Push-pull power amplifier circuit and RF front-end module

Abstract

The present application discloses a push-pull power amplification circuit, which includes a first differential amplification transistor, a second differential amplification transistor, an impedance matching circuit, and a balun. The first end of the impedance matching circuit is connected to the output end of the first differential amplification transistor, and the second end of the impedance matching circuit is connected to the output end of the second differential amplification transistor. The impedance matching circuit includes a first impedance matching unit, a second impedance matching unit, and a third impedance unit. The impedance matching circuit provided in the present application, through a clever design, uses the method of multiplexing impedance matching elements to form different harmonic impedance adjustment units to meet the impedance matching requirements of the push-pull power amplification circuit. On the premise of achieving impedance matching, the impedance matching circuit provided in this embodiment has a simpler structure, fewer components, and higher integration.

Description

Technical Field

[0001] The present invention relates to the field of radio frequency technology, and particularly to a push-pull power amplifier circuit and a radio frequency front-end module. Background Art

[0002] With the rapid development of mobile communication, the 5G era has arrived, and all walks of life have put forward high requirements for the technological development of the communication industry. As a core module in the communication system, the power amplifier shoulders the heavy responsibility of technological development. Coupled with the advocacy of environmental protection and energy conservation in recent years, the power amplifier is developing in the direction of high efficiency, large bandwidth, and high gain.

[0003] The push-pull power amplifier circuit is a common type of power amplifier circuit. It is widely used in various wireless communication devices. Generally speaking, a corresponding impedance matching circuit needs to be set for the push-pull power amplifier circuit for impedance matching. At present, the number of components in the impedance matching circuit of the existing push-pull power amplifier circuit is too large, resulting in an excessive design area occupied by the push-pull power amplifier circuit. Summary of the Invention

[0004] The purpose of the present invention is to provide a push-pull power amplifier circuit and a radio frequency front-end module to solve the problem of low integration in the push-pull power amplifier circuit in related technologies.

[0005] To achieve the above object, the present invention provides a push-pull power amplifier circuit, including a first differential amplification transistor, a second differential amplification transistor, an impedance matching circuit, and a balun; a first end of the impedance matching circuit is connected to an output end of the first differential amplification transistor, and a second end of the impedance matching circuit is connected to an output end of the second differential amplification transistor; the impedance matching circuit includes a first impedance matching unit, a second impedance matching unit, and a third impedance matching unit. Among them, a first end of the first impedance matching unit is connected to the output end of the first differential amplification transistor, and a second end of the first impedance matching unit is grounded; a first end of the second impedance matching unit is connected to the second differential amplification transistor, and a second end of the second impedance matching unit is grounded; a first end of the third impedance matching unit is connected to a third end of the first impedance matching unit, and a second end of the third impedance matching unit is connected to a third end of the second impedance matching unit; the balun includes a first coil, a first end of the first coil is connected to the output end of the first differential amplification transistor, and a second end of the first coil is connected to the output end of the second differential amplification transistor.

[0006] Further, preferably, the first impedance matching unit includes: a first impedance matching element and a second impedance matching element; the first impedance matching element and the second impedance matching element are connected in series to form a first LC resonance circuit; the second impedance matching unit includes: a third impedance matching element and a fourth impedance matching element; the third impedance matching element and the fourth impedance matching element are connected in series to form a second LC resonance circuit, and the resonance frequency points of the first LC resonance circuit and the second LC resonance circuit are the same.

[0007] Further, preferably, the resonance frequency points of the first LC resonance circuit and the second LC resonance circuit are the first resonance frequency points.

[0008] Further, preferably, the resonance frequency point of the first LC resonance circuit is the same as the signal frequency point of the second harmonic at the output end of the first differential amplification transistor; the resonance frequency point of the second LC resonance circuit is the same as the frequency point of the second harmonic at the output end of the second differential amplification transistor.

[0009] Further, preferably, the third impedance matching unit includes: a fifth impedance matching element, the first end of the fifth impedance matching element is connected to the common node of the first impedance matching element and the second impedance matching element, the second end of the fifth impedance matching element is connected to the common node of the third impedance matching element and the fourth impedance matching element, and the fifth impedance matching element is a capacitive element or an inductive element.

[0010] Further, preferably, the first impedance matching element, the third impedance matching element, and the fifth impedance matching element are capacitive elements, the second impedance matching element and the fourth impedance matching element are inductive elements, or the first impedance matching element, the third impedance matching element, and the fifth impedance matching element are inductive elements, and the second impedance matching element and the fourth impedance matching element are capacitive elements.

[0011] Further, preferably, the first impedance matching unit and the third impedance matching unit form a third LC resonance circuit; the second impedance matching unit and the third impedance matching unit form a fourth LC resonance circuit; the resonance frequency points of the third LC resonance circuit and the fourth LC resonance circuit are the same.

[0012] Further, preferably, the resonance frequency points of the third LC resonance circuit and the fourth LC resonance circuit are the second resonance frequency points.

[0013] Further, preferably, the first impedance matching unit, the third impedance matching unit, and the balun form a fifth resonant circuit; the second impedance matching unit, the third impedance matching unit, and the balun form a sixth resonant circuit; the resonant frequency points of the fifth LC resonant circuit and the sixth LC resonant circuit are the same.

[0014] Further, preferably, the resonant frequency points of the fifth LC resonant circuit and the sixth LC resonant circuit are the third resonant frequency points.

[0015] Further, preferably, the resonant frequency point of the fifth LC resonant circuit is the same as the signal frequency point of the third harmonic of the output end of the first differential amplification transistor; the resonant frequency point of the second LC resonant circuit is the same as the frequency point of the third harmonic of the output end of the second differential amplification transistor.

[0016] Further, preferably, the first resonant frequency point is less than the second resonant frequency point, and the second resonant frequency point is less than the third resonant frequency point.

[0017] Further, preferably, the impedance matching circuit and the balun are configured to make the push-pull power amplifier circuit operate in class F.

[0018] Further, preferably, the impedance matching circuit further includes a fourth impedance matching unit and a fifth impedance matching unit, wherein the first end of the fourth impedance matching unit is connected to the output end of the first differential amplification transistor, and the second end of the fourth impedance matching unit is grounded; the first end of the fifth impedance matching unit is connected to the output end of the second differential amplification transistor, and the second end of the fifth impedance matching unit is grounded.

[0019] Further, preferably, the first impedance matching unit includes: a first impedance matching element and a second impedance matching element; the first impedance matching element and the second impedance matching element are connected in series to form a first LC resonant circuit; the second impedance matching unit includes: a third impedance matching element and a fourth impedance matching element; the third impedance matching element and the fourth impedance matching element are connected in series to form a second LC resonant circuit, and the resonant frequency points of the first LC resonant circuit and the second LC resonant circuit are the same.

[0020] Further, preferably, the resonant frequency points of the first LC resonant circuit and the second LC resonant circuit are the fourth resonant frequency points.

[0021] Further, preferably, the resonant frequency point of the first LC resonant circuit is the same as the signal frequency point of the second harmonic at the output end of the first differential amplification transistor; the resonant frequency point of the second LC resonant circuit is the same as the frequency point of the second harmonic at the output end of the second differential amplification transistor.

[0022] Further, preferably, the third impedance matching unit includes: a fifth impedance matching element, the first end of the fifth impedance matching element is connected to the common node of the first impedance matching element and the second impedance matching element, the second end of the fifth impedance matching element is connected to the common node of the third impedance matching element and the fourth impedance matching element, and the fifth impedance matching element is a capacitive element or an inductive element.

[0023] Further, preferably, the first impedance matching element, the third impedance matching element and the fifth impedance matching element are capacitive elements, the second impedance matching element and the fourth impedance matching element are inductive elements, or the first impedance matching element, the third impedance matching element and the fifth impedance matching element are inductive elements, and the second impedance matching element and the fourth impedance matching element are capacitive elements.

[0024] Further, preferably, the first impedance matching unit and the third impedance matching unit form a third LC resonant circuit; the second impedance matching unit and the third impedance matching unit form a fourth LC resonant circuit; the resonant frequency points of the third LC resonant circuit and the fourth LC resonant circuit are the same.

[0025] Further, preferably, the resonant frequency points of the third LC resonant circuit and the fourth LC resonant circuit are the fifth resonant frequency points.

[0026] Further, preferably, the fourth impedance matching unit includes: a sixth impedance matching element and a seventh impedance matching element, the sixth impedance matching element and the seventh impedance matching element are connected in series to form a seventh LC resonant circuit; the fifth impedance matching unit includes: an eighth impedance matching element and a ninth impedance matching element, the eighth impedance matching element and the ninth impedance matching element are connected in series to form an eighth LC resonant circuit; the resonant frequency points of the seventh LC resonant circuit and the eighth LC resonant circuit are the same.

[0027] Further, preferably, the resonant frequency points of the seventh LC resonant circuit and the eighth LC resonant circuit are the sixth resonant frequency points.

[0028] Further, preferably, the resonance frequency point of the seventh LC resonance circuit is the same as the signal frequency point of the fourth harmonic of the output end of the first differential amplification transistor; the resonance frequency point of the eighth LC resonance circuit is the same as the frequency point of the fourth harmonic of the output end of the second differential amplification transistor.

[0029] Further, preferably, the first impedance matching unit, the third impedance matching unit, the fourth impedance matching unit and the balun form a ninth LC resonance circuit; the second impedance matching unit, the third impedance matching unit, the fifth impedance matching unit and the balun form a tenth LC resonance circuit; the resonance frequency points of the ninth LC resonance circuit and the tenth LC resonance circuit are the same.

[0030] Further, preferably, the resonance frequency points of the ninth LC resonance circuit and the tenth LC resonance circuit are the seventh resonance frequency points.

[0031] Further, preferably, the resonance frequency point of the ninth LC resonance circuit is the same as the signal frequency point of the third harmonic and / or the fifth harmonic of the output end of the first differential amplification transistor; the resonance frequency point of the tenth LC resonance circuit is the same as the frequency point of the third harmonic and / or the fifth harmonic of the output end of the second differential amplification transistor.

[0032] Further, preferably, the third resonance frequency point is less than the fourth resonance frequency point, the fourth resonance frequency point is less than the fifth resonance frequency point, the fifth resonance frequency point is less than the sixth resonance frequency point, and the sixth resonance frequency point is less than the seventh resonance frequency point.

[0033] Further, preferably, the impedance matching circuit and the balun are configured to make the push-pull power amplifier circuit operate in class F.

[0034] Further, preferably, the first differential amplification transistor and the second differential amplification transistor are HBT transistors or MOS transistors.

[0035] The present application also provides a push-pull power amplifier circuit, including a first differential amplification transistor, a second differential amplification transistor, a first circuit and a balun; a first end of the first circuit is connected to an output end of the first differential amplification transistor, and a second end of the first circuit is connected to an output end of the second differential amplification transistor; the first circuit includes: a first passive element, a second passive element, a third passive element, a fourth passive element and a fifth passive element, wherein a first end of the first passive element is connected to the output end of the first differential amplification transistor, and a second end of the first passive element is connected to a first end of the second passive element; a second end of the second passive element is grounded; a first end of the third passive element is connected to the output end of the second differential amplification transistor, and a second end of the third passive element is connected to a first end of the fourth passive element; a second end of the fourth passive element is grounded; a first end of the fifth passive element is connected to the first end of the second passive element, and a second end of the fifth passive element is connected to the first end of the fourth passive element; the balun includes a first coil, a first end of the first coil is connected to the output end of the first differential amplification transistor, and a second end of the first coil is connected to the output end of the second differential amplification transistor.

[0036] Further, preferably, the first passive element, the third passive element and the fifth passive element are capacitive elements, and the second passive element and the fourth passive element are inductive elements, or the first passive element, the third passive element and the fifth passive element are inductive elements, and the second passive element and the fourth passive element are capacitive elements.

[0037] Further, preferably, the first circuit further includes a sixth passive element, a seventh passive element, an eighth passive element and a ninth passive element, wherein a first end of the sixth passive element is connected to the output end of the first differential amplification transistor, a second end of the sixth passive element is connected to a first end of the seventh passive element, and a second end of the seventh passive element is grounded; a first end of the eighth passive element is connected to the output end of the second differential amplification transistor, a second end of the eighth passive element is connected to a first end of the ninth passive element, and a second end of the ninth passive element is grounded.

[0038] Further, preferably, the first passive element, the third passive element, the fifth passive element, the sixth passive element, and the eighth passive element are capacitive elements, and the second passive element, the fourth passive element, the seventh passive element, and the ninth passive element are inductive elements; or the first passive element, the third passive element, the fifth passive element, the sixth passive element, and the eighth passive element are inductive elements, and the second passive element, the fourth passive element, the seventh passive element, and the ninth passive element are capacitive elements.

[0039] The present application also provides a radio frequency front-end module, including the push-pull power amplifier circuit as described in any one of the above.

[0040] Compared with the prior art, the beneficial effects of a push-pull power amplifier circuit and a radio frequency front-end module according to an embodiment of the present application are as follows:

[0041] A push - pull power amplifier circuit provided by an embodiment of the present application includes a first differential amplifier transistor, a second differential amplifier transistor, an impedance matching circuit, and a balun; a first end of the impedance matching circuit is connected to an output end of the first differential amplifier transistor, and a second end of the impedance matching circuit is connected to an output end of the second differential amplifier transistor; the impedance matching circuit includes a first impedance matching unit, a second impedance matching unit, and a third impedance matching unit. Among them, a first end of the first impedance matching unit is connected to the output end of the first differential amplifier transistor, and a second end of the first impedance matching unit is grounded; a first end of the second impedance matching unit is connected to the second differential amplifier transistor, and a second end of the second impedance matching unit is grounded; a first end of the third impedance matching unit is connected to a third end of the first impedance matching unit, and a second end of the third impedance matching unit is connected to a third end of the second impedance matching unit; the balun includes a first coil, a first end of the first coil is connected to the output end of the first differential amplifier transistor, and a second end of the first coil is connected to the output end of the second differential amplifier transistor. The push - pull power amplifier circuit provided by the present application includes a first differential amplifier transistor, a second differential amplifier transistor, an impedance matching circuit, and a balun. The impedance matching circuit is arranged between the output ends of the first differential transistor and the second differential amplifier transistor. The impedance matching circuit includes a plurality of impedance matching units. The plurality of impedance matching units can not only individually form harmonic impedance adjustment units to adjust the harmonic impedance in the push - pull power amplifier circuit, but also be combined with other impedance matching units and the balun to form new harmonic impedance adjustment units to adjust the harmonic impedance, so that the impedance matching circuit can adjust the harmonic impedance of different orders for the push - pull power amplifier circuit to meet the corresponding impedance matching requirements. That is, the impedance matching circuit provided in the present application, through a clever design, uses the method of multiplexing impedance matching elements to form different harmonic impedance adjustment units to meet the impedance matching requirements of the push - pull power amplifier circuit. On the premise of realizing impedance matching, the impedance matching circuit structure provided in this embodiment is simpler, the number of components is less, and the integration degree is higher. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] Figure 1 is a schematic structural diagram of a push - pull power amplifier circuit provided by an embodiment of the present application;

[0043] Figure 2 is a schematic structural diagram of the impedance matching circuit provided by an embodiment of the present application;

[0044] Figure 3 is a schematic structural diagram of another impedance matching circuit provided by an embodiment of the present application;

[0045] Figure 4It is a schematic diagram of the balun inductor equivalent model provided by the embodiments of the present application;

[0046] Figure 5 It is a schematic structural diagram of another push - pull power amplifier circuit provided by the embodiments of the present application;

[0047] Figure 6 It is a schematic structural diagram of yet another impedance matching circuit provided by the embodiments of the present application;

[0048] Figure 7 It is a schematic structural diagram of yet another impedance matching circuit provided by the embodiments of the present application;

[0049] Figure 8 It is a schematic structural diagram of yet another push - pull power amplifier circuit provided by the embodiments of the present application;

[0050] Figure 9 It is a schematic structural diagram of yet another push - pull power amplifier circuit provided by the embodiments of the present application;

[0051] In the figure: 10, the first differential amplification transistor; 20, the second differential amplification transistor; 30, the balun; 40, the impedance matching circuit; 41, the first impedance matching unit; 42, the second impedance matching unit; 43, the third unit; 44, the third impedance matching unit; 45, the fourth harmonic suppression unit; 411, the first impedance matching element; 412, the second impedance matching element; 421, the third impedance matching element; 422, the fourth impedance matching element; 431, the fifth impedance matching element; 441, the sixth impedance matching element; 442, the seventh impedance matching element; 451, the eighth impedance matching element; 452, the ninth impedance matching element; 50, the first circuit; 501, the first passive element; 502, the second passive element; 503, the third passive element; 504, the fourth passive element; 505, the fifth passive element; 506, the sixth passive element; 507, the seventh passive element; 508, the eighth passive element; 509, the ninth passive element. Detailed implementation manners

[0052] Next, the technical solutions in the embodiments of the present application will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, rather than all of the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present application without making creative efforts belong to the scope of protection of the present application.

[0053] It should be understood that the present application can be implemented in different forms and should not be construed as limited to the embodiments presented herein. On the contrary, providing these embodiments will make the disclosure thorough and complete and will fully convey the scope of the present application to those skilled in the art. In the drawings, for clarity, the dimensions and relative dimensions of layers and regions may be exaggerated. The same reference numerals throughout the drawings denote the same elements.

[0054] It should be understood that when an element or layer is referred to as being "on", "adjacent to", "connected to" or "coupled to" another element or layer, it can be directly on, adjacent to, connected or coupled to the other element or layer, or there may be intervening elements or layers. In contrast, when an element is referred to as being "directly on", "directly adjacent to", "directly connected to" or "directly coupled to" another element or layer, there are no intervening elements or layers. It should be understood that although the terms first, second, third, etc. may be used to describe various elements, components, regions, layers and / or parts, these elements, components, regions, layers and / or parts should not be limited by these terms. These terms are only used to distinguish one element, component, region, layer or part from another element, component, region, layer or part. Thus, a first element, component, region, layer or part discussed below may be denoted as a second element, component, region, layer or part without departing from the teachings of the present application.

[0055] Spatial relationship terms such as "under", "below", "beneath", "underneath", "above", "over", etc. may be used herein for convenience in describing the relationship of one element or feature shown in the figures to other elements or features. It should be understood that, in addition to the orientation shown in the figures, spatial relationship terms are intended to also include different orientations of the device in use and operation. For example, if the device in the figures is flipped, then an element or feature described as "under" or "beneath" or "underneath" another element or feature will be oriented "over" the other element or feature. Thus, the exemplary terms "under" and "beneath" can include both an upper and a lower orientation. The device may be otherwise oriented (rotated 90 degrees or other orientations) and the spatial descriptors used herein are to be interpreted accordingly.

[0056] The purpose of the terms used herein is only to describe specific embodiments and is not a limitation of the present application. As used herein, the singular forms "a", "an" and "the" are also intended to include the plural forms unless the context clearly dictates otherwise. It should also be understood that the terms "comprising" and / or "including", when used in this specification, specify the presence of the stated features, integers, steps, operations, elements and / or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components and / or groups. As used herein, the term "and / or" includes any and all combinations of the associated listed items.

[0057] To thoroughly understand the present application, detailed structures and steps will be presented in the following description to illustrate the technical solutions proposed by the present application. The preferred embodiments of the present application are described in detail below. However, in addition to these detailed descriptions, the present application may also have other implementation manners.

[0058] A push-pull power amplifier circuit provided by the present application, as Figure 1 shown, includes a first differential amplifier transistor 10, a second differential amplifier transistor 20, and an impedance matching circuit 40;

[0059] Specifically, it can be understood that the first differential amplifier transistor 10 and the second differential amplifier transistor 20 can be bipolar junction transistors (BJTs) or field effect transistors (FETs), etc. Optionally, the first differential amplifier transistor 10 includes at least one bipolar junction transistor (for example, an HBT transistor) or at least one field effect transistor. Exemplarily, the first differential amplifier transistor 10 can be formed by multiple transistors connected in parallel. The second differential amplifier transistor 20 includes at least one bipolar junction transistor (for example, an HBT transistor) or at least one field effect transistor. Exemplarily, the second differential amplifier transistor 20 can be formed by multiple transistors connected in parallel. In one implementation manner, both the first differential amplifier transistor 10 and the second differential amplifier transistor 20 are NPN transistors.

[0060] It can be understood that the first differential amplifier transistor 10 and the second differential amplifier transistor 20 can be any amplification stage in the push-pull radio frequency power amplifier circuit. Exemplarily, when the push-pull radio frequency power amplifier circuit includes a drive stage, an intermediate stage, and an output stage, the first differential amplifier transistor 10 and the second differential amplifier transistor 20 can be any amplification stage in the above push-pull radio frequency power amplifier circuit.

[0061] In a specific embodiment, the push-pull power amplifier circuit further includes a pre-stage conversion circuit (not shown). For example, the pre-stage conversion circuit can be implemented through a pre-stage conversion balun. The pre-stage conversion balun is used to convert an unbalanced radio frequency input signal into a balanced first radio frequency input signal and a second radio frequency input signal, and input the first radio frequency input signal to the input end of the first differential amplifier transistor 10, and input the second radio frequency input signal to the input end of the second differential amplifier transistor 20.

[0062] The first end of the impedance matching circuit 40 is connected to the output end of the first differential amplifier transistor 10, and the second end of the impedance matching circuit 40 is connected to the output end of the second differential amplifier transistor 20;

[0063] Specifically, the first differential amplifying transistor 10 and the second differential amplifying transistor 20 can be HBT transistors and MOS transistors. When the first differential amplifying transistor 10 and / or the second differential amplifying transistor 20 is an HBT transistor, the output terminal of the first differential amplifying transistor 10 and / or the second differential amplifying transistor 20 is the collector. When the first differential amplifying transistor 10 and / or the second differential amplifying transistor 20 is a MOS transistor, the output terminal of the first differential amplifying transistor 10 and / or the second differential amplifying transistor 20 is the source.

[0064] In a specific embodiment, the first differential amplifying transistor 10 and the second differential amplifying transistor 20 can be NPN transistors in HBT transistors.

[0065] The impedance matching circuit 40 includes: a first impedance matching unit 41, a second impedance matching unit 42, and a third impedance matching unit 43. Among them, the first end of the first impedance matching unit 41 is connected to the output terminal of the first differential amplifying transistor 10, and the second end of the first impedance matching unit 41 is grounded; the first end of the second impedance matching unit 42 is connected to the output terminal of the second differential amplifying transistor 20, and the second end of the second impedance matching unit 42 is grounded; the first end of the third impedance matching unit 43 is connected to the first impedance matching unit, and the second end of the third impedance matching unit 43 is connected to the second impedance matching unit 42; the first end of the third impedance matching unit 43 is connected to the third end of the first impedance matching unit 41, and the second end of the third impedance matching unit 43 is connected to the third end of the second impedance matching unit 42.

[0066] In this embodiment, since the first end of the first impedance matching unit 41 is connected to the output terminal of the first differential amplifying transistor 10, the second end of the first impedance matching unit 41 is grounded, and the first impedance matching unit 41 can adjust the harmonic impedance, the first impedance matching unit 41 can adjust the harmonic impedance of the output terminal of the first differential amplifying transistor. Similarly, since the first end of the second impedance matching unit 42 is connected to the output terminal of the second differential amplifying transistor 20, the first end of the first impedance matching unit 42 is grounded, and the second impedance matching unit 42 can adjust the harmonic impedance, the second impedance matching unit 42 can adjust the harmonic impedance of the output terminal of the second differential amplifying transistor.

[0067] In this embodiment, since the first end and the second end of the third impedance matching unit 43 are respectively connected to the third end of the first impedance matching unit 41 and the third end of the second impedance matching unit 42, the first impedance matching unit 41 and the third impedance matching unit 43 can be combined to form a new harmonic impedance adjustment unit, so as to adjust the harmonic impedance of different orders for the push-pull power amplifier circuit. For example, in a specific embodiment, the first impedance matching unit 41 can adjust the second-order harmonic impedance at the output end of the first differential amplification transistor, and the new harmonic impedance unit formed by the first impedance matching unit 41 and the third impedance matching unit 43 can adjust the harmonic impedance at any frequency point from the second order to the third order at the output end of the first differential amplification transistor, such as the 2.6th-order harmonic impedance. Similarly, in a specific embodiment, the second impedance matching unit 42 can adjust the second-order harmonic impedance at the output end of the second differential amplification transistor, and the new harmonic impedance unit formed by the second impedance matching unit 42 and the third impedance matching unit 43 can adjust the harmonic impedance at any frequency point from the second order to the third order at the output end of the second differential amplification transistor, such as the 2.6th-order harmonic impedance.

[0068] The balun 30 includes a first coil. The first end of the first coil is connected to the output end of the first differential amplification transistor 10, and the second end of the first coil is connected to the output end of the second differential amplification transistor 20.

[0069] Specifically, it can be understood that in a specific embodiment, the balun 30 further includes a second coil. The first end of the second coil is coupled to the output matching circuit of the push-pull power, and the second end of the coil is grounded.

[0070] The push-pull power amplifier circuit provided in this embodiment includes a first differential amplification transistor, a second differential amplification transistor, an impedance matching circuit, and a balun. The impedance matching circuit is disposed between the output ends of the first differential transistor and the second differential amplification transistor. The impedance matching circuit includes a plurality of impedance matching units. The plurality of impedance matching units can not only separately form a harmonic impedance adjustment unit to adjust the harmonic impedance in the push-pull power amplifier circuit, but also be combined with other impedance matching units and the balun to form a new harmonic impedance adjustment unit to adjust the harmonic impedance. Compared with the traditional technology, the impedance matching circuit provided in this application forms different harmonic impedance adjustment units by means of ingenious design and the reuse of impedance matching elements to meet the impedance matching requirements of the push-pull power amplifier circuit. On the premise of achieving impedance matching, the impedance matching circuit provided in this embodiment has a simpler structure, fewer components, and higher integration.

[0071] In an embodiment, such as Figure 2As shown, the first impedance matching unit 41 includes: a first impedance matching element 411 and a second impedance matching element 412; the first impedance matching element 411 and the second impedance matching element 412 are connected in series to form a first LC resonance circuit; the second impedance matching unit 42 includes: a third impedance matching element 421 and a fourth impedance matching element 422; the third impedance matching element 421 and the fourth impedance matching element 422 are connected in series to form a second LC resonance circuit; the resonance frequency points of the first LC resonance circuit and the second LC resonance circuit are the same.

[0072] In this embodiment, the resonance frequency points of the first LC resonance circuit and the second LC resonance circuit are the first resonance frequency points.

[0073] In this embodiment, the first impedance matching unit 41 includes: a first impedance matching element 411 and a second impedance matching element 412; the first impedance matching element 411 and the second impedance matching element 412 are connected in series to form a first LC resonance circuit; the first LC resonance circuit can be used to adjust the harmonic impedance at the output end of the first differential amplification transistor 10; the second impedance matching unit 42 includes: a third impedance matching element 421 and a fourth impedance matching element 422; the third impedance matching element 421 and the fourth impedance matching element 422 are connected in series to form a second LC resonance circuit. Similarly, the second LC resonance circuit can be used to adjust the harmonic impedance at the output end of the second differential amplification transistor 20, or to short-circuit or open-circuit the harmonics in the radio frequency signal at the output end of the second differential amplification transistor 20. Since in the push-pull power amplification circuit, the radio frequency signals passing through the first differential amplification transistor 10 and the radio frequency signals passing through the second differential amplification transistor 20 are a pair of radio frequency signals with the same signal magnitude and a phase difference of 180 degrees, therefore, it is necessary to set the resonance frequency points of the first LC resonance circuit and the second LC resonance circuit at the same frequency point so that in the working state of the push-pull power amplification circuit, the first LC resonance circuit and the second LC resonance circuit can resonate at the same resonance point to adjust the harmonic impedance in the push-pull power amplification circuit.

[0074] In a specific embodiment, the first resonance frequency point can be the resonance frequency point of even harmonics.

[0075] In a specific embodiment, the first resonance frequency point is the resonance frequency point of the second harmonic.

[0076] In an embodiment, the resonance frequency point of the first LC resonance circuit is the same as the signal frequency point of the second harmonic at the output end of the first differential amplification transistor 10; the resonance frequency point of the second LC resonance circuit is the same as the frequency point of the second harmonic at the output end of the second differential amplification transistor 20.

[0077] In this embodiment, the resonance frequency point of the first LC resonance circuit is set to be the same as the frequency point of the second harmonic signal at the output end of the first differential amplification transistor 10. The first LC resonance circuit can short-circuit the second harmonic at the output end of the first differential amplification transistor 10. The resonance frequency point of the second LC resonance circuit is set to be the same as the frequency point of the second harmonic signal at the output end of the second differential amplification transistor 20. The second LC resonance circuit can be used to short-circuit the second harmonic at the output end of the second differential amplification transistor 20.

[0078] In a specific embodiment, as Figure 3 shown, the first impedance matching unit 41 includes a first capacitor C1 and a first inductor L1. The first capacitor C1 and the first inductor L1 are connected in series to form the first LC resonance circuit. The second impedance matching unit 42 includes a second capacitor C2 and a second inductor L2. The second capacitor C2 and the second inductor L2 are connected in series to form the second LC resonance circuit. The first LC resonance circuit short-circuits the second harmonic at the output end of the first differential amplification transistor 10. It can be understood that the values of the first capacitor C1 and the first inductor L1 follow the formula: where fo is the fundamental frequency, L is the value of the first inductor L1, and C is the value of the first capacitor C1. Similarly, the second LC resonance circuit short-circuits the second harmonic at the output end of the second differential amplification transistor 20. It can be understood that the values of the second capacitor C2 and the second inductor L2 follow the formula: where fo is the fundamental frequency, L is the value of the second inductor L2, and C is the value of the second capacitor C2.

[0079] In a certain embodiment, as Figure 2 shown, the third impedance matching unit 43 includes: a fifth impedance matching element 431. The first end of the fifth impedance matching element 431 is connected to the common node of the first impedance matching element 411 and the second impedance matching element 412. The second end of the fifth impedance matching element 431 is connected to the common node of the third impedance matching element 421 and the fourth impedance matching element 422. The fifth impedance matching element 431 is a capacitive element or an inductive element.

[0080] In this embodiment, as Figure 2As shown, the third impedance matching unit 43 includes: a fifth impedance matching element 431. The fifth impedance matching element 431 can be a capacitive element or an inductive element. It should be noted that when the element type of the fifth impedance matching element 431 changes, the element types of the first impedance matching element 411, the second impedance matching element 412, the third impedance matching element 421, and the fourth impedance matching element 422 will also change accordingly. For example, in a certain preferred embodiment, the first impedance matching element 411, the third impedance matching element 421, and the fifth impedance matching element 431 are capacitive elements, and the second impedance matching element 412 and the fourth impedance matching element 422 are inductive elements; or the first impedance matching element 411, the third impedance matching element 421, and the fifth impedance matching element 431 are inductive elements, and the second impedance matching element 421 and the fourth impedance matching element 422 are capacitive elements. In the embodiment, by setting the first impedance matching element 411, the third impedance matching element 421, and the fifth impedance matching element 431 as elements of the same type, it is possible to make impedance adjustment more convenient, thereby optimizing the overall performance of the impedance matching circuit.

[0081] In a certain embodiment, the first impedance matching unit 41 and the third impedance matching unit 43 form a third LC resonance circuit; the second impedance matching unit 42 and the third impedance matching unit 43 form a fourth LC resonance circuit; the resonance frequency points of the third LC resonance circuit and the resonance frequency points of the fourth LC resonance circuit are the same.

[0082] In this embodiment, the resonance frequency points of the third LC resonance circuit and the fourth LC resonance circuit are the second resonance frequency points.

[0083] In this embodiment, the first impedance matching unit 41 and the third impedance matching unit 43 form a third LC resonance circuit. The third LC resonance circuit can be used to adjust the harmonic impedance at the output end of the first differential amplification transistor 10, or can be used to short-circuit or open-circuit the harmonics in the radio frequency signal at the output end of the first differential amplification transistor 10; the second impedance matching unit 42 and the third impedance matching unit 43 form a fourth LC resonance circuit. Similarly, the fourth LC resonance circuit can be used to adjust the harmonic impedance at the output end of the second differential amplification transistor 20, or can be used to short-circuit or open-circuit the harmonics in the radio frequency signal at the output end of the second differential amplification transistor 20. Since in the push-pull power amplifier circuit, the radio frequency signals passing through the first differential amplification transistor 10 and the radio frequency signals passing through the second differential amplification transistor 20 are a pair of radio frequency signals with the same signal magnitude and a phase difference of 180 degrees, therefore, the resonance frequency points of the third LC resonance circuit and the fourth LC resonance circuit need to be set at the same frequency point so that when the push-pull power amplifier circuit is in the working state, the third LC resonance circuit and the fourth LC resonance circuit can resonate at the same resonance point to adjust the harmonic impedance in the push-pull power amplifier circuit.

[0084] As a preferred embodiment, for example, when the first impedance matching element 411, the third impedance matching element 421, and the fifth impedance matching element 431 are capacitive elements, and the second impedance matching element 412 and the fourth impedance matching element 422 are inductive elements, the second impedance matching element 412 and the fifth impedance matching element 431 form a third LC resonance circuit (parallel resonance circuit). The third LC resonance circuit can open-circuit the harmonic signals at the output end of the first differential amplification transistor 10. The fourth impedance matching element 422 and the fifth impedance matching element 431 form a fourth LC resonance circuit (parallel resonance circuit). The fourth LC resonance circuit can open-circuit the harmonic signals at the output end of the second differential amplification transistor, thus avoiding the influence of harmonic signals on the performance of the push-pull power amplifier circuit. The harmonics in this embodiment can be harmonics at any frequency point between the second harmonic and the third harmonic, for example, 2.2 harmonics, 2.6 harmonics, 2.9 harmonics, and so on.

[0085] In a specific embodiment, such as Figure 3As shown, the first impedance matching unit 41 includes a first capacitor C1 and a first inductor L1, the second impedance matching unit 42 includes a second capacitor C2 and a second inductor L2, and the third impedance matching unit 43 includes a third capacitor C3. In this embodiment, the third LC resonant circuit (parallel resonant circuit) formed by the first inductor L1 and the third capacitor C3 can be used to open-circuit the harmonics between the second harmonic and the third harmonic at the output end of the first differential amplification transistor 10. For example, for the 2.6th harmonic, the values of the first inductor L1 and the third capacitor C3 follow the formula: Where, fo is the fundamental frequency, L is the value of the first inductor L1, and C is the value of the first capacitor C3. Similarly, the fourth LC resonant circuit (parallel resonant circuit) formed by the second inductor L1 and the third capacitor C3 can be used to open-circuit the harmonics between the second harmonic and the third harmonic at the output end of the second differential amplification transistor 20. For example, for the 2.6th harmonic, the values of the second inductor L1 and the third capacitor C3 follow the formula: Where, fo is the fundamental frequency, L is the value of the first inductor L2, and C is the value of the first capacitor C3.

[0086] In an embodiment, the first impedance matching unit 41, the third impedance matching unit 43, and the balun 30 form a fifth LC resonant circuit; the second impedance matching unit 42, the third impedance matching unit 43, and the balun 30 form a sixth LC resonant circuit; the resonant frequency points of the fifth LC resonant circuit and the sixth LC resonant circuit are the same.

[0087] In this embodiment, the resonant frequency points of the fifth LC resonant circuit and the sixth LC resonant circuit are the third resonant frequency points.

[0088] Specifically, it can be understood that since the balun 30 will generate parasitic inductance when powered on, in this embodiment, the equivalent model of the parasitic inductance generated by the balun 30 is as Figure 4 shown, Figure 4 where Lj is the parasitic inductance generated by the balun 30.

[0089] In this embodiment, the parasitic inductances of the first impedance matching unit 41, the third impedance matching unit 43, and the balun 30 form a fifth LC resonance circuit. The fifth LC resonance circuit can be used to adjust the harmonic impedance at the output end of the first differential amplifying transistor 10, and can also be used to short-circuit or open-circuit the harmonics in the radio frequency signal at the output end of the first differential amplifying transistor 10. The parasitic inductances of the second impedance matching unit 42, the third impedance matching unit 43, and the balun 30 form a sixth LC resonance circuit. Similarly, the sixth LC resonance circuit can be used to adjust the harmonic impedance at the output end of the second differential amplifying transistor 20, and can also be used to short-circuit or open-circuit the harmonics in the radio frequency signal at the output end of the second differential amplifying transistor 20. Since in the push-pull power amplifier circuit, the radio frequency signals passing through the first differential amplifying transistor 10 and the radio frequency signals passing through the second differential amplifying transistor 20 are a pair of radio frequency signals with the same signal magnitude and a phase difference of 180 degrees, therefore, the resonance frequency points of the fifth LC resonance circuit and the resonance frequency points of the sixth LC resonance circuit need to be set at the same frequency point, so that in the working state of the push-pull power amplifier circuit, the first LC resonance circuit and the second LC resonance circuit can resonate at the same resonance point to adjust the harmonic impedance in the push-pull power amplifier circuit. The harmonics in this embodiment can be odd harmonics, such as the third harmonic, the fifth harmonic, and so on.

[0090] In an embodiment, the resonance frequency point of the fifth LC resonance circuit is the same as the signal frequency point of the third harmonic at the output end of the first differential amplifying transistor 10; the resonance frequency point of the second LC resonance circuit is the same as the frequency point of the third harmonic at the output end of the second differential amplifying transistor 20.

[0091] In this embodiment, the parasitic inductances of the first impedance matching unit 41, the third impedance matching unit 43, and the balun 30 form a fifth LC resonance circuit. The fifth LC resonance circuit can open-circuit the third harmonic in the radio frequency signal at the output end of the first differential amplifying transistor. The parasitic inductances of the second impedance matching unit 42, the third impedance matching unit 43, and the balun 30 form a sixth LC resonance circuit. The sixth LC resonance circuit can be used to short-circuit or open-circuit the third harmonic in the radio frequency signal at the output end of the second differential amplifying transistor 20. The specific working process is as follows: for the third harmonic, the first impedance matching unit 41 and the third impedance matching unit 43 are equivalent to a first equivalent capacitor. The first equivalent capacitor and the parasitic inductance Lj generated by the balun 30 form a first parallel resonance circuit, and the first parallel resonance circuit opens the third harmonic. Similarly, the second impedance matching unit 42 and the third impedance matching unit 43 are equivalent to a second equivalent capacitor. The second equivalent capacitor and the parasitic inductance Lj generated by the balun 30 form a second parallel resonance circuit, and the second parallel resonance circuit opens the third harmonic.

[0092] In a specific embodiment, as Figure 3 shown, the first inductor L1, the first capacitor C1, the third capacitor C3, and the parasitic inductance of the balun (such as Figure 4 Lj in) jointly form a fifth LC resonance circuit for open-circuit processing of the third harmonic at the output end of the first differential amplification transistor 10. It can be understood that the values of the first inductor L1, the first capacitor C1, and the third capacitor C3 follow the formula: where fo is the fundamental frequency, C is the equivalent capacitance formed by the first inductor L1, the first capacitor C1, and the third capacitor C3 at the third harmonic, and L is the parasitic inductance of the balun. Similarly, the second inductor L2, the second capacitor C2, the third capacitor C3, and the parasitic inductance of the balun (such as Figure 4 Lj in) jointly form a sixth resonance circuit, and the values of the second inductor L2, the second capacitor C2, and the third capacitor C3 follow the formula: where fo is the fundamental frequency, C is the equivalent capacitance formed by the second inductor L2, the second capacitor C2, and the third capacitor C3 at the third harmonic, and L is the parasitic inductance of the balun.

[0093] In an embodiment, the first resonance frequency point is less than the second resonance frequency point, and the second resonance frequency point is less than the third resonance frequency point.

[0094] As a preferred embodiment, the first resonance frequency point can be at the frequency point of the second harmonic, the second resonance frequency point resonates at a frequency point between the second harmonic and the third harmonic, and the third resonance frequency point resonates at the frequency point of the third harmonic.

[0095] In an embodiment, the impedance matching circuit 40 and the balun 30 are configured to make the push-pull power amplifier circuit operate in class F.

[0096] In this embodiment, the first impedance matching unit 41 can be used to short-circuit the second harmonic in the radio frequency signal at the output end of the first differential amplification transistor 10. The first impedance matching unit 41, the third impedance matching unit 43, and the balun 30 are used to open-circuit the third harmonic in the radio frequency signal at the output end of the first differential amplification transistor. Similarly, the second impedance matching unit 42 can be used to short-circuit the second harmonic in the radio frequency signal at the output end of the second differential amplification transistor 20. The second impedance matching unit, the third impedance matching unit, and the balun are used to open-circuit the third harmonic in the radio frequency signal at the output end of the second differential amplification transistor. Through the above processing, the push-pull power amplifier circuit operates in class F.

[0097] In an embodiment, as Figure 5As shown, the impedance matching circuit 40 further includes a fourth impedance matching unit 44 and a fifth impedance matching unit 45. Among them, the first end of the fourth impedance matching unit 44 is connected to the output end of the first differential amplification transistor 10, and the second end of the fourth impedance matching unit 44 is grounded; the first end of the fifth impedance matching unit 45 is connected to the output end of the second differential amplification transistor 20, and the second end of the fifth impedance matching unit 45 is grounded.

[0098] In this embodiment, since the first end of the fourth impedance matching unit 44 is connected to the output end of the first differential amplification transistor 10, the second end of the fourth impedance matching unit 44 is grounded, and the fourth impedance matching unit 44 can adjust the harmonic impedance, therefore, the fourth impedance matching unit 41 can adjust the harmonic impedance at the output end of the first differential amplification transistor. Similarly, since the first end of the fifth impedance matching unit 45 is connected to the output end of the second differential amplification transistor 20, the second end of the fifth impedance matching unit 45 is grounded, and the fifth impedance matching unit 45 can adjust the harmonic impedance, therefore, the fifth impedance matching unit 45 can adjust the harmonic impedance at the output end of the second differential amplification transistor.

[0099] In a certain embodiment, as Figure 6 shown, the first impedance matching unit 41 includes: a first impedance matching element 411 and a second impedance matching element 412; the first impedance matching element 411 and the second impedance matching element 412 are connected in series to form a first LC resonance circuit; the second impedance matching unit 42 includes: a third impedance matching element 421 and a fourth impedance matching element 422; the third impedance matching element 421 and the fourth impedance matching element 422 are connected in series to form a second LC resonance circuit; the resonance frequency points of the first LC resonance circuit and the second LC resonance circuit are the same.

[0100] In this embodiment, the resonance frequency points of the first LC resonance circuit and the second LC resonance circuit are the fourth resonance frequency points.

[0101] In this embodiment, the first impedance matching unit 41 includes: a first impedance matching element 411 and a second impedance matching element 412; the first impedance matching element 411 and the second impedance matching element 412 are connected in series to form a first LC resonance circuit; the first LC resonance circuit can be used to adjust the harmonic impedance at the output end of the first differential amplification transistor 10, and can also be used to short-circuit or open-circuit the harmonics in the radio frequency signal at the output end of the first differential amplification transistor 10; the second impedance matching unit 42 includes: a third impedance matching element 421 and a fourth impedance matching element 422; the third impedance matching element 421 and the fourth impedance matching element 422 are connected in series to form a second LC resonance circuit. Similarly, the second LC resonance circuit can be used to adjust the harmonic impedance at the output end of the second differential amplification transistor 20, and can also be used to short-circuit or open-circuit the harmonics in the radio frequency signal at the output end of the second differential amplification transistor 20. Since in the push-pull power amplification circuit, the radio frequency signals passing through the first differential amplification transistor 10 and the radio frequency signals passing through the second differential amplification transistor 20 are a pair of radio frequency signals with the same signal magnitude and a phase difference of 180 degrees, therefore, it is necessary to set the resonance frequency points of the first LC resonance circuit and the second LC resonance circuit at the same frequency point, so that when the push-pull power amplification circuit is in the working state, the first LC resonance circuit and the second LC resonance circuit can resonate at the same resonance point to adjust the harmonic impedance in the push-pull power amplification circuit.

[0102] In a specific embodiment, the fourth resonance frequency point can be the resonance frequency point of even harmonics.

[0103] In a specific embodiment, the fourth resonance frequency point is the resonance frequency point of the second harmonic.

[0104] In an embodiment, the resonance frequency point of the first LC resonance circuit is the same as the signal frequency point of the second harmonic at the output end of the first differential amplification transistor 10; the resonance frequency point of the second LC resonance circuit is the same as the frequency point of the second harmonic at the output end of the second differential amplification transistor 20.

[0105] In this embodiment, by setting the resonance frequency point of the first LC resonance circuit to be the same as the frequency point of the second harmonic signal at the output end of the first differential amplification transistor 10, the first LC resonance circuit can short-circuit the second harmonic at the output end of the first differential amplification transistor 10, thereby avoiding the influence of the second harmonic on the performance of the push-pull power amplification circuit; by setting the resonance frequency point of the second LC resonance circuit to be the same as the frequency point of the second harmonic signal at the output end of the second differential amplification transistor 20, the second LC resonance circuit can be used to short-circuit the second harmonic at the output end of the second differential amplification transistor 20.

[0106] In a specific embodiment, such asFigure 7 As shown, the first impedance matching unit 41 includes a first capacitor C1 and a first inductor L1. The first capacitor C1 and the first inductor L1 are connected in series to form a first LC resonance circuit. The second impedance matching unit 42 includes a second capacitor C2 and a second inductor L2. The second capacitor C2 and the second inductor L2 are connected in series to form a second LC resonance circuit. The first LC resonance circuit shorts the second harmonic of the output terminal of the first differential amplification transistor 10. It can be understood that the values of the first capacitor C1 and the first inductor L1 follow the formula: Wherein, fo is the fundamental frequency, L is the value of the first inductor L1, and C is the value of the first capacitor C1. Similarly, the second LC resonance circuit shorts the second harmonic of the output terminal of the second differential amplification transistor 20. It can be understood that the values of the second capacitor C2 and the second inductor L2 follow the formula: Wherein, fo is the fundamental frequency, L is the value of the second inductor L2, and C is the value of the second capacitor C2.

[0107] In an embodiment, as Figure 6 shown, the third impedance matching unit 43 includes: a fifth impedance matching element 431. The first end of the fifth impedance matching element 431 is connected to the common node of the first impedance matching element 411 and the second impedance matching element 412. The second end of the fifth impedance matching element 431 is connected to the common node of the third impedance matching element 421 and the fourth impedance matching element 422. The fifth impedance matching element 431 is a capacitive element or an inductive element.

[0108] In this embodiment, as Figure 6 shown, the third impedance matching unit 43 includes: a fifth impedance matching element 431. The fifth impedance matching element 431 can be a capacitive element or an inductive element. It should be noted that when the element type of the fifth impedance matching element 431 changes, the first impedance matching element 411, the second impedance matching element 412, the third impedance matching element 421, and the fourth impedance matching element 422 will also change accordingly. For example, in a preferred embodiment, the first impedance matching element 411, the third impedance matching element 421, and the fifth impedance matching element 431 are capacitive elements, and the second impedance matching element 412 and the fourth impedance matching element 422 are inductive elements, or the first impedance matching element 411, the third impedance matching element 421, and the fifth impedance matching element 431 are inductive elements, and the second impedance matching element 421 and the fourth impedance matching element 422 are capacitive elements. In the embodiment, by setting the first impedance matching element 411, the third impedance matching element 421, and the fifth impedance matching element 431 into elements of the same type, it can make the impedance adjustment more convenient, and further optimize the overall performance of the impedance matching circuit.

[0109] In one embodiment, the first impedance matching unit 41 and the third impedance matching unit 43 form a third LC resonance circuit; the second impedance matching unit 42 and the third impedance matching unit 43 form a fourth LC resonance circuit; the resonance frequency points of the third LC resonance circuit and the fourth LC resonance circuit are the same.

[0110] In this embodiment, the resonance frequency points of the third LC resonance circuit and the fourth LC resonance circuit are the fifth resonance frequency point.

[0111] In this embodiment, the first impedance matching unit 41 and the third impedance matching unit 43 form a third LC resonance circuit. The third LC resonance circuit can be used to adjust the harmonic impedance at the output end of the first differential amplification transistor 10, and can also be used to short-circuit or open-circuit the harmonics in the radio frequency signal at the output end of the first differential amplification transistor 10; the second impedance matching unit 42 and the third impedance matching unit 43 form a fourth LC resonance circuit. Similarly, the fourth LC resonance circuit can be used to adjust the harmonic impedance at the output end of the second differential amplification transistor 20, and can also be used to short-circuit or open-circuit the harmonics in the radio frequency signal at the output end of the second differential amplification transistor 20. Since in the push-pull power amplifier circuit, the radio frequency signal passing through the first differential amplification transistor 10 and the radio frequency signal passing through the second differential amplification transistor 20 are a pair of radio frequency signals with the same signal magnitude and a phase difference of 180 degrees, therefore, it is necessary to set the resonance frequency points of the third LC resonance circuit and the fourth LC resonance circuit at the same frequency point so that in the working state of the push-pull power amplifier circuit, the third LC resonance circuit and the fourth LC resonance circuit can resonate at the same resonance point to adjust the harmonic impedance in the push-pull power amplifier circuit.

[0112] As a preferred embodiment, for example, when the first impedance matching element 411, the third impedance matching element 421, and the fifth impedance matching element 431 are capacitive elements, and the second impedance matching element 412 and the fourth impedance matching element 422 are inductive elements, the second impedance matching element 412 and the fifth impedance matching element 431 form a third LC resonant circuit (parallel resonant circuit), and the third LC resonant circuit can be used to open-circuit the harmonic signals at the output end of the first differential amplification transistor. The fourth impedance matching element 422 and the fifth impedance matching element 431 form a fourth LC resonant circuit (parallel resonant circuit), and the fourth LC resonant circuit can be used to open-circuit the first harmonic signals at the output end of the second differential amplification transistor. In this way, the influence of harmonic signals on the performance of the push-pull power amplification circuit can be avoided. The harmonics in this embodiment can be harmonics at any frequency point between the third harmonic and the fourth harmonic, for example, 3.2 times harmonic, 3.6 times harmonic, 3.9 times harmonic, and so on.

[0113] In a specific embodiment, as Figure 7 shown, the first impedance matching unit 41 includes a first capacitor C1 and a first inductor L1, the second impedance matching unit 42 includes a second capacitor C2 and a second inductor L2, and the third impedance matching unit 43 includes a third capacitor C3. In this embodiment, the third LC resonant circuit (parallel resonant circuit) formed by the first inductor L1 and the third capacitor C3 can be used to open-circuit the harmonics between the third harmonic and the fourth harmonic at the output end of the first differential amplification transistor 10. For example, for the 3.6 times harmonic, the values of the first inductor L1 and the third capacitor C3 follow the formula: where fo is the fundamental frequency, L is the value of the first inductor L1, and C is the value of the first capacitor C3. Similarly, the fourth LC resonant circuit (parallel resonant circuit) formed by the second inductor L1 and the third capacitor C3 can be used to open-circuit the harmonics between the third harmonic and the fourth harmonic at the output end of the second differential amplification transistor 20. For example, for the 3.6 times harmonic, the values of the second inductor L1 and the third capacitor C3 follow the formula: where fo is the fundamental frequency, L is the value of the first inductor L2, and C is the value of the first capacitor C3.

[0114] In one embodiment, the fourth impedance matching unit 44 includes a sixth impedance matching element 441 and a seventh impedance matching element 442. The sixth impedance matching element 441 and the seventh impedance matching element 442 are connected in series to form a seventh LC resonance circuit. The fifth impedance matching unit includes an eighth impedance matching element 451 and a ninth impedance matching element 452. The eighth impedance matching element 451 and the ninth impedance matching element 452 are connected in series to form an eighth LC resonance circuit. The resonance frequency point of the seventh LC resonance circuit is the same as that of the eighth LC resonance circuit.

[0115] In this embodiment, the resonance frequency point of the seventh LC resonance circuit and that of the eighth LC resonance circuit are the sixth resonance frequency point.

[0116] In this embodiment, as Figure 6 shown, the fourth impedance matching unit 44 includes a sixth impedance matching element 441 and a seventh impedance matching element 442. The sixth impedance matching element 441 and the seventh impedance matching element 442 are connected in series to form a seventh LC resonance circuit. The seventh LC resonance circuit can be used to adjust the harmonic impedance at the output end of the first differential amplification transistor 10, and can also be used to short-circuit or open-circuit the harmonics in the radio frequency signal at the output end of the first differential amplification transistor 10. The fifth impedance matching unit 45 includes an eighth impedance matching element 451 and a ninth impedance matching element 452. The eighth impedance matching element 451 and the ninth impedance matching element 452 are connected in series to form an eighth LC resonance circuit. Similarly, the eighth LC resonance circuit can be used to adjust the harmonic impedance at the output end of the second differential amplification transistor 20, and can also be used to short-circuit or open-circuit the harmonics in the radio frequency signal at the output end of the second differential amplification transistor 20. Since in the push-pull power amplification circuit, the radio frequency signals passing through the first differential amplification transistor 10 and the second differential amplification transistor 20 are a pair of radio frequency signals with the same signal magnitude and a phase difference of 180 degrees, therefore, it is necessary to set the resonance frequency point of the seventh LC resonance circuit and the second LC resonance circuit at the same frequency point, so that in the working state of the push-pull power amplification circuit, the seventh LC resonance circuit and the eighth LC resonance circuit can resonate at the same resonance point to adjust the harmonic impedance in the push-pull power amplification circuit.

[0117] In a specific embodiment, the sixth resonance frequency point can be the resonance frequency point of even harmonics.

[0118] In a specific embodiment, the sixth resonance frequency point is the resonance frequency point of the fourth harmonic.

[0119] In an embodiment, the resonance frequency point of the seventh LC resonance circuit is the same as the signal frequency point of the fourth harmonic of the output end of the first differential amplification transistor; the resonance frequency point of the eighth LC resonance circuit is the same as the frequency point of the fourth harmonic of the output end of the second differential amplification transistor.

[0120] In this embodiment, the resonance frequency point of the seventh LC resonance circuit is set to be the same as the frequency point of the fourth harmonic signal of the output end of the first differential amplification transistor 10. The seventh LC resonance circuit can short-circuit the fourth harmonic of the output end of the first differential amplification transistor 10, thereby avoiding the influence of the fourth harmonic on the performance of the push-pull power amplification circuit; the resonance frequency point of the eighth LC resonance circuit is set to be the same as the frequency point of the fourth harmonic signal of the output end of the second differential amplification transistor 20, and the seventh LC resonance circuit can short-circuit the fourth harmonic of the output end of the second differential amplification transistor 20.

[0121] In a specific embodiment, as Figure 7 shown, the fourth impedance matching unit 44 includes a fourth capacitor C4 and a third inductor L3. The fourth capacitor C4 and the third inductor L3 are connected in series to form the seventh LC resonance circuit. The fifth impedance matching unit 45 includes a fifth capacitor C5 and a fourth inductor L4. The fifth capacitor C5 and the fourth inductor L4 are connected in series to form the eighth LC resonance circuit. The seventh LC resonance circuit shorts the fourth harmonic of the output end of the first differential amplification transistor 10. It can be understood that the values of the fourth capacitor C4 and the third inductor L3 follow the formula: where, fo is the fundamental frequency, L is the value of the third inductor L3, and C is the value of the fourth capacitor C4. Similarly, the eighth LC resonance circuit shorts the fourth harmonic of the output end of the second differential amplification transistor 20. It can be understood that the values of the fifth capacitor C5 and the fourth inductor L4 follow the formula: where, fo is the fundamental frequency, L is the value of the fourth inductor L4, and C is the value of the fifth capacitor C5.

[0122] In an embodiment, the first impedance matching unit 41, the third impedance matching unit 43, the fourth impedance matching unit 44, and the balun 30 form a ninth LC resonance circuit; the second impedance matching unit 42, the third impedance matching unit 43, the fifth impedance matching unit 45, and the balun 30 form a tenth LC resonance circuit; the resonance frequency point of the ninth LC resonance circuit is the same as the resonance frequency point of the tenth LC resonance circuit.

[0123] In this embodiment, the resonance frequency point of the ninth LC resonance circuit and the resonance frequency point of the tenth LC resonance circuit are the seventh resonance frequency point.

[0124] Specifically, it can be understood that since the balun 30 generates parasitic inductance when powered on, in this embodiment, the equivalent model of the parasitic inductance generated by the balun 30 is as Figure 4 shown, Figure 4 where Lj is the parasitic inductance generated by the balun 30.

[0125] In this embodiment, the first impedance matching unit 41, the third impedance matching unit 43, the fourth impedance matching unit 44 and the parasitic inductance of the balun 30 form a ninth LC resonance circuit. The ninth LC resonance circuit can be used to adjust the harmonic impedance at the output end of the first differential amplification transistor 10, or to short-circuit or open-circuit the harmonics in the radio frequency signal at the output end of the first differential amplification transistor 10; the second impedance matching unit 42, the third impedance matching unit 43, the fifth impedance matching unit 45 and the parasitic inductance of the balun 30 form a tenth LC resonance circuit. Similarly, the tenth LC resonance circuit can be used to adjust the harmonic impedance at the output end of the second differential amplification transistor 20, or to short-circuit or open-circuit the harmonics in the radio frequency signal at the output end of the second differential amplification transistor 20. Since in the push-pull power amplifier circuit, the radio frequency signals passing through the first differential amplification transistor 10 and the radio frequency signals passing through the second differential amplification transistor 20 are a pair of radio frequency signals with the same signal magnitude and a phase difference of 180 degrees, therefore, it is necessary to set the resonance frequency points of the ninth LC resonance circuit and the tenth LC resonance circuit at the same frequency point, so that when the push-pull power amplifier circuit is in the working state, the seventh LC resonance circuit and the eighth LC resonance circuit can resonate at the same resonance point to adjust the harmonic impedance in the push-pull power amplifier circuit. The harmonics in this embodiment can be odd harmonics, such as the 3rd harmonic, the 5th harmonic, and so on.

[0126] In a specific embodiment, the seventh resonance frequency point is the resonance frequency point of odd harmonics.

[0127] In an embodiment, the seventh resonance frequency point is the resonance frequency point of the 3rd harmonic.

[0128] In an embodiment, the resonance frequency point of the ninth LC resonance circuit is the same as the signal frequency point of the third harmonic at the output end of the first differential amplification transistor; the resonance frequency point of the tenth LC resonance circuit is the same as the frequency point of the third harmonic at the output end of the second differential amplification transistor.

[0129] In a specific embodiment, as Figure 7As shown, since the fourth capacitor C4 and the third inductor L3 resonate at the frequency point of the fourth harmonic, in the third harmonic state, the fourth capacitor C4 and the third inductor L3 are equivalent to the first equivalent capacitor. Since the first inductor L1 and the third capacitor C3 resonate between the third harmonic and the fourth harmonic, the first inductor L1 and the third capacitor C3 are equivalent to the first equivalent inductor. The first equivalent inductor is connected in series with the first capacitor to form the second equivalent inductor. The second equivalent inductor is connected in parallel with the parasitic inductor of the balun to form the third equivalent inductor. The third equivalent inductor and the first equivalent capacitor form a parallel resonance circuit to open-circuit the third harmonic at the output end of the first differential amplification transistor 10. It can be understood that the values of the third equivalent inductor and the first equivalent capacitor need to satisfy: where, fo is the fundamental frequency, L is the value of the third equivalent inductor, and C is the value of the first equivalent capacitor. Similarly, since the fifth capacitor C5 and the fourth inductor L4 resonate at the frequency point of the fourth harmonic, in the third harmonic state, the fifth capacitor C5 and the fourth inductor L4 are equivalent to the second equivalent capacitor. Since the second inductor L2 and the third capacitor C3 resonate between the third harmonic and the fourth harmonic, the second inductor L2 and the third capacitor C3 are equivalent to the fourth equivalent inductor. The fourth equivalent inductor is connected in series with the second capacitor to form the fifth equivalent inductor. The fifth equivalent inductor is connected in parallel with the parasitic inductor of the balun to form the sixth equivalent inductor. The sixth equivalent inductor and the second equivalent capacitor form the second parallel resonance circuit to open-circuit the third harmonic at the output end of the second differential amplification transistor 20. Among them, the values of the sixth equivalent inductor and the second equivalent capacitor need to satisfy: where, fo is the fundamental frequency, L is the value of the sixth equivalent inductor, and C is the value of the second equivalent capacitor.

[0130] As a preferred embodiment, the seventh resonance frequency point is the resonance frequency point of the fifth harmonic.

[0131] In an embodiment, the resonance frequency point of the ninth LC resonance circuit is the same as the signal frequency point of the fifth harmonic at the output end of the first differential amplification transistor; the resonance frequency point of the tenth LC resonance circuit is the same as the frequency point of the fifth harmonic at the output end of the second differential amplification transistor.

[0132] In a specific embodiment, such as Figure 7As shown, since the fourth capacitor C4 and the third inductor L3 resonate at the frequency point of the fourth harmonic, in the fifth harmonic state, the fourth capacitor C4 and the third inductor L3 are equivalent to a first equivalent inductor, and the first equivalent inductor is connected in parallel with the parasitic inductor of the balun to form a second equivalent inductor. Since the first inductor L1 and the third capacitor C3 resonate between the third harmonic and the fourth harmonic, the first inductor L1 and the third capacitor C3 are equivalent to a first equivalent capacitor, and the first equivalent capacitor is connected in series with the first capacitor C1 to form a second equivalent capacitor. The second equivalent inductor and the second equivalent capacitor form a parallel resonance circuit to open-circuit the fifth harmonic at the output end of the first differential amplifier transistor 10. It can be understood that the values of the second equivalent inductor and the second equivalent capacitor need to satisfy: Where, fo is the fundamental frequency, L is the value of the second equivalent inductor, and C is the value of the second equivalent capacitor. Similarly, since the fifth capacitor C5 and the fourth inductor L4 resonate at the frequency point of the fourth harmonic, in the fifth harmonic state, the fifth capacitor C5 and the fourth inductor L4 are equivalent to a third equivalent inductor, and the third equivalent inductor is connected in parallel with the parasitic inductor of the balun to form a fourth equivalent inductor. Since the second inductor L2 and the third capacitor C3 resonate between the third harmonic and the fourth harmonic, the second inductor L2 and the third capacitor C3 are equivalent to a third equivalent capacitor, and the third equivalent capacitor is connected in series with the second capacitor C2 to form a fourth equivalent capacitor. The fourth equivalent inductor and the fourth equivalent capacitor form a parallel resonance circuit to open-circuit the fifth harmonic at the output end of the second differential amplifier transistor 20. Where, the values of the fourth equivalent inductor and the fourth equivalent capacitor need to satisfy: Where, fo is the fundamental frequency, L is the value of the fourth equivalent inductor, and C is the value of the fourth equivalent capacitor.

[0133] In an embodiment, the third resonance frequency point is less than the fourth resonance frequency point, the fourth resonance frequency point is less than the fifth resonance frequency point, the fifth resonance frequency point is less than the sixth resonance frequency point, and the sixth resonance frequency point is less than the seventh resonance frequency point.

[0134] In this embodiment, the fourth resonance frequency point can be at the frequency point of the second harmonic, the fifth resonance frequency point resonates at a frequency point between the third harmonic and the fourth harmonic, the sixth resonance frequency point resonates at the frequency point of the fourth harmonic, and the seventh resonance frequency point resonates at the frequency point of the fifth harmonic.

[0135] In an embodiment, the impedance matching circuit and the balun are configured to make the push-pull power amplifier circuit operate in class F.

[0136] In this embodiment, the first impedance matching unit 41 can be used to short-circuit the second harmonic in the radio frequency signal at the output end of the first differential amplification transistor 10, and the fourth impedance matching unit can be used to short-circuit the fourth harmonic in the radio frequency signal at the output end of the first differential amplification transistor 10. The first impedance matching unit 41, the third impedance matching unit 43, the fourth impedance matching circuit, and the balun 30 are used to open-circuit the third harmonic and the fifth harmonic in the radio frequency signal at the output end of the first differential amplification transistor. Similarly, the second impedance matching unit 42 can be used to short-circuit the second harmonic in the radio frequency signal at the output end of the second differential amplification transistor 20, and the fifth impedance matching unit can be used to short-circuit the fourth harmonic in the radio frequency signal at the output end of the second differential amplification transistor 10. The second impedance matching unit, the third impedance matching unit, the fifth impedance matching unit, and the balun are used to short-circuit the third harmonic and the fifth harmonic in the radio frequency signal at the output end of the second differential amplification transistor. Through the above processing, the push-pull power amplifier circuit operates in class F operating state.

[0137] In one embodiment, the first differential amplification transistor and the second differential amplification transistor are HBT transistors or MOS transistors.

[0138] In this embodiment, the first differential amplification transistor 10 and the second differential amplification transistor 20 can be bipolar junction transistors (BJTs) or field effect transistors (FETs), etc. Optionally, the first differential amplification transistor 10 includes at least one bipolar junction transistor (e.g., HBT transistor) or at least one field effect transistor. Exemplarily, the first differential amplification transistor 10 can be formed by multiple transistors in parallel. The second differential amplification transistor 20 includes at least one bipolar junction transistor (e.g., HBT transistor) or at least one field effect transistor. Exemplarily, the second differential amplification transistor 20 can be formed by multiple transistors in parallel. In one implementation, both the first differential amplification transistor 10 and the second differential amplification transistor 20 are NPN transistors.

[0139] Such as Figure 8As shown, the present application also provides a push-pull power amplifier circuit, including a first differential amplification transistor 10, a second differential amplification transistor 20, a first circuit 50, and a balun 30; a first end of the first circuit 50 is connected to an output end of the first differential amplification transistor 10, and a second end of the first circuit 50 is connected to an output end of the second differential amplification transistor 20; the first circuit 50 includes: a first passive element 501, a second passive element 5022, a third passive element 503, a fourth passive element 504, and a fifth passive element 505, wherein a first end of the first passive element 501 is connected to the output end of the first differential amplification transistor 10, and a second end of the first passive element 501 is connected to a first end of the second passive element 502; a second end of the second passive element 502 is grounded; a first end of the third passive element 503 is connected to the output end of the second differential amplification transistor 20, and a second end of the third passive element 503 is connected to a first end of the fourth passive element 504; a second end of the fourth passive element 504 is grounded; a first end of the fifth passive element 505 is connected to the first end of the second passive element 502, and a second end of the fifth passive element 505 is connected to the first end of the fourth passive element 504, and the balun includes a first coil, a first end of the first coil is connected to the output end of the first differential amplification transistor, and a second end of the first coil is connected to the output end of the second differential amplification transistor.

[0140] In this embodiment, the first passive element 501 and the second passive element 502 can form an impedance matching circuit, and the first passive element 501, the second passive element 502, and the fifth passive element 505 can also construct an impedance matching circuit. Similarly, the third passive element 503 and the fourth passive element 504 can be constructed into an impedance matching circuit, and the third passive element 503, the fourth passive element 504, and the fifth passive element 505 can also construct a new impedance matching circuit. That is, in the first circuit provided in this embodiment, different impedance matching circuits are formed by adopting the method of passive element reuse. On the premise of achieving impedance matching, the impedance matching circuit structure provided in this embodiment is simpler, the number of components is less, and the integration degree is higher.

[0141] In a certain embodiment, the first passive element 501, the third passive element 503, and the fifth passive element are capacitive elements, and the second passive element and the fourth passive element are inductive elements, or the first passive element, the third passive element, and the fifth passive element are inductive elements, and the second passive element and the fourth passive element are capacitive elements.

[0142] As a preferred embodiment, the first passive element 501, the third passive element 503, and the fifth passive element 505 are capacitor elements, and the second passive element 502 and the fourth passive element 504 are inductor elements for specific illustration. In this embodiment, the first circuit 50 includes a first capacitor C1, a second capacitor C2, a third capacitor C3, a first inductor L1, and a second inductor L2. The first circuit 50 provides corresponding impedance matching for the push-pull power amplifier circuit. The specific working principle can refer to Figure 3 the description, and no repetitive description will be made here.

[0143] In a specific embodiment, the first circuit 50 further includes a sixth passive element 506, a seventh passive element 507, an eighth passive element 508, and a ninth passive element 509. Among them, the first end of the sixth passive element 506 is connected to the output end of the first differential amplification transistor 10, the second end of the sixth passive element 506 is connected to the first end of the seventh passive element 507, and the second end of the seventh passive element 507 is grounded; the first end of the eighth passive element 508 is connected to the output end of the second differential amplification transistor 20, the second end of the eighth passive element 508 is connected to the first end of the ninth passive element 509, and the second end of the ninth passive element 509 is grounded.

[0144] In a specific embodiment, the first passive element 501, the third passive element 503, the fifth passive element 505, the sixth passive element 506, and the eighth passive element 508 are capacitor elements, and the second passive element 502, the fourth passive element 504, the seventh passive element 507, and the ninth passive element 509 are inductor elements, or the first passive element 501, the third passive element 503, the fifth passive element 505, the sixth passive element 506, and the eighth passive element 508 are inductor elements, and the second passive element 502, the fourth passive element 504, the seventh passive element 507, and the ninth passive element 509 are capacitor elements.

[0145] In this embodiment, taking the first passive element 501, the third passive element 503, the fifth passive element 505, the sixth passive element 506, and the eighth passive element 508 as capacitor elements, and the second passive element 502, the fourth passive element 504, the seventh passive element 507, and the ninth passive element 509 as inductor elements for example, the specific description is as follows: The first circuit 40 includes a first capacitor C1, a first inductor L1, a second capacitor C2, a second inductor L2, a third capacitor C3, a fourth capacitor C4, a third inductor L3, a fifth capacitor C5, and a fourth inductor L4. The specific working principle can refer to Figure 7 the corresponding description, and no repetitive description will be made again.

[0146] The present application also provides a radio frequency front-end module, including the push-pull power amplifier circuit described in any one of the above.

[0147] The above are only the preferred embodiments of the present invention. It should be noted that for those of ordinary skill in the art, without departing from the technical principle of the present invention, several improvements and substitutions can be made, and these improvements and substitutions should also be regarded as the protection scope of the present invention.

Claims

1. A push-pull power amplifier circuit, characterized in that, It includes a first differential amplification transistor, a second differential amplification transistor, an impedance matching circuit, and a balun; The first end of the impedance matching circuit is connected to the output end of the first differential amplification transistor, and the second end of the impedance matching circuit is connected to the output end of the second differential amplification transistor; The impedance matching circuit includes a first impedance matching unit, a second impedance matching unit, and a third impedance matching unit. Among them, the first end of the first impedance matching unit is connected to the output end of the first differential amplification transistor, and the second end of the first impedance matching unit is grounded; the first end of the second impedance matching unit is connected to the second differential amplification transistor, and the second end of the second impedance matching unit is grounded; the first end of the third impedance matching unit is connected to the third end of the first impedance matching unit, and the second end of the third impedance matching unit is connected to the third end of the second impedance matching unit; The balun includes a first coil. The first end of the first coil is connected to the output end of the first differential amplification transistor, and the second end of the first coil is connected to the output end of the second differential amplification transistor; The first impedance matching unit includes a first impedance matching element and a second impedance matching element connected in series; the second impedance matching unit includes a third impedance matching element and a fourth impedance matching element connected in series; the third impedance matching unit includes a fifth impedance matching element. The first end of the fifth impedance matching element is connected to the common node of the first impedance matching element and the second impedance matching element, and the second end of the fifth impedance matching element is connected to the common node of the third impedance matching element and the fourth impedance matching element.

2. The push-pull power amplifier circuit according to claim 1, wherein The first impedance matching element and the second impedance matching element are connected in series to form a first LC resonant circuit; the third impedance matching element and the fourth impedance matching element are connected in series to form a second LC resonant circuit. The resonant frequency points of the first LC resonant circuit and the second LC resonant circuit are the same.

3. The push-pull power amplifier circuit according to claim 2, wherein The fifth impedance matching element is a capacitive element or an inductive element.

4. The push-pull power amplification circuit according to claim 3, wherein, The first impedance matching element, the third impedance matching element, and the fifth impedance matching element are capacitive elements, and the second impedance matching element and the fourth impedance matching element are inductive elements, or the first impedance matching element, the third impedance matching element, and the fifth impedance matching element are inductive elements, and the second impedance matching element and the fourth impedance matching element are capacitive elements.

5. The push-pull power amplification circuit according to claim 3, characterized in that The first impedance matching unit and the third impedance matching unit form a third LC resonant circuit; the second impedance matching unit and the third impedance matching unit form a fourth LC resonant circuit; the resonant frequency points of the third LC resonant circuit and the fourth LC resonant circuit are the same.

6. The push-pull power amplifier circuit according to claim 5, characterized in that The first impedance matching unit, the third impedance matching unit, and the balun form a fifth LC resonant circuit; the second impedance matching unit, the third impedance matching unit, and the balun form a sixth LC resonant circuit; the resonant frequency points of the fifth LC resonant circuit and the sixth LC resonant circuit are the same.

7. The push-pull power amplification circuit according to claim 1, wherein The impedance matching circuit further includes a fourth impedance matching unit and a fifth impedance matching unit. Wherein, the first end of the fourth impedance matching unit is connected to the output end of the first differential amplifying transistor, and the second end of the fourth impedance matching unit is grounded; the first end of the fifth impedance matching unit is connected to the output end of the second differential amplifying transistor, and the second end of the fifth impedance matching unit is grounded.

8. The push-pull power amplifier circuit according to claim 7, wherein The fourth impedance matching unit includes: a sixth impedance matching element and a seventh impedance matching element, and the sixth impedance matching element and the seventh impedance matching element are connected in series to form a seventh LC resonant circuit; the fifth impedance matching unit includes: an eighth impedance matching element and a ninth impedance matching element, and the eighth impedance matching element and the ninth impedance matching element are connected in series to form an eighth LC resonant circuit; the resonant frequency points of the seventh LC resonant circuit and the eighth LC resonant circuit are the same.

9. The push-pull power amplifier circuit according to claim 8, wherein The first impedance matching unit, the third impedance matching unit, the fourth impedance matching unit, and the balun form a ninth LC resonant circuit; the second impedance matching unit, the third impedance matching unit, the fifth impedance matching unit, and the balun form a tenth LC resonant circuit; the resonant frequency points of the ninth LC resonant circuit and the tenth LC resonant circuit are the same.

10. A push-pull power amplifier circuit, characterized in that, Comprising a first differential amplifying transistor, a second differential amplifying transistor, a first circuit, and a balun; The first end of the first circuit is connected to the output end of the first differential amplifying transistor, and the second end of the first circuit is connected to the output end of the second differential amplifying transistor; The first circuit includes: a first passive element, a second passive element, a third passive element, a fourth passive element, and a fifth passive element. Wherein, the first end of the first passive element is connected to the output end of the first differential amplifying transistor, and the second end of the first passive element is connected to the first end of the second passive element; the second end of the second passive element is grounded; the first end of the third passive element is connected to the output end of the second differential amplifying transistor, and the second end of the third passive element is connected to the first end of the fourth passive element; the second end of the fourth passive element is grounded; the first end of the fifth passive element is connected to the first end of the second passive element, and the second end of the fifth passive element is connected to the first end of the fourth passive element; the balun includes a first coil, the first end of the first coil is connected to the output end of the first differential amplifying transistor, and the second end of the first coil is connected to the output end of the second differential amplifying transistor.

11. The push-pull power amplifier circuit according to claim 10, wherein The first passive component, the third passive component, and the fifth passive component are capacitive components, the second passive component and the fourth passive component are inductive components, or the first passive component, the third passive component, and the fifth passive component are inductive components, and the second passive component and the fourth passive component are capacitive components.

12. The push-pull power amplifier circuit according to claim 11, wherein The first circuit further includes a sixth passive component, a seventh passive component, an eighth passive component, and a ninth passive component. Among them, the first end of the sixth passive component is connected to the output end of the first differential amplification transistor, the second end of the sixth passive component is connected to the first end of the seventh passive component, and the second end of the seventh passive component is grounded; the first end of the eighth passive component is connected to the output end of the second differential amplification transistor, the second end of the eighth passive component is connected to the first end of the ninth passive component, and the second end of the ninth passive component is grounded.

13. The push-pull power amplifier circuit according to claim 11, characterized in that, The first passive component, the third passive component, the fifth passive component, the sixth passive component, and the eighth passive component are capacitive components, the second passive component, the fourth passive component, the seventh passive component, and the ninth passive component are inductive components, or the first passive component, the third passive component, the fifth passive component, the sixth passive component, and the eighth passive component are inductive components, and the second passive component, the fourth passive component, the seventh passive component, and the ninth passive component are capacitive components.

14. A radio frequency front-end module, characterized in that, Comprising the push-pull power amplifier circuit according to any one of claims 1-13.

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