Push-pull power amplifier circuit, radio frequency power amplifier circuit and radio frequency front-end module

Abstract

The present invention discloses a push-pull power amplifier circuit, comprising a first differential amplifier transistor and a second differential amplifier transistor, a first LC resonant circuit, a second LC resonant circuit, a third capacitor, a fourth capacitor and a first balun; the output end of the first differential amplifier transistor is coupled to the first input end of the first balun through the third capacitor, the output end of the second differential amplifier transistor is coupled to the second input end of the first balun through the fourth capacitor, the first end of the first LC resonant circuit is connected to the output end of the first differential amplifier transistor, the second end of the first LC resonant circuit is connected to the ground end, the first end of the second LC resonant circuit is connected to the output end of the second differential amplifier transistor, and the second end of the second LC resonant circuit is connected to the ground end; thereby improving the working efficiency and linearity of the push-pull power amplifier circuit, and optimizing the overall performance of the push-pull power amplifier circuit in the entire working frequency band.

Description

Technical Field

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

[0002] With the increasing popularity of 5G communications, the performance requirements for receiving and transmitting RF signals in terminals and other communication devices are becoming increasingly stringent. For example, the power amplifier circuits in the RF front-end circuit are required to have better linearity, power, efficiency, and bandwidth. However, existing push-pull power amplifier circuits often fail to meet the broadband requirements while maintaining other performance requirements (such as linearity, output power, impedance, and efficiency). Therefore, improving the overall performance of push-pull power amplifier circuits across the entire broadband has become a pressing issue. Summary of the Invention

[0003] An embodiment of the present invention provides a push-pull power amplifier circuit to solve the problem of poor overall performance of the push-pull power amplifier circuit within a wide frequency band.

[0004] A push-pull power amplifier circuit includes a first differential amplifier transistor and a second differential amplifier transistor, a first LC resonant circuit, a second LC resonant circuit, a third capacitor, a fourth capacitor, and a first balun; the output end of the first differential amplifier transistor is coupled to the first input end of the first balun via the third capacitor, the output end of the second differential amplifier transistor is coupled to the second input end of the first balun via the fourth capacitor, the first end of the first LC resonant circuit is connected to the output end of the first differential amplifier transistor, the second end of the first LC resonant circuit is connected to the ground end, the first end of the second LC resonant circuit is connected to the output end of the second differential amplifier transistor, and the second end of the second LC resonant circuit is connected to the ground end;

[0005] The first LC resonant circuit includes a first capacitor and a first inductor connected in series, and the second LC resonant circuit includes a second capacitor and a second inductor connected in series.

[0006] Furthermore, the first LC resonant circuit and the second LC resonant circuit are configured to adjust the second-order harmonic impedance of the push-pull power amplifier circuit.

[0007] Furthermore, the first capacitor, the second capacitor, the third capacitor, the fourth capacitor and the first balun are configured to adjust the fundamental impedance of the push-pull power amplifier circuit.

[0008] Furthermore, the operating frequency band of the push-pull power amplifier circuit is 2300MHz to 2700MHz, the capacitance values ​​of the third capacitor and the fourth capacitor are both between [5pF-12pF], and the capacitance values ​​of the first capacitor and the second capacitor are between [2pF-8pF].

[0009] Furthermore, the operating frequency band of the push-pull power amplifier circuit is 2300MHz to 2700MHz, the capacitance values ​​of the third capacitor and the fourth capacitor are both between [7pF-10pF], and the capacitance values ​​of the first capacitor and the second capacitor are between [4pF-6pF].

[0010] Furthermore, the operating frequency band of the push-pull power amplifier circuit is 1700MHz to 2000MHz, the capacitance values ​​of the third capacitor and the fourth capacitor are both between [8pF-15pF], and the capacitance values ​​of the first capacitor and the second capacitor are between [3pF-10pF].

[0011] Furthermore, the operating frequency band of the push-pull power amplifier circuit is 1700MHz to 2000MHz, the capacitance values ​​of the third capacitor and the fourth capacitor are both between [9pF-12pF], and the capacitance values ​​of the first capacitor and the second capacitor are between [5pF-7pF].

[0012] Furthermore, the operating frequency band of the push-pull power amplifier circuit is 1700MHz to 2000MHz, the capacitance values ​​of the third capacitor and the fourth capacitor are both between [10pF-13pF], and the capacitance values ​​of the first capacitor and the second capacitor are between [6pF-10pF].

[0013] Furthermore, the operating frequency band of the push-pull power amplifier circuit is the N77 frequency band, the capacitance values ​​of the third capacitor and the fourth capacitor are both between [3pF-9pF], and the capacitance values ​​of the first capacitor and the second capacitor are between [1pF-5pF].

[0014] Furthermore, the operating frequency band of the push-pull power amplifier circuit is the N77 frequency band, the capacitance values ​​of the third capacitor and the fourth capacitor are both between [4.5pF-6.5pF], and the capacitance values ​​of the first capacitor and the second capacitor are between

[0015] Between [1.5pF-3.5pF].

[0016] Furthermore, the first balun includes a first winding and a second winding, and a turns ratio of the second winding to the first winding is less than 3:1.

[0017] Furthermore, the operating frequency band of the push-pull power amplifier circuit is [Fa, Fb];

[0018] The resonant frequencies of the first LC resonant circuit and the second LC resonant circuit at the Fa frequency point are: The resonant frequencies of the first LC resonant circuit and the second LC resonant circuit at the Fb frequency point are

[0019] Furthermore, the push-pull power amplifier circuit also includes a third inductor and a fourth inductor, the first end of the third inductor is connected to the output end of the first differential amplifier transistor, the second end of the third inductor is connected to the first end of the fourth inductor, and the second end of the fourth inductor is connected to the output end of the second differential amplifier transistor.

[0020] Furthermore, the first capacitor, the third capacitor and the third inductor are configured to make the imaginary part of the fundamental impedance of the push-pull power amplifier circuit plus or minus forty percent of the real part;

[0021] The second capacitor, the fourth capacitor, and the fourth inductor are configured to make the imaginary part of the fundamental impedance of the push-pull power amplifier circuit plus or minus 40 percent of the real part.

[0022] Furthermore, the first capacitor, the third capacitor and the third inductor are configured to make the imaginary part of the fundamental impedance of the push-pull power amplifier circuit plus or minus 20 percent of the real part;

[0023] The second capacitor, the fourth capacitor, and the fourth inductor are configured to make the imaginary part of the fundamental impedance of the push-pull power amplifier circuit plus or minus 20 percent of the real part.

[0024] Furthermore, the first power supply terminal is coupled to the second terminal of the third inductor.

[0025] Furthermore, the second winding includes a first part of the secondary coil arranged on the second metal layer and a second part of the secondary coil arranged on the first metal layer, the first winding includes a first primary coil arranged on the second metal layer, the first primary coil and the first part of the secondary coil are coupled on the same layer, and the first primary coil and the second part of the secondary coil are coupled on the upper and lower layers.

[0026] Furthermore, the first winding and the second winding are arranged in the same metal layer, the first winding includes a first primary coil segment and a second primary coil segment, the second winding includes a secondary coil, the first primary coil segment and the second primary coil segment, the first primary coil segment and the second primary coil segment are connected in parallel, the first primary coil segment is arranged inside the secondary coil, and the second primary coil segment is arranged outside the secondary coil.

[0027] Furthermore, the first differential amplifier transistor is an HBT transistor, the base of the first differential amplifier transistor is the input terminal of the first differential amplifier transistor, the collector of the first differential amplifier transistor is the output terminal of the first differential amplifier transistor, and the emitter of the first differential amplifier transistor is grounded; the base of the second differential amplifier transistor is the input terminal of the second differential amplifier transistor, the collector of the second differential amplifier transistor is the output terminal of the second differential amplifier transistor, and the emitter of the second differential amplifier transistor is grounded.

[0028] A radio frequency power amplifier circuit includes a first differential pair, a second differential pair, a first balun, a second balun, a first LC resonant circuit, a second LC resonant circuit, a third LC resonant circuit, a fourth LC resonant circuit, a third capacitor, a fourth capacitor, a seventh capacitor, and an eighth capacitor;

[0029] The first output terminal of the first differential pair is coupled to the first input terminal of the first balun through the third capacitor, and the second output terminal of the first differential pair is coupled to the second input terminal of the first balun through the fourth capacitor;

[0030] The first output terminal of the second differential pair is coupled to the first input terminal of the second balun through the seventh capacitor, and the second output terminal of the second differential pair is coupled to the second input terminal of the second balun through the eighth capacitor;

[0031] The first output end of the first balun is used to output a radio frequency signal, the second output end of the first balun is connected to the first output end of the second balun, and the second output end of the second balun is grounded;

[0032] A first end of the first LC resonant circuit is connected to the first output end of the first differential pair, a second end of the first LC resonant circuit is connected to the ground end, a first end of the second LC resonant circuit is connected to the second output end of the first differential pair, and a second end of the second LC resonant circuit is connected to the ground end;

[0033] A first end of the third LC resonant circuit is connected to the first output end of the second differential pair, and a second end of the third LC resonant circuit is connected to the ground end; a first end of the fourth LC resonant circuit is connected to the second output end of the second differential pair, and a second end of the fourth LC resonant circuit is connected to the ground end;

[0034] The first LC resonant circuit includes a first capacitor and a first inductor connected in series, the second LC resonant circuit includes a second capacitor and a second inductor connected in series, the third LC resonant circuit includes a fifth capacitor and a fifth inductor connected in series, and the fourth LC resonant circuit includes a sixth capacitor and a sixth inductor connected in series.

[0035] Furthermore, the first LC resonant circuit, the second LC resonant circuit, the third LC resonant circuit and the fourth LC resonant circuit are configured to adjust the second-order harmonic impedance of the radio frequency power amplification circuit.

[0036] Furthermore, the first capacitor, the second capacitor, the third capacitor, the fourth capacitor, the fifth capacitor, the sixth capacitor, the seventh capacitor, the eighth capacitor, the first balun and the second balun are configured to adjust the fundamental impedance of the RF power amplifier circuit.

[0037] Furthermore, the operating frequency band of the RF power amplifier circuit is 2300MHz~2700MHz, the capacitance values ​​of the third capacitor, the fourth capacitor, the seventh capacitor and the eighth capacitor are all between [5pF-12pF], and the capacitance values ​​of the first capacitor, the second capacitor, the fifth capacitor and the sixth capacitor are all between [2pF-8pF].

[0038] Furthermore, the operating frequency band of the RF power amplifier circuit is 1700MHz to 2000MHz, the capacitance values ​​of the third capacitor, the fourth capacitor, the seventh capacitor and the eighth capacitor are all between [8pF-15pF], and the capacitance values ​​of the first capacitor, the second capacitor, the fifth capacitor and the sixth capacitor are all between [3pF-10pF].

[0039] Furthermore, the first balun includes a first winding and a second winding, the turns ratio of the second winding to the second winding is less than 3:1, and the second balun includes a third winding and a fourth winding, the turns ratio of the fourth winding to the third winding is less than 3:1.

[0040] Furthermore, the operating frequency band of the radio frequency power amplifier circuit is [Fa, Fb];

[0041] The resonant frequencies of the first LC resonant circuit, the second LC resonant circuit, the third LC resonant circuit and the fourth LC resonant circuit at the Fa frequency point are: The resonant frequencies of the first LC resonant circuit, the second LC resonant circuit, the third LC resonant circuit and the fourth LC resonant circuit at the frequency Fb are

[0042]

[0043] A radio frequency front-end module comprises the above-mentioned push-pull power amplifier circuit and a radio frequency power amplifier circuit.

[0044] The push-pull power amplifier circuit includes a first differential amplifier transistor and a second differential amplifier transistor, a first LC resonant circuit, a second LC resonant circuit, a third capacitor, a fourth capacitor, and a first balun; the output end of the first differential amplifier transistor is coupled to the first input end of the first balun through the third capacitor, and the output end of the second differential amplifier transistor is coupled to the second input end of the first balun through the fourth capacitor; the first end of the first LC resonant circuit is connected to the output end of the first differential amplifier transistor, the second end of the first LC resonant circuit is connected to the ground end, the first end of the second LC resonant circuit is connected to the output end of the second differential amplifier transistor, and the second end of the second LC resonant circuit is connected to the ground end; the first LC resonant circuit includes a first capacitor and a first inductor connected in series, and the second LC resonant circuit includes a second capacitor and a second inductor connected in series. In this embodiment, by configuring the first LC resonant circuit, the second LC resonant circuit, the third capacitor, the fourth capacitor and the first balun, it is possible to optimize the harmonic impedance (especially the second-order harmonic impedance) of the push-pull power amplifier circuit without affecting the fundamental impedance, so that the harmonic impedance (especially the second-order harmonic impedance) of the push-pull power amplifier circuit within the entire operating frequency band is more converged, and the operating efficiency and linearity of the push-pull power amplifier circuit can be improved, thereby optimizing the overall performance of the push-pull power amplifier circuit within the entire operating frequency band. BRIEF DESCRIPTION OF THE DRAWINGS

[0045] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following briefly introduces the drawings required for use in the description of the embodiments of the present invention. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative labor.

[0046] Figure 1 is a circuit diagram of a push-pull power amplifier circuit in one embodiment of the present invention;

[0047] Figure 2 is another circuit diagram of a push-pull power amplifier circuit in one embodiment of the present invention;

[0048] Figure 3 is another circuit diagram of a push-pull power amplifier circuit in one embodiment of the present invention;

[0049] Figure 4 is another circuit diagram of a push-pull power amplifier circuit in one embodiment of the present invention;

[0050] Figure 5 is another circuit diagram of a push-pull power amplifier circuit in one embodiment of the present invention;

[0051] Figure 6 is another circuit diagram of a push-pull power amplifier circuit in one embodiment of the present invention;

[0052] Figure 7 FIG. 2 is another circuit diagram of a radio frequency power amplifier circuit according to an embodiment of the present invention.

[0053] In the figure: 11, first differential amplifier transistor; 12, second differential amplifier transistor; 13, third differential amplifier transistor; 14, fourth differential amplifier transistor; 10, first LC resonant circuit; 20, second LC resonant circuit; 50, third LC resonant circuit; 60, fourth LC resonant circuit; 30, first balun; 40, second balun; C1, first capacitor; C2, second capacitor; C3, third capacitor; C4, fourth capacitor; C5, fifth capacitor; C6, sixth capacitor; C7, seventh capacitor;

[0054] C8, eighth capacitor; L1, first inductor; L2, second inductor; L3, third inductor; L4, fourth inductor; L5, fifth inductor; L6, sixth inductor. DETAILED DESCRIPTION

[0055] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them. All other embodiments obtained by ordinary technicians in this field based on the embodiments of the present invention without making any creative efforts shall fall within the scope of protection of the present invention.

[0056] It should be understood that the present invention can be embodied in various forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided to make the disclosure thorough and complete and to fully convey the scope of the invention to those skilled in the art. In the drawings, the dimensions and relative dimensions of layers and regions may be exaggerated for clarity. Like reference numerals denote like elements throughout.

[0057] 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 may be directly on, adjacent to, connected to, or coupled to the other element or layer, or there may be intervening elements or layers. Conversely, 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 may be 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 merely 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 represented as a second element, component, region, layer, or part without departing from the teachings of the present invention.

[0058] Spatially relative terms such as "under," "beneath," "below," "under," "above," "above," etc., may be used herein for convenience of description to describe the relationship of one element or feature shown in the figures to other elements or features. It should be understood that the spatially relative terms are intended to include different orientations of the device in use and operation in addition to the orientations shown in the figures. For example, if the device in the drawings is flipped, then the elements or features described as "under" or "beneath" or "beneath" the other elements will be oriented as "over" the other elements or features. Thus, the exemplary terms "under" and "under" may include both the upper and lower orientations. The device may be oriented otherwise (rotated 90 degrees or in other orientations) and the spatial descriptors used herein are interpreted accordingly.

[0059] The purpose of the terms used herein is only to describe specific embodiments and is not intended to limit the present invention. When used herein, the singular forms "a", "an", and "the" are intended to include the plural forms, unless the context clearly indicates otherwise. It should also be understood that the terms "comprising" and / or "comprising", when used in this specification, determine the presence of the features, integers, steps, operations, elements and / or parts, but do not exclude the presence or addition of one or more other features, integers, steps, operations, elements, parts and / or groups. When used herein, the term "and / or" includes any and all combinations of the relevant listed items.

[0060] In order to fully understand the present invention, detailed structures and steps will be provided in the following description to illustrate the technical solutions proposed by the present invention. Preferred embodiments of the present invention are described in detail below. However, in addition to these detailed descriptions, the present invention may also have other implementations.

[0061] This embodiment provides a push-pull power amplifier circuit, such as Figure 1 As shown, the circuit includes a first differential amplifier transistor 11 and a second differential amplifier transistor 12, a first LC resonant circuit 10, a second LC resonant circuit 20, a third capacitor C3, a fourth capacitor C4, and a first balun 30. The output of the first differential amplifier transistor 11 is coupled to the first input of the first balun 30 via the third capacitor C3, and the output of the second differential amplifier transistor 12 is coupled to the second input of the first balun 30 via the fourth capacitor C4. The first end of the first LC resonant circuit 10 is connected to the output of the first differential amplifier transistor 11, and the second end of the first LC resonant circuit 10 is connected to the ground. The first end of the second LC resonant circuit 20 is connected to the output of the second differential amplifier transistor 12, and the second end of the second LC resonant circuit 20 is connected to the ground. The first LC resonant circuit 10 includes a first capacitor C1 and a first inductor L1 connected in series, and the second LC resonant circuit 20 includes a second capacitor C2 and a second inductor L2 connected in series.

[0062] Among them, the first differential amplifier transistor 11 and the second differential amplifier transistor 12 can be BJT transistors or field effect transistors (FETs). Optionally, the first differential amplifier transistor 11 includes at least one BJT transistor (for example, an HBT transistor) or at least one field effect transistor. Exemplarily, the first differential amplifier transistor 11 can be formed by connecting multiple BJT transistors in parallel. The second differential amplifier transistor 12 includes at least one BJT transistor (for example, an HBT transistor) or at least one field effect transistor. Exemplarily, the second differential amplifier transistor 12 can be formed by connecting multiple BJT transistors in parallel. It can be understood that the first differential amplifier transistor 11 and the second differential amplifier transistor 12 can be any amplifier stage in a push-pull power amplifier circuit. Exemplarily, the amplifier stage can be any amplifier stage in a driver stage, an intermediate stage, or an output stage.

[0063] In a specific embodiment, the first differential amplifier transistor 11 is configured to amplify the first RF input signal and output the first RF amplified signal (the amplified first RF input signal), the first RF amplified signal is input to the first input terminal of the first balun 30 through the third capacitor C3, and the second differential amplifier transistor 12 is configured to amplify the second RF input signal and output the second RF amplified signal (the amplified second RF input signal), the second RF amplified signal is input to the second input terminal of the first balun 30 through the fourth capacitor C4. The first balun converts and synthesizes the first RF amplified signal and the second RF amplified signal to output the RF output signal. The third capacitor C3 can block the DC signal in the first RF amplified signal, and the fourth capacitor C4 can block the DC signal in the second RF amplified signal, thereby avoiding the influence of the DC signal. The first RF input signal can be the RF signal output after amplification by the corresponding pre-amplifier circuit, or it can be one of the balanced RF signals obtained after converting the unbalanced input RF signal. Similarly, the second RF input signal may be a RF signal output after amplification by the corresponding pre-amplifier circuit, or may be a balanced RF signal obtained by converting an unbalanced input RF signal.

[0064] In a specific embodiment, the push-pull RF power amplifier circuit further includes a pre-stage conversion circuit (not shown). For example, the pre-stage conversion circuit can be implemented by a pre-stage conversion balun. The pre-stage conversion balun is used to convert an unbalanced RF input signal into a balanced first RF input signal and a second RF input signal, and input the first RF input signal to the input end of the first differential amplifier transistor 11, and input the second RF input signal to the input end of the second differential amplifier transistor 12.

[0065] Among them, the third capacitor C3 and the fourth capacitor C4 are matching capacitors that participate in the impedance matching of the push-pull power amplifier circuit. Since the capacitive reactance value of the first capacitor C1 and the capacitive reactance value of the second capacitor C1 are easily connected to the inductance offset of the power supply end during actual application, the first capacitor C1 and the second capacitor C2 have almost no effect on the fundamental impedance conversion of the push-pull power amplifier circuit. If only the first balun 30 participates in the impedance conversion of the push-pull power amplifier circuit at this time, the turns ratio of the first balun 30 needs to be set to a large value (for example: the turns ratio of the first balun 30 is less than or equal to 1:3, for example: the turns ratio of the first balun 30 needs to be set to 1:3.5), thereby making the occupied area of ​​the first balun 30 very large. Therefore, the present application connects a third capacitor C3 between the output end of the first differential amplifier transistor 11 and the first input end of the first balun 30, and connects a fourth capacitor C4 between the output end of the second differential amplifier transistor 12 and the second input end of the first balun 30. The third capacitor C3, the fourth capacitor C4 and the first balun 30 jointly participate in the impedance conversion of the push-pull power amplifier circuit, thereby not only alleviating the impedance conversion pressure of the first balun (for example: alleviating the impedance conversion pressure of the first balun to convert the high impedance of the output end of the push-pull power amplifier circuit into the low impedance of the input end), but also reducing the turns ratio of the second winding and the first winding of the first balun, thereby reducing the occupied area of ​​the first balun and optimizing the performance of the first balun.

[0066] It should be noted that the turns ratio of the first balun in this embodiment is the ratio of the number of coil turns of the second winding to the number of coil turns of the first winding. The larger the ratio of the number of coil turns of the second winding to the number of coil turns of the first winding, the larger the turns ratio of the first balun. Conversely, the smaller the ratio of the number of coil turns of the second winding to the number of coil turns of the first winding, the smaller the turns ratio of the first balun.

[0067] In this embodiment, a push-pull power amplifier circuit includes a first differential amplifier transistor and a second differential amplifier transistor, a first LC resonant circuit, a second LC resonant circuit, a third capacitor, a fourth capacitor and a first balun; the output end of the first differential amplifier transistor is coupled to the first input end of the first balun through the third capacitor, the output end of the second differential amplifier transistor is coupled to the second input end of the first balun through the fourth capacitor, the first end of the first LC resonant circuit is connected to the output end of the first differential amplifier transistor, the second end of the first LC resonant circuit is connected to the ground end, the first end of the second LC resonant circuit is connected to the output end of the second differential amplifier transistor, and the second end of the second LC resonant circuit is connected to the ground end; the first LC resonant circuit includes a first capacitor and a first inductor connected in series, and the second LC resonant circuit includes a second capacitor and a second inductor connected in series. In this embodiment, by configuring the first LC resonant circuit, the second LC resonant circuit, the third capacitor, the fourth capacitor and the first balun, it is possible to optimize the harmonic impedance (especially the second-order harmonic impedance) of the push-pull power amplifier circuit without affecting the fundamental impedance, so that the harmonic impedance (especially the second-order harmonic impedance) of the push-pull power amplifier circuit within the entire operating frequency band is more converged, and the operating efficiency and linearity of the push-pull power amplifier circuit can be improved, thereby optimizing the overall performance of the push-pull power amplifier circuit within the entire operating frequency band.

[0068] In a specific embodiment, the first LC resonant circuit 10 and the second LC resonant circuit 20 are configured to adjust the second-order harmonic impedance of the push-pull power amplifier circuit.

[0069] Furthermore, in a specific embodiment, the first capacitor C1, the second capacitor C2, the third capacitor C3, the fourth capacitor C4 and the first balun 30 are configured to adjust the fundamental impedance of the push-pull power amplifier circuit.

[0070] In a specific embodiment, the first LC resonant circuit 10 and the second LC resonant circuit are configured to adjust the harmonic impedance (especially the second-order harmonic impedance) of the push-pull power amplifier circuit. The first capacitor C1 in the first LC resonant circuit 10, the second capacitor C2 in the second LC resonant circuit 20, and the third capacitor C3, the fourth capacitor C4, and the first balun 30 are configured to adjust the fundamental impedance of the push-pull power amplifier circuit. Therefore, by configuring the first LC resonant circuit, the second LC resonant circuit, the third capacitor C2, the fourth capacitor C4, and the first balun 30, the harmonic impedance (especially the second-order harmonic impedance) of the push-pull power amplifier circuit can be optimized without affecting the fundamental impedance, making the harmonic impedance (especially the second-order harmonic impedance) of the push-pull power amplifier circuit more convergent across the entire operating frequency band. The operating efficiency and linearity of the push-pull power amplifier circuit can also be improved, thereby optimizing the overall performance of the push-pull power amplifier circuit across the entire operating frequency band.

[0071] In a specific embodiment, the operating frequency band of the push-pull power amplifier circuit is 2300MHz-2700MHz, the capacitance values ​​of the third capacitor C3 and the fourth capacitor C4 are both between [5pF-12pF], and the capacitance values ​​of the first capacitor C1 and the second capacitor C2 are both between [2pF-8pF].

[0072] Among them, the operating frequency band corresponding to 2300MHz~2700MHz can be N41 band / n40 band / n7 band, etc. When the push-pull power amplifier circuit supports RF signal transmission with an operating frequency band of 2300MHz~2700MHz, the capacitance values ​​of the third capacitor C3 and the fourth capacitor C4 are both between [5pF-12pF]. For example: the capacitance values ​​of the third capacitor C3 and the fourth capacitor C4 can be 6pF, 7pF, 8pF, 9pF, 10pF, 11pF, etc. The capacitance values ​​of the first capacitor C1 and the second capacitor C2 are between [2pF-8pF]. For example: the capacitance values ​​of the first capacitor C1 and the second capacitor C2 can be 3pF, 4pF, 5pF, 6pF, 7pF, etc.

[0073] Furthermore, the operating frequency band of the push-pull power amplifier circuit is 2300MHz to 2700MHz, and the capacitance values ​​of the third capacitor and the fourth capacitor are both between [7pF-10pF]. For example, the capacitance values ​​of the third capacitor C3 and the fourth capacitor C4 can be 7.2pF, 7.5pF, 7.8pF, 8.3pF, 8.5pF, 9.3pF, 9.5pF, etc. The capacitance values ​​of the first capacitor and the second capacitor are both between [4pF-6pF]. For example, the capacitance values ​​of the first capacitor C1 and the second capacitor C2 can be 4.3pF, 4.5pF, 4.8pF, 5.3pF, 5.6pF, etc.

[0074] In a specific embodiment, the operating frequency band of the push-pull power amplifier circuit is 1700MHz to 2000MHz, the capacitance values ​​of the third capacitor C3 and the fourth capacitor C4 are both between [8pF-15pF], and the capacitance values ​​of the first capacitor C1 and the second capacitor C2 are both between [3pF-10pF].

[0075] Among them, the operating frequency band corresponding to 1700MHz~2000MHz can be n1 band / n2 band / n3 band. When the push-pull power amplifier circuit supports RF signal transmission with an operating frequency band of 1700MHz~2000MHz, the capacitance values ​​of the third capacitor C3 and the fourth capacitor C4 are both between [8pF-15pF]. For example, the capacitance values ​​of the third capacitor C3 and the fourth capacitor C4 can be 8pF, 9pF, 10pF, 11pF, 12pF, 13pF, 14pF, etc. The capacitance values ​​of the first capacitor C1 and the second capacitor C2 are both between [3pF-10pF]. For example, the capacitance values ​​of the first capacitor C1 and the second capacitor C2 can be 3pF, 4pF, 5pF, 6pF, 7pF, 8pF, 9pF, 10pF, etc.

[0076] Furthermore, the operating frequency band of the push-pull power amplifier circuit is 1700MHz to 2000MHz, and the capacitance values ​​of the third capacitor C3 and the fourth capacitor C4 are both between [9pF-12pF]. For example, the capacitance values ​​of the third capacitor C3 and the fourth capacitor C4 are 9.2pF, 9.5pF, 9.8pF, 10.3pF, 10.5pF, 10.8pF, 11.3pF, 11.5pF, 11.8pF, etc. The capacitance values ​​of the first capacitor C1 and the second capacitor C2 are both between [5pF-7pF]. For example, the capacitance values ​​of the first capacitor C1 and the second capacitor C2 are 5.2pF, 5.5pF, 5.8pF, 6.3pF, 6.5pF, 6.8pF, etc.

[0077] Furthermore, the operating frequency band of the push-pull power amplifier circuit is 1700MHz to 2000MHz, and the capacitance values ​​of the third capacitor and the fourth capacitor are both between [10pF-13pF]. For example, the capacitance values ​​of the third capacitor C3 and the fourth capacitor C4 are 10.2pF, 10.5pF, 10.8pF, 11.3pF, 11.5pF, 11.8pF, 12.3pF, 12.5pF, 12.8pF, etc. The capacitance values ​​of the first capacitor and the second capacitor are both between [6pF-10pF]. For example, the capacitance values ​​of the first capacitor and the second capacitor are 6.2pF, 6.5pF, 6.8pF, 7.3pF, 7.5pF, 7.8pF, 8.3pF, 8.8pF, 9.5pF, 9.8pF, etc.

[0078] In a specific embodiment, the operating frequency band of the push-pull power amplifier circuit is 1700 MHz to 2000 MHz, and the capacitance values ​​of the third capacitor and the fourth capacitor are both between [10 pF and 13 pF]. For example, the capacitance values ​​of the third capacitor and the fourth capacitor can be 10 pF, 11 pF, 12 pF, 13 pF, etc. The capacitance values ​​of the first capacitor and the second capacitor are both between [6 pF and 10 pF]. For example, the capacitance values ​​of the first capacitor and the second capacitor can be 6 pF, 7 F, 8 pF, 9 pF, 10 pF, etc.

[0079] Furthermore, the operating frequency band of the push-pull power amplifier circuit is the N77 frequency band, and the capacitance values ​​of the third capacitor and the fourth capacitor are both between [4.5pF-6.5pF]. For example, the capacitance values ​​of the third capacitor C3 and the fourth capacitor C4 are 4.7pF, 5.2pF, 5.5pF, 5.7pF, 6.2ppF, 6.5pF, etc. The capacitance values ​​of the first capacitor and the second capacitor are both between [1.5pF-3.5pF]. For example, the capacitance values ​​of the first capacitor and the second capacitor are 1.7pF, 2.2pF, 2.5pF, 2.7pF, 3.2ppF, 3.5pF, etc.

[0080] In one specific embodiment, the capacitance values ​​of the third capacitor C3 and the fourth capacitor C4 are associated with the turns ratio of the first balun 30 and the operating frequency band of the push-pull power amplifier circuit. Assuming other influencing factors remain constant, a larger turns ratio of the first balun 30 results in smaller capacitance values ​​of the third capacitor C3 and the fourth capacitor C4, and a smaller turns ratio of the first balun 30 results in larger capacitance values ​​of the third capacitor C3 and the fourth capacitor C4. The turns ratio of the first balun 30 is the ratio of the number of turns of the second winding to the number of turns of the first winding of the first balun 30. Assuming other influencing factors remain constant, a larger operating frequency band of the push-pull power amplifier circuit results in smaller capacitance values ​​of the third capacitor C3 and the fourth capacitor C4. Since larger capacitance values ​​of the third capacitor C3 and the fourth capacitor C4 increase their occupied area and cost, appropriate capacitance values ​​of the third capacitor C3 and the fourth capacitor C4 can be selected based on the actual application scenario of the circuit.

[0081] In a specific embodiment, the first balun includes a first winding and a second winding, and a turns ratio of the second winding to the first winding is less than 3:1.

[0082] The first winding and the second winding are coupled to each other to form a first balun. In this embodiment, the first end of the first winding is the first input end of the first balun, the second end of the first winding is the second input end of the first balun, the first end of the second winding is the first output end of the first balun, and the second end of the second winding is the second output end of the first balun.

[0083] Specifically, the first end of the first winding is connected to the output end of the first differential amplifier transistor 11, and the second end of the first winding is connected to the output end of the second differential amplifier transistor 12. The first end of the second winding is the output end of the push-pull power amplifier circuit, and the second end of the second winding is connected to the ground end.

[0084] Because the third capacitor C3 and the fourth capacitor C4 in this embodiment participate in impedance conversion together with the first balun, a first balun with a smaller turns ratio can be used in this embodiment, i.e., a first balun with a smaller ratio of the turns of the second winding to the turns of the first winding. In this embodiment, the turns ratio of the second winding to the first winding of the first balun is less than 3:1. For example, the turns ratio of the second winding to the first winding of the first balun is 2:1. This reduces the occupied area and cost of the push-pull power amplifier circuit while maintaining the overall performance of the push-pull power amplifier circuit.

[0085] In another specific embodiment, refer to the following Figure 2As shown, the third capacitor C3 and the fourth capacitor C4 can also be equivalent to capacitor C10. Wherein, capacitor C10 is a matching capacitor participating in the impedance matching of the push-pull power amplifier circuit. The present application separates the first winding into a first coil segment and a second coil segment, and connects capacitor C10 between the first coil segment and the second coil segment. Capacitor C10 and the first balun 30 jointly participate in the impedance conversion of the push-pull power amplifier circuit, thereby not only alleviating the impedance conversion pressure of the first balun (for example: alleviating the impedance conversion pressure of converting the high impedance of the output end of the push-pull power amplifier circuit into the low impedance of the input end of the push-pull power amplifier circuit), but also reducing the turns ratio of the second winding and the first winding of the first balun, thereby reducing the occupied area of ​​the first balun and optimizing the performance of the first balun.

[0086] In this embodiment, by placing the capacitor C10 between the first coil segment and the second coil segment, compared with the implementation scheme of connecting the third capacitor C3 between the output end of the first differential amplifier transistor 11 and the first input end of the first balun 30, and connecting the fourth capacitor C4 between the output end of the second differential amplifier transistor 12 and the second input end of the first balun 30; this embodiment uses a single capacitor C10 to realize the functions of the third capacitor C3 and the fourth capacitor C4, and achieves the same technical effect; thereby, while ensuring the overall performance of the push-pull power amplifier circuit, it can also further reduce the occupied area of ​​the push-pull power amplifier circuit and optimize its overall layout.

[0087] In a specific embodiment, the operating frequency band of the push-pull power amplifier circuit is [Fa, Fb];

[0088] The resonant frequencies of the first LC resonant circuit and the second LC resonant circuit at the Fa frequency point are: The resonant frequencies of the first LC resonant circuit and the second LC resonant circuit at the Fb frequency point are

[0089] As an example, the present application configures the first LC resonant circuit and the second LC resonant circuit. Specifically, by adjusting the resonant frequency point of the first LC resonant circuit and the resonant frequency point of the second LC resonant circuit, the resonant frequency of the first LC resonant circuit and the second LC resonant circuit at the Fa frequency point is The resonant frequencies of the first LC resonant circuit and the second LC resonant circuit at the Fb frequency point are Therefore, without affecting the fundamental impedance, not only can the harmonic impedance (especially the second-order harmonic impedance) of the push-pull power amplifier circuit be optimized, making the harmonic impedance (especially the second-order harmonic impedance) of the push-pull power amplifier circuit more convergent within the entire operating frequency band, but also the working efficiency and linearity of the push-pull power amplifier circuit can be improved, thereby optimizing the overall performance of the push-pull power amplifier circuit within the entire operating frequency band.

[0090] It should be noted that the first LC resonant circuit 10 and the second LC resonant circuit 20 in this embodiment are circuits for adjusting the impedance of the push-pull power amplifier circuit. Specifically, the resonant frequency band points of the first LC resonant circuit 10 and the second LC resonant circuit 20 are adjusted to adjust the second-order impedance of the push-pull power amplifier circuit. That is, the first LC resonant circuit and the second LC resonant circuit are impedance adjustment circuits in the push-pull power amplifier circuit, and participate in the second-order impedance adjustment of the push-pull power amplifier circuit.

[0091] As an example, the first LC resonant circuit includes a first capacitor C1 and a first inductor L1 connected in series. The first end of the first capacitor C1 is connected to the output end of the first differential amplifier transistor 11, the second end of the first capacitor C1 is connected to the first end of the first inductor L1, and the second end of the first inductor L1 is connected to ground. Optionally, the first capacitor C1 may be a chip capacitor. The first inductor L1 may be implemented using a chip inductor or a wire bond.

[0092] Similarly, the second LC resonant circuit 20 includes a second capacitor C2 and a second inductor L2 connected in series. A first end of the second capacitor C2 is connected to the output terminal of the second differential amplifier transistor 12, a second end of the second capacitor C2 is connected to the first end of the second inductor L2, and a second end of the second inductor L2 is connected to ground. Optionally, the second capacitor C2 may be a chip capacitor. The second inductor L2 may be implemented using a chip inductor or a wirebond.

[0093] As an example, if the push-pull power amplifier circuit operates in the n41 frequency band, that is, the operating frequency band of the push-pull power amplifier circuit is [2515MHz, 2675MHz], according to the LC resonance formula It can be seen that by configuring the inductance and capacitance values ​​in the first LC resonant circuit and the second LC resonant circuit, the resonant frequency of the first LC resonant circuit and the second LC resonant circuit at 2515 MHz is And the resonant frequency of the first LC resonant circuit and the second LC resonant circuit at a frequency of 2675 MHz is

[0094] As another example, if the push-pull power amplifier circuit operates in the n77 frequency band, that is, the operating frequency band of the push-pull power amplifier circuit is [3300MHz, 4200MHz], according to the LC resonance formula It can be seen that by configuring the inductance and capacitance values ​​in the first LC resonant circuit and the second LC resonant circuit, the resonant frequency of the first LC resonant circuit and the second LC resonant circuit at 2515 MHz is And the resonant frequency of the first LC resonant circuit and the second LC resonant circuit at 4200 MHz is

[0095] In a specific embodiment, the operating frequency band of the push-pull power amplifier circuit is [Fa, Fb]; by configuring the capacitance value of the first capacitor C1 and the inductance value of the first inductor L1 connected in series in the first LC resonant circuit, and the capacitance value of the second capacitor C2 and the inductance value of the second inductor L2 connected in series in the second LC resonant circuit, the resonant frequency of the first LC resonant circuit and the second LC resonant circuit at the frequency point Fa is The resonant frequencies of the first LC resonant circuit and the second LC resonant circuit at the Fb frequency point are This improves the working efficiency and linearity of the push-pull power amplifier circuit, and makes the second-order harmonic impedance of the push-pull power amplifier circuit more convergent within the entire working frequency band, thereby optimizing the overall performance of the push-pull power amplifier circuit within the entire working frequency band.

[0096] In a specific embodiment, refer to the following Figure 3 As shown, the push-pull power amplifier circuit also includes a third inductor L3 and a fourth inductor L4. The first end of the third inductor L3 is connected to the output end of the first differential amplifier transistor 11, the second end of the third inductor L3 is connected to the first end of the fourth inductor L4, and the second end of the fourth inductor L4 is connected to the output end of the second differential amplifier transistor M4.

[0097] The first capacitor C1, the third capacitor C3 and the third inductor L3 are configured so that the imaginary part of the fundamental impedance of the push-pull power amplifier circuit is plus or minus forty percent of the real part; the second capacitor C2, the fourth capacitor C4 and the fourth inductor L4 are configured so that the imaginary part of the fundamental impedance of the push-pull power amplifier circuit is plus or minus forty percent of the real part.

[0098] In one specific embodiment, because the push-pull power amplifier circuit has extremely high bandwidth requirements, it is necessary not only to ensure that the second-order harmonic impedance is sufficiently convergent, but also to have extremely high requirements for the fundamental impedance of the push-pull power amplifier circuit, and to ensure that the fundamental impedance of the push-pull power amplifier circuit is sufficiently convergent. To this end, the present application configures the first capacitor C1, the third capacitor C3, and the third inductor L3, as well as the second capacitor C2, the fourth capacitor C4, and the fourth inductor L4, so that the imaginary part of the fundamental impedance of the push-pull power amplifier circuit is plus or minus 40% of the real part.

[0099] Preferably, the first capacitor C1, the third capacitor C3 and the third inductor L3 are configured so that the imaginary part value of the fundamental impedance of the push-pull power amplifier circuit is [-2j, +2j], and the second capacitor C2, the fourth capacitor C4 and the fourth inductor L4 are configured so that the imaginary part value of the fundamental impedance of the push-pull power amplifier circuit is [-2j, +2j].

[0100] In an actual application, the fundamental impedance Z0 of the push-pull power amplifier circuit is Z=R+j(ωL–1 / ωC). Wherein, R is the real impedance of the push-pull power amplifier circuit, and j(ωL–1 / ωC) is the imaginary impedance of the push-pull power amplifier circuit. When the imaginary part of the fundamental impedance of the push-pull power amplifier circuit is plus or minus forty percent of the real part, the impedance of the push-pull power amplifier circuit is sufficiently converged, which can improve the bandwidth performance of the push-pull power amplifier circuit. Therefore, the present application configures the first capacitor C1, the third capacitor C3, and the third inductor L3, as well as the second capacitor C2, the fourth capacitor C4, and the fourth inductor L4, so that the imaginary part of the fundamental impedance of the push-pull power amplifier circuit is plus or minus forty percent of the real part. The closer the imaginary part of the fundamental impedance of the push-pull power amplifier circuit is to zero, the more convergent the impedance of the push-pull power amplifier circuit is, and the better the bandwidth performance of the push-pull power amplifier circuit is. It should be noted that this application does not impose any limitation on the real part value of the fundamental impedance.

[0101] Furthermore, the first capacitor C1, the third capacitor C3 and the third inductor L3 are configured so that the imaginary part value of the fundamental impedance of the push-pull power amplifier circuit is plus or minus 20 percent of the real part value; the second capacitor C2, the fourth capacitor C4 and the fourth inductor L4 are configured so that the imaginary part value of the fundamental impedance of the push-pull power amplifier circuit is plus or minus 20 percent of the real part value.

[0102] For example, the first capacitor C1, the third capacitor C3 and the third inductor L3 are configured to make the imaginary part of the fundamental impedance of the push-pull power amplifier circuit be [-1j, +1j]; the second capacitor C2, the fourth capacitor C4 and the fourth inductor L4 are configured to make the imaginary part of the fundamental impedance of the push-pull power amplifier circuit be [-1j, +1j].

[0103] In this embodiment, the first LC resonant circuit 10 and the second resonant circuit 20 work together to adjust the second-order harmonic impedance of the push-pull power amplifier circuit. The first capacitor C1, the third capacitor C3, and the third inductor L3, as well as the second capacitor C2, the fourth capacitor C4, and the fourth inductor L4, work together to adjust the fundamental impedance of the push-pull power amplifier circuit. Therefore, it can be seen that under the joint action of the first LC resonant circuit 10, the second resonant circuit 20, the third capacitor C3, the fourth capacitor C4, the third inductor L3, and the fourth inductor L4, not only the second-order harmonic impedance of the push-pull power amplifier circuit can be adjusted, but also the fundamental impedance can be adjusted. The second-order harmonic impedance and the fundamental impedance are the main factors affecting the bandwidth performance of the push-pull power amplifier circuit. Therefore, in this embodiment, under the joint action of the first LC resonant circuit 10, the second resonant circuit 20, the third capacitor C3, the fourth capacitor C4, the third inductor L3, and the fourth inductor L4, the overall performance of the push-pull power amplifier circuit within the entire operating frequency band is guaranteed.

[0104] In this embodiment, the first capacitor C1, the third capacitor C3, and the third inductor L3 are configured so that the imaginary part of the fundamental impedance of the push-pull power amplifier circuit is plus or minus 20% of the real part; the second capacitor C2, the fourth capacitor C4, and the fourth inductor L4 are configured so that the imaginary part of the fundamental impedance of the push-pull power amplifier circuit is plus or minus 20% of the real part. In this way, the impedance of the push-pull power amplifier circuit is more converged, and the bandwidth performance of the push-pull power amplifier circuit is better.

[0105] In a specific embodiment, refer to the following Figure 3 As shown, the first power supply terminal is coupled to the second terminal of the third inductor L3. It is understandable that the first power supply terminal supplies power to the first differential amplifier transistor 11 via the third inductor L3 to ensure normal operation of the first differential amplifier transistor 11, and the second power supply terminal supplies power to the second differential amplifier transistor 12 via the fourth inductor L4 to ensure normal operation of the second differential amplifier transistor 12.

[0106] Specifically, the connection node between the third inductor L3 and the fourth inductor L4 is connected to the first power supply terminal VCC, so that the first power supply terminal VCC feeds the first differential amplifier transistor 11 through the third inductor L3 and feeds the second differential amplifier transistor 12 through the fourth inductor L4. In this example, the connection node between the third inductor L3 and the fourth inductor L4 is connected to the first power supply terminal VCC, so that the third inductor L3 and the fourth inductor L4 can not only cooperate with the first capacitor C1, the second capacitor C2, the first capacitor C3, and the second capacitor C4 to adjust the imaginary part of the fundamental impedance, but can also be connected to the first power supply terminal VCC to provide a power feeding function. It can be understood that the reuse of the first inductor L21 and the second inductor L22 eliminates the need for additional components, helping to reduce the number of components in the circuit, saving area, and reducing costs.

[0107] In this embodiment, the first capacitor C1, the third capacitor C3, and the third inductor L3 in the first LC resonant circuit, and the second capacitor C2, the fourth capacitor C4, and the fourth inductor L4 in the second LC resonant circuit are used together to ensure that the imaginary part of the fundamental impedance of the push-pull power amplifier circuit is plus or minus 20 percent of the real part, without requiring additional circuit structures or components. This ensures the overall performance of the push-pull power amplifier circuit across the entire operating frequency band while also reducing the occupied area of ​​the push-pull power amplifier circuit and optimizing the overall layout of the push-pull power amplifier circuit.

[0108] In a specific embodiment, a difference between the capacitive reactance values ​​of the first capacitor C1 and the third capacitor C3 and the inductive reactance value of the third inductor L3 is within a first threshold value, and a difference between the capacitive reactance values ​​of the second capacitor C2 and the fourth capacitor C4 and the inductive reactance value of the fourth inductor L4 is within the first threshold value.

[0109] Among them, according to the relationship between inductance and impedance ZL = jwL, and the relationship between capacitance and impedance ZC = 1 / jwC, it can be seen that the impedance of inductance increases with increasing frequency, and the impedance of capacitance decreases with increasing frequency. The total impedance Z1 after the inductor and capacitor are connected in series is equal to the absolute value of the difference between the inductive reactance ZL and the capacitive reactance ZC, that is, Z1 = |Z L -Z C In this embodiment, the imaginary part of the fundamental impedance of the push-pull power amplifier circuit is mainly determined by the capacitance and inductance. Therefore, in order to make the imaginary part of the fundamental impedance of the push-pull power amplifier circuit plus or minus 40% of the real part, the difference Z1 between the capacitive reactance ZC of the first capacitor C1 and the third capacitor C3 and the inductive reactance ZL of the third inductor L3 should be equal to |Z L -Z C |Within the first threshold, and the difference Z1 between the capacitive reactance ZC of the second capacitor C2 and the fourth capacitor C4 and the inductive reactance ZL of the fourth inductor L4 is equal to |Z L-Z C Within a first threshold. The first threshold is associated with the imaginary part of the fundamental impedance of the push-pull power amplifier circuit. The smaller the third threshold, the closer the imaginary part of the fundamental impedance of the push-pull power amplifier circuit is to zero, the more convergent the impedance of the push-pull power amplifier circuit is, and the better the bandwidth performance of the push-pull power amplifier circuit is.

[0110] In a specific embodiment, refer to the following Figure 4 As shown, the second group includes a first secondary coil S21 and a second secondary coil S22 disposed on the second metal layer. The first winding includes a first primary coil S11 disposed on the second metal layer. The first primary coil S11 and the first secondary coil S21 are coupled on the same layer, and the first primary coil S11 and the second secondary coil S22 are coupled on upper and lower layers. Optionally, the first secondary coil S21 and the second secondary coil S22 disposed on different metal layers can be connected via a through-hole.

[0111] Reference Figure 7 As shown, the gray coils are set in the second metal layer, and the black coils are set in the first metal layer. Specifically, the first primary coil S11 set in the second metal layer is coupled to the first secondary coil S21 set in the second metal layer on the same layer, and the first primary coil S11 set in the second metal layer is coupled to the second secondary coil S22 set in the first metal layer on the upper layer. Furthermore, the first secondary coil S21 set in the second metal layer is divided into a first secondary coil segment and a second secondary coil segment. The first secondary coil segment is set within the first primary coil S11, and the second secondary coil segment is set within the first primary coil S11, thereby improving the coupling between the first secondary coil S21 and the first primary coil S11.

[0112] In this embodiment, the first primary coil S11 is coupled with the first partial secondary coil S21, and the first primary coil S11 is coupled with the second partial secondary coil S22. The first primary coil S11 and the first partial secondary coil S21 are coupled on the same layer, and the first primary coil and the second partial secondary coil S22 are coupled in upper and lower layers. The first winding and the second winding are coupled on the same metal layer, and coupled in the upper and lower layers on different metal layers, thereby achieving cross-coupling between the first winding and the second winding, thereby improving the coupling degree between the first winding and the second winding, and achieving the effect of improving the overall performance of the first balun.

[0113] In a specific embodiment, further, the first winding and the second winding are arranged in the same metal layer.

[0114] In this embodiment, because the turns ratio of the second winding to the first winding is less than 3:1, impedance matching can be achieved with a smaller number of turns for the first and second windings. In this embodiment, the first and second windings are arranged on the same metal layer, further reducing footprint and cost while ensuring performance. For example, the first and second windings are both arranged on the first metal layer, and the first and second windings are coupled on the same layer.

[0115] In one embodiment, referring to Figure 6 As shown, the first winding includes a first primary coil segment S11 and a second primary coil segment S12, and the second winding includes a secondary coil S21. The first primary coil segment S11 and the second primary coil segment S12 are connected in parallel. The first primary coil segment S11 is arranged inside the secondary coil S21, and the second primary coil segment S12 is arranged outside the secondary coil S21.

[0116] The second winding is integrally configured, based on its wiring position, and is divided into a first secondary coil section and a second secondary coil section, which are connected via a jumper. The first winding is separately configured, and is divided into a first primary coil section S11 and a second primary coil section S12. The first primary coil section S11 and the second primary coil section S12 are connected in parallel and then coupled to the first differential amplifier transistor 11 and the second differential amplifier transistor 12 (for example, connected to the first differential amplifier transistor 11 and the second differential amplifier transistor 12 via a third capacitor C3 and a fourth capacitor C4).

[0117] Specifically, the first primary coil segment S11 is disposed within the secondary coil S21, and the second primary coil segment S12 is disposed outside the secondary coil S21. The secondary coil S21 is coupled to the first primary coil segment S12 and the second primary coil segment S12, respectively, thereby improving the coupling strength of the first balun. Preferably, in this embodiment, the turns ratio of the first winding to the second winding is 1:1, thereby ensuring the coupling strength of the first balun while reducing the occupied area and operating cost of the first balun.

[0118] In a specific embodiment, refer to the following Figure 5As shown, the first differential amplifier transistor is an HBT transistor, the base of the first differential amplifier transistor is the input terminal of the first differential amplifier transistor, the collector of the first differential amplifier transistor is the output terminal of the first differential amplifier transistor, and the emitter of the first differential amplifier transistor is grounded; the base of the second differential amplifier transistor is the input terminal of the second differential amplifier transistor, the collector of the second differential amplifier transistor is the output terminal of the second differential amplifier transistor, and the emitter of the second differential amplifier transistor is grounded.

[0119] This embodiment also provides a radio frequency power amplifier circuit, see the following Figure 7 As shown, it includes a first differential pair, a second differential pair, a first balun 30, a second balun 40, a first LC resonant circuit 10, a second LC resonant circuit 20, a third LC resonant circuit 50, a fourth LC resonant circuit 60, a third capacitor C3, a fourth capacitor C4, a seventh capacitor C7 and an eighth capacitor C8.

[0120] The first output terminal of the first differential pair is coupled to the first input terminal of the first balun 30 through the third capacitor C3 , and the second output terminal of the first differential pair is coupled to the second input terminal of the first balun through the fourth capacitor C4 .

[0121] The first output terminal of the second differential pair is coupled to the first input terminal of the second balun through the seventh capacitor C7, and the second output terminal of the second differential pair is coupled to the second input terminal of the second balun through the eighth capacitor C8.

[0122] The first output end of the first balun is used to output a radio frequency signal, the second output end of the first balun is connected to the first output end of the second balun, and the second output end of the second balun is grounded.

[0123] The first end of the first LC resonant circuit 10 is connected to the first output end of the first differential pair, and the second end of the first LC resonant circuit 10 is connected to the ground end. The first end of the second LC resonant circuit 20 is connected to the second output end of the first differential pair, and the second end of the second LC resonant circuit 20 is connected to the ground end.

[0124] A first end of the third LC resonant circuit 50 is connected to the first output end of the second differential pair, and a second end of the third LC resonant circuit 50 is connected to the ground end; a first end of the fourth LC resonant circuit 60 is connected to the second output end of the second differential pair, and a second end of the fourth LC resonant circuit 60 is connected to the ground end;

[0125] The first LC resonant circuit 10 includes a first capacitor C1 and a first inductor L1 connected in series, the second LC resonant circuit 20 includes a second capacitor C2 and a second inductor L2 connected in series, the third LC resonant circuit 30 includes a seventh capacitor C7 and a seventh inductor L7 connected in series, and the fourth LC resonant circuit includes an eighth capacitor C8 and an eighth inductor L8 connected in series.

[0126] As an example, the first differential pair includes a first differential amplifier transistor 11 and a second differential amplifier transistor 12. The second differential pair includes a third differential amplifier transistor 13 and a fourth differential amplifier transistor 14. The first differential amplifier transistor 11, the second differential amplifier transistor 12, the third differential amplifier transistor 13, and the fourth differential amplifier transistor 14 can be BJT transistors or field effect transistors (FETs).

[0127] In a specific embodiment, the first LC resonant circuit 10, the second LC resonant circuit 20, the third LC resonant circuit 30 and the fourth LC resonant circuit 40 are configured to adjust the second-order harmonic impedance of the RF power amplifier circuit.

[0128] Furthermore, the first capacitor, the second capacitor, the third capacitor, the fourth capacitor, the fifth capacitor, the sixth capacitor, the seventh capacitor, the eighth capacitor, the first balun and the second balun are configured to adjust the fundamental impedance of the RF power amplifier circuit.

[0129] In a specific embodiment, the first LC resonant circuit 10, the second LC resonant circuit 20, the third LC resonant circuit 50, and the fourth LC resonant circuit 60 are configured to adjust the harmonic impedance (especially the second-order harmonic impedance) of the push-pull power amplifier circuit. The first capacitor C1 in the first LC resonant circuit 10, the second capacitor C2 in the second LC resonant circuit 20, the fifth capacitor C5 in the third LC resonant circuit 50, the sixth capacitor C6 in the fourth LC resonant circuit 60, the third capacitor C3, the fourth capacitor C3, the seventh capacitor C7, the eighth capacitor C8, the first balun 30, and the second balun 40 are configured to adjust the fundamental impedance of the push-pull power amplifier circuit; therefore, by configuring the first LC resonant circuit, the second LC resonant circuit, the third LC resonant circuit 50, and the fourth LC resonant circuit 60, the first capacitor C1, the second capacitor C2 in the second LC resonant circuit 20, the fifth capacitor C5 in the third LC resonant circuit 50, and the sixth capacitor C6 in the fourth LC resonant circuit 60, the third capacitor C3, the fourth capacitor C3, the seventh capacitor C7, the eighth capacitor C8, the first balun 30, and the second balun 40, the first balun 40 are configured to adjust the fundamental impedance of the push-pull power amplifier circuit. 0 and the fourth LC resonant circuit 60, the third capacitor C2, the fourth capacitor C4, the seventh capacitor C7, the eighth capacitor C8, the first balun 30 and the second balun 40, so that without affecting the fundamental impedance, not only can the harmonic impedance (especially the second-order harmonic impedance) of the push-pull power amplifier circuit be optimized, so that the harmonic impedance (especially the second-order harmonic impedance) of the push-pull power amplifier circuit within the entire working frequency band is more converged, but also the working efficiency and linearity of the push-pull power amplifier circuit can be improved, thereby optimizing the overall performance of the push-pull power amplifier circuit within the entire working frequency band.

[0130] In a specific embodiment, the operating frequency band of the RF power amplifier circuit is 2300 MHz to 2700 MHz, the capacitance values ​​of the third capacitor C3, the fourth capacitor C4, the seventh capacitor C7 and the eighth capacitor C8 are all between [5 pF-12 pF], and the capacitance values ​​of the first capacitor C1, the second capacitor C2, the fifth capacitor C5 and the sixth capacitor C6 are all between [2 pF-8 pF].

[0131] Furthermore, the operating frequency band of the RF power amplifier circuit is 2300MHz~2700MHz, the capacitance values ​​of the third capacitor C3, the fourth capacitor C4, the seventh capacitor C7 and the eighth capacitor C8 are all between [7pF-10pF], and the capacitance values ​​of the first capacitor C1, the second capacitor C2, the fifth capacitor C5 and the sixth capacitor C6 are all between [4pF-6pF].

[0132] In another specific embodiment, the operating frequency band of the RF power amplifier circuit is 1700 MHz to 2000 MHz, the capacitance values ​​of the third capacitor C3, the fourth capacitor C4, the seventh capacitor C7 and the eighth capacitor C8 are all between [8 pF and 15 pF], and the capacitance values ​​of the first capacitor C1, the second capacitor C2, the fifth capacitor C5 and the sixth capacitor C6 are all between [3 pF and 10 pF].

[0133] Furthermore, the operating frequency band of the RF power amplifier circuit is 1700MHz to 2000MHz, the capacitance values ​​of the third capacitor C3, the fourth capacitor C4, the seventh capacitor C7 and the eighth capacitor C8 are all between [9pF-12pF], and the capacitance values ​​of the first capacitor C1, the second capacitor C2, the fifth capacitor C5 and the sixth capacitor C6 are all between [5pF-7pF].

[0134] Furthermore, the operating frequency band of the RF power amplifier circuit is 1700MHz~2000MHz, the capacitance values ​​of the third capacitor C3, the fourth capacitor C4, the seventh capacitor C7 and the eighth capacitor C8 are all between [10pF-13pF], and the capacitance values ​​of the first capacitor C1, the second capacitor C2, the fifth capacitor C5 and the sixth capacitor C6 are all between [6pF-10pF].

[0135] In a specific embodiment, the first balun includes a first winding and a second winding, the turns ratio of the second winding to the second winding is less than 3:1, and the second balun includes a third winding and a fourth winding, the turns ratio of the fourth winding to the third winding is less than 3:1.

[0136] Since the third capacitor C3 and the fourth capacitor C4 in this embodiment jointly participate in impedance conversion with the first balun, and the seventh capacitor C7 and the eighth capacitor C8 jointly participate in impedance conversion with the second balun in this embodiment, a first balun and a second balun with relatively small turns ratios can be used, i.e., a first balun having a smaller ratio of the number of turns of the second winding to the number of turns of the first winding, and a second balun having a smaller ratio of the number of turns of the fourth winding to the number of turns of the third winding. In this embodiment, the turns ratio of the second winding to the first winding of the first balun is less than 3:1. For example, the turns ratio of the second winding to the first winding of the first balun is 2:1, and the turns ratio of the fourth winding to the third winding of the second balun is 2:1. This achieves the goal of reducing the occupied area and cost of the push-pull power amplifier circuit while ensuring the overall performance of the push-pull power amplifier circuit.

[0137] In a specific embodiment, the operating frequency band of the radio frequency power amplifier circuit is [Fa, Fb]; the resonant frequencies of the first LC resonant circuit, the second LC resonant circuit, the third LC resonant circuit and the fourth LC resonant circuit at the frequency point Fa are The resonant frequencies of the first LC resonant circuit, the second LC resonant circuit, the third LC resonant circuit and the fourth LC resonant circuit at the frequency Fb are

[0138]

[0139] As an example, if the push-pull power amplifier circuit operates in the n41 frequency band, that is, the operating frequency band of the push-pull power amplifier circuit is [2515MHz, 2675MHz], according to the LC resonance formula It can be seen that by configuring the inductance and capacitance values ​​in the first LC resonant circuit, the second LC resonant circuit, the third LC resonant circuit, and the fourth LC resonant circuit, the resonant frequencies of the first LC resonant circuit, the second LC resonant circuit, the third LC resonant circuit, and the fourth LC resonant circuit at 2515 MHz are: And the resonant frequencies of the first LC resonant circuit, the second LC resonant circuit, the third LC resonant circuit and the fourth LC resonant circuit at a frequency of 2675 MHz are

[0140]

[0141] As another example, if the push-pull power amplifier circuit operates in the n77 frequency band, that is, the operating frequency band of the push-pull power amplifier circuit is [3300MHz, 4200MHz], according to the LC resonance formula It can be seen that by configuring the inductance and capacitance values ​​in the first LC resonant circuit, the second LC resonant circuit, the third LC resonant circuit, and the fourth LC resonant circuit, the resonant frequencies of the first LC resonant circuit, the second LC resonant circuit, the third LC resonant circuit, and the fourth LC resonant circuit at 2515 MHz are: And the resonant frequency of the first LC resonant circuit and the second LC resonant circuit at 4200 MHz is

[0142] In a specific embodiment, the operating frequency band of the push-pull power amplifier circuit is [Fa, Fb]; by configuring the capacitance value of the first capacitor C1 and the inductance value of the first inductor L1 connected in series in the first LC resonant circuit, and the capacitance value of the second capacitor C2 and the inductance value of the second inductor L2 connected in series in the second LC resonant circuit, and configuring the capacitance value of the seventh capacitor C7 and the inductance value of the seventh inductor L7 connected in series in the third LC resonant circuit, and configuring the capacitance value of the eighth capacitor C8 and the inductance value of the eighth inductor L8 connected in series in the fourth LC resonant circuit, the resonant frequency of the first LC resonant circuit, the second LC resonant circuit, the third LC resonant circuit and the fourth LC resonant circuit at the frequency point Fa is The resonant frequencies of the first LC resonant circuit and the second LC resonant circuit at the Fb frequency point are This improves the working efficiency and linearity of the push-pull power amplifier circuit, and makes the second-order harmonic impedance of the push-pull power amplifier circuit more convergent within the entire working frequency band, thereby optimizing the overall performance of the push-pull power amplifier circuit within the entire working frequency band.

[0143] This embodiment further provides a radio frequency front-end module, including the push-pull power amplifier circuit described in the above embodiment, or including the radio frequency power amplifier circuit described in the above embodiment.

[0144] The embodiments described above are only used to illustrate the technical solutions of the present invention, rather than to limit the same. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. These modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the various embodiments of the present invention, and should all be included in the scope of protection of the present invention.

Claims

1. A push-pull power amplifier circuit, characterized in that: The invention comprises a first differential amplifier transistor and a second differential amplifier transistor, a first LC resonant circuit, a second LC resonant circuit, a third capacitor, a fourth capacitor and a first balun; the output end of the first differential amplifier transistor is coupled to the first input end of the first balun through the third capacitor, the output end of the second differential amplifier transistor is coupled to the second input end of the first balun through the fourth capacitor, the first end of the first LC resonant circuit is connected to the output end of the first differential amplifier transistor, the second end of the first LC resonant circuit is connected to the ground end, the first end of the second LC resonant circuit is connected to the output end of the second differential amplifier transistor, and the second end of the second LC resonant circuit is connected to the ground end; The first differential amplifier transistor is configured to amplify a first RF input signal, and the second differential amplifier transistor is configured to amplify a second RF input signal, and the first RF input signal and the second RF input signal are two balanced RF signals obtained after converting an unbalanced input RF signal; The first LC resonant circuit includes a first capacitor and a first inductor connected in series, and the second LC resonant circuit includes a second capacitor and a second inductor connected in series; The push-pull power amplifier circuit further includes a third inductor and a fourth inductor, wherein a first end of the third inductor is connected to the output end of the first differential amplifier transistor, a second end of the third inductor is connected to the first power supply end, a first end of the fourth inductor is connected to the first power supply end, and a second end of the fourth inductor is connected to the output end of the second differential amplifier transistor. The first capacitor, the third capacitor and the third inductor are configured so that the imaginary part value of the fundamental impedance of the push-pull power amplifier circuit is -40% to 40% of the real part value; the second capacitor, the fourth capacitor and the fourth inductor are configured so that the imaginary part value of the fundamental impedance of the push-pull power amplifier circuit is -40% to 40% of the real part value.

2. The push-pull power amplifier circuit according to claim 1, characterized in that: The operating frequency band of the push-pull power amplifier circuit is 2300MHz-2700MHz, the capacitance values ​​of the third capacitor and the fourth capacitor are both between [5pF-12pF], and the capacitance values ​​of the first capacitor and the second capacitor are both between [2pF-8pF].

3. The push-pull power amplifier circuit according to claim 1, characterized in that: The operating frequency band of the push-pull power amplifier circuit is 2300MHz-2700MHz, the capacitance values ​​of the third capacitor and the fourth capacitor are both between [7pF-10pF], and the capacitance values ​​of the first capacitor and the second capacitor are both between [4pF-6pF].

4. The push-pull power amplifier circuit according to claim 1, characterized in that: The operating frequency band of the push-pull power amplifier circuit is 1700MHz-2000MHz, the capacitance values ​​of the third capacitor and the fourth capacitor are both between [8pF-15pF], and the capacitance values ​​of the first capacitor and the second capacitor are both between [3pF-10pF].

5. The push-pull power amplifier circuit according to claim 1, characterized in that: The operating frequency band of the push-pull power amplifier circuit is 1700MHz-2000MHz, the capacitance values ​​of the third capacitor and the fourth capacitor are both between [9pF-12pF], and the capacitance values ​​of the first capacitor and the second capacitor are both between [5pF-7pF].

6. The push-pull power amplifier circuit according to claim 1, characterized in that: The operating frequency band of the push-pull power amplifier circuit is 1700MHz-2000MHz, the capacitance values ​​of the third capacitor and the fourth capacitor are both between [10pF-13pF], and the capacitance values ​​of the first capacitor and the second capacitor are both between [6pF-10pF].

7. The push-pull power amplifier circuit according to claim 1, characterized in that: The operating frequency band of the push-pull power amplifier circuit is the N77 frequency band, the capacitance values ​​of the third capacitor and the fourth capacitor are both between [3pF-9pF], and the capacitance values ​​of the first capacitor and the second capacitor are both between [1pF-5pF].

8. The push-pull power amplifier circuit according to claim 1, characterized in that: The operating frequency band of the push-pull power amplifier circuit is the N77 frequency band, the capacitance values ​​of the third capacitor and the fourth capacitor are both between [4.5pF-6.5pF], and the capacitance values ​​of the first capacitor and the second capacitor are both between [1.5pF-3.5pF].

9. The push-pull power amplifier circuit according to claim 1, characterized in that: The first balun includes a first winding and a second winding, and a turns ratio of the second winding to the first winding is less than 3:

1.

10. The push-pull power amplifier circuit according to claim 1, characterized in that: The operating frequency band of the push-pull power amplifier circuit is [Fa, Fb]; The resonant frequencies of the first LC resonant circuit and the second LC resonant circuit at the Fa frequency point are: The resonant frequencies of the first LC resonant circuit and the second LC resonant circuit at the Fb frequency point are:

11. The push-pull power amplifier circuit according to claim 1, characterized in that: The second end of the third inductor is connected to the first end of the fourth inductor.

12. The push-pull power amplifier circuit according to claim 11, characterized in that: The first capacitor, the third capacitor and the third inductor are configured to make the imaginary part value of the fundamental impedance of the push-pull power amplifier circuit plus or minus 40% of the real part value; The second capacitor, the fourth capacitor and the fourth inductor are configured to make the imaginary part of the fundamental impedance of the push-pull power amplifier circuit plus or minus 40 percent of the real part.

13. The push-pull power amplifier circuit according to claim 11, characterized in that: The first capacitor, the third capacitor and the third inductor are configured to make the imaginary part value of the fundamental impedance of the push-pull power amplifier circuit plus or minus 20% of the real part value; The second capacitor, the fourth capacitor and the fourth inductor are configured to make the imaginary part of the fundamental impedance of the push-pull power amplifier circuit be plus or minus 20 percent of the real part.

14. The push-pull power amplifier circuit according to claim 9, characterized in that: The second winding includes a first partial secondary coil arranged on the second metal layer and a second partial secondary coil arranged on the first metal layer, the first winding includes a first primary coil arranged on the second metal layer, the first primary coil is coupled with the first partial secondary coil on the same layer, and the first primary coil is coupled with the second partial secondary coil on the upper and lower layers.

15. The push-pull power amplifier circuit according to claim 9, characterized in that: The first winding and the second winding are arranged on the same metal layer, the first winding includes a first primary coil segment and a second primary coil segment, the second winding includes a secondary coil, the first primary coil segment and the second primary coil segment, the first primary coil segment and the second primary coil segment are connected in parallel, the first primary coil segment is arranged inside the secondary coil, and the second primary coil segment is arranged outside the secondary coil.

16. The push-pull power amplifier circuit according to claim 1, characterized in that: The first differential amplifier transistor is an HBT transistor, the base of the first differential amplifier transistor is the input terminal of the first differential amplifier transistor, the collector of the first differential amplifier transistor is the output terminal of the first differential amplifier transistor, and the emitter of the first differential amplifier transistor is grounded; the base of the second differential amplifier transistor is the input terminal of the second differential amplifier transistor, the collector of the second differential amplifier transistor is the output terminal of the second differential amplifier transistor, and the emitter of the second differential amplifier transistor is grounded.

17. A radio frequency front-end module, characterized in that: It comprises a push-pull power amplifier circuit as described in any one of claims 1 to 16.

Images