A power amplifier transmitter

Abstract

The present invention discloses a power amplifier transmitter, which includes an Outphasing signal separation circuit, a Doherty signal separation circuit, a first adder, a second adder, and a power amplification circuit. The Outphasing signal separation circuit performs signal separation processing on a first baseband signal and outputs a first Outphasing separated signal and a second Outphasing separated signal with opposite phases. The Doherty signal separation circuit performs signal separation processing on a second baseband signal and outputs a first Doherty separated signal and a second Doherty separated signal based on Doherty time domain adjustment. The first adder adds the first Outphasing separated signal and the first Doherty separated signal, and the second adder adds the second Outphasing separated signal and the second Doherty separated signal and inputs them into the power amplification circuit for power amplification. Compared with the existing dual-input working mode architecture, the present invention does not need to satisfy the same impedance trend at different frequency points, but there are two impedance trends corresponding to different power amplifier working modes to choose from, which simplifies the circuit structure and reduces the design difficulty of the power amplifier transmitter.

Description

Technical Field

[0001] The present invention relates to the field of communication technologies, and in particular, to a power amplifier transmitter. Background Art

[0002] With the development of communication technologies, the requirements for the efficiency index of radio frequency power amplifiers (Power Amplifier, abbreviated as PA) in the communication base station transmitter architecture are gradually increasing. At the same time, the support for multi-carrier modes has been widely applied in communication networks. Therefore, as the main energy-consuming device in communication base stations, the power amplifier needs to support signals in two or even more frequency bands simultaneously.

[0003] Existing dual-input power amplifiers use the same dual-input working mode in broadband multi-frequency scenarios, which requires the output matching circuit to satisfy the same impedance trend at different frequency points, increasing the complexity of the matching circuit design of the power amplifier. Summary of the Invention

[0004] The main purpose of the embodiments of the present invention is to propose a power amplifier transmitter, aiming to simplify the structure of the matching circuit of the power amplifier and reduce the design difficulty of the power amplifier transmitter.

[0005] To achieve the above purpose, the embodiments of the present invention provide a power amplifier transmitter, including:

[0006] A first input terminal for inputting a first baseband signal;

[0007] A second input terminal for inputting a second baseband signal;

[0008] An Outphasing signal separation circuit for connecting to the first input terminal to perform signal separation processing on the first baseband signal and output a first Outphasing separation signal and a second Outphasing separation signal with opposite phases;

[0009] A Doherty signal separation circuit for connecting to the second input terminal to perform signal separation processing on the second baseband signal and output a first Doherty separation signal and a second Doherty separation signal based on Doherty time domain adjustment;

[0010] A first adder for adding the first Outphasing separation signal and the first Doherty separation signal;

[0011] A second adder for adding the second Outphasing separation signal and the second Doherty separation signal; and

[0012] A power amplifier circuit is used to support the Outphasing operating mode in the frequency band of the first baseband signal and support the Doherty operating mode in the frequency band of the second baseband signal. The power amplifier circuit is connected to the output ends of the first adder and the second adder to amplify the signals output by the first adder and the second adder.

[0013] An amplifier transmitter proposed in an embodiment of the present invention sets an Outphasing signal separation circuit to perform differential phase signal separation processing on the first baseband signal to obtain a first Outphasing separation signal and a second Outphasing separation signal, and also sets a Doherty signal separation circuit to perform digital Doherty signal separation processing on the second baseband signal to obtain a first Doherty separation signal and a second Doherty separation signal. By adding the first Outphasing separation signal and the first Doherty separation signal, and adding the second Outphasing separation signal and the second Doherty separation signal, two signals input to the power amplifier circuit are obtained. After mixing processing by the power amplifier circuit, a combined and amplified radio frequency signal is output. Compared with the existing dual-input operating mode architecture, the embodiment of the present invention does not need to meet the same impedance trend at different frequency points, but there are two impedance trends corresponding to different power amplifier operating modes to choose from, simplifying the circuit structure and reducing the design difficulty of the amplifier transmitter. Description of the Drawings

[0014] Figure 1 is the circuit diagram of the amplifier transmitter with dual-frequency concurrent input provided in Embodiment 1 of the present invention;

[0015] Figure 2 is the circuit diagram of the power amplifier circuit provided in Embodiment 1 of the present invention;

[0016] Figure 3 is the circuit diagram of the amplifier transmitter with multi-frequency concurrent input provided in Embodiment 2 of the present invention;

[0017] Figure 4 is the circuit diagram of the power amplifier circuit provided in Embodiment 2 of the present invention. Detailed Embodiments

[0018] It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0019] In subsequent descriptions, suffixes such as "module", "component", or "unit" used to represent elements are only for the convenience of explaining the present invention and have no specific meaning of their own. Therefore, "module", "component", or "unit" can be used interchangeably.

[0020] Embodiment 1

[0021] As Figure 1 shown, this embodiment provides a power amplifier transmitter, including

[0022] A first input terminal for inputting a first baseband signal;

[0023] A second input terminal for inputting a second baseband signal;

[0024] An Outphasing signal separation circuit 100 for connecting to the first input terminal to perform signal separation processing on the first baseband signal, and outputting a first Outphasing separated signal and a second Outphasing separated signal with opposite phases;

[0025] A Doherty signal separation circuit 200 for connecting to the second input terminal to perform signal separation processing on the second baseband signal, and outputting a first Doherty separated signal and a second Doherty separated signal based on Doherty time domain adjustment;

[0026] A first adder 300 for adding the first Outphasing separated signal and the first Doherty separated signal;

[0027] A second adder 400 for adding the second Outphasing separated signal and the second Doherty separated signal; and

[0028] A power amplification circuit 500 for supporting the Outphasing operating mode in the frequency band of the first baseband signal and supporting the Doherty operating mode in the frequency band of the second baseband signal. The power amplification circuit 500 is connected to the output terminals of the first adder 300 and the second adder 400 to perform power amplification on the signals output by the first adder 300 and the second adder 400.

[0029] In this embodiment, the first baseband signal is taken as Band1 and the second baseband signal is taken as Band2 as an example for illustration. The frequency bands of the first baseband signal Band1 and the second baseband signal Band2 are different from each other. Therefore, the power amplifier transmitter of this embodiment is a dual - frequency dual - input amplification circuit, and can support the Outphasing operating mode in the frequency band of Band1 and support the Doherty operating mode in the frequency band of Band2. Therefore, the first baseband signal Band1 and the second baseband signal Band2 are respectively amplified in the power amplification circuit 500 in the Outphasing operating mode and the Doherty operating mode and then combined and output.

[0030] Based on this, a matching Outphasing signal separation circuit 100 and Doherty signal separation circuit 200 are provided for the power amplifier circuit 500. The Outphasing signal separation circuit 100 stores the out-of-phase information corresponding to Band1. The first baseband signal Band1 outputs the out-of-phase first Outphasing separation signal and the second Outphasing separation signal after phase angle transformation in the Outphasing signal separation circuit 100. The Doherty signal separation circuit 200 is also divided into two paths for output. One path is directly output as the first Doherty separation signal, and the other path outputs the second Doherty separation signal after Doherty time domain adjustment. The first Outphasing separation signal and the first Doherty separation signal are added by the first adder 300, and the second Outphasing separation signal and the second Doherty separation signal are added by the second adder 400 to obtain the two inputs of the power amplifier circuit 500 respectively. Since the two inputs of the power amplifier circuit 500 operate in different working modes, there is no need to satisfy the same impedance trend at different frequency points. Instead, there are two impedance trends corresponding to different power amplifier working modes to choose from, which simplifies the circuit structure and reduces the circuit design difficulty and the complexity of circuit debugging at the same time.

[0031] It can be understood that the first baseband signal Band1 and the second baseband signal Band2 with dual-frequency concurrent input are frequency-divided at the digital end. For example, in an FPGA device, the input frequency is divided into two frequency bands based on the Outphasing working mode and the Doherty working mode supported by the power amplifier circuit 500, and the high-efficiency characteristics of Outphasing and dual-input Doherty are used to improve the power amplifier performance of the traditional single-input Doherty.

[0032] Referring to Figure 2 , to achieve the combined output of dual inputs, the power amplifier circuit 500 includes a third adder 510, a first amplifier PA1, and a second amplifier PA2. The input end of the first amplifier PA1 is connected to the output end of the first adder 300, the input end of the second amplifier PA2 is connected to the output end of the second adder 400, and the output ends of the first amplifier PA1 and the second amplifier PA2 are connected to the input end of the third adder 510. The power amplifier circuit 500 is a dual-input and dual-band power amplifier, which internally has a single-input and single-output first amplifier PA1 and second amplifier PA2, and the two outputs of the first amplifier PA1 and the second amplifier PA2 are added by the third adder 510 to achieve power amplification of the dual-frequency concurrent input signal.

[0033] To improve the efficiency of the power amplifier circuit 500 and reduce the distortion generated when the power amplifier circuit 500 operates in its non-linear region, this embodiment uses digital pre-distortion to linearize the first baseband signal Band1 and the second baseband signal Band2. Specifically, the power amplifier transmitter further includes:

[0034] The first digital pre-distortion unit DPD1, which is used to connect to the first input end to perform digital pre-distortion processing on the first baseband signal Band1 and then input it into the Outphasing signal separation circuit 100;

[0035] The second digital pre-distortion unit DPD2, which is used to connect to the second input end to perform digital pre-distortion processing on the second baseband signal Band2 and then input it into the Doherty signal separation circuit 200;

[0036] The first digital-to-analog conversion unit DAC1, the output end of the first adder 300 is connected to the power amplifier circuit 500 through the first digital-to-analog conversion unit DAC1; and

[0037] The second digital-to-analog conversion unit DAC2, the output end of the second adder 400 is connected to the power amplifier circuit 500 through the second digital-to-analog conversion unit DAC2.

[0038] Digitally process the baseband signal based on digital pre-distortion technology, and perform digital-to-analog signal conversion at the output end to adapt to the working mode of the power amplifier circuit 500, thereby improving the linearity of the entire system architecture and the efficiency of the power amplifier circuit 500.

[0039] To reduce the influence of the second baseband signal Band2 on the linearity of the first baseband signal Band1, the first digital pre-distortion unit DPD1 introduces the second baseband signal Band2 as an input on the basis of performing digital pre-distortion processing on the first baseband signal Band1. Similarly, the second digital pre-distortion unit DPD2 introduces the first baseband signal Band1 as an input on the basis of performing digital pre-distortion processing on the second baseband signal Band2, reducing the influence of the first baseband signal Band1 on the linearity of the second baseband signal Band2. It can be understood that in this embodiment, the output of the first digital pre-distortion unit DPD1 is the signal after pre-distortion processing of the first baseband signal Band1, and the output of the second digital pre-distortion unit DPD2 is the signal after pre-distortion processing of the second baseband signal Band2. Obviously, for the two frequency bands of the first baseband signal Band1 and the second baseband signal Band2, both the first digital pre-distortion unit DPD1 and the second digital pre-distortion unit DPD2 are dual-band DPDs, and their outputs are single-channel outputs.

[0040] In one embodiment, in order to achieve two-phase outphasing of the Outphasing signal separation circuit 100, a look-up table storing outphasing information needs to be set in the Outphasing signal separation circuit 100. Specifically, the Outphasing signal separation circuit 100 includes:

[0041] A first modulo unit 130, configured to connect to the first input terminal and perform a modulo operation on the first baseband signal Band1;

[0042] A second modulo unit 140, configured to connect to the second input terminal and perform a modulo operation on the second baseband signal Band2;

[0043] A first look-up table unit, storing first outphasing information, the first look-up table unit is configured to connect to the first modulo unit 130 and the second modulo unit 140, and output a first Outphasing phase angle according to the first outphasing information, the modulo value of the first baseband signal Band1, and the modulo value of the second baseband signal Band2;

[0044] A second look-up table unit, storing second outphasing information, the second look-up table unit is configured to connect to the first modulo unit 130 and the second modulo unit 140, and output a second Outphasing phase angle according to the second outphasing information, the modulo value of the first baseband signal Band1, and the modulo value of the second baseband signal Band2;

[0045] A first multiplier 110, configured to connect to the first input terminal and the output terminal of the first look-up table unit, multiply the first baseband signal Band1 by the phase information represented by the first Outphasing phase angle, and then output a first Outphasing separated signal; and

[0046] A second multiplier 120, configured to connect to the first input terminal and the output terminal of the second look-up table unit, multiply the first baseband signal Band1 by the phase information represented by the second Outphasing phase angle, and then output a second Outphasing separated signal.

[0047] The first modulo unit 130 and the second modulo unit 140 respectively perform modulo operations on the first baseband signal Band1 and the second baseband signal Band2 to obtain the modulus values of the two baseband signals. The significance of the modulus value lies in quantifying the influence of two concurrent baseband signals on the architecture efficiency of the power amplifier circuit 500. Since the Doherty operating mode of Band2 will affect the Outphasing phase angle on Band1, the modulus values of the two baseband signals are respectively input into the first look-up table unit and the second look-up table unit. The outputs of the first look-up table unit and the second look-up table unit are the Outphasing phase angles corresponding to each power amplitude of the baseband signal. This angle represents the high-efficiency state of the power amplifier circuit 500. According to the out-of-phase information contained in the look-up table, the operating mode of the power amplifier can be adjusted corresponding to the first baseband signal Band1 and the second baseband signal Band2, thereby improving the efficiency of the power amplifier. It can be understood that since there are two modulus values respectively input into the two look-up table units, the look-up tables stored in the first look-up table unit and the second look-up table unit are two-dimensional, that is, 2D-LUT.

[0048] In an embodiment, the Outphasing signal separation circuit 100 further includes a first digital up-conversion unit DUC1 and a second digital up-conversion unit DUC2. The first multiplier 110, the first digital up-conversion unit DUC1, and the first adder 300 are connected in sequence. The second multiplier 120, the second digital up-conversion unit DUC2, and the second adder 400 are connected in sequence. By using digital up-conversion technology to modulate the first Outphasing separation signal and the second Outphasing separation signal to medium and high frequencies, the design difficulty can be reduced, and the data volume and transmission speed of the baseband data can be reduced, which is convenient for subsequent processing.

[0049] In one embodiment, to achieve the adjustment of the Doherty separated signal, the Doherty signal separation circuit 200 further includes a signal adjustment unit for adjusting one or more of the gain, phase, and waveform of the second baseband signal. After being processed by the signal adjustment unit, the second baseband signal becomes the second Doherty separated signal. The function of the signal adjustment unit is to offset the disadvantages of traditional Doherty circuits. Generally, in traditional Doherty circuits, the auxiliary power amplifier is biased in class C. Once the bias state is determined, the turn-on position of the auxiliary power amplifier is fixed, resulting in a decline in the efficiency of the auxiliary power amplifier and failing to reach the ideal state. Through the signal adjustment unit, one or more of the gain, phase, and waveform can be adjusted to improve the working efficiency of Doherty. The theoretical basis is that by digital terminal control, strategies such as flexibly configuring the turn-on position, power distribution ratio, and phase adjustment of the auxiliary power amplifier in the dual-input Doherty power amplifier can be used to improve the efficiency and linearity of the Doherty power amplifier and make up for the non-ideal characteristics of traditional single-input Doherty power amplifiers. For example, by adjusting the gain of the signal and injecting more power into the auxiliary power amplifier through unbalanced power splitting, on the one hand, the turn-on position of the auxiliary power amplifier is controlled, and on the other hand, the power distribution ratio of the auxiliary power amplifier is controlled, so as to maximize the efficiency of the Doherty power amplifier while maintaining linear performance. Another example is to adjust the phase of the signal to make the phase matching degree higher. Adjustment can also be carried out in other ways, which will not be exemplified one by one here.

[0050] Similarly, through digital upconversion technology, the design of the Doherty signal separation circuit 200 can be made simpler. It also includes a third digital upconversion unit DUC3 and a fourth digital upconversion unit DUC4. The second baseband signal Band2 is input to the first adder 300 after being processed by the third digital upconversion unit DUC3, and is input to the second adder 400 after being processed by the signal adjustment unit and the fourth digital upconversion unit DUC4.

[0051] It can be understood that there is no limitation on which frequency band the power amplifier circuit 500 supports the Outphasing working mode and which frequency band it supports the Doherty working mode. Considering the working performance and parameters of other components in the circuit design, as well as the efficiency of the mixed RF output, different frequency bands can be selected as the Band1 signal and the Band2 signal.

[0052] The power amplification circuit 500 based on dual inputs matches and sets the Outphasing signal separation circuit 100 and the Doherty signal separation circuit 200, simplifying the circuit structure. The first baseband signal Band1 and the second baseband signal Band2 are mixed and output after passing through the signal separation circuits with two different operating modes. Instead of considering meeting the same impedance trend at different frequency points, there are two impedance trends corresponding to different power amplifier operating modes to choose from, reducing the design difficulty of the power amplifier transmitter.

[0053] Embodiment 2

[0054] As Figure 3 and Figure 4 shown, this embodiment provides a power amplifier transmitter, including

[0055] A first input terminal for inputting a first baseband signal, where the first baseband signal includes a plurality of first sub-baseband signals with different frequency bands;

[0056] A second input terminal for inputting a second baseband signal, where the second baseband signal includes a plurality of second sub-baseband signals with different frequency bands;

[0057] The Outphasing signal separation circuit 100 is used to connect to the first input terminal to perform signal separation processing on the first baseband signal, and output a first Outphasing separation signal and a second Outphasing separation signal with opposite phases. The number of Outphasing signal separation circuits 100 is the same as the number of first sub-baseband signals;

[0058] The Doherty signal separation circuit 200 is used to connect to the second input terminal to perform signal separation processing on the second baseband signal, and output a first Doherty separation signal and a second Doherty separation signal based on Doherty time domain adjustment. The number of Doherty signal separation circuits 200 is the same as the number of second sub-baseband signals;

[0059] A first adder 300 for adding the first Outphasing separation signal and the first Doherty separation signal;

[0060] A second adder 400 for adding the second Outphasing separation signal and the second Doherty separation signal; and

[0061] The power amplifier circuit 500 is used to support the Outphasing operating mode in the frequency band of the first baseband signal and the Doherty operating mode in the frequency band of the second baseband signal. The power amplifier circuit 500 is connected to the output ends of the first adder 300 and the second adder 400 to amplify the signals output by the first adder 300 and the second adder 400.

[0062] In this embodiment, the case of multi-frequency concurrent input is described. Each first sub-baseband signal is represented as Band1 to Bandm, and each second sub-baseband signal is represented as Bandm + 1 to Bandn, where both m and n are positive integers greater than 1. Obviously, each first sub-baseband signal corresponds to a frequency band, that is, the first baseband signal contains more than 1 frequency band, and each second sub-baseband signal corresponds to a frequency band, that is, the second baseband signal contains more than 1 frequency band.

[0063] Each frequency band of the first sub-baseband signal corresponds to an Outphasing signal separation circuit 100, and each frequency band of the second sub-baseband signal corresponds to a Doherty signal separation circuit 200. Specifically, the out-of-phase information in each Outphasing signal separation circuit 100 corresponds to different first sub-baseband signals, and the Doherty time domain adjustment in each Doherty signal separation circuit 200 corresponds to different second sub-baseband signals. After the first sub-baseband signals Band1 to Bandm and the second sub-baseband signals Bandm + 1 to Bandn are processed by the Outphasing signal separation circuit 100 and the Doherty signal separation circuit 200, the first adder 300 adds all the first-path Outphasing separation signals and the first-path Doherty separation signals to obtain different first-path Outphasing separation signals, second-path Outphasing separation signals, first-path Doherty separation signals, and second-path Doherty separation signals, and finally inputs them through one input end of the input power amplifier circuit 500. The second adder 400 adds all the second-path Outphasing separation signals and the second-path Doherty separation signals and inputs them through the other input end of the input power amplifier circuit 500.

[0064] Based on the above multi-frequency concurrent input situation, in order to achieve digital processing and frequency band separation, improve the efficiency of the power amplifier circuit 500, and reduce the distortion generated when the power amplifier circuit 500 operates in its non-linear region, this embodiment further includes:

[0065] The first digital pre-distortion unit DPD1 is used to connect to the first input end to perform digital pre-distortion processing on the first sub-baseband signals Band1 to Bandm and then input them into the Outphasing signal separation circuit 100;

[0066] A second digital pre-distortion unit DPD2, which is used to connect to a second input end to perform digital pre-distortion processing on second sub-baseband signals Bandm+1 to Bandn and then input them into the Doherty signal separation circuit 200;

[0067] A first digital-to-analog conversion unit DAC1, and the output end of the first adder 300 is connected to the power amplification circuit 500 through the first digital-to-analog conversion unit DAC1; and

[0068] A second digital-to-analog conversion unit DAC2, and the output end of the second adder 400 is connected to the power amplification circuit 500 through the second digital-to-analog conversion unit DAC2.

[0069] The above-mentioned first digital pre-distortion unit DPD1 and second digital pre-distortion unit DPD2 are multi-input single-output DPD devices. For the description of the linear influence between their input frequency bands, refer to the first embodiment and will not be repeated here.

[0070] Since a single Outphasing signal separation circuit 100 and a single Doherty signal separation circuit 200 are respectively the same in structure as the Outphasing signal separation circuit 100 and the Doherty signal separation circuit 200 in the first embodiment, and the input and output processing of the first sub-baseband signals Band1 to Bandm and the second sub-baseband signals Bandm+1 to Bandn are similar, in order to avoid repeated description, the structures and working modes of the single Outphasing signal separation circuit 100 and the single Doherty signal separation circuit 200 will not be described in detail.

[0071] It should be noted that since multiple signals are added, the first adder 300 and the second adder 400 are actually composed of multiple cascaded sub-adders. Each sub-adder adds two of the signals, and its output is used as one of the inputs of the next sub-adder, thus constituting the above-mentioned first adder 300 and second adder 400.

[0072] Based on the above Embodiment 1 and Embodiment 2, an embodiment of the present invention further provides a power amplifier transmitter, including a power amplifier transmitter as in Embodiment 1 or Embodiment 2. The power amplifier transmitter uses the above power amplifier transmitter. By setting the Outphasing signal separation circuit 100 to perform in-phase and quadrature signal separation processing on the first baseband signal, a first Outphasing separation signal and a second Outphasing separation signal are obtained. The Doherty signal separation circuit 200 is also set to perform digital Doherty signal separation processing on the second baseband signal to obtain a first Doherty separation signal and a second Doherty separation signal. By adding the first Outphasing separation signal and the first Doherty separation signal, and adding the second Outphasing separation signal and the second Doherty separation signal, two signals input to the power amplification circuit 500 are obtained. The power amplification circuit 500 performs mixing processing and then combines and outputs the amplified radio frequency signal. Compared with the existing dual-input working mode architecture, the embodiment of the present invention does not need to meet the same impedance trend at different frequency points, but there are two impedance trends corresponding to different power amplifier working modes to choose from, which simplifies the circuit structure and reduces the design difficulty of the power amplifier transmitter.

[0073] The preferred embodiments of the present invention have been described above with reference to the accompanying drawings. However, the scope of the present invention is not limited thereby. Any modifications, equivalent substitutions, and improvements made by those skilled in the art without departing from the scope and essence of the present invention shall fall within the scope of the present invention.

Claims

1. A power amplifier transmitter, characterized in that, Comprising: A first input terminal for inputting a first baseband signal; A second input terminal for inputting a second baseband signal; An Outphasing signal separation circuit for connecting to the first input terminal to perform signal separation processing on the first baseband signal, and outputting a first Outphasing separated signal and a second Outphasing separated signal with opposite phases; A Doherty signal separation circuit for connecting to the second input terminal to perform signal separation processing on the second baseband signal, and outputting a first Doherty separated signal and a second Doherty separated signal based on Doherty time domain adjustment; A first adder for adding the first Outphasing separated signal and the first Doherty separated signal; A second adder for adding the second Outphasing separated signal and the second Doherty separated signal; And A power amplification circuit for supporting the Outphasing operating mode in the frequency band of the first baseband signal and supporting the Doherty operating mode in the frequency band of the second baseband signal. The power amplification circuit is connected to the output terminals of the first adder and the second adder to perform power amplification on the signals output by the first adder and the second adder.

2. The power amplifier transmitter according to claim 1, characterized in that, The power amplification circuit includes a first amplifier, a second amplifier, and a third adder. The input terminal of the first amplifier is connected to the output terminal of the first adder, the input terminal of the second amplifier is connected to the output terminal of the second adder, and the output terminals of the first amplifier and the second amplifier are connected to the input terminal of the third adder.

3. The power amplifier transmitter according to claim 1, characterized in that, Further comprising: A first digital predistortion unit for connecting to the first input terminal to perform digital predistortion processing on the first baseband signal and then inputting it into the Outphasing signal separation circuit; A second digital predistortion unit for connecting to the second input terminal to perform digital predistortion processing on the second baseband signal and then inputting it into the Doherty signal separation circuit; A first digital-to-analog conversion unit, and the output terminal of the first adder is connected to the power amplification circuit through the first digital-to-analog conversion unit; And A second digital-to-analog conversion unit, and the output terminal of the second adder is connected to the power amplification circuit through the second digital-to-analog conversion unit.

4. The power amplifier transmitter according to claim 3, wherein The first digital predistortion unit is further used for connecting to the second input terminal to simultaneously perform digital predistortion processing on the first baseband signal and the second baseband signal, and the second digital predistortion unit is further used for connecting to the first input terminal to simultaneously perform digital predistortion processing on the first baseband signal and the second baseband signal.

5. The power amplifier transmitter according to claim 1, characterized in that, The Outphasing signal separation circuit includes: A first modulus-taking unit for connecting to the first input terminal and performing modulus-taking processing on the first baseband signal; A second modulus-taking unit for connecting to the second input terminal and performing modulus-taking processing on the second baseband signal; The first look-up table unit stores first outphasing information. The first look-up table unit is used to connect the first modulo unit and the second modulo unit, and output a first Outphasing phase angle according to the first outphasing information, the modulus value of the first baseband signal, and the modulus value of the second baseband signal; The second look-up table unit stores second outphasing information. The second look-up table unit is used to connect the first modulo unit and the second modulo unit, and output a second Outphasing phase angle according to the second outphasing information, the modulus value of the first baseband signal, and the modulus value of the second baseband signal; The first multiplier is used to connect the first input end and the output end of the first look-up table unit, multiply the first baseband signal by the phase information represented by the first Outphasing phase angle, and output the first path of Outphasing separation signal; and The second multiplier is used to connect the first input end and the output end of the second look-up table unit, multiply the first baseband signal by the phase information represented by the second Outphasing phase angle, and output the second path of Outphasing separation signal.

6. The power amplifier transmitter according to claim 5, characterized in that, The Outphasing signal separation circuit further includes a first digital up-conversion unit and a second digital up-conversion unit. The first multiplier, the first digital up-conversion unit, and the first adder are connected in sequence. The second multiplier, the second digital up-conversion unit, and the second adder are connected in sequence.

7. The power amplifier transmitter according to claim 5, wherein Both the first look-up table unit and the second look-up table unit store a two-dimensional look-up table 2D-LUT.

8. The power amplifier transmitter according to claim 1, characterized in that, The Doherty signal separation circuit further includes a signal adjustment unit. The signal adjustment unit is used to perform one or more adjustments on the second baseband signal in terms of gain, phase, and waveform. After being processed by the signal adjustment unit, the second baseband signal obtains the second path of Doherty separation signal.

9. The power amplifier transmitter according to claim 8, characterized in that, The Doherty signal separation circuit further includes a third digital up-conversion unit and a fourth digital up-conversion unit. After being processed by the third digital up-conversion unit, the second baseband signal is input to the first adder. After being processed by the signal adjustment unit and the fourth digital up-conversion unit, the second baseband signal is input to the second adder.

10. The power amplifier transmitter according to claim 1, characterized in that, The first baseband signal includes a plurality of first sub-baseband signals with different frequency bands. The second baseband signal includes a plurality of second sub-baseband signals with different frequency bands. The number of Outphasing signal separation circuits is the same as the number of first sub-baseband signals. The number of Doherty signal separation circuits is the same as the number of second sub-baseband signals.

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