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

Abstract

The present invention discloses a push-pull power amplifier circuit, which includes a first power amplifier, a second power amplifier, a first balun and an adjustable capacitor network; the primary winding of the first balun includes a first coil segment and a second coil segment; the first end of the adjustable capacitor network is connected to the second end of the first coil segment, and the second end of the adjustable capacitor network is connected to the first end of the second coil segment; the output end of the first power amplifier is connected to the first end of the first coil segment, and the output end of the second power amplifier is connected to the second end of the second coil segment; wherein the adjustable capacitor network is configured to switch the capacitance value based on the working frequency band of the push-pull power amplifier circuit. This technical solution can improve the working bandwidth of the push-pull power amplifier circuit, thereby improving the overall performance of the push-pull power amplifier circuit.

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 and a radio frequency front-end module. Background Art

[0002] The key performance goal of the fifth generation mobile communication technology (5G) is to significantly increase the transmission rate compared to 4G. The new 5G technology requires the use of a higher frequency, larger working bandwidth, and higher order QAM modulation RF front-end, which places more stringent requirements on the design of the power amplifier of the RF front-end. However, when designing a push-pull power amplifier circuit, the working bandwidth performance of the push-pull power amplifier circuit is ignored for other performance requirements or performance indicators such as high frequency or high power. Therefore, while ensuring the overall performance of the push-pull power amplifier circuit, how to improve the working bandwidth of the push-pull power amplifier circuit has become a problem that needs to be solved urgently. Summary of the invention

[0003] The embodiments of the present invention provide a push-pull power amplifier circuit and a radio frequency front-end module to solve the problem of poor working bandwidth of the push-pull power amplifier circuit.

[0004] A push-pull power amplifier circuit includes a first power amplifier, a second power amplifier, a first balun and an adjustable capacitor network;

[0005] The primary winding of the first balun includes a first coil segment and a second coil segment;

[0006] The first end of the adjustable capacitor network is connected to the second end of the first coil segment, and the second end of the adjustable capacitor network is connected to the first end of the second coil segment;

[0007] The output end of the first power amplifier is connected to the first end of the first coil segment, and the output end of the second power amplifier is connected to the second end of the second coil segment;

[0008] Wherein, the adjustable capacitor network is configured to switch the capacitance value based on the working frequency band of the push-pull power amplifier circuit.

[0009] Furthermore, the capacitance value of the adjustable capacitor network is negatively correlated with the operating frequency band of the push-pull power amplifier circuit.

[0010] Furthermore, when the operating frequency band of the push-pull power amplifier circuit is a high frequency band, the capacitance value of the adjustable capacitor network is a first capacitance value; when the operating frequency band of the push-pull power amplifier circuit is a medium frequency band, the capacitance value of the adjustable capacitor network is a second capacitance value, and the first capacitance value is less than the second capacitance value.

[0011] Further, the adjustable capacitor network includes a first switch, a first capacitor and a second capacitor;

[0012] The first end of the first capacitor is connected to the second end of the first coil segment, the second end of the first capacitor is connected to the first end of the second capacitor, and the second end of the second capacitor is connected to the first end of the second coil segment; the first switch is connected in parallel to the first capacitor, or the first switch is connected in parallel to the second capacitor;

[0013] Alternatively, the first switching switch and the first capacitor are connected in series between the second end of the first coil segment and the first end of the second coil segment; the first end of the second capacitor is connected to the second end of the first coil segment, and the second end of the second capacitor is connected to the first end of the second coil segment.

[0014] Furthermore, the push-pull power amplifier circuit also includes an impedance adjustment circuit; the input end of the impedance adjustment circuit is connected to the first output end of the first balun, and is configured to match the output impedance of the push-pull power amplifier circuit according to the operating frequency band of the push-pull power amplifier circuit.

[0015] Furthermore, the capacitance value presented by the impedance adjustment circuit is negatively correlated with the operating frequency band of the push-pull power amplifier circuit, and the inductance value presented by the impedance adjustment circuit is negatively correlated with the operating frequency band of the push-pull power amplifier circuit.

[0016] Further, when the push-pull power amplifier circuit operates in the first frequency band, the capacitance value of the adjustable capacitor network is the first capacitance value, the total capacitance value presented by the impedance adjustment circuit is the third capacitance value, and the total inductance value presented by the impedance adjustment circuit is the first inductance value;

[0017] When the push-pull power amplifier circuit operates in the second frequency band, the capacitance value of the adjustable capacitor network is the second capacitance value, the total capacitance value presented by the impedance adjustment circuit is the fourth capacitance value, and the total inductance value presented by the impedance adjustment circuit is the second inductance value;

[0018] The first frequency band is greater than the second frequency band, the first capacitance value is less than the second capacitance value, the third capacitance value is less than the fourth capacitance value, and the first inductance value is less than the second inductance value.

[0019] Further, the impedance adjustment circuit includes a second switch, a third switch, a first adjustment circuit and a second adjustment circuit;

[0020] The second switch and the first adjustment circuit are connected in series between the first output end of the first balun and the signal output end of the push-pull power amplifier circuit;

[0021] The third switch and the second adjustment circuit are connected in series between the first output end of the first balun and the signal output end of the push-pull power amplifier circuit;

[0022] When the operating frequency band of the push-pull power amplifier circuit is the first frequency band, the second switch is closed, the third switch is opened, and the first adjustment circuit is configured to match the output impedance of the push-pull power amplifier circuit whose operating frequency band is the first frequency band;

[0023] When the operating frequency band of the push-pull power amplifier circuit is the second frequency band, the second switch is disconnected, the third switch is closed, and the second adjustment circuit is configured to match the output impedance of the push-pull power amplifier circuit whose operating frequency band is the second frequency band;

[0024] The first frequency band is greater than the second frequency band.

[0025] Further, a total capacitance value presented by the first adjustment circuit is smaller than a total capacitance value presented by the second adjustment circuit, and a total inductance value presented by the first adjustment circuit is smaller than a total inductance value presented by the second adjustment circuit.

[0026] Further, the first adjustment circuit includes a third capacitor, a fourth capacitor, a first inductor, and a second inductor; the first end of the third capacitor is connected to the second switch, the second end of the third capacitor is connected to the first end of the fourth capacitor, and the second end of the fourth capacitor is connected to the signal output end; the first end of the first inductor is connected to the second end of the third capacitor and the first end of the fourth capacitor, and the second end of the first inductor is grounded; the first end of the second inductor is connected to the second end of the fourth capacitor and the signal output end, and the second end of the second inductor is grounded;

[0027] The second adjustment circuit includes a fifth capacitor, a sixth capacitor, a third inductor and a fourth inductor; the first end of the third inductor is connected to the third switching switch, 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 signal output end; the first end of the fifth capacitor is connected to the second end of the third inductor and the first end of the fourth inductor, and the second end of the fifth capacitor is grounded; the first end of the sixth capacitor is connected to the second end of the fourth inductor and the signal output end, and the second end of the sixth capacitor is grounded.

[0028] Further, the first power amplifier is an HBT tube, including a base, a collector and an emitter, the base of the first power amplifier receives the input first radio frequency input signal, the collector of the first power amplifier is connected to the first end of the first coil segment, and the emitter of the first power amplifier is grounded;

[0029] The second power amplifier is an HBT tube, including a base, a collector and an emitter. The base of the second power amplifier receives the input second RF input signal, the collector of the second power amplifier is connected to the second end of the second coil segment, and the emitter of the second power amplifier is grounded.

[0030] A radio frequency front-end module comprises a substrate, a push-pull power amplifier chip arranged on the substrate, a first balun arranged on the substrate, and a first chip arranged on the substrate, wherein the push-pull power amplifier chip comprises a first power amplifier and a second power amplifier, the first chip comprises an adjustable capacitor network, and the primary winding of the first balun comprises a first coil segment and a second coil segment;

[0031] The output end of the first power amplifier is connected to the first pad of the push-pull power amplifier chip, the output end of the second power amplifier is connected to the second pad of the push-pull power amplifier chip, the first pad is connected to the first end of the first coil segment, and the second pad is connected to the second end of the second coil segment;

[0032] The first chip buckle is arranged between the second end of the first coil segment and the first end of the second coil segment;

[0033] Wherein, the adjustable capacitor network is configured to switch the capacitance value based on the working frequency band of the push-pull power amplifier circuit.

[0034] The push-pull power amplifier circuit and the RF front-end module, the push-pull power amplifier circuit includes a first power amplifier, a second power amplifier, a first balun and an adjustable capacitor network. The primary winding of the first balun includes a first coil segment and a second coil segment. The output end of the first power amplifier is connected to the first end of the first coil segment, and the output end of the second power amplifier is connected to the second end of the second coil segment; the first end of the adjustable capacitor network is connected to the second end of the first coil segment, and the second end of the adjustable capacitor network is connected to the first end of the second coil segment; the adjustable capacitor network is configured to switch the capacitance value based on the working frequency band of the push-pull power amplifier circuit. In this embodiment, by connecting the first end of the adjustable capacitor network to the second end of the first coil segment and connecting the second end of the adjustable capacitor network to the first end of the second coil segment, when the push-pull power amplifier circuit works in different working frequency bands, the capacitance value of the adjustable capacitor network is different, and the first balun is used to participate in the impedance matching of the output impedance of the push-pull power amplifier circuit to achieve the output impedance matching of the push-pull power amplifier circuit under different working frequency bands, thereby optimizing the working bandwidth performance of the push-pull power amplifier circuit, and then improving the overall performance of the push-pull power amplifier circuit. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings required for use in the description of the embodiments of the present invention will be briefly introduced below. Obviously, the accompanying drawings in the following description are only some embodiments of the present invention. For ordinary technicians in this field, other accompanying drawings can be obtained based on these accompanying drawings without paying creative labor.

[0036] Figure 1 is a circuit diagram of a push-pull power amplifier circuit in one embodiment of the present invention;

[0037] Figure 2 is another circuit diagram of a push-pull power amplifier circuit in one embodiment of the present invention;

[0038] Figure 3 is another circuit diagram of a push-pull power amplifier circuit in one embodiment of the present invention;

[0039] Figure 4 is another circuit diagram of a push-pull power amplifier circuit in one embodiment of the present invention;

[0040] Figure 5 is another circuit diagram of a push-pull power amplifier circuit in one embodiment of the present invention;

[0041] Figure 6 Schematic diagram of a circuit of a radio frequency front-end module in one embodiment of the present invention.

[0042] In the figure: 10, push-pull power amplifier chip; 11, first power amplifier; 12, second power amplifier; 20, first balun; 30, first chip; 31, adjustable capacitor network; 40, impedance adjustment circuit; 41, first adjustment circuit; 42, second adjustment circuit; 50, substrate. DETAILED DESCRIPTION

[0043] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0044] It should be understood that the present invention can be implemented in different forms and should not be construed as being limited to the embodiments set forth herein. On the contrary, providing these embodiments will make the disclosure thorough and complete and fully convey the scope of the present invention to those skilled in the art. In the accompanying drawings, the sizes and relative sizes of layers and regions may be exaggerated for clarity. The same reference numerals throughout represent the same elements.

[0045] It should be understood that when an element or layer is referred to as being "on, "adjacent to, "connected to, or "connected to" other elements or layers, it may be directly on, adjacent to, connected to, or connected to other elements or layers, 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 connected to" other elements or layers, 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 merely used to distinguish one element, component, region, layer, or part from another element, component, region, layer, or part. Therefore, without departing from the teachings of the present invention, the first element, component, region, layer, or part discussed below may be represented as a second element, component, region, layer, or part.

[0046] Spatially relative terms such as "under," "beneath," "below," "under," "above," "above," and the like may be used herein for ease of description to describe the relationship of an 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 accompanying drawings is flipped, then the elements or features described as "under other elements" or "under" or "under" will be oriented as "above" the other elements or features. Thus, the exemplary terms "under" and "under" may include both upper and lower orientations. The device may be otherwise oriented (rotated 90 degrees or other orientations) and the spatial descriptors used herein are interpreted accordingly.

[0047] The purpose of the terms used herein is only to describe specific embodiments and is not intended to be limiting of the present invention. When used herein, the singular forms "a", "an" and " / the" are also intended to include plural forms, unless the context clearly indicates another way. It should also be understood that the terms "consisting of" and / or "comprising" when used in this specification determine the presence of 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.

[0048] In order to fully understand the present invention, detailed structures and steps will be presented in the following description to illustrate the technical solutions proposed by the present invention. The preferred embodiments of the present invention are described in detail below, but in addition to these detailed descriptions, the present invention may also have other implementations.

[0049] This embodiment provides a push-pull power amplifier circuit, such as Figure 1 As shown, it includes a first power amplifier 11, a second power amplifier 12, a first balun 20 and an adjustable capacitor network 31; the primary winding of the first balun 20 includes a first coil segment T1 and a second coil segment T2; the first end of the adjustable capacitor network 31 is connected to the second end of the first coil segment T1, and the second end of the adjustable capacitor network 31 is connected to the first end of the second coil segment T2; the output end of the first power amplifier 11 is connected to the first end of the first coil segment T1, and the output end of the second power amplifier 12 is connected to the second end of the second coil segment T2; the adjustable capacitor network 31 is configured to switch the capacitance value based on the working frequency band of the push-pull power amplifier circuit.

[0050] In a specific embodiment, the push-pull power amplifier circuit includes a first power amplifier 11, a second power amplifier 12 and a first balun 20. The input end of the first power amplifier 11 is configured to receive a first RF input signal, the output end of the first power amplifier 11 is connected to the first input end of the first balun 20, and the first power amplifier 11 is configured to amplify the first RF input signal and output the first RF amplified signal. The input end of the second power amplifier 12 is configured to receive a second RF input signal, the output end of the second power amplifier 12 is connected to the second input end of the first balun 20, and the second power amplifier 12 is configured to amplify the second RF input signal and output the second RF amplified signal. The first output end of the first balun 20 is connected to the signal output end of the push-pull power amplifier circuit, the second output end of the first balun 20 is grounded, and the first balun 20 is configured to convert the first RF amplified signal and the second RF amplified signal and output the RF output signal.

[0051] Optionally, the first power amplifier 11 includes at least one first power amplifier transistor (not shown in the figure), and the at least one first power amplifier transistor is configured to amplify the first RF input signal. The second power amplifier 12 includes at least one second power amplifier transistor (not shown in the figure), and the at least one second power amplifier 12 is configured to amplify the second RF input signal.

[0052] In a specific embodiment, the first RF input signal and the second RF input signal are signals of equal magnitude and opposite phases. Exemplarily, the push-pull power amplifier circuit further includes a second balun (not shown in the figure), the first input end of the second balun is connected to the signal input end of the push-pull power amplifier circuit, and is configured to receive the RF signal, the second input end of the second balun is grounded, the first output end of the second balun is connected to the input end of the first power amplifier 11, the second output end of the second balun is connected to the input end of the second power amplifier 12, and the second balun is configured to convert the RF signal and output the first RF input signal and the second RF input signal of equal magnitude and opposite phases.

[0053] In a specific embodiment, the first balun 20 includes a primary winding and a secondary winding, and the primary winding includes a first coil segment T1 and a second coil segment T2. The first end of the first coil segment T1 is the first input end of the first balun 20, the second end of the second coil segment T2 is the second output end of the second balun, the first end of the secondary winding is the first output end of the first balun 20, and the second end of the secondary winding is the second output end of the first balun 20.

[0054] In a specific embodiment, the push-pull power amplifier circuit further includes an adjustable capacitor network 31. The first end of the adjustable capacitor network 31 is connected to the second end of the first coil segment T1, and the second end of the adjustable capacitor network 31 is connected to the first end of the second coil segment T2; the output end of the first power amplifier 11 is connected to the first end of the first coil segment T1, and the output end of the second power amplifier 12 is connected to the second end of the second coil segment T2; the adjustable capacitor network 31 is configured to switch the capacitance value based on the working frequency band of the push-pull power amplifier circuit. In this embodiment, by connecting the first end of the adjustable capacitor network 31 to the second end of the first coil segment T1, and connecting the second end of the adjustable capacitor network 31 to the first end of the second coil segment T2, when the push-pull power amplifier circuit is in different working frequency bands, the capacitance value of the adjustable capacitor network 31 is different, and the adjustable capacitor network 31 and the first balun 20 jointly participate in the impedance matching of the output impedance of the push-pull power amplifier circuit, so as to achieve the output impedance matching of the push-pull power amplifier circuit under different working frequency bands, thereby optimizing the working bandwidth performance of the push-pull power amplifier circuit, and then improving the overall performance of the push-pull power amplifier circuit.

[0055] In this embodiment, the push-pull power amplifier circuit includes a first power amplifier 11, a second power amplifier 12, a first balun 20 and an adjustable capacitor network 31. The primary winding of the first balun 20 includes a first coil segment T1 and a second coil segment T2. The output end of the first power amplifier 11 is connected to the first end of the first coil segment T1, and the output end of the second power amplifier 12 is connected to the second end of the second coil segment T2; the first end of the adjustable capacitor network 31 is connected to the second end of the first coil segment T1, and the second end of the adjustable capacitor network 31 is connected to the first end of the second coil segment T2; the adjustable capacitor network 31 is configured to switch the capacitance value based on the working frequency band of the push-pull power amplifier circuit. In this embodiment, by connecting the first end of the adjustable capacitor network 31 to the second end of the first coil segment T1, and connecting the second end of the adjustable capacitor network 31 to the first end of the second coil segment T2, when the push-pull power amplifier circuit operates in different operating frequency bands, the capacitance value of the adjustable capacitor network 31 is different, and together with the first balun 20, the impedance matching of the output impedance of the push-pull power amplifier circuit is achieved, so as to achieve output impedance matching of the push-pull power amplifier circuit in different operating frequency bands, thereby optimizing the operating bandwidth performance of the push-pull power amplifier circuit, and further improving the overall performance of the push-pull power amplifier circuit.

[0056] In one embodiment, the capacitance value of the adjustable capacitor network 31 is negatively correlated with the operating frequency band of the push-pull power amplifier circuit.

[0057] In a specific embodiment, the capacitance value presented by the adjustable capacitor network 31 is negatively correlated with the operating frequency band of the push-pull power amplifier circuit. In this embodiment, the output impedance required for the push-pull power amplifier circuit to achieve impedance matching is often fixed, for example, the output impedance is generally 50 ohms, and the output impedance of the push-pull power amplifier circuit is related to the inductive reactance provided by the first balun 20 and the capacitive reactance provided by the adjustable capacitor network 31. Under the premise that the first balun 20 and other impedance matching circuits are determined, the capacitive reactance provided by the adjustable capacitor network 31 to achieve impedance matching is also determined. According to the capacitive reactance calculation formula: Wherein, Zc is the capacitive reactance value, w is the operating frequency, and c is the capacitance value. Under the premise that the capacitive reactance Zc provided by the adjustable capacitor network 31 for achieving impedance matching is determined, the capacitance value c of the adjustable capacitor network 31 is negatively correlated with the operating frequency w of the push-pull power amplifier circuit, and therefore, the capacitance value of the adjustable capacitor network 31 is negatively correlated with the operating frequency band of the push-pull power amplifier circuit.

[0058] In this embodiment, the capacitance value presented by the adjustable capacitor network 31 is negatively correlated with the operating frequency band of the push-pull power amplifier circuit. The higher the operating frequency band of the push-pull power amplifier circuit, the smaller the capacitance value of the adjustable capacitor network 31, and the lower the operating high frequency of the push-pull power amplifier circuit, the larger the capacitance value of the adjustable capacitor network 31. By adjusting the capacitance value of the adjustable capacitor network 31, the output impedance matching of the push-pull power amplifier circuit within a wider operating frequency band can be achieved, thereby optimizing the operating bandwidth performance of the push-pull power amplifier circuit and further improving the overall performance of the push-pull power amplifier circuit.

[0059] In one embodiment, when the operating frequency band of the push-pull power amplifier circuit is a high frequency band, the capacitance value presented by the adjustable capacitor network 31 is a first capacitance value; when the operating frequency band of the push-pull power amplifier circuit is a medium frequency band, the capacitance value presented by the adjustable capacitor network 31 is a second capacitance value; when the operating frequency band of the push-pull power amplifier circuit is a low frequency band, the capacitance value presented by the adjustable capacitor network 31 is a third capacitance value, the first capacitance value is smaller than the second capacitance value, and the second capacitance value is smaller than the third capacitance value.

[0060] In a specific embodiment, when the working frequency band of the push-pull power amplifier circuit is the first frequency band (for example, the working frequency band is the high frequency band: 2.3-2.7 GHz), the capacitance value presented by the adjustable capacitor network 31 is the first capacitance value, and when the working frequency band of the push-pull power amplifier circuit is the second frequency band (for example, the working frequency band is the medium frequency band: 1.7-2.1 GHz), the capacitance value presented by the adjustable capacitor network 31 is the second capacitance value. The larger the working frequency band of the push-pull power amplifier circuit, that is, the larger the working frequency of the push-pull power amplifier circuit, according to the capacitive reactance calculation formula: Under the premise that the capacitive reactance presented by the adjustable capacitor network 31 remains unchanged, the larger the working frequency band of the push-pull power amplifier circuit is, the smaller the capacitance value presented by the adjustable capacitor network 31 is. Therefore, the first capacitance value is smaller than the second capacitance value to ensure that the push-pull power amplifier circuit can ensure impedance matching at the output end in both the high frequency band and the low frequency band, so as to achieve impedance matching of the push-pull power amplifier circuit in a wider frequency band.

[0061] Optionally, when the working frequency band of the push-pull power amplifier circuit is a low frequency band (660-960MHz), the capacitance value presented by the adjustable capacitor network 31 is the third capacitor C411 value, and the third capacitor C411 value is greater than the second capacitor value. In this embodiment, when the working frequency band of the push-pull power amplifier circuit is a low frequency band (660-960MHz), the capacitance value presented by the adjustable capacitor network 31 is the third capacitor C411 value, and the third capacitor C411 value is greater than the second capacitor value. By adjusting the capacitance value of the adjustable capacitor network 31, it is possible to ensure that the push-pull power amplifier circuit can ensure impedance matching at the output end in the high frequency band, the low frequency band and the low frequency band, so as to achieve impedance matching of the push-pull power amplifier circuit in a wider frequency band and optimize the working bandwidth performance of the push-pull power amplifier circuit.

[0062] In this embodiment, when the operating frequency band of the push-pull power amplifier circuit is a high frequency band, the capacitance value presented by the adjustable capacitor network 31 is a first capacitance value, and when the operating frequency band of the push-pull power amplifier circuit is a medium frequency band, the capacitance value presented by the adjustable capacitor network 31 is a second capacitance value, and the first capacitance value is smaller than the second capacitance value. By adjusting the capacitance value of the adjustable capacitor network 31, it is possible to ensure that the impedance matching of the output end of the push-pull power amplifier circuit is ensured in both the high frequency band and the medium frequency band, so as to achieve impedance matching of the push-pull power amplifier circuit in a wider frequency band and optimize the working bandwidth performance of the push-pull power amplifier circuit.

[0063] In one embodiment, the adjustable capacitor network 31 includes a first switch S311, a first capacitor C311, and a second capacitor C312; the first end of the first capacitor C311 is connected to the second end of the first coil segment, the second end of the first capacitor C311 is connected to the first end of the second capacitor C312, and the second end of the second capacitor C312 is connected to the first end of the second coil segment; the first switch S311 is connected in parallel with the first capacitor C311, or the first switch S311 is connected in parallel with the second capacitor C312;

[0064] Alternatively, the first switching switch S311 and the first capacitor C311 are connected in series between the second end of the first coil segment and the first end of the second coil segment; the first end of the second capacitor C312 is connected to the second end of the first coil segment, and the second end of the second capacitor C312 is connected to the first end of the second coil segment.

[0065] In a specific embodiment, if Figure 1As shown, the adjustable capacitor network 31 includes a first switch S311, a first capacitor C311 and a second capacitor C312; the first end of the first capacitor C311 is connected to the second end of the first coil segment T1, the second end of the first capacitor C311 is connected to the first end of the second capacitor C312, and the second end of the second capacitor C312 is connected to the first end of the second coil segment T2; the first end of the first switch S311 is connected to the second end of the first capacitor C311 and the first end of the second capacitor C312, and the second end of the first switch S311 is connected to the first end of the first capacitor C311; or, the first end of the first switch S311 is connected to the second end of the first capacitor C311 and the first end of the second capacitor C312, and the second end of the first switch S311 is connected to the second end of the second capacitor C312; when the working frequency band of the push-pull power amplifier circuit is the first frequency band, the first switch S311 is disconnected; when the working frequency band of the push-pull power amplifier circuit is the second frequency band, the first switch S311 is closed.

[0066] The first frequency band is greater than the second frequency band.

[0067] This embodiment is described by taking the working frequency band of the push-pull power amplifier circuit as the first frequency band or the second frequency band as an example. In a specific embodiment, the first end of the first capacitor C311 is connected to the second end of the first coil segment T1, the second end of the first capacitor C311 is connected to the first end of the second capacitor C312, and the second end of the second capacitor C312 is connected to the first end of the second coil segment T2; the first end of the first switch S311 is connected to the second end of the first capacitor C311 and the first end of the second capacitor C312, and the second end of the first switch S311 is connected to the first end of the first capacitor C311. In this embodiment, when the working frequency band of the push-pull power amplifier circuit is the first frequency band, the first switching switch S311 is disconnected, and the capacitance value presented by the adjustable capacitor network 31 is the capacitance value of the first capacitor C311 and the second capacitor C312 connected in series, and the capacitance value of the first capacitor C311 and the second capacitor C312 connected in series is less than the capacitance value of the first capacitor C311 or the capacitance value of the second capacitor C312; when the working frequency band of the push-pull power amplifier circuit is the second frequency band, the first switching switch S311 is closed, and the capacitance value presented by the adjustable capacitor network 31 is the capacitance value of the second capacitor C312, so that the capacitance value presented by the adjustable capacitor network 31 when the working frequency band of the push-pull power amplifier circuit is the first frequency band is less than the capacitance value presented when the working frequency band of the push-pull power amplifier circuit is the second frequency band. By adjusting the capacitance value of the adjustable capacitor network 31, it can be ensured that the output impedance matching of the push-pull power amplifier circuit can be ensured in both the first frequency band and the second frequency band, so as to achieve impedance matching of the push-pull power amplifier circuit in a wider frequency band and optimize the working bandwidth performance of the push-pull power amplifier circuit.

[0068] In a specific embodiment, the first end of the first capacitor C311 is connected to the second end of the first coil segment T1, the second end of the first capacitor C311 is connected to the first end of the second capacitor C312, the second end of the second capacitor C312 is connected to the first end of the second coil segment T2, the first end of the first switch S311 is connected to the second end of the first capacitor C311 and the first end of the second capacitor C312, and the second end of the first switch S311 is connected to the second end of the second capacitor C312. In this embodiment, when the working frequency band of the push-pull power amplifier circuit is the first frequency band, the first switch S311 is disconnected, and the capacitance value presented by the adjustable capacitor network 31 is the capacitance value of the first capacitor C311 and the second capacitor C312 connected in series, and the capacitance value of the first capacitor C311 and the second capacitor C312 connected in series is less than the capacitance value of the first capacitor C311 or the capacitance value of the second capacitor C312; when the working frequency band of the push-pull power amplifier circuit is the second frequency band, the first switch S311 is closed, and the capacitance value presented by the adjustable capacitor network 31 is The capacitance value of the second capacitor C312 is greater in the first frequency band than in the second frequency band, so that the capacitance value presented by the adjustable capacitor network 31 when the working frequency band of the push-pull power amplifier circuit is the first frequency band is smaller than the capacitance value presented when the working frequency band of the push-pull power amplifier circuit is the second frequency band. By adjusting the capacitance value of the adjustable capacitor network 31, it is possible to ensure that the push-pull power amplifier circuit can ensure impedance matching at the output end in both the first frequency band and the second frequency band, so as to achieve impedance matching of the push-pull power amplifier circuit in a wider frequency band and optimize the working bandwidth performance of the push-pull power amplifier circuit.

[0069] In a specific embodiment, if Figure 2 As shown, the adjustable capacitor network 31 includes a first switching switch S311, a first capacitor C311 and a second capacitor C312; the first switching switch S311 and the first capacitor C311 are connected in series between the second end of the first coil segment T1 and the first end of the second coil segment T2; the first end of the second capacitor C312 is connected to the second end of the first coil segment T1, and the second end of the second capacitor C312 is connected to the first end of the second coil segment T2; when the working frequency band of the push-pull power amplifier circuit is the first frequency band, the first switching switch S311 is disconnected; when the working frequency band of the push-pull power amplifier circuit is the second frequency band, the first switching switch S311 is closed.

[0070] In a specific embodiment, the adjustable capacitor network 31 includes a first switch S311, a first capacitor C311, and a second capacitor C312. The first switch S311 and the first capacitor C311 are connected in series between the second end of the first coil segment T1 and the first end of the second coil segment T2. The first end of the second capacitor C312 is connected to the second end of the first coil segment T1, and the second end of the second capacitor C312 is connected to the first end of the second coil segment T2. In this embodiment, when the working frequency band of the push-pull power amplifier circuit is the first frequency band, the first switch S311 is disconnected, and the capacitance value presented by the adjustable capacitor network 31 is the capacitance value of the second capacitor C312. When the working frequency band of the push-pull power amplifier circuit is the second frequency band, the first switch S311 is closed, and the capacitance value presented by the adjustable capacitor network 31 is the capacitance value of the first capacitor C311 and the second capacitor C312 in parallel. The capacitance value of the first capacitor C311 and the second capacitor C312 in parallel is greater than the capacitance value of the second capacitor C312, that is, the adjustable capacitor network 3 The capacitance value presented by 1 is the capacitance value of the first capacitor C311 and the second capacitor C312 connected in parallel. The capacitance value presented by the adjustable capacitor network 31 when the working frequency band of the push-pull power amplifier circuit is the first frequency band is smaller than the capacitance value presented when the working frequency band of the push-pull power amplifier circuit is the second frequency band. By adjusting the capacitance value of the adjustable capacitor network 31, it is possible to ensure that the output end of the push-pull power amplifier circuit can ensure impedance matching in both the first frequency band and the second frequency band, so as to achieve impedance matching of the push-pull power amplifier circuit in a wider frequency band and optimize the working bandwidth performance of the push-pull power amplifier circuit.

[0071] In a specific embodiment, the capacitance values ​​of the first capacitor C311 and the second capacitor C312 in the above embodiment can be set according to actual needs. For example, after determining the working frequency band of the push-pull power amplifier circuit, the capacitance reactance calculation formula is used: The capacitance values ​​of the first capacitor C311 and the second capacitor C312 are determined.

[0072] In one embodiment, if Figure 3 As shown, the push-pull power amplifier circuit also includes an impedance adjustment circuit 40; the input end of the impedance adjustment circuit 40 is connected to the first output end of the first balun 20, and is configured to match the output impedance of the push-pull power amplifier circuit according to the operating frequency band of the push-pull power amplifier circuit.

[0073] In a specific embodiment, the push-pull power amplifier circuit further includes an impedance adjustment circuit 40, the input end of the impedance adjustment circuit 40 is connected to the first output end of the first balun 20, and the output end of the impedance adjustment circuit 40 is connected to the signal output end of the push-pull power amplifier circuit. In this embodiment, when the push-pull power amplifier circuit operates in different operating frequency bands, the output impedance of the push-pull power amplifier circuit is also different. Therefore, by connecting the input end of the impedance adjustment circuit 40 to the first output end of the first balun 20, and connecting the output end of the impedance adjustment circuit 40 to the signal output end of the push-pull power amplifier circuit, the impedance adjustment circuit 40 adjusts the output impedance of the push-pull power amplifier circuit according to the operating frequency band of the push-pull power amplifier circuit to achieve impedance matching, thereby improving the overall performance of the push-pull power amplifier circuit.

[0074] In one embodiment, the capacitance value of the impedance adjustment circuit 40 is negatively correlated with the operating frequency band of the push-pull power amplifier circuit, and the inductance value of the impedance adjustment circuit 40 is negatively correlated with the operating frequency band of the push-pull power amplifier circuit.

[0075] In a specific embodiment, the output impedance of the push-pull power amplifier circuit is fixed, and the output impedance of the push-pull power amplifier circuit is determined by the inductive reactance value of the first balun 20, the capacitive reactance value of the adjustable capacitor network 31, and the impedance value of the impedance adjustment circuit 40. Since the inductive reactance value of the first balun 20 and the capacitive reactance value of the adjustable capacitor network 31 are unchanged in different working frequency bands, the impedance value of the impedance adjustment circuit 40 is also unchanged in different working frequency bands, that is, the capacitive reactance value or inductive reactance value of the impedance adjustment circuit 40 is unchanged. According to the capacitive reactance calculation formula: The capacitive reactance value Zc of the impedance adjustment circuit 40 remains unchanged. The operating frequency band of the push-pull power amplifier circuit, that is, the larger the operating frequency w, the smaller the capacitance value presented by the impedance adjustment circuit 40. The smaller the operating frequency w of the push-pull power amplifier circuit, the larger the capacitance value presented by the impedance adjustment circuit 40. Therefore, the capacitance value presented by the impedance adjustment circuit 40 is negatively correlated with the operating frequency band of the push-pull power amplifier circuit.

[0076] In a specific embodiment, according to the capacitive reactance calculation formula: Among them, Z L is the inductance value, L is the inductance value, and the inductance value Z of the impedance adjustment circuit 40 is L The operating frequency band of the push-pull power amplifier circuit remains unchanged, that is, the larger the operating frequency w, the smaller the inductance value presented by the impedance adjustment circuit 40, and the smaller the operating frequency w of the push-pull power amplifier circuit, the larger the inductance value presented by the impedance adjustment circuit 40. Therefore, the inductance value presented by the impedance adjustment circuit 40 is negatively correlated with the operating frequency band of the push-pull power amplifier circuit.

[0077] In this embodiment, the capacitance value presented by the impedance adjustment circuit 40 is negatively correlated with the operating frequency band of the push-pull power amplifier circuit, and the inductance value presented by the impedance adjustment circuit 40 is negatively correlated with the operating frequency band of the push-pull power amplifier circuit, thereby optimizing the operating bandwidth performance of the push-pull power amplifier circuit and further improving the overall performance of the push-pull power amplifier circuit.

[0078] In a specific embodiment, the push-pull power amplifier circuit also includes a harmonic suppression circuit, a first end of the harmonic suppression circuit is connected to the output end of the impedance adjustment circuit 40, a second end of the harmonic suppression circuit is connected to the signal output end of the push-pull power amplifier circuit, and the harmonic suppression circuit is configured to suppress the harmonic signal of the push-pull power amplifier circuit.

[0079] In one embodiment, when the push-pull power amplifier circuit operates in a first frequency band, the capacitance value of the adjustable capacitor network 31 is a first capacitance value, the total capacitance value presented by the impedance adjustment circuit 40 is a third capacitance value, and the total inductance value presented by the impedance adjustment circuit 40 is a first inductance value; when the push-pull power amplifier circuit operates in a second frequency band, the capacitance value of the adjustable capacitor network 31 is a second capacitance value, the total capacitance value presented by the impedance adjustment circuit 40 is a fourth capacitance value, and the total inductance value presented by the impedance adjustment circuit 40 is a second inductance value; wherein, the first frequency band is greater than the second frequency band, the first capacitance value is less than the second capacitance value, the third capacitance value is less than the fourth capacitance value, and the first inductance value is less than the second inductance value.

[0080] In a specific embodiment, when the push-pull power amplifier circuit works in a high frequency band, the capacitance value of the adjustable capacitor network 31 is a first capacitance value, the total capacitance value presented by the impedance adjustment circuit 40 is a third capacitance value, and the total inductance value presented by the impedance adjustment circuit 40 is a first inductance value; when the push-pull power amplifier circuit works in a medium frequency band, the capacitance value of the adjustable capacitor network 31 is a second capacitance value, the total capacitance value presented by the impedance adjustment circuit 40 is a fourth capacitance value, and the total inductance value presented by the impedance adjustment circuit 40 is a second inductance value, the first capacitance value is smaller than the second capacitance value, the third capacitance value is smaller than the fourth capacitance value, and the first inductance value is smaller than the second inductance value. In this embodiment, when the push-pull power amplifier circuit works in a high frequency band, according to the content of the above embodiment, the adjustable capacitor network 31 needs a first capacitance value with a smaller capacitance value, and the impedance adjustment circuit 40 also needs a third capacitance value with a smaller total capacitance value and a first inductance value with a smaller total inductance value, so as to adjust the output impedance of the push-pull power amplifier circuit whose working frequency band is a high frequency band, so as to achieve impedance matching. When the push-pull power amplifier circuit operates in the intermediate frequency band, according to the contents in the above embodiments, the adjustable capacitor network 31 requires a second capacitance value with a larger capacitance value, and the impedance adjustment circuit 40 also requires a fourth capacitance value with a larger total capacitance value and a second inductance value with a larger total inductance value, so as to adjust the output impedance of the push-pull power amplifier circuit whose operating frequency band is the intermediate frequency band to achieve impedance matching.

[0081] In one embodiment, if Figure 3 As shown, the impedance adjustment circuit 40 includes a second switch S41, a third switch S42, a first adjustment circuit 41 and a second adjustment circuit 42; the second switch S41 and the first adjustment circuit 41 are connected in series between the first output end of the first balun 20 and the signal output end of the push-pull power amplifier circuit; the third switch S42 and the second adjustment circuit 42 are connected in series between the first output end of the first balun 20 and the signal output end of the push-pull power amplifier circuit; when the working frequency band of the push-pull power amplifier circuit is the first frequency band, the second switch S41 is closed, the third switch S42 is disconnected, and the first adjustment circuit 41 is configured to adjust the output impedance of the push-pull power amplifier circuit whose working frequency band is the first frequency band to achieve impedance matching; when the working frequency band of the push-pull power amplifier circuit is the second frequency band, the second switch S41 is disconnected, the third switch S42 is closed, and the second adjustment circuit 42 is configured to adjust the output impedance of the push-pull power amplifier circuit whose working frequency band is the second frequency band to achieve impedance matching. Wherein, the first frequency band is greater than the second frequency band.

[0082] In a specific embodiment, the second switching switch S41 and the first adjustment circuit 41 are connected in series between the first output end of the first balun 20 and the signal output end of the push-pull power amplifier circuit. The third switching switch S42 and the second adjustment circuit 42 are connected in series between the first output end of the first balun 20 and the signal output end of the push-pull power amplifier circuit. When the working frequency band of the push-pull power amplifier circuit is the first frequency band, the second switching switch S41 is closed, the third switching switch S42 is opened, and the first adjustment circuit 41 adjusts the output impedance of the push-pull power amplifier circuit whose working frequency band is the first frequency band to achieve impedance matching; when the working frequency band of the push-pull power amplifier circuit is the second frequency band, the second switching switch S41 is opened, the third switching switch S42 is closed, and the second adjustment circuit 42 adjusts the output impedance of the push-pull power amplifier circuit whose working frequency band is the second frequency band to achieve impedance matching.

[0083] In this embodiment, the first adjustment circuit 41 adjusts the output impedance of the push-pull power amplifier circuit whose working frequency band is the first frequency band, and the second adjustment circuit 42 adjusts the output impedance of the push-pull power amplifier circuit whose working frequency band is the second frequency band, so as to achieve impedance matching and further optimize the working bandwidth performance of the push-pull power amplifier circuit.

[0084] In one embodiment, the total capacitance value of the first adjustment circuit 41 is smaller than the total capacitance value of the second adjustment circuit 42 , and the total inductance value of the first adjustment circuit 41 is smaller than the total inductance value of the second adjustment circuit 42 .

[0085] In a specific embodiment, the output impedance of the push-pull power amplifier circuit is fixed, and the output impedance of the push-pull power amplifier circuit is determined by the inductive reactance value of the first balun 20, the capacitive reactance value of the adjustable capacitor network 31, the impedance value of the first adjustment circuit 41, and the impedance value of the second adjustment circuit 42. Since the inductive reactance value of the first balun 20 and the capacitive reactance value of the adjustable capacitor network 31 remain unchanged in different working frequency bands, the impedance value of the first adjustment circuit 41 and the impedance value of the second adjustment circuit 42 need to be equal, that is, the capacitive reactance value of the first adjustment circuit 41 is equal to the capacitive reactance value of the second adjustment circuit 42, and the inductive reactance value of the first adjustment circuit 41 and the inductive reactance value of the second adjustment circuit 42 are equal. According to the capacitive reactance calculation formula: When the push-pull power amplifier circuit operates in the first frequency band, the capacitive reactance value of the first adjustment circuit 41 is equal to the capacitive reactance value of the second adjustment circuit 42, and the operating frequency w of the push-pull power amplifier circuit in the first frequency band is greater than the power frequency w at a low frequency. Therefore, the total capacitance value in the first adjustment circuit 41 is less than the total capacitance value in the second adjustment circuit 42.

[0086] In a specific embodiment, according to the capacitive reactance calculation formula: Among them, Z L is the inductance value, L is the inductance value, when the push-pull power amplifier circuit operates in the first frequency band, the inductance value of the first adjustment circuit 41 is equal to the inductance value of the second adjustment circuit 42, and the operating frequency w of the push-pull power amplifier circuit in the first frequency band is greater than the power frequency w at the low frequency, therefore, the total inductance value in the first adjustment circuit 41 is less than the total inductance value in the second adjustment circuit 42.

[0087] In this embodiment, the capacitive reactance value of the first adjustment circuit 41 is smaller than the capacitive reactance value of the second adjustment circuit 42, and the inductive reactance value of the first adjustment circuit 41 is smaller than the inductive reactance value of the second adjustment circuit 42, thereby optimizing the working bandwidth performance of the push-pull power amplifier circuit and further improving the overall performance of the push-pull power amplifier circuit.

[0088] In one embodiment, if Figure 4As shown, the first adjustment circuit 41 includes a third capacitor C411, a fourth capacitor C412, a first inductor L411 and a second inductor L412; the first end of the third capacitor C411 is connected to the second switch S41, the second end of the third capacitor C411 is connected to the first end of the fourth capacitor C412, and the second end of the fourth capacitor C412 is connected to the signal output end; the first end of the first inductor L411 is connected to the second end of the third capacitor C411 and the first end of the fourth capacitor C412, and the second end of the first inductor L411 is grounded; the first end of the second inductor L412 is connected to the second end of the fourth capacitor C412 and the signal output end, and the second end of the second inductor L412 is connected to the ground; the second adjustment circuit 42 includes a fifth capacitor C421, a sixth capacitor C422, a third inductor L421 and a fourth inductor L422; a first end of the third inductor L421 is connected to the third switch S42, a second end of the third inductor L421 is connected to the first end of the fourth inductor L422, and a second end of the fourth inductor L422 is connected to the signal output end; a first end of the fifth capacitor C421 is connected to the second end of the third inductor L421 and the first end of the fourth inductor L422, and a second end of the fifth capacitor C421 is grounded; a first end of the sixth capacitor C422 is connected to the second end of the fourth inductor L422 and the signal output end, and a second end of the sixth capacitor C422 is grounded.

[0089] In a specific embodiment, the first adjustment circuit 41 includes a third capacitor C411, a fourth capacitor C412, a first inductor L411 and a second inductor L412; the first end of the third capacitor C411 is connected to the second switch S41, the second end of the third capacitor C411 is connected to the first end of the fourth capacitor C412, and the second end of the fourth capacitor C412 is connected to the signal output end; the first end of the first inductor L411 is connected to the second end of the third capacitor C411 and the first end of the fourth capacitor C412, and the second end of the first inductor L411 is grounded; the first end of the second inductor L412 is connected to the second end of the fourth capacitor C412 and the signal output end, and the second end of the second inductor L412 is grounded. In this embodiment, by connecting the first end of the third capacitor C411 to the first output end of the first balun 20, connecting the second end of the third capacitor C411 to the first end of the fourth capacitor C412, and connecting the second end of the fourth capacitor C412 to the signal output end, and connecting the first end of the first inductor L411 to the second end of the third capacitor C411 and the first end of the fourth capacitor C412, and grounding the second end of the first inductor L411; connecting the first end of the second inductor L412 to the second end of the fourth capacitor C412 and the signal output end, and grounding the second end of the second inductor L412, it is possible to match the output impedance of the push-pull power amplifier circuit whose operating frequency band is the first frequency band when the operating frequency band of the push-pull power amplifier circuit is the first frequency band, that is, when the second switching switch S41 is closed and the third switching switch S42 is disconnected.

[0090] In a specific embodiment, the second adjustment circuit 42 includes a fifth capacitor C421, a sixth capacitor C422, a third inductor L421 and a fourth inductor L422; the first end of the third inductor L421 is connected to the third switch S42, the second end of the third inductor L421 is connected to the first end of the fourth inductor L422, and the second end of the fourth inductor L422 is connected to the signal output end; the first end of the fifth capacitor C421 is connected to the second end of the third inductor L421 and the first end of the fourth inductor L422, and the second end of the fifth capacitor C421 is grounded; the first end of the sixth capacitor C422 is connected to the second end of the fourth inductor L422 and the signal output end, and the second end of the sixth capacitor C422 is grounded. In this embodiment, by connecting the first end of the third inductor L421 to the first output end of the first balun 20, connecting the second end of the third inductor L421 to the first end of the fourth inductor L422, and connecting the second end of the fourth inductor L422 to the signal output end, connecting the first end of the fifth capacitor C421 to the second end of the third inductor L421 and the first end of the fourth inductor L422, grounding the second end of the fifth capacitor C421, and connecting the first end of the sixth capacitor C422 to the second end of the fourth inductor L422 and the signal output end, and grounding the second end of the sixth capacitor C422, it is possible to match the output impedance of the push-pull power amplifier circuit whose operating frequency band is the second frequency band when the operating frequency band of the push-pull power amplifier circuit is the second frequency band, that is, when the second switching switch S41 is disconnected and the third switching switch S42 is closed, thereby optimizing the operating bandwidth performance of the push-pull power amplifier circuit, and further improving the overall performance of the push-pull power amplifier circuit.

[0091] In one embodiment, if Figure 5 As shown, the first power amplifier 11 is an HBT tube, including a base, a collector and an emitter, the base of the first power amplifier 11 receives an input first RF input signal, the collector of the first power amplifier 11 is connected to the first end of the first coil segment, and the emitter of the first power amplifier 11 is grounded; the second power amplifier 12 is an HBT tube, including a base, a collector and an emitter, the base of the second power amplifier 12 receives an input second RF input signal, the collector of the second power amplifier 12 is connected to the second end of the second coil segment, and the emitter of the second power amplifier 12 is grounded.

[0092] This embodiment provides a radio frequency front-end module, such as Figure 6As shown, it includes a substrate 50, a push-pull power amplifier chip 10, a first balun 20 arranged on the substrate 50, and a first chip 30 arranged on the substrate 50, the push-pull power amplifier chip 10 includes a first power amplifier 11 and a second power amplifier 12, the first chip 30 includes an adjustable capacitor network 31, and the primary winding of the first balun 20 includes a first coil segment T1 and a second coil segment T2; the output end of the first power amplifier 11 is connected to the first pad of the push-pull power amplifier chip 10, the output end of the second power amplifier 12 is connected to the second pad of the push-pull power amplifier chip 10, the first pad is connected to the first end of the first coil segment T1, and the second pad is connected to the second end of the second coil segment T2; the first chip 30 is inverted and arranged between the second end of the first coil segment T1 and the first end of the second coil segment T2; wherein the adjustable capacitor network 31 is configured to switch the capacitance value based on the working frequency band of the push-pull power amplifier circuit.

[0093] Preferably, the first chip 30 is a SOI (Silicon-On-Insulator, silicon technology, referred to as SOI) chip, which can reduce parasitic capacitance and has a higher operating speed.

[0094] In this embodiment, the RF front-end module includes a substrate 50, a push-pull power amplifier chip 10 disposed on the substrate, a first balun 20 disposed on the substrate 50, and a first chip 30 disposed on the substrate 50. The push-pull power amplifier chip 10 includes a first power amplifier 11 and a second power amplifier 12, the first chip 30 includes an adjustable capacitor network 31, and the primary winding of the first balun 20 includes a first coil segment T1 and a second coil segment T2; the output end of the first power amplifier 11 is connected to the first pad of the push-pull power amplifier chip 10, the output end of the second power amplifier 12 is connected to the second pad of the push-pull power amplifier chip 10, the first pad is connected to the first end of the first coil segment T1, and the second pad is connected to the second end of the second coil segment T2; the first chip 30 is inverted and disposed on the first coil segment The first chip 30 is disposed in an inverted manner between the second end of the first coil segment T1 and the first end of the second coil segment T2, so as to optimize the working bandwidth performance of the push-pull power amplifier chip 10 and thereby improve the overall performance of the RF front-end module. The first chip 30 is disposed in an inverted manner between the second end of the first coil segment T1 and the first end of the second coil segment T2, so as to optimize the occupied area of ​​the first chip 30 on the RF front-end module and improve the integration of the RF front-end module.

[0095] 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 the technical solutions described in the aforementioned embodiments may still be modified, or some of the technical features may be replaced by equivalents. Such modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention, and should all be included in the protection scope of the present invention.

Claims

1. A push-pull power amplifier circuit, characterized in that: It includes a first power amplifier, a second power amplifier, a first balun and an adjustable capacitor network; The primary winding of the first balun includes a first coil segment and a second coil segment; The first end of the adjustable capacitor network is connected to the second end of the first coil segment, and the second end of the adjustable capacitor network is connected to the first end of the second coil segment; The output end of the first power amplifier is connected to the first end of the first coil segment, and the output end of the second power amplifier is connected to the second end of the second coil segment; Among them, the adjustable capacitor network is configured to switch the capacitance value based on the working frequency band of the push-pull power amplifier circuit, and participate in the impedance matching of the output impedance of the push-pull power amplifier circuit together with the first balun; the capacitance value of the adjustable capacitor network is negatively correlated with the working frequency band of the push-pull power amplifier circuit; when the working frequency band of the push-pull power amplifier circuit is a high frequency band, the capacitance value of the adjustable capacitor network is a first capacitance value; when the working frequency band of the push-pull power amplifier circuit is a medium frequency band, the capacitance value of the adjustable capacitor network is a second capacitance value, and the first capacitance value is less than the second capacitance value, so as to keep the capacitive reactance of the adjustable capacitor network unchanged.

2. The push-pull power amplifier circuit according to claim 1, characterized in that: The adjustable capacitor network includes a first switch, a first capacitor and a second capacitor; The first end of the first capacitor is connected to the second end of the first coil segment, the second end of the first capacitor is connected to the first end of the second capacitor, and the second end of the second capacitor is connected to the first end of the second coil segment; the first switch is connected in parallel to the first capacitor, or the first switch is connected in parallel to the second capacitor; Alternatively, the first switching switch and the first capacitor are connected in series between the second end of the first coil segment and the first end of the second coil segment; the first end of the second capacitor is connected to the second end of the first coil segment, and the second end of the second capacitor is connected to the first end of the second coil segment.

3. The push-pull power amplifier circuit according to claim 1, characterized in that: The push-pull power amplifier circuit also includes an impedance adjustment circuit; the input end of the impedance adjustment circuit is connected to the first output end of the first balun, and is configured to match the output impedance of the push-pull power amplifier circuit according to the operating frequency band of the push-pull power amplifier circuit.

4. The push-pull power amplifier circuit according to claim 3, characterized in that: The capacitance value presented by the impedance adjustment circuit is negatively correlated with the operating frequency band of the push-pull power amplifier circuit, and the inductance value presented by the impedance adjustment circuit is negatively correlated with the operating frequency band of the push-pull power amplifier circuit.

5. The push-pull power amplifier circuit as claimed in claim 3, characterized in that: When the push-pull power amplifier circuit operates in the first frequency band, the capacitance value of the adjustable capacitor network is the first capacitance value, the total capacitance value presented by the impedance adjustment circuit is the third capacitance value, and the total inductance value presented by the impedance adjustment circuit is the first inductance value; When the push-pull power amplifier circuit operates in the second frequency band, the capacitance value of the adjustable capacitor network is the second capacitance value, the total capacitance value presented by the impedance adjustment circuit is the fourth capacitance value, and the total inductance value presented by the impedance adjustment circuit is the second inductance value; The first frequency band is greater than the second frequency band, the first capacitance value is less than the second capacitance value, the third capacitance value is less than the fourth capacitance value, and the first inductance value is less than the second inductance value.

6. The push-pull power amplifier circuit as claimed in claim 3, characterized in that: The impedance adjustment circuit includes a second switch, a third switch, a first adjustment circuit and a second adjustment circuit; The second switch and the first adjustment circuit are connected in series between the first output end of the first balun and the signal output end of the push-pull power amplifier circuit; The third switch and the second adjustment circuit are connected in series between the first output end of the first balun and the signal output end of the push-pull power amplifier circuit; When the operating frequency band of the push-pull power amplifier circuit is the first frequency band, the second switch is closed, the third switch is opened, and the first adjustment circuit is configured to match the output impedance of the push-pull power amplifier circuit whose operating frequency band is the first frequency band; When the operating frequency band of the push-pull power amplifier circuit is the second frequency band, the second switch is disconnected, the third switch is closed, and the second adjustment circuit is configured to match the output impedance of the push-pull power amplifier circuit whose operating frequency band is the second frequency band; The first frequency band is greater than the second frequency band.

7. The push-pull power amplifier circuit according to claim 6, characterized in that: A total capacitance value presented by the first adjustment circuit is smaller than a total capacitance value presented by the second adjustment circuit, and a total inductance value presented by the first adjustment circuit is smaller than a total inductance value presented by the second adjustment circuit.

8. The push-pull power amplifier circuit according to claim 6, characterized in that: The first adjustment circuit includes a third capacitor, a fourth capacitor, a first inductor, and a second inductor; the first end of the third capacitor is connected to the second switch, the second end of the third capacitor is connected to the first end of the fourth capacitor, and the second end of the fourth capacitor is connected to the signal output end; the first end of the first inductor is connected to the second end of the third capacitor and the first end of the fourth capacitor, and the second end of the first inductor is grounded; the first end of the second inductor is connected to the second end of the fourth capacitor and the signal output end, and the second end of the second inductor is grounded; The second adjustment circuit includes a fifth capacitor, a sixth capacitor, a third inductor and a fourth inductor; the first end of the third inductor is connected to the third switching switch, 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 signal output end; the first end of the fifth capacitor is connected to the second end of the third inductor and the first end of the fourth inductor, and the second end of the fifth capacitor is grounded; the first end of the sixth capacitor is connected to the second end of the fourth inductor and the signal output end, and the second end of the sixth capacitor is grounded.

9. The push-pull power amplifier circuit according to claim 1, characterized in that: The first power amplifier is an HBT tube, including a base, a collector and an emitter, the base of the first power amplifier receives the input first radio frequency input signal, the collector of the first power amplifier is connected to the first end of the first coil segment, and the emitter of the first power amplifier is grounded; The second power amplifier is an HBT tube, including a base, a collector and an emitter. The base of the second power amplifier receives the input second RF input signal, the collector of the second power amplifier is connected to the second end of the second coil segment, and the emitter of the second power amplifier is grounded.

10. A radio frequency front-end module, characterized in that: The invention comprises a substrate, a push-pull power amplifier chip arranged on the substrate, a first balun arranged on the substrate, and a first chip arranged on the substrate, wherein the push-pull power amplifier chip comprises a first power amplifier and a second power amplifier, the first chip comprises an adjustable capacitor network, and the primary winding of the first balun comprises a first coil segment and a second coil segment; The output end of the first power amplifier is connected to the first pad of the push-pull power amplifier chip, the output end of the second power amplifier is connected to the second pad of the push-pull power amplifier chip, the first pad is connected to the first end of the first coil segment, and the second pad is connected to the second end of the second coil segment; The first chip buckle is arranged between the second end of the first coil segment and the first end of the second coil segment; Wherein, the adjustable capacitor network is configured to switch the capacitance value based on the working frequency band of the push-pull power amplifier circuit according to any one of claims 1 to 9, and participate in the impedance matching of the output impedance of the push-pull power amplifier circuit together with the first balun; the capacitance value of the adjustable capacitor network is negatively correlated with the working frequency band of the push-pull power amplifier circuit; when the working frequency band of the push-pull power amplifier circuit is a high frequency band, the capacitance value of the adjustable capacitor network is a first capacitance value; when the working frequency band of the push-pull power amplifier circuit is a medium frequency band, the capacitance value of the adjustable capacitor network is a second capacitance value, and the first capacitance value is less than the second capacitance value, so as to keep the capacitive reactance of the adjustable capacitor network unchanged.

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