Power amplifier output matching circuit and radio frequency power amplification circuit

Abstract

The present invention relates to a power amplifier output matching circuit and a radio frequency power amplification circuit. The power amplifier output matching circuit comprises a high-order harmonic suppression module, a second harmonic suppression module, and an output matching module. In the circuit structure provided by the present invention, the output matching module can match the impedance provided to a power amplifier to an appropriate test impedance to meet the bandwidth requirements, and the second harmonic component is suppressed by means of an improved structure formed by the second harmonic suppression module and the high-order harmonic suppression module, and the requirement for high-order harmonic suppression is met at the same time, thereby improving the fundamental impedance point position of the power amplifier and improving the performance of the power amplifier.

Description

Power amplifier output matching circuit and RF power amplifier circuit Technical Field

[0001] This invention relates to the field of power amplifier circuit technology, and particularly to a power amplifier output matching circuit and an RF power amplifier circuit. Background Technology

[0002] Due to continuous technological advancements, the wireless communication field has a persistent demand for high performance and high data rates in radio frequency (RF) equipment. In this process, reducing costs and power consumption has brought significant challenges to the design of radio frequency power amplifiers (PAs).

[0003] In practice, achieving high performance in wireless radio frequency (RF) devices requires proper matching of their fundamental and harmonic frequencies. With technological advancements, many impedance matching techniques have been thoroughly explored. RF power amplifiers generally have low output impedance, making matching more challenging, and their actual application results in relatively high bandwidth.

[0004] Existing RF output matching structures mainly consist of capacitors and / or inductors, typically CLLC, LCLC, or more than two matching segments. Among them, CLLC has a higher bandwidth than LCLC, achieving higher bandwidth and stronger practical application, but it cannot meet the high-order harmonic suppression requirements of 3-7f0. This type of matching circuit structure is difficult to balance bandwidth, impedance matching, and in-band flatness, which limits the performance of RF equipment. Summary of the Invention

[0005] This invention provides a power amplifier output matching circuit and an RF power amplifier circuit, aiming to solve the problem that existing power amplifier matching circuit structures cannot simultaneously achieve bandwidth and impedance matching.

[0006] To solve the above-mentioned technical problems, in a first aspect, the present invention provides a power amplifier output matching circuit, the power amplifier output matching circuit comprising a high-order harmonic suppression module, a second-order harmonic suppression module, and an output matching module, wherein:

[0007] The input terminal of the high-order harmonic suppression module is connected to an external power supply voltage, and the output terminal of the high-order harmonic suppression module is used to connect to the output terminal of the power amplifier. The high-order harmonic suppression module is used to suppress high-order harmonics in the power amplifier and improve the fundamental impedance point of the power amplifier.

[0008] The input terminal of the second harmonic suppression module is connected to the output terminal of the power amplifier, and the output terminal of the second harmonic suppression module is grounded. The second harmonic suppression module is used to suppress the second harmonics of the power amplifier.

[0009] The input terminal of the output matching module is used to connect to the output terminal of the power amplifier. The output terminal of the output matching module serves as the output terminal of the power amplifier output matching circuit. The output matching module is used to match the output impedance of the power amplifier. The output terminal of the higher harmonic suppression module, the input terminal of the second harmonic suppression module, and the input terminal of the output matching module together serve as the input terminal of the power amplifier output matching circuit.

[0010] Furthermore, the output matching module includes a first capacitor, a second capacitor, a first inductor, a second inductor, and a third inductor. The first terminal of the first capacitor serves as the input terminal of the output matching module, and the second terminal of the first capacitor is connected to the first terminal of the first inductor and the first terminal of the second inductor, respectively.

[0011] The second terminal of the first inductor is grounded;

[0012] The second terminal of the second inductor serves as the output terminal of the power amplifier output matching circuit, outputting a signal.

[0013] The first terminal of the second capacitor is connected to the second terminal of the second inductor, and the second terminal of the second capacitor is connected to the first terminal of the third inductor;

[0014] The second terminal of the third inductor is grounded.

[0015] Furthermore, the high-order harmonic suppression module includes a fourth inductor, a fifth inductor, and a third capacitor. The first end of the fourth inductor serves as the output terminal of the high-order harmonic suppression module, and the second end of the fourth inductor is connected to the first end of the fifth inductor and the first end of the third capacitor, respectively.

[0016] The second end of the fifth inductor serves as the input terminal of the high-order harmonic suppression module and is connected to an external power supply voltage.

[0017] The second terminal of the third capacitor is grounded.

[0018] Furthermore, the second harmonic suppression module includes a fourth capacitor and a sixth inductor. The first terminal of the fourth capacitor serves as the input terminal of the second harmonic suppression module, and the second terminal of the fourth capacitor is connected to the first terminal of the sixth inductor.

[0019] The second terminal of the sixth inductor is grounded as the output terminal of the second harmonic suppression module.

[0020] In a second aspect, the present invention also provides an RF power amplifier circuit, including a power amplifier, a bias circuit, and a power amplifier output matching circuit as described above.

[0021] The output terminal of the bias circuit is connected to the input terminal of the power amplifier, and the output terminal of the power amplifier is connected to the input terminal of the power amplifier output matching circuit.

[0022] The output of the bias circuit is connected to the input of the power amplifier, and the bias circuit is used to provide a stable bias current for the power amplifier.

[0023] Furthermore, the RF power amplifier circuit also includes an input matching circuit. The input terminal of the input matching circuit is used to connect to an external RF signal, and the output terminal of the input matching circuit is connected to the input terminal of the power amplifier. The input matching circuit is used to match the input impedance of the power amplifier.

[0024] Furthermore, the input matching circuit includes an input capacitor, with the first end of the input capacitor serving as the input terminal of the input matching circuit and the second end of the input capacitor serving as the output terminal of the input matching circuit.

[0025] The beneficial effect achieved by this invention lies in proposing a power amplifier output matching circuit with multiple harmonic suppression function. In this circuit structure, the output matching module can match the impedance provided to the power amplifier to a suitable test impedance to meet the bandwidth requirements. The improved structure formed by the second harmonic suppression module and the higher harmonic suppression module suppresses the second harmonic component and meets the higher harmonic suppression requirements, thereby improving the fundamental impedance point position of the power amplifier and improving the performance of the power amplifier. Attached Figure Description

[0026] Figure 1 is a schematic diagram of the module structure of the power amplifier output matching circuit provided in an embodiment of the present invention;

[0027] Figure 2 is a schematic diagram of the circuit structure of the power amplifier output matching circuit provided in an embodiment of the present invention. Detailed Implementation

[0028] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention.

[0029] Please refer to Figure 1, which is a schematic diagram of the module structure of the power amplifier output matching circuit provided in an embodiment of the present invention. The power amplifier output matching circuit 100 includes a high-order harmonic suppression module 101, a second-order harmonic suppression module 102, and an output matching module 103, wherein:

[0030] The input terminal of the high-order harmonic suppression module 101 is connected to the external power supply voltage VCC, and the output terminal of the high-order harmonic suppression module 101 is used to connect to the output terminal of the power amplifier 200. The high-order harmonic suppression module 101 is used to suppress high-order harmonics in the power amplifier 200 and improve the fundamental impedance point of the power amplifier 200.

[0031] The input terminal of the second harmonic suppression module 102 is connected to the output terminal of the power amplifier 200, and the output terminal of the second harmonic suppression module 102 is grounded. The second harmonic suppression module 102 is used to suppress second harmonics in the power amplifier 200.

[0032] The input terminal of the output matching module 103 is used to connect to the output terminal of the power amplifier 200. The output terminal of the output matching module 103 serves as the output terminal of the power amplifier output matching circuit 100. The output matching module 103 is used to match the output impedance of the power amplifier 200. The output terminal of the higher harmonic suppression module 101, the input terminal of the second harmonic suppression module 102, and the input terminal of the output matching module 103 together serve as the input terminal of the power amplifier output matching circuit 100.

[0033] In this embodiment of the invention, the power amplifier 200 can be implemented in various ways, such as a high-voltage transistor (HBT) or a MOSFET. This embodiment uses a transistor structure for illustration, where the collector of the power amplifier 200 serves as its output terminal, and its base serves as its input terminal. It is understood that the structural implementation of the power amplifier 200 does not affect the technical effect achievable by the power amplifier output matching circuit in this embodiment; therefore, this invention does not limit the specific structure of the power amplifier 200.

[0034] Specifically, please refer to Figure 2. Figure 2 is a schematic diagram of the circuit structure of the power amplifier output matching circuit provided in the embodiment of the present invention. The output matching module includes a first capacitor C1, a second capacitor C2, a first inductor L1, a second inductor L2, and a third inductor L3. The first end of the first capacitor C1 serves as the input end of the output matching module 103, and the second end of the first capacitor C1 is connected to the first end of the first inductor L1 and the first end of the second inductor L2, respectively.

[0035] The second terminal of the first inductor L1 is grounded;

[0036] The second terminal of the second inductor L2 serves as the output terminal of the power amplifier output matching circuit 100, outputting the signal RFout.

[0037] The first terminal of the second capacitor C2 is connected to the second terminal of the second inductor L2, and the second terminal of the second capacitor C2 is connected to the first terminal of the third inductor L3;

[0038] The second terminal of the third inductor L3 is grounded.

[0039] The high-order harmonic suppression module 101 includes a fourth inductor L4, a fifth inductor L5, and a third capacitor C3. The first end of the fourth inductor L4 serves as the output end of the high-order harmonic suppression module 101, and the second end of the fourth inductor L4 is connected to the first end of the fifth inductor L5 and the first end of the third capacitor C3, respectively.

[0040] The second terminal of the fifth inductor L5 is connected to the external power supply voltage VCC as the input terminal of the high-order harmonic suppression module 101.

[0041] The second terminal of the third capacitor C3 is grounded.

[0042] The second harmonic suppression module 102 includes a fourth capacitor C4 and a sixth inductor L6. The first end of the fourth capacitor C4 serves as the input terminal of the second harmonic suppression module 102, and the second end of the fourth capacitor C4 is connected to the first end of the sixth inductor L6.

[0043] The second terminal of the sixth inductor L6 is grounded as the output terminal of the second harmonic suppression module 102.

[0044] In the above circuit structure, since the external radio frequency signal RFin is amplified by the power amplifier 200 and output at the collector, the fourth capacitor C4 and the sixth inductor L6 form a TRAP filter circuit to suppress the second harmonic, the fourth inductor L4 and the third capacitor C3 form a filter circuit to suppress the higher harmonic, and the fifth inductor L5 acts as a choke inductor, so the fifth inductor L5 and the fourth capacitor C4 also form a notch filter circuit. Therefore, the overall circuit has a low impedance to the second harmonic component.

[0045] The external power supply voltage VCC is used to power the power amplifier and provide impedance matching. The output matching module 103 can be set to a matching impedance of 50 ohms. Furthermore, the output matching module 103 in this embodiment combines second and higher harmonic circuit design to achieve high bandwidth, strong practical applicability, and meet the 3-7f0 higher harmonic suppression requirement.

[0046] This invention also provides an RF power amplifier circuit 400, including a power amplifier 200, a bias circuit 300, and a power amplifier output matching circuit 100 as described above;

[0047] The output terminal of the bias circuit 300 is connected to the input terminal of the power amplifier 200, and the output terminal of the power amplifier 200 is connected to the input terminal of the power amplifier output matching circuit 100.

[0048] The output terminal of the bias circuit 300 is connected to the input terminal of the power amplifier 200, and the bias circuit 300 is used to provide a stable bias current BIAS for the power amplifier.

[0049] The radio frequency power amplifier circuit also includes an input matching circuit 500. The input terminal of the input matching circuit 500 is used to connect to an external radio frequency signal RFin, and the output terminal of the input matching circuit 500 is connected to the input terminal of the power amplifier 200. The input matching circuit 500 is used to match the input impedance of the power amplifier 200.

[0050] The input matching circuit 500 includes an input capacitor Cin, the first end of which serves as the input terminal of the input matching circuit 500, and the second end of which serves as the output terminal of the input matching circuit 500.

[0051] It is understood that the RF power amplifier circuit 400 provided in the embodiments of the present invention, based on the power amplifier output matching circuit 100 in the embodiments of the present invention, can have better impedance matching under high bandwidth, and its power amplifier output performance is superior. Referring to the description in the above embodiments, it will not be repeated here.

[0052] The beneficial effect achieved by this invention lies in proposing a power amplifier output matching circuit with multiple harmonic suppression function. In this circuit structure, the output matching module can match the impedance provided to the power amplifier to a suitable test impedance to meet the bandwidth requirements. The improved structure formed by the second harmonic suppression module and the higher harmonic suppression module suppresses the second harmonic component while meeting the higher harmonic suppression requirements, thereby improving the fundamental impedance point position of the power amplifier and enhancing the performance of the power amplifier.

[0053] It should be noted that, in this document, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Unless otherwise specified, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes that element.

[0054] The embodiments of the present invention have been described above with reference to the accompanying drawings. The disclosed embodiments are merely preferred embodiments of the present invention. However, the present invention is not limited to the specific embodiments described above. The specific embodiments described above are merely illustrative and not restrictive. Those skilled in the art can make many equivalent changes in form without departing from the spirit and scope of the claims of the present invention, and all such changes are within the protection scope of the present invention.

Claims

1. A power amplifier output matching circuit, characterized in that, The power amplifier output matching circuit includes a high-order harmonic suppression module, a second-order harmonic suppression module, and an output matching module, wherein: The input terminal of the high-order harmonic suppression module is connected to an external power supply voltage, and the output terminal of the high-order harmonic suppression module is used to connect to the output terminal of the power amplifier. The high-order harmonic suppression module is used to suppress high-order harmonics in the power amplifier and improve the fundamental impedance point of the power amplifier. The input terminal of the second harmonic suppression module is connected to the output terminal of the power amplifier, and the output terminal of the second harmonic suppression module is grounded. The second harmonic suppression module is used to suppress second harmonics in the power amplifier. The input terminal of the output matching module is used to connect to the output terminal of the power amplifier. The output terminal of the output matching module serves as the output terminal of the power amplifier output matching circuit. The output matching module is used to match the output impedance of the power amplifier. The output terminal of the higher harmonic suppression module, the input terminal of the second harmonic suppression module, and the input terminal of the output matching module together serve as the input terminal of the power amplifier output matching circuit.

2. The power amplifier output matching circuit according to claim 1, characterized in that, The output matching module includes a first capacitor, a second capacitor, a first inductor, a second inductor, and a third inductor. The first terminal of the first capacitor serves as the input terminal of the output matching module, and the second terminal of the first capacitor is connected to the first terminal of the first inductor and the first terminal of the second inductor, respectively. The second terminal of the first inductor is grounded; The second terminal of the second inductor serves as the output terminal of the power amplifier output matching circuit, outputting a signal. The first terminal of the second capacitor is connected to the second terminal of the second inductor, and the second terminal of the second capacitor is connected to the first terminal of the third inductor; The second terminal of the third inductor is grounded.

3. The power amplifier output matching circuit according to claim 2, characterized in that, The high-order harmonic suppression module includes a fourth inductor, a fifth inductor, and a third capacitor. The first end of the fourth inductor serves as the output end of the high-order harmonic suppression module, and the second end of the fourth inductor is connected to the first end of the fifth inductor and the first end of the third capacitor, respectively. The second end of the fifth inductor serves as the input terminal of the high-order harmonic suppression module and is connected to an external power supply voltage. The second terminal of the third capacitor is grounded.

4. The power amplifier output matching circuit according to claim 2, characterized in that, The second harmonic suppression module includes a fourth capacitor and a sixth inductor. The first terminal of the fourth capacitor serves as the input terminal of the second harmonic suppression module, and the second terminal of the fourth capacitor is connected to the first terminal of the sixth inductor. The second terminal of the sixth inductor is grounded as the output terminal of the second harmonic suppression module.

5. A radio frequency power amplifier circuit, characterized in that, Includes a power amplifier, a bias circuit, and a power amplifier output matching circuit as described in any one of claims 1-4; The output terminal of the bias circuit is connected to the input terminal of the power amplifier, and the output terminal of the power amplifier is connected to the input terminal of the power amplifier output matching circuit. The output of the bias circuit is connected to the input of the power amplifier, and the bias circuit is used to provide a stable bias current for the power amplifier.

6. The radio frequency power amplifier circuit according to claim 5, characterized in that, The radio frequency power amplifier circuit also includes an input matching circuit. The input terminal of the input matching circuit is used to connect to an external radio frequency signal, and the output terminal of the input matching circuit is connected to the input terminal of the power amplifier. The input matching circuit is used to match the input impedance of the power amplifier.

7. The radio frequency power amplifier circuit according to claim 6, characterized in that, The input matching circuit includes an input capacitor, with the first end of the input capacitor serving as the input terminal of the input matching circuit and the second end of the input capacitor serving as the output terminal of the input matching circuit.

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