Power amplifier and radio frequency front-end module

Abstract

The invention relates to the technical field of wireless communication, and provides a power amplifier and a radio frequency front-end module, and the power amplifier comprises an input matching circuit, a first-stage amplifier, a second-stage amplifier, an inter-stage matching circuit and a third-stage amplifier which are electrically connected in sequence; the first current unit, the second current unit and the third current unit respectively provide bias current for the input end of the first-stage amplifier, the input end of the second-stage amplifier and the input end of the third-stage amplifier; the first-stage amplifier comprises a first triode, a first resistor, a first capacitor and a first inductor, the base electrode of the first triode serves as the input end of the first-stage amplifier, the emitter electrode of the first triode is connected with the first resistor in series and then grounded, and the collector electrode of the first triode is connected with the first end of the first inductor and the first end of the first capacitor; the second end of the first capacitor serves as the output end of the first-stage amplifier. The power amplifier disclosed by the invention can be used for reducing the output nonlinear noise under the condition of meeting high gain.

Description

Technical Field

[0001] The present invention relates to the field of wireless communication technology, and in particular to a power amplifier and a radio frequency front-end module. Background Art

[0002] Existing RF front-end modules have been widely used in wireless communications, the Internet of Things, smart homes and other fields. Among them, the power amplifier is the core unit of the RF front-end module, and its performance has a great impact on the signal output indicators of the RF front-end module. With the rapid development of wireless communications, higher requirements are placed on the linear power of the RF front-end module. However, due to the output power of the RF transceiver, some application scenarios have higher requirements for the gain of the RF front-end module power amplifier.

[0003] In existing RF front-end modules with high gain requirements, the power amplifier usually adopts a three-stage amplification design. In this case, in order to control the gain of the power amplifier, negative feedback is usually added to the first and second stages of amplification. The gain improvement of the power amplifier depends greatly on the number of amplification stages of the power amplifier.

[0004] However, increasing the number of amplification stages will aggravate the deterioration of the nonlinear noise of the power amplifier output, especially the receiving band noise when the power amplifier works in frequency division duplex (FDD) mode. The nonlinear noise of the first-stage amplifier is amplified in the second and third stages in turn, resulting in the deterioration of the final output nonlinear total noise. Summary of the invention

[0005] In view of the above deficiencies in the prior art, the present invention proposes a power amplifier and a radio frequency front-end module to solve the problem of nonlinear noise deterioration of the prior power amplifier.

[0006] In order to solve the above technical problems, the present invention adopts the following technical solutions: In a first aspect, an embodiment of the present invention provides a power amplifier, comprising an input matching circuit, a first-stage amplifier, a second-stage amplifier, an inter-stage matching circuit, and a third-stage amplifier electrically connected in sequence; the input end of the input matching circuit is used to access a radio frequency signal, and the output end of the third-stage amplifier is used to connect to a load; the power amplifier further comprises a first current unit, a second current unit, and a third current unit, the first current unit, the second current unit, and the third current unit respectively provide bias currents for the input end of the first-stage amplifier, the input end of the second-stage amplifier, and the input end of the third-stage amplifier; The first-stage amplifier includes a first transistor, a first resistor, a first capacitor and a first inductor. The base of the first transistor serves as the input end of the first-stage amplifier, the emitter of the first transistor is connected in series with the first resistor and then grounded, the collector of the first transistor is respectively connected to the first end of the first inductor and the first end of the first capacitor, the second end of the first capacitor serves as the output end of the first-stage amplifier, and the second end of the first inductor is used to connect to a first power supply.

[0007] Preferably, the first current unit includes a second power supply and a second resistor, one end of the second power supply is grounded, the other end of the second power supply is connected to the first end of the second resistor, and the second end of the second resistor is connected to the base of the first transistor.

[0008] Preferably, the second-stage amplifier includes a second transistor, a second inductor and a second capacitor, the first end of the second capacitor serves as the input end of the second-stage amplifier, the second end of the second capacitor is connected to the base of the second transistor, the emitter of the second transistor is grounded, the collector of the second transistor is connected to the first end of the second inductor and serves as the output end of the second-stage amplifier, the second end of the second inductor is used to connect to a third power supply; the second current unit is connected to the base of the second transistor.

[0009] Preferably, the power amplifier further comprises a negative feedback circuit, and the negative feedback circuit is used to provide negative feedback for the second stage amplifier; The negative feedback circuit includes a third capacitor and a third resistor; the first end of the third resistor is connected to the first end of the second capacitor, the second end of the third resistor is connected to the first end of the third capacitor, and the second end of the third capacitor is connected to the collector of the second transistor.

[0010] Preferably, the second current unit includes a fourth power supply and a fourth resistor, one end of the fourth power supply is grounded, the other end of the fourth power supply is connected to the first end of the fourth resistor, and the second end of the fourth resistor is connected to the base of the second transistor.

[0011] Preferably, the third-stage amplifier includes a third triode and a third inductor; the base of the third triode serves as the input end of the third-stage amplifier, the emitter of the third triode is grounded, the collector of the third triode is connected to the first end of the third inductor and serves as the output end of the third-stage amplifier, and the second end of the third inductor is used to connect to a fifth power supply.

[0012] Preferably, the third current unit includes a sixth power supply and a fifth resistor, one end of the sixth power supply is grounded, the other end of the sixth power supply is connected to the first end of the fifth resistor, and the second end of the fifth resistor is connected to the base of the third transistor.

[0013] Preferably, the input matching circuit is a fourth capacitor, a first end of the fourth capacitor serves as an input end of the input matching circuit, and a second end of the fourth capacitor serves as an output end of the input matching circuit connected to the input end of the first stage amplifier.

[0014] Preferably, the inter-stage matching circuit includes a fifth capacitor, a sixth capacitor and a fourth inductor, the first end of the fifth capacitor is connected to the output end of the second-stage amplifier as the input end of the inter-stage matching circuit, the second end of the fifth capacitor is respectively connected to the first end of the fourth inductor and the first end of the sixth capacitor, the second end of the fourth inductor is grounded, and the second end of the sixth capacitor is connected to the input end of the third-stage amplifier as the output end of the inter-stage matching circuit.

[0015] In a second aspect, an embodiment of the present invention provides a radio frequency front-end module, comprising a power amplifier as described above. Compared with the related art, in the embodiment of the present invention, an input matching circuit, a first-stage amplifier, a second-stage amplifier, an inter-stage matching circuit and a third-stage amplifier are electrically connected in sequence; the input end of the input matching circuit is used to access the radio frequency signal, and the output end of the third-stage amplifier is used to connect to the load; the first current unit, the second current unit and the third current unit respectively provide bias current for the input end of the first-stage amplifier, the input end of the second-stage amplifier and the input end of the third-stage amplifier; the base of the first triode of the first-stage amplifier serves as the input end of the first-stage amplifier, the emitter of the first triode is connected in series with the first resistor and then grounded, the collector of the first triode is respectively connected to the first end of the first inductor and the first end of the first capacitor, the second end of the first capacitor serves as the output end of the first-stage amplifier, and the second end of the first inductor is used to connect to the first power supply; thereby, the nonlinear noise output by the power amplifier can be reduced while maintaining a high gain of the power amplifier; first, the nonlinear noise generated by the first-stage amplifier itself is reduced through the linearization effect of the first resistor; second, the gain of the first-stage amplifier is increased and the gain of the second-stage amplifier is reduced, so that the gain of the nonlinear noise generated by the first-stage amplifier to the output port of the power amplifier is reduced, so as to reduce its output nonlinear noise. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] The present invention will be described in detail below in conjunction with the accompanying drawings. The above and other aspects of the present invention will become clearer and easier to understand through the detailed description made in conjunction with the following drawings. In the accompanying drawings: Figure 1A circuit structure block diagram of a power amplifier provided in an embodiment of the present invention; Figure 2 A gain comparison diagram of the power amplifier provided in the embodiment of the present invention and the power amplifier in the prior art; Figure 3 A comparison diagram of the nonlinear noise of the power amplifier provided by the embodiment of the present invention and the power amplifier in the prior art.

[0017] Among them, 100, power amplifier, 1, input matching circuit, 2, first stage amplifier, 3, second stage amplifier, 4, inter-stage matching circuit, 5, third stage amplifier, 6, negative feedback circuit, 7, first current unit, 8, second current unit, 9, third current unit. DETAILED DESCRIPTION Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by technicians in the technical field of the present application; the terms used in the specification of the application herein are only for the purpose of describing specific embodiments and are not intended to limit the present application; the terms "including" and "having" and any variations thereof in the specification and claims of the present application and the above-mentioned drawings are intended to cover non-exclusive inclusions. The terms "first", "second", etc. in the specification and claims of the present application or the above-mentioned drawings are used to distinguish different objects, not to describe a specific order.

[0018] Reference to "embodiments" herein means that a particular feature, structure, or characteristic described in conjunction with the embodiments may be included in at least one embodiment of the present application. The appearance of the phrase in various locations in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment that is mutually exclusive with other embodiments. It is explicitly and implicitly understood by those skilled in the art that the embodiments described herein may be combined with other embodiments.

[0019] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0020] Embodiment 1 See also Figure 1As shown, an embodiment of the present invention provides a power amplifier 100, comprising an input matching circuit 1, a first-stage amplifier 2, a second-stage amplifier 3, an inter-stage matching circuit 4, and a third-stage amplifier 5 electrically connected in sequence; the input end of the input matching circuit 1 is used to access the radio frequency signal, and the output end of the third-stage amplifier 5 is used to connect to the load. The power amplifier 100 also includes a first current unit 7, a second current unit 8, and a third current unit 9, and the first current unit 7, the second current unit 8, and the third current unit 9 provide bias currents for the input end of the first-stage amplifier 2, the input end of the second-stage amplifier 3, and the input end of the third-stage amplifier 5, respectively. The radio frequency signal is matched through the input matching circuit 1, and the signal is amplified through the first-stage amplifier 2, the second-stage amplifier 3, the inter-stage matching circuit 4, and the third-stage amplifier 5 in sequence, and the amplified signal is output to the load.

[0021] Optionally, the power amplifier 100 is not limited to the three-stage amplifier 2, the second-stage amplifier 3 and the third-stage amplifier 5 mentioned above. In corresponding needs, it can also be more than three stages, for example, four stages, five stages, etc. The technical effects produced by the two are the same and will not be described here.

[0022] Among them, the first stage amplifier 2, the second stage amplifier 3 and the third stage amplifier 5 are generally HBT transistors or BJT transistor devices. The heterojunction bipolar transistor (HBT) is a high-speed, high-frequency, low-noise, and low-power transistor based on a semiconductor heterojunction. Compared with the traditional homojunction bipolar transistor (BJT), the HBT has a higher current gain and a faster switching speed. The BJT transistor is called a bipolar junction transistor (BJT), commonly known as a triode. It is an electronic device with three terminals, made of three parts of semiconductors with different doping levels. The charge flow in the transistor is mainly due to the diffusion and drift motion of carriers at the PN junction.

[0023] Specifically, the first-stage amplifier 2 includes a first transistor Q1, a first resistor R1, a first capacitor C1 and a first inductor L1. The base of the first transistor Q1 serves as the input end of the first-stage amplifier 2, and the emitter of the first transistor Q1 is connected in series with the first resistor R1 and then grounded. The collector of the first transistor Q1 is connected to the first end of the first inductor L1 and the first end of the first capacitor C1 respectively, the second end of the first capacitor C1 serves as the output end of the first-stage amplifier 2, and the second end of the first inductor L1 is used to connect to the first power supply SRC1. The emitter of the first transistor Q1 is connected in series with the first resistor R1 and grounded as a negative feedback resistor, which is convenient for reducing the feedback depth, and the resistance value of the first resistor R1 directly affects the gain of the first-stage amplifier 2, which can effectively control the amplification gain. At the same time, the linearity of the first-stage amplifier 2 can also be improved, and the nonlinear noise generated by the first-stage amplifier 2 can be reduced; thereby, the nonlinear noise output by the power amplifier 100 can be reduced while maintaining the high gain of the power amplifier 100. First, the nonlinear noise generated by the first-stage amplifier 2 itself is reduced through the linearization effect of the first resistor R1; second, the gain of the first-stage amplifier 2 is increased and the gain of the second-stage amplifier 3 is reduced, so that the gain of the nonlinear noise generated by the first-stage amplifier 2 to the output port of the power amplifier 100 is reduced, thereby reducing its output nonlinear noise.

[0024] Among them, from the analysis of the DC operating point, when nonlinearity occurs, the DC operating point of the base current of the first transistor Q1 will change, and the collector current will also change accordingly. Because the collector current flows through the first resistor R1, the voltage on the first resistor R1 will also change accordingly, so that the output voltage remains stable. That is, most of the changes in the DC operating point of the base current of the first transistor Q1 are borne by the first resistor R1, which is the linearization effect of the first resistor R1. At the same time, the first resistor R1 acts as a negative feedback resistor, and its resistance directly affects the gain of the first-stage amplifier 2, which can effectively control the amplification gain.

[0025] By connecting the first capacitor C1 between the first stage amplifier 2 and the second stage amplifier 3, the capacitive coupling function between the first stage amplifier 2 and the second stage amplifier 3 can be realized. At the same time, the first capacitor C1 and the first inductor L1 are connected to each other to form a high-pass filter, which can reduce the gain of the second stage amplifier 3. At this time, since the gain of the first stage amplifier 2 is increased, the gain of the second stage amplifier 3 is reduced, so that the overall power amplifier 100 still maintains a high gain. However, the nonlinear noise generated by the first transistor Q1 is effectively reduced after passing through the second stage amplifier 3 and the third stage amplifier 5.

[0026] In this embodiment, the first current unit 7 includes a second power supply SRC2 and a second resistor R2, one end of the second power supply SRC2 is grounded, the other end of the second power supply SRC2 is connected to the first end of the second resistor R2, and the second end of the second resistor R2 is connected to the base of the first transistor Q1. The second power supply SRC2 is connected in series with the second resistor R2 to provide a bias current for the base of the first transistor Q1. The second resistor R2 can also provide a path protection effect for the second power supply SRC2 passing through. First, it can isolate the RF signal from the DC signal; second, it can act as a ballast resistor to prevent the first transistor Q1 from thermal runaway when working at high power, thereby improving the safety performance of the circuit.

[0027] In this embodiment, the second stage amplifier 3 includes a second transistor Q2, a second inductor L2 and a second capacitor C2. The first end of the second capacitor C2 serves as the input end of the second stage amplifier 3, the second end of the second capacitor C2 is connected to the base of the second transistor Q2, and the emitter of the second transistor Q2 is grounded. The collector of the second transistor Q2 is connected to the first end of the second inductor L2 and serves as the output end of the second stage amplifier 3, and the second end of the second inductor L2 is used to connect the third power supply SRC3. The second current unit 8 is connected to the base of the second transistor Q2. The second capacitor C2 is used to perform capacitive coupling or direct isolation effect on the enhanced gain of the first transistor Q1, so that the base of the second transistor Q2 receives the high gain and nonlinear noise of the first transistor Q1, and the second transistor Q2 reduces the gain, thereby reducing the nonlinear noise outputted by it. The third power supply SRC3 is connected through the second inductor L2, which can provide a power supply function for the collector of the second transistor Q2.

[0028] In this embodiment, the power amplifier 100 further includes a negative feedback circuit 6, and the negative feedback circuit 6 is used to provide negative feedback for the second stage amplifier 3. The negative feedback circuit 6 includes a third capacitor C3 and a third resistor R3. The first end of the third resistor R3 is connected to the first end of the second capacitor C2, the second end of the third resistor R3 is connected to the first end of the third capacitor C3, and the second end of the third capacitor C3 is connected to the collector of the second transistor Q2. The third capacitor C3 and the third resistor R3 provide negative feedback for the second transistor Q2, thereby further optimizing the nonlinear noise output by the first transistor Q1 and reducing the nonlinear noise.

[0029] In this embodiment, the second current unit 8 includes a fourth power supply SRC4 and a fourth resistor R4. One end of the fourth power supply SRC4 is grounded, the other end of the fourth power supply SRC4 is connected to the first end of the fourth resistor R4, and the second end of the fourth resistor R4 is connected to the base of the second transistor Q2. The fourth power supply SRC4 is connected in series with the fourth resistor R4 to provide a bias current for the base of the second transistor Q2. The fourth resistor R4 can also provide a path protection effect for the fourth power supply SRC4 passing through. First, it can isolate the RF signal from the DC signal; second, it can act as a ballast resistor to prevent the second transistor Q2 from thermal runaway when working at high power, thereby improving the safety performance of the circuit.

[0030] In this embodiment, the third-stage amplifier 5 includes a third triode Q3 and a third inductor L3. The base of the third triode Q3 serves as the input end of the third-stage amplifier 5, and the emitter of the third triode Q3 is grounded. The collector of the third triode Q3 is connected to the first end of the third inductor L3 and serves as the output end of the third-stage amplifier 5, and the second end of the third inductor L3 is used to connect the fifth power supply SRC5. By connecting to the fifth power supply SRC5 through the third inductor L3, a power supply function can be provided for the collector of the third triode Q3. Optionally, the sizes of the first power supply SRC1, the third power supply SRC3 and the fifth power supply SRC5 can be the same or different.

[0031] In this embodiment, the third current unit 9 includes a sixth power supply SRC6 and a fifth resistor R5. One end of the sixth power supply SRC6 is grounded, the other end of the sixth power supply SRC6 is connected to the first end of the fifth resistor R5, and the second end of the fifth resistor R5 is connected to the base of the third transistor Q3. The sixth power supply SRC6 is connected in series with the fifth resistor R5 to provide a bias current for the base of the third transistor Q3. The fifth resistor R5 can also provide a path protection effect for the sixth power supply SRC6 passing through. First, it can isolate the RF signal from the DC signal; second, it can act as a ballast resistor to prevent the third transistor Q3 from thermal runaway when working at high power, thereby improving the safety performance of the circuit.

[0032] Optionally, the second power source SRC2, the fourth power source SRC4 and the sixth power source SRC6 may be the same or different in size. By using the same or different current source sizes, a bias current can be provided to the corresponding first transistor Q1, the second transistor Q2 and the third transistor Q3, thereby improving the gain adjustment and nonlinear noise reduction performance of the first transistor Q1, the second transistor Q2 and the third transistor Q3.

[0033] In this embodiment, the input matching circuit 1 is a fourth capacitor C4, a first end of the fourth capacitor C4 is used as an input end of the input matching circuit 1, and a second end of the fourth capacitor C4 is used as an output end of the input matching circuit 1 and is connected to the input end of the first stage amplifier 2. The input RF signal is matched by the fourth capacitor C4 and then output to the first transistor Q1, so that the base of the first transistor Q1 receives the matched RF signal, and the performance is better.

[0034] Optionally, the input matching circuit 1 may also be an inductor or a resistor.

[0035] In this embodiment, the inter-stage matching circuit 4 includes a fifth capacitor C5, a sixth capacitor C6 and a fourth inductor L4. The first end of the fifth capacitor C5 is connected to the output end of the second stage amplifier 3 as the input end of the inter-stage matching circuit 4, the second end of the fifth capacitor C5 is respectively connected to the first end of the fourth inductor L4 and the first end of the sixth capacitor C6, the second end of the fourth inductor L4 is grounded, and the second end of the sixth capacitor C6 is connected to the input end of the third stage amplifier 5 as the output end of the inter-stage matching circuit 4. The fifth capacitor C5, the sixth capacitor C6 and the fourth inductor L4 are used for inter-stage matching between the second triode Q2 and the third triode Q3. The inter-stage matching circuit 4 is used to amplify the voltage output by the second triode Q2, amplify the weak input voltage to a sufficient amplitude, and output it to the third triode Q3. The third triode Q3 is amplified to achieve the power required by the output load, and it is required to match the load.

[0036] In this embodiment, Figure 2-3 As shown, Figure 2 The simulation data comparison diagram of the power amplifier of the prior art and the power amplifier 100 of the present invention is shown in FIG. 1 , in which the emitter of the first transistor Q1 is connected in series with the first resistor R1. Figure 2 It can be seen that the gains of the two power amplifiers are close, both maintaining a high gain of 36dB. Figure 3 It can be seen that the output nonlinear noise of the power amplifier 100 of the present invention is significantly optimized. Therefore, the power amplifier 100 can reduce its output nonlinear noise under the condition of high gain.

[0037] Embodiment 2 The embodiment of the present invention provides a radio frequency front-end module, including the power amplifier 100 as described above. The technical effect produced by the radio frequency front-end module is the same as that of the power amplifier 100 described above, and can reduce its output nonlinear noise when the radio frequency front-end module has a high gain.

[0038] It should be noted that the various embodiments described above with reference to the accompanying drawings are only used to illustrate the present invention rather than to limit the scope of the present invention. Those skilled in the art should understand that any modification or equivalent substitution of the present invention without departing from the spirit and scope of the present invention should be included within the scope of the present invention. In addition, unless otherwise indicated by the context, words appearing in the singular include the plural form, and vice versa. In addition, unless otherwise specified, all or part of any embodiment may be used in combination with all or part of any other embodiment.

Claims

1. A power amplifier, comprising an input matching circuit, a first-stage amplifier, a second-stage amplifier, an inter-stage matching circuit and a third-stage amplifier electrically connected in sequence; the input end of the input matching circuit is used to access a radio frequency signal, and the output end of the third-stage amplifier is used to connect to a load; characterized in that: The power amplifier further comprises a first current unit, a second current unit and a third current unit, wherein the first current unit, the second current unit and the third current unit respectively provide bias currents for the input end of the first stage amplifier, the input end of the second stage amplifier and the input end of the third stage amplifier; The first-stage amplifier includes a first transistor, a first resistor, a first capacitor and a first inductor. The base of the first transistor serves as the input end of the first-stage amplifier, the emitter of the first transistor is connected in series with the first resistor and then grounded, the collector of the first transistor is respectively connected to the first end of the first inductor and the first end of the first capacitor, the second end of the first capacitor serves as the output end of the first-stage amplifier, and the second end of the first inductor is used to connect to a first power supply.

2. The power amplifier according to claim 1, characterized in that: The first current unit includes a second power supply and a second resistor, one end of the second power supply is grounded, the other end of the second power supply is connected to the first end of the second resistor, and the second end of the second resistor is connected to the base of the first transistor.

3. The power amplifier according to claim 1, characterized in that: The second-stage amplifier includes a second transistor, a second inductor and a second capacitor, the first end of the second capacitor serves as the input end of the second-stage amplifier, the second end of the second capacitor is connected to the base of the second transistor, the emitter of the second transistor is grounded, the collector of the second transistor is connected to the first end of the second inductor and serves as the output end of the second-stage amplifier, the second end of the second inductor is used to connect to a third power supply; the second current unit is connected to the base of the second transistor.

4. The power amplifier according to claim 3, characterized in that: The power amplifier further comprises a negative feedback circuit, wherein the negative feedback circuit is used to provide negative feedback for the second stage amplifier; The negative feedback circuit includes a third capacitor and a third resistor; the first end of the third resistor is connected to the first end of the second capacitor, the second end of the third resistor is connected to the first end of the third capacitor, and the second end of the third capacitor is connected to the collector of the second transistor.

5. The power amplifier according to claim 3, characterized in that: The second current unit includes a fourth power supply and a fourth resistor, one end of the fourth power supply is grounded, the other end of the fourth power supply is connected to the first end of the fourth resistor, and the second end of the fourth resistor is connected to the base of the second transistor.

6. The power amplifier according to claim 3, characterized in that: The third-stage amplifier includes a third triode and a third inductor; the base of the third triode serves as the input end of the third-stage amplifier, the emitter of the third triode is grounded, the collector of the third triode is connected to the first end of the third inductor and serves as the output end of the third-stage amplifier, and the second end of the third inductor is used to connect to a fifth power supply.

7. The power amplifier according to claim 6, characterized in that: The third current unit includes a sixth power supply and a fifth resistor, one end of the sixth power supply is grounded, the other end of the sixth power supply is connected to the first end of the fifth resistor, and the second end of the fifth resistor is connected to the base of the third transistor.

8. The power amplifier according to claim 1, characterized in that: The input matching circuit is a fourth capacitor, a first end of the fourth capacitor serves as an input end of the input matching circuit, and a second end of the fourth capacitor serves as an output end of the input matching circuit connected to the input end of the first stage amplifier.

9. The power amplifier according to claim 6, characterized in that: The inter-stage matching circuit includes a fifth capacitor, a sixth capacitor and a fourth inductor. The first end of the fifth capacitor is connected to the output end of the second-stage amplifier as the input end of the inter-stage matching circuit, the second end of the fifth capacitor is respectively connected to the first end of the fourth inductor and the first end of the sixth capacitor, the second end of the fourth inductor is grounded, and the second end of the sixth capacitor is connected to the input end of the third-stage amplifier as the output end of the inter-stage matching circuit.

10. A radio frequency front-end module, characterized in that: Comprising a power amplifier as described in any one of claims 1-9.

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