Radio frequency power amplification circuit based on doherty amplifier

Abstract

The present invention provides a radio frequency power amplification circuit suitable for a mobile terminal, said circuit comprising: an input balun module configured to receive a single-ended radio frequency input and output two differential radio frequency signals; a main power amplifier module configured to receive one of the two differential radio frequency signals from the input balun module and output a first amplified signal; an auxiliary power amplifier module configured to receive the other one of the two differential radio-frequency signals from the input balun module and output a second amplified signal; and an output balun module configured as a balun in the form of a single transformer and used for receiving the first amplified signal outputted by the main power amplifier module and the second amplified signal outputted by the auxiliary power amplifier module, and generating a single-ended radio frequency output signal.

Description

Radio frequency power amplification circuit based on doherty amplifier

[0001] This application claims priority to Chinese Patent Application No. 202411237174.X, filed on September 4, 2024, the disclosure of which is incorporated herein in its entirety by reference as part of the present application. TECHNICAL FIELD

[0002] The present application relates to the field of radio frequency integrated circuits, and in particular, to a radio frequency power amplification circuit based on a Doherty amplifier. BACKGROUND

[0003] In a 5G communication system (e.g., a mobile phone or other user equipment), a radio frequency power amplifier is a key module, and the radio frequency power amplifier is a major power consumption unit module. In order to improve the spectrum utilization to improve the communication rate, more and more complex modulation methods such as Orthogonal Frequency Division Multiplexing (OFDM) are adopted by the 5G communication system, and the Peak to Average Ratio (PAR) of the radio frequency signal reaches 7dB-9dB. In order to take into account the linearity of the power amplifier when performing power amplification, the radio frequency power amplifier is usually used in a backoff mode. The larger the Peak to Average Ratio (PAR) of the radio frequency signal, the more the radio frequency power amplifier needs to back off in order to ensure the linearity of the amplified signal, and the lower the efficiency is correspondingly. This causes the efficiency of the entire wireless communication system to be reduced, the battery power of the mobile device to be consumed too quickly, and the standby time to be shortened.

[0004] At present, the power amplifier efficiency improvement schemes in the academic and industrial circles mainly fall into two categories: power modulation and load modulation. The power modulation is envelope tracking (ET), which requires a relatively high power supply system. The power supply voltage dynamically follows the envelope change of the radio frequency signal, resulting in that the envelope tracking is relatively complex for the system. Compared with the envelope tracking (ET), the Doherty structure power amplifier is a load modulation technology. The main amplifier and the auxiliary amplifier cooperate to change the load impedance at different output power levels. The impedance is relatively small at high power, and the power output capability is relatively large. At low power, the impedance becomes large, and high efficiency is achieved. That is, the Doherty power amplifier can effectively improve the backoff efficiency of the power amplifier and improve the average efficiency of the power amplifier. The Doherty power amplifier is widely used in base stations. In cooperation with the digital pre-distortion (DPD) system, high power, high efficiency and high linearity are achieved. In most cases, the Doherty amplifier used in the base station is built by discrete devices, and the entire power amplifier occupies a large volume.

[0005] With the advent of 5G, the data transmission speed of the communication system is further improved, and the peak-to-average ratio of the 5G radio frequency signal is further improved. The efficiency of the traditional Class-AB power amplifier circuit cannot meet the demand of the mobile terminal, and the demand for high-efficiency and high-linearity power amplifiers of the mobile terminal is becoming more and more intense. FIG. 1 is a diagram showing a traditional Doherty power amplifier structure. Referring to FIG. 1, the input network uses a power divider to achieve power distribution, a quarter-wave line is connected in series with an auxiliary path amplifier circuit input path to achieve a 90° phase delay. Due to the limited output power of the traditional Doherty power amplifier, it is difficult to output higher power.

[0006] In order to solve the problem of higher output power, there are two common methods, one is to increase the output voltage, and the other is to increase the output current. The DC-DC conversion method can be used to increase the output voltage, but the increase of the voltage will cause the power amplifier to be easily burned out.

[0007] Therefore, it is desirable to have a radio frequency power amplifier circuit that occupies a small space and has high output power. SUMMARY

[0008] The technical scheme of the present application adopts a transformer-based input balun to output two paths. The transformer-based input balun realizes single-ended to differential conversion, so as to combine the power of the two Doherty power amplifiers with a phase difference of 180°, and realize higher power output. The present application utilizes the load modulation principle to realize high backoff efficiency.

[0009] The application adopts a multi-chip module (MCM) form to realize a differential synthesis Doherty structure power amplifier, and a quarter wavelength transformer is equivalent to an inductor and a capacitor, so that the volume of the amplifier is reduced, the amplifier is easy to integrate, and the amplifier is suitable for use in mobile terminal equipment.

[0010] An aspect of the application provides a radio frequency power amplifier circuit, comprising: an input balun module configured to receive a single-ended radio frequency input and output two-way differential radio frequency signals; a main power amplifier module configured to receive one of the two-way differential radio frequency signals from the input balun module and output a first amplified signal; an auxiliary power amplifier module configured to receive the other of the two-way differential radio frequency signals from the input balun module and output a second amplified signal; and an output balun module configured to receive the first amplified signal output by the main power amplifier module and the second amplified signal output by the auxiliary power amplifier module and generate a single-ended radio frequency output signal based on the differential first amplified signal and the second amplified signal.

[0011] An aspect of the application provides a radio frequency power amplifier circuit, wherein the main power amplifier module comprises a first power divider, a first main path amplifier circuit and a first auxiliary path amplifier circuit, and the auxiliary power amplifier module comprises a second power divider, a second main path amplifier circuit and a second auxiliary path amplifier circuit.

[0012] An aspect of the application provides a radio frequency power amplifier circuit, wherein the main power amplifier module further comprises a first driving stage circuit, an input end of the first driving stage circuit is connected to the input balun module, and an output end of the first driving stage circuit is connected to the first power divider, and the auxiliary power amplifier module further comprises a second driving stage circuit, an input end of the second driving stage circuit is connected to the input balun module, and an output end of the second driving stage circuit is connected to the second power divider.

[0013] An aspect of the present application provides a radio frequency power amplification circuit, wherein the first main path amplification circuit comprises a first main amplifier and a first quarter wavelength transformer, an input end of the first main amplifier is connected to a first power divider, an output end of the first main amplifier is connected to the first quarter wavelength transformer, wherein the first auxiliary path amplification circuit comprises a second quarter wavelength transformer and a first auxiliary amplifier, one end of the second quarter wavelength transformer is connected to a second power divider, the other end of the second quarter wavelength transformer is connected to an input end of the first auxiliary amplifier; wherein the second main path amplification circuit comprises a second main amplifier and a third quarter wavelength transformer, an input end of the second main amplifier is connected to the second power divider, an output end of the second main amplifier is connected to the third quarter wavelength transformer, wherein the second auxiliary path amplification circuit comprises a fourth quarter wavelength transformer and a second auxiliary amplifier, one end of the fourth quarter wavelength transformer is connected to the second power divider, the other end of the fourth quarter wavelength transformer is connected to an input end of the second auxiliary amplifier.

[0014] An aspect of the present application provides a radio frequency power amplification circuit, wherein each of the first quarter wavelength transformer, the second quarter wavelength transformer, the third quarter wavelength transformer and the fourth quarter wavelength transformer is implemented by a π-type LC network formed by a capacitor and an inductor, and each of the first quarter wavelength transformer, the second quarter wavelength transformer, the third quarter wavelength transformer and the fourth quarter wavelength transformer is configured to perform 90° phase compensation on a signal passing therethrough while achieving impedance modulation at different power outputs.

[0015] An aspect of the present application provides a radio frequency power amplification circuit, wherein each of the first power divider and the second power divider comprises two π-type LC networks formed by a capacitor and an inductor and a resistance connected between the two π-type LC networks, and each of the first power divider and the second power divider is configured to distribute power passing therethrough into two paths.

[0016] An aspect of the present application provides a radio frequency power amplification circuit, wherein one or more of the first main amplifier, the first auxiliary amplifier, the second main amplifier and the second auxiliary amplifier is formed by at least one of a BJT transistor, a FET transistor and a MOS transistor.

[0017] An aspect of the present application provides a radio frequency power amplification circuit, wherein the input balun module and the output balun module are formed by a ring pattern of a three-layer metal structure.

[0018] An aspect of the present application provides a radio frequency power amplification circuit, wherein the inductor in each of the first quarter wave transformer, the second quarter wave transformer, the third quarter wave transformer, and the fourth quarter wave transformer is formed by a combination of a bond wire and a microstrip line of a substrate.

[0019] An aspect of the present application provides a radio frequency power amplification circuit, wherein the radio frequency power amplifier is packaged by a multi-layer substrate package for multi-chip. BRIEF DESCRIPTION OF DRAWINGS

[0020] FIG. 1 is a schematic diagram showing a conventional Doherty power amplifier structure;

[0021] FIG. 2 is a schematic diagram showing a radio frequency power amplification circuit according to an embodiment of the present application;

[0022] FIG. 3 is a schematic diagram showing a radio frequency power amplification circuit according to an embodiment of the present application;

[0023] FIG. 4 is a schematic diagram showing a radio frequency power amplification circuit according to an embodiment of the present application;

[0024] FIG. 5 is a schematic diagram showing the relationship between the output power and the power-added efficiency (PAE) curves of a Doherty radio frequency power amplifier and a conventional Class AB class power amplifier according to an embodiment of the present application;

[0025] FIG. 6 is a schematic diagram showing an implementation of an input balun module T1 according to an embodiment of the present application;

[0026] FIGS. 7A-7C are schematic diagrams showing an implementation of an output balun T2 according to an embodiment of the present application;

[0027] FIG. 8 is a schematic diagram showing an implementation of the inductor of a quarter wave transformer in a Doherty radio frequency power amplifier according to an embodiment of the present application;

[0028] FIG. 9 is a plan view showing a multi-chip package of a Doherty radio frequency power amplifier according to an embodiment of the present application; and

[0029] FIG. 10 is a side view showing a multi-chip package of a Doherty radio frequency power amplifier according to an embodiment of the present application. DETAILED DESCRIPTION

[0030] Before undertaking a detailed description of the foregoing, it can be advantageous to set forth definitions of certain words and phrases used throughout this patent document. The term “coupled” and variations thereof, means any direct or indirect communication or interaction between two or more elements, regardless of the type of physical connection or physical contact between them. The terms “transmit,” “receive,” and “communicate,” as well as variations thereof, encompass direct and indirect communication. The terms “include” and “comprise,” as well as variations thereof, mean “including but not limited to.” The term “or” is inclusive, meaning and / or. The phrase “associated with,” as well as variations thereof, means includes, is included within, interconnects with, contains, is contained within, connects or is connected with, couples or is coupled with, communicates or is in communication with, cooperates or is cooperative with, interleafs with, is proximate to, is bound to or binds with, has, has a property of, has a relationship with, or is associated with, or the like. The term “controller” means any device, system or part thereof that controls at least one operation. Such a controller can be implemented in hardware or a combination of hardware and software and / or firmware. The functionality associated with any particular controller can be centralized or distributed, whether locally or remotely. The phrase “at least one of,” when used with a list of items, means that different combinations of one or more of the listed items can be utilized and that only one member from the list can be needed. For example, “at least one of A, B, and C” includes any of the following combinations: A, B, C, A and B, A and C, B and C, and A and B and C.

[0031] Definitions for other certain words and phrases are provided throughout this patent document. Those of ordinary skill in the art should understand that in many if not most instances, such definitions apply to prior as well as future uses of such defined words and phrases.

[0032] In this patent document, the application combination of modules and the division level of sub-modules are only for illustration, and the application combination of modules and the division level of sub-modules can have different manners without departing from the scope of the disclosure.

[0033] The technical scheme of the present application adopts a transformer-based input balun to output two paths. The transformer-based input balun realizes single-ended to differential, thereby synthesizing two Doherty power amplifiers with a phase difference of 180° to realize higher power output. The present application utilizes the load modulation principle to realize high backoff efficiency. The present application adopts a multi-chip module form to realize differential synthesis Doherty structure power amplifier, and the quarter-wave transformer is equivalent to inductance and capacitance, which reduces the volume of the amplifier and is easy to integrate, and is suitable for use in mobile terminal equipment.

[0034] FIG. 2 is a schematic diagram showing a radio frequency power amplification circuit according to an embodiment of the present application.

[0035] Referring to FIG. 2, the radio frequency power amplification circuit according to the embodiment of the present application includes an input balun module T1, a main power amplifier module, an auxiliary power amplifier module, an output balun T2, and the like. Among them, the radio frequency input is connected to the main power amplifier module and the auxiliary power amplifier module through the input balun module T1. The input balun module T1 is based on the transformer form, and the input balun module T1 can be configured to receive a single-ended radio frequency input and output two-way differential radio frequency signals. In addition, the radio frequency power amplification circuit further includes an input capacitor Cin configured between two input terminals of the input balun module T1. The input capacitor Cin can be input matched to match the input impedance to a specific impedance, for example, 50Ω.

[0036] The differential output signals output by the input balun module T1 are provided to the main power amplifier module and the auxiliary power amplifier module. The main power amplifier module and the auxiliary power amplifier module can respectively amplify the differential signals output by the input balun module T1 with a phase difference of 180°. For example, the main power amplifier module can receive one of the two-way differential radio frequency signals from the input balun module and output a first amplified signal. The auxiliary power amplifier module can receive the other of the two-way differential radio frequency signals from the input balun module and output a second amplified signal.

[0037] The output balun module T2 can be configured as a balun in the form of a single transformer, for realizing differential-to-single-ended output of the first amplified signal and the second amplified signal, and outputting a single-ended radio frequency output signal through the output balun module T3. The output balun module T3 can include the output balun T2 and a plurality of capacitors. The output balun T2 in the output balun module can receive the first amplified signal output by the main power amplifier module and the second amplified signal output by the auxiliary power amplifier module, and generate a single-ended radio frequency output signal based on the differential first amplified signal and the second amplified signal.

[0038] The plurality of capacitors of the output balun module T2 can further include capacitors C1-C3, wherein the capacitor C1 is configured to be connected between one output terminal of the output balun module T2 and the radio frequency output, the capacitor C2 is configured to be connected between the other output terminal of the output balun module T2 and a ground node, and the capacitor C3 is configured to be connected between the radio frequency output of the amplifier and the ground node. The output is performed through the output balun T2 and the plurality of capacitors, which can realize impedance transformation while realizing power synthesis, and reduce the chip area.

[0039] FIG. 3 is a schematic diagram illustrating a radio frequency power amplification circuit according to an embodiment of the present application.

[0040] Referring to FIG. 3, the radio frequency power amplification circuit according to the embodiment of the present application comprises an input balun module T1, a main power amplifier module, an auxiliary power amplifier module, an output balun T2, etc.

[0041] Referring to FIG. 3, the main power amplifier module can comprise a first driving stage circuit, a first power divider, a first main path amplification circuit, and a first auxiliary path amplification circuit. The auxiliary power amplifier module can comprise a second driving stage circuit, a second power divider, a second main path amplification circuit, and a second auxiliary path amplification circuit.

[0042] The input end of the first driving stage circuit can be connected to the input balun module, and the output end of the first driving stage circuit can be connected to the first power divider. The first power divider can include two π-type LC networks formed by capacitors and inductors and a resistance connected between the two π-type LC networks. The first driving stage circuit can adjust the power of one differential signal (main power amplifier module power) output by the input balun module. In some embodiments, a matching circuit 1 can be connected between the first driving stage circuit and the input balun. The matching circuit 1 can be implemented in the form of an LC network. The matching circuit 1 can be configured to adjust impedance. The output of the first driving stage circuit can be connected to the input end of the first power divider. In some embodiments, a capacitor C4 can be connected between the first driving stage circuit and the first power divider, which can further adjust the impedance for impedance matching between the front and back stages. The first power divider can be configured to divide the power output by the first driving stage circuit into two paths. One of the powers divided by the first power divider (e.g., main path power) can be transmitted to a first main path amplification circuit including a main amplifier 1, and the other power divided by the first power divider (e.g., auxiliary path power) can be transmitted to a first auxiliary path amplification circuit including an auxiliary amplifier 1. The main amplifier 1 can receive the main path power from the first power divider to amplify the main path power. The input end of the main amplifier 1 can be connected to the first power divider. In some embodiments, a matching circuit 2 can be connected between the main amplifier 1 and the first power divider. The matching circuit 2 can be implemented in the form of an LC network. The matching circuit 2 can be configured to adjust impedance for impedance matching between the front and back stages. The output end of the main amplifier 1 can be connected to a first quarter-wave transformer. The first quarter-wave transformer can be implemented in the form of a π-type LC network formed by capacitors and inductors, and can be configured to perform 90° phase compensation on the signal passing therethrough while achieving impedance modulation at different power outputs. The quarter-wave transformer structure using an LC network is compact in size, occupies a small area, and is easy to integrate. The auxiliary amplifier 1 can receive the auxiliary path power from the first power divider to amplify the auxiliary path power. The input end of the auxiliary amplifier 1 can be connected to a second quarter-wave transformer. One end of the second quarter-wave transformer can be connected to the first power divider, and the other end of the second quarter-wave transformer can be connected to the auxiliary amplifier 1. The second quarter-wave transformer can be implemented in the form of a π-type LC network formed by capacitors and inductors, and can be configured to perform 90° phase compensation on the signal passing therethrough while achieving impedance modulation at different power outputs. In some embodiments, a matching circuit 3 can be connected between the auxiliary amplifier 1 and the second quarter-wave transformer. The matching circuit 3 can be implemented in the form of an LC network. The matching circuit 3 can be configured to adjust impedance for impedance matching between the front and back stages.The output of the auxiliary amplifier 1 can be connected to a first quarter wavelength transformer to achieve power combining of the main power amplifier module. The power combined by the main power amplifier module can be one of the differential signals in the input of the output balun T2.

[0043] The input end of the second driving stage circuit can be connected to the input balun module, and the output end of the second driving stage circuit can be connected to the second power divider. The second driving stage circuit can adjust the power of another differential signal (auxiliary power amplifier module power) output by the input balun module. In some embodiments, a matching circuit 4 can be connected between the second driving stage circuit and the input balun. The matching circuit 4 can be implemented in the form of an LC network. The matching circuit 4 can be configured to adjust the impedance for front-to-back impedance matching. The output of the second driving stage circuit can be connected to the input end of the second power divider. In some embodiments, a capacitor C5 can be connected between the second driving stage circuit and the second power divider, which can further adjust the impedance for front-to-back impedance matching. The second power divider can include two π-type LC networks formed by capacitors and inductors, and a resistance connected between the two π-type LC networks. The second power divider can be configured to divide the power output by the second driving stage circuit into two paths. One of the powers divided by the second power divider (e.g., main path power) can be transmitted to a second main path amplification circuit including a main amplifier 2, and the other power divided by the second power divider (e.g., auxiliary path power) can be transmitted to a second auxiliary path amplification circuit including an auxiliary amplifier 2. The main amplifier 2 can receive the main path power from the second power divider to amplify the main path power. The input end of the main amplifier 2 can be connected to the second power divider. In some embodiments, a matching circuit 6 can be connected between the main amplifier 2 and the second power divider. The matching circuit 6 can be implemented in the form of an LC network. The matching circuit 6 can be configured to adjust the impedance for front-to-back impedance matching. The output end of the main amplifier 2 can be connected to a third quarter-wave transformer. The third quarter-wave transformer can be implemented by a π-type LC network formed by capacitors and inductors, and the third quarter-wave transformer can be configured to perform 90° phase compensation on the signal passing therethrough while achieving impedance modulation at different power outputs. The auxiliary amplifier 2 can receive the auxiliary path power from the second power divider to amplify the auxiliary path power. The input end of the auxiliary amplifier 2 can be connected to a fourth quarter-wave transformer. One end of the fourth quarter-wave transformer can be connected to the second power divider, and the other end of the fourth quarter-wave transformer can be connected to the auxiliary amplifier 2. The fourth quarter-wave transformer can be implemented by a π-type LC network formed by capacitors and inductors, and the fourth quarter-wave transformer can be configured to perform 90° phase compensation on the signal passing therethrough while achieving impedance modulation at different power outputs. In some embodiments, a matching circuit 5 can be connected between the auxiliary amplifier 2 and the fourth quarter-wave transformer. The matching circuit 5 can be implemented in the form of an LC network. The matching circuit 5 can be configured to adjust the impedance for front-to-back impedance matching. The output end of the auxiliary amplifier 2 can be connected to the third quarter-wave transformer to achieve power synthesis of the auxiliary power amplifier module.The power synthesized by the auxiliary power amplifier module can be another differential signal in the input of the output balun T2. In some embodiments, between the outputs of the main power amplifier module and the auxiliary power amplifier module, a capacitor C6 can be connected to adjust the impedance for front-end and back-end impedance matching.

[0044] According to embodiments of the present disclosure, the main amplifier 1 and the main amplifier 2 are configured to work in the condition of Class AB + deep Class AB biasing to achieve better linearity and smoothness.

[0045] The output balun T2 can receive the synthesized power from the main power amplifier module and the auxiliary power amplifier module respectively as two-way differential signals to generate a single-ended radio frequency output signal.

[0046] The plurality of capacitors of the output balun module T2 can further include capacitors C1-C3, wherein the capacitor C1 is configured to be connected between one output terminal of the output balun module T2 and the radio frequency output, the capacitor C2 is configured to be connected between the other output terminal of the output balun module T2 and the ground node, and the capacitor C3 is configured to be connected between the radio frequency output of the amplifier and the ground node. By outputting through the output balun T2 and the plurality of capacitors, the power synthesis can be achieved while the impedance transformation is achieved, and the chip area is reduced.

[0047] In one embodiment, one or more of the main amplifier 1, the auxiliary amplifier 1, the main amplifier 2, and the auxiliary amplifier 2 can be formed by at least one of a BJT transistor, a FET transistor, and a MOS transistor.

[0048] FIG. 4 is a schematic diagram illustrating a radio frequency power amplification circuit according to an embodiment of the present disclosure.

[0049] The same elements in FIG. 4 as in FIG. 3 are not described repeatedly. The radio frequency power amplification circuit of FIG. 4 further includes a filter and switch module to meet the application scenarios of out-of-band suppression and multi-antenna transmission. The filter and switch module can be connected between the capacitor C1 and the radio frequency output. The filter and switch module can be connected in series. The filter can filter the signal output by the output balun module T2. The switch module can be configured to switch different antenna ports. Although not shown in FIG. 6, the Doherty radio frequency power amplifier of FIG. 6 can further include a control unit, which can be configured to control the biasing of the power amplifier and the on state of the switch module.

[0050] Figure 5 is a graph showing the output power versus power-added efficiency (PAE) curves of a Doherty RF power amplifier and a conventional Class AB power amplifier, according to an embodiment of the present application. As can be seen from Figure 5, the Doherty RF power amplifier according to an embodiment of the present application can achieve greater power-added efficiency than the conventional Class AB power amplifier at output powers below 35 dBm.

[0051] Figure 6 is a graph showing an implementation of the input balun module Tl, and Figures 7A-7C are graphs showing implementations of the output balun T2, according to an embodiment of the present application.

[0052] Referring to Figure 6, the input balun module Tl can be formed by a three- layer metal formed ring pattern, in which the center is connected to ground by the metal layer 3 in the ring pattern. Compared to the conventional power divider and quarter- wave line structure, the input balun module Tl according to an embodiment of the present application formed by three-layer metal is easier to integrate and occupies less volume.

[0053] As shown in Figure 7A, the output balun T2 can be formed by a three-layer metal structure pattern. As shown in Figure 9B, the first layer metal can include an upper portion open circle and a lower portion downward extending circle. The pattern in Figure 7B can correspond to the input winding of the output balun T2. As shown in Figure 7C, the second layer metal can include an arc pattern, and the third layer metal can include a pattern connecting the arc pattern in the second layer metal by connecting regions. The pattern in Figure 7C can correspond to the output winding of the output balun.

[0054] Figure 8 is a graph showing an implementation of the inductor in the quarter- wave transformer in the Doherty RF power amplifier, according to an embodiment of the present application. Referring to Figure 10, to reduce the overall module area and lower the overall module cost, the inductor in the quarter-wave transformer can be implemented by a combination of a bonding wire and a substrate microstrip line trace.

[0055] Figure 9 is a plan view showing a multi-chip package of the Doherty RF power amplifier, and Figure 10 is a side view showing the multi-chip package of the Doherty RF power amplifier, according to an embodiment of the present application.

[0056] Multi-Chip Module Doherty structure power amplifier is gradually used in mobile terminal. Referring to FIG. 9 and FIG. 10, multiple chips (for example, controller, power amplifier, low noise amplifier, switch module, output balun module) are integrated into one module through multi-layer substrate, and the multiple chips can be interconnected through bonding wires. For example, referring to FIG. 0, the power amplifier chip and the output balun module are interconnected through bonding wires. By adopting the multi-chip integrated module structure, the Doherty power amplifier according to the embodiment of the present application can be further applied to the mobile terminal.

[0057] Although the present disclosure has been described with an example embodiment, various changes and modifications can be suggested to one skilled in the art. It is intended that the present disclosure encompass such changes and modifications as fall within the scope of the appended claims.

[0058] None of the description in this application should be read as implying that any particular element, step, or function is an essential element that must be included in the claim scope. The scope of patented subject matter is defined only by the claims.

Claims

1. A radio frequency power amplification circuit, comprising: an input balun module configured to receive a single-ended radio frequency input and output two differential radio frequency signals; a main power amplifier module configured to receive one of the two differential radio frequency signals from the input balun module and output a first amplified signal; an auxiliary power amplifier module configured to receive the other of the two differential radio frequency signals from the input balun module and output a second amplified signal; an output balun module configured to receive the first amplified signal output by the main power amplifier module and the second amplified signal output by the auxiliary power amplifier module and generate a single-ended radio frequency output signal based on the differential first and second amplified signals.

2. The radio frequency power amplifying circuit of claim 1, wherein, the main power amplifier module comprises a first power divider, a first main path amplification circuit, a first auxiliary path amplification circuit, wherein the auxiliary power amplifier module comprises a second power divider, a second main path amplification circuit, a second auxiliary path amplification circuit.

3. The radio frequency power amplifying circuit of claim 2, wherein, the main power amplifier module further comprises a first driver stage circuit, an input of the first driver stage circuit being connected to the input balun module, an output of the first driver stage circuit being connected to the first power divider, and wherein the auxiliary power amplifier module further comprises a second driver stage circuit, an input of the second driver stage circuit being connected to the input balun module, an output of the second driver stage circuit being connected to the second power divider.

4. The radio frequency power amplifying circuit of claim 2, wherein, the first main path amplification circuit comprises a first main amplifier and a first quarter wavelength transformer, an input of the first main amplifier being connected to the first power divider, an output of the first main amplifier being connected to the first quarter wavelength transformer, wherein the first auxiliary path amplification circuit comprises a second quarter wavelength transformer and a first auxiliary amplifier, one end of the second quarter wavelength transformer being connected to the second power divider, the other end of the second quarter wavelength transformer being connected to an input of the first auxiliary amplifier; wherein the second main path amplification circuit comprises a second main amplifier and a third quarter wavelength transformer, an input of the second main amplifier being connected to the second power divider, an output of the second main amplifier being connected to the third quarter wavelength transformer, wherein the second auxiliary path amplification circuit comprises a fourth quarter wavelength transformer and a second auxiliary amplifier, one end of the fourth quarter wavelength transformer being connected to the second power divider, the other end of the fourth quarter wavelength transformer being connected to an input of the second auxiliary amplifier.

5. The radio frequency power amplifying circuit of claim 4, wherein, each of the first, second, third, and fourth quarter wavelength transformers is implemented by a pi-type LC network formed by a capacitor and an inductor, each of the first, second, third, and fourth quarter wavelength transformers being configured to perform 90° phase compensation on a signal passing therethrough while implementing impedance modulation at different power outputs.

6. The radio frequency power amplifying circuit of claim 2, wherein, Each of the first power splitter and the second power splitter includes two π-type LC networks formed by a capacitor and an inductor and a resistance connected between the two π-type LC networks, and each of the first power splitter and the second power splitter is configured to split power passing therethrough into two paths.

7. The radio frequency power amplifying circuit of claim 4, wherein, One or more of the first main amplifier, the first auxiliary amplifier, the second main amplifier, and the second auxiliary amplifier is formed by at least one of a BJT transistor, a FET transistor, and a MOS transistor.

8. The radio frequency power amplifying circuit of claim 1, wherein, The input balun module and the output balun module are formed by a ring pattern of a three-layer metal structure.

9. The radio frequency power amplifying circuit according to claim 4 or 5, wherein, The inductor in each of the first quarter-wave transformer, the second quarter-wave transformer, the third quarter-wave transformer, and the fourth quarter-wave transformer is formed by a combination of a bonding wire and a substrate microstrip line.

10. The radio frequency power amplifying circuit of claim 1, wherein, The radio frequency power amplifier is packaged by a multi-layer substrate package for multi-chip.

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