second port of the second switch 110 The two ports 15 are disconnected.

The second switch 110 can be a radio frequency switch or an RF relay.

Compared with the first embodiment shown in FIG. 1 to FIG. 5, in the embodiment, when the power amplifying device is switched from the Doherty power amplifier mode to the balanced power amplifier mode, the second output terminal 10 of the second bridge 107 is used by the second switch 110. The connected load is changed from an open transmission line to a 50 ohm load connected in series with the transmission line, which is advantageous for absorbing the power generated by the amplification of the two power amplifiers in the power amplifying device, preventing the power from being output by the second output of the second bridge 107. 10 is reflected back to the power amplifier, thereby further improving the performance of the power amplifier.

FIG. 8 is a schematic diagram of a base station according to Embodiment 4 of the present invention. As shown in FIG. 8, a base station, including a transmitter 81, according to Embodiment 4 of the present invention, further includes: The power amplifying device 82 provided in any one of the first embodiment to the third embodiment; the input end of the power amplifying device 82 is connected to the output end of the transmitter 81 for amplifying the signal output by the transmitter 81.

The transmitter 81 described above may be a radio frequency transmitter or a microwave transmitter.

The base station provided in the fourth embodiment of the present invention uses the power amplifying device provided in any one of the first embodiment to the third embodiment, so that the power amplifier hardware of the same base station can support the balanced power amplifier mode (for linear requirements and efficiency) Low-demand scenarios, such as multi-mode operation, and Doherty power amplifier mode (for scenarios with high efficiency requirements and low linearity requirements, such as single-mode operation), and flexible switching between the two modes, which can be operated Enterprise networking and base station upgrades provide a more flexible and lower cost solution.

FIG. 9 is a schematic flowchart of a power amplification method according to Embodiment 5 of the present invention. As shown in FIG. 9 , in conjunction with the apparatus embodiment shown in FIG. 1 to FIG. 8 , Embodiment 5 of the present invention provides a power amplification method. Includes:

Step 901: The first bridge receives the signal to be amplified, and divides the signal to be amplified into two outputs. Step 902: The first power amplifier module and the second power amplifier module respectively enlarge the two channels of the first bridge output to be amplified according to the working state thereof. Signal

Step 903: The second bridge combines the two signals to be amplified and amplified by the first power amplifier module and the second power amplifier module;

Step 904: The gate voltage module changes a gate bias voltage provided to the first power amplifier module or the second power amplifier module according to the instruction or the type of the signal to be amplified; when the switch to the balanced power amplifier mode is needed, the gate of the power amplifier module may be changed. The bias voltage is such that the first power amplifier module 103 in the embodiment shown in FIG. 1 to FIG. 8 operates in class AB or class A or class B, and the second power amplifier module 104 operates in class AB or class A or class B; When it is required to switch to the Doherty power amplifier mode, the first power amplifier module 103 is operated in class AB or class A or class B, and the second power amplifier module 104 is operated in class C; or, the first power amplifier module 103 operates in class C, second The power amplifier module 104 operates in class AB or class A or class B. High performance requirements and low efficiency requirements), can also support Doherty power amplifier mode (for high efficiency, low linearity requirements), and flexible switching between the two modes, expanding the scope of application of power amplification methods, Provides a more flexible and lower cost solution for operators' networking and base station upgrades.

Through the description of the above embodiments, those skilled in the art can clearly understand that the present invention can be implemented by hardware or by software plus a necessary general hardware platform. Based on such understanding, the technical solution of the present invention may be embodied in the form of a software product, which may be stored in a non-volatile storage medium (which may be a CD-ROM, a USB flash drive, a mobile hard disk, etc.), including several The instructions are for causing a computer device (which may be a personal computer, server, or network device, etc.) to perform the methods described in various embodiments of the present invention.

The above disclosure is only a few specific embodiments of the present invention, but the present invention is not limited thereto, and any changes that can be considered by those skilled in the art should fall within the protection scope of the present invention.

Claims

Rights request

A power amplifying device, comprising:

The first bridge is configured to split the signal to be amplified, wherein the first input end of the first bridge serves as an isolated end, and the second input end of the first bridge serves as a signal input end for receiving the to be amplified a signal, the first output end and the second output end of the first bridge are used as shunt output ends, respectively, for respectively outputting the signal to be amplified after shunting;

a gate voltage module, configured to change a gate bias voltage supplied to the first power amplifier module or the second power amplifier module according to an instruction or a type of a signal to be amplified;

2. The device according to claim 1, wherein the gate voltage module further comprises: a state control module, configured to output a mode switching command according to an instruction or a type of a signal to be amplified; a gate voltage providing module, according to the The mode switching command output by the state control module changes the gate bias voltage supplied to the first power amplifier module or the second power amplifier module.

3. The apparatus according to claim 1, further comprising: a first load, a second load;

The first input end of the first bridge serves as an isolated end and is grounded through the first load; The second output of the second bridge acts as an isolated end and is electrically coupled to one end of the second load.

4. The device according to claim 3, further comprising: a third load, a first switch;

The first port of the first switch is connected to the second output end of the second bridge, and the second port of the first switch is connected to one end of the second load;

The third port of the first switch is grounded through a third load;

The first switch turns on the first port and the second port of the first switch according to the mode switching command output by the state control module, or turns on the first port and the third port of the first switch.

5. The device according to claim 3, further comprising: a third load, a second switch;

The first port of the second switch is connected to the second output end of the second bridge through a second load, and the second port of the second switch is grounded through the third load;

The second switch turns on the first port and the second port of the second switch or disconnects the first port and the second port of the second switch according to a mode switching command output by the state control module.

6. Apparatus according to any one of claims 1 to 4 wherein the first bridge and the second bridge are 3 decibel bridges.

The apparatus according to any one of claims 3 to 5, wherein the first load is a 50 ohm load and the second load is a transmission line.

The device according to any one of claims 1 to 5, wherein the first power amplifier module or the second power amplifier module is composed of one power amplifier or a plurality of power amplifiers.

A base station, comprising a transmitter, further comprising:

A power amplifying device according to any one of claims 1 to 8;

10. A power amplification method, comprising:

The first bridge receives the signal to be amplified, and divides the signal to be amplified into two outputs; The first power amplifier module and the second power amplifier module respectively amplify two signals to be amplified outputted by the first bridge according to the working state thereof;