Power amplifier output matching circuit and radio frequency power amplification circuit

Abstract

The invention relates to a power amplifier output matching circuit and a radio frequency power amplification circuit. The power amplifier output matching circuit comprises a higher harmonic suppression module, a second harmonic suppression module and an output matching module. In the circuit structure provided by the invention, the output matching module can match the impedance provided for the power amplifier to the impedance suitable for testing, the bandwidth requirement is met, the secondary harmonic component is suppressed through an improved structure formed by the secondary harmonic suppression module and the higher harmonic suppression module, and meanwhile, the higher harmonic suppression requirement is met; therefore, the fundamental wave impedance point position of the power amplifier is improved, and the performance of the power amplifier is improved.

Description

Technical Field

[0001] The present invention is applicable to the technical field of power amplifier circuits, and in particular relates to a power amplifier output matching circuit and a radio frequency power amplifier circuit. Background Art

[0002] Due to the continuous development of technology, the field of wireless communications has a continuous demand for high performance and high data rate of RF equipment. In this process, in order to reduce cost and power consumption, the design of RF power amplifiers (PA) has brought major challenges.

[0003] In practice, achieving high performance of wireless RF equipment requires proper matching of its fundamental and harmonics, and with the development of technology, many impedance matching technologies have been thoroughly explored. The output impedance of RF power amplifiers is generally low, the matching difficulty is high, and the actual use relative bandwidth is relatively high.

[0004] The existing RF output matching structure is mainly composed of capacitors and / or inductors, generally with CLLC, LCLC structures, or more than two-stage matching. Among them, CLLC bandwidth is larger than LCLC matching, which can achieve high bandwidth and strong practical applicability, but it cannot meet the high-order harmonic suppression requirements of 3-7f0. This type of matching circuit structure is difficult to take into account bandwidth, impedance matching and in-band flatness, which limits the performance of RF equipment. Summary of the invention

[0005] The present invention provides a power amplifier output matching circuit and a radio frequency power amplifier circuit, aiming to solve the problem that the existing power amplifier matching circuit structure is difficult to take into account both bandwidth and impedance matching.

[0006] In order to solve the above technical problems, in a first aspect, the present invention provides a power amplifier output matching circuit, wherein the power amplifier output matching circuit comprises a high-order harmonic suppression module, a second harmonic suppression module and an output matching module, wherein: The input end of the high-order harmonic suppression module is connected to the external power supply voltage, the output end of the high-order harmonic suppression module is used to be connected to the output end of the power amplifier, and the high-order harmonic suppression module is used to suppress the high-order harmonics of the power amplifier and improve the fundamental impedance point of the power amplifier; The input end of the second harmonic suppression module is used to be connected to the output end of the power amplifier, the output end of the second harmonic suppression module is grounded, and the second harmonic suppression module is used to suppress the second harmonic of the power amplifier; The input end of the output matching module is used to be connected to the output end of the power amplifier, the output end of the output matching module serves as the output end of the output matching circuit of the power amplifier, and the output matching module is used to match the output impedance of the power amplifier; the output end of the high-order harmonic suppression module, the input end of the second harmonic suppression module and the input end of the output matching module serve together as the input end of the output matching circuit of the power amplifier.

[0007] Furthermore, the output matching module includes a first capacitor, a second capacitor, a first inductor, a second inductor and a third inductor, the first end of the first capacitor serves as the input end of the output matching module, and the second end of the first capacitor is respectively connected to the first end of the first inductor and the first end of the second inductor; The second end of the first inductor is grounded; The second end of the second inductor serves as the output end of the power amplifier output matching circuit to output a signal; The first end of the second capacitor is connected to the second end of the second inductor, and the second end of the second capacitor is connected to the first end of the third inductor; A second terminal of the third inductor is grounded.

[0008] 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 end of the high-order harmonic suppression module, and the second end of the fourth inductor is respectively connected to the first end of the fifth inductor and the first end of the third capacitor; The second end of the fifth inductor is connected to the external power supply voltage as the input end of the high-order harmonic suppression module; A second terminal of the third capacitor is grounded.

[0009] Furthermore, the second harmonic suppression module includes a fourth capacitor and a sixth inductor, the first end of the fourth capacitor serves as an input end of the second harmonic suppression module, and the second end of the fourth capacitor is connected to the first end of the sixth inductor; The second end of the sixth inductor is grounded as the output end of the second harmonic suppression module.

[0010] In a second aspect, the present invention further provides a radio frequency power amplifier circuit, comprising a power amplifier, a bias circuit and the power amplifier output matching circuit as described above; The output end of the bias circuit is connected to the input end of the power amplifier, and the output end of the power amplifier is connected to the input end of the power amplifier output matching circuit; The output end of the bias circuit is connected to the input end of the power amplifier, and the bias circuit is used to provide a stable bias current for the power amplifier.

[0011] Furthermore, the RF power amplifier circuit also includes an input matching circuit, the input end of the input matching circuit is used to connect to an external RF signal, the output end of the input matching circuit is connected to the input end of the power amplifier, and the input matching circuit is used to match the input impedance of the power amplifier.

[0012] Furthermore, the input matching circuit includes an input capacitor, a first end of the input capacitor serves as an input end of the input matching circuit, and a second end of the input capacitor serves as an output end of the input matching circuit.

[0013] The beneficial effect achieved by the present invention is that a power amplifier output matching circuit with multiple harmonic suppression function is proposed. In the circuit structure, the output matching module can match the impedance provided to the power amplifier to the impedance of the appropriate test to meet the bandwidth requirement, and suppress the second harmonic component through the improved structure formed by the second harmonic suppression module and the higher harmonic suppression module, while meeting the higher harmonic suppression requirements, thereby improving the fundamental impedance point position of the power amplifier and improving the performance of the power amplifier. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 It is a schematic diagram of the module structure of a power amplifier output matching circuit provided by an embodiment of the present invention; Figure 2 The figure is a schematic diagram of the circuit structure of a power amplifier output matching circuit provided in an embodiment of the present invention. DETAILED DESCRIPTION

[0015] In order to make the purpose, technical solution and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0016] Please refer to Figure 1 , Figure 1 1 is a schematic diagram of the module structure of a 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 harmonic suppression module 102 and an output matching module 103, wherein: The input end of the high-order harmonic suppression module 101 is connected to the external power supply voltage VCC, and the output end of the high-order harmonic suppression module 101 is used to be connected to the output end of the power amplifier 200. The high-order harmonic suppression module 101 is used to suppress the high-order harmonics of the power amplifier 200 and improve the fundamental impedance point of the power amplifier 200; The input end of the second harmonic suppression module 102 is used to be connected to the output end of the power amplifier 200, the output end of the second harmonic suppression module 102 is grounded, and the second harmonic suppression module 102 is used to suppress the second harmonic of the power amplifier 200; The input end of the output matching module 103 is used to be connected to the output end of the power amplifier 200, and the output end of the output matching module 103 serves as the output end 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 end of the high-order harmonic suppression module 101, the input end of the second harmonic suppression module 102, and the input end of the output matching module 103 serve together as the input end of the power amplifier output matching circuit 100.

[0017] In the embodiment of the present invention, the power amplifier 200 can be implemented in a variety of ways, such as a triode (HBT) or a MOS tube, etc. The embodiment of the present invention is described with a triode structure, wherein the collector of the power amplifier 200 serves as its output terminal and the base serves as its input terminal. It can be understood that the structure of the power amplifier 200 does not affect the technical effect that can be achieved by the power amplifier output matching circuit in the embodiment of the present invention, so the present invention does not limit the specific structure of the power amplifier 200.

[0018] For details, please refer to Figure 2 , Figure 2 : is a schematic diagram of the circuit structure of a power amplifier output matching circuit provided in an embodiment of the present invention, wherein the output matching module comprises a first capacitor C1, a second capacitor C2, a first inductor L1, a second inductor L2 and a third inductor L3, wherein a first end of the first capacitor C1 serves as an input end of the output matching module 103, and a second end of the first capacitor C1 is connected to a first end of the first inductor L1 and a first end of the second inductor L2 respectively; The second end of the first inductor L1 is grounded; The second end of the second inductor L2 serves as the output end of the power amplifier output matching circuit 100 to output a signal RFout; The first end of the second capacitor C2 is connected to the second end of the second inductor L2, and the second end of the second capacitor C2 is connected to the first end of the third inductor L3; A second end of the third inductor L3 is grounded.

[0019] 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 respectively connected to the first end of the fifth inductor L5 and the first end of the third capacitor C3; The second end of the fifth inductor L5 is connected to the external power supply voltage VCC as the input end of the high-order harmonic suppression module 101; A second terminal of the third capacitor C3 is grounded.

[0020] The second harmonic suppression module 102 includes a fourth capacitor C4 and a sixth inductor L6, wherein a first end of the fourth capacitor C4 serves as an input end of the second harmonic suppression module 102, and a second end of the fourth capacitor C4 is connected to a first end of the sixth inductor L6; The second end of the sixth inductor L6 is grounded as an output end of the second harmonic suppression module 102 .

[0021] In the above circuit structure, since the external RF 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 for suppressing the second harmonic, the fourth inductor L4 and the third capacitor C3 form a filter circuit for suppressing high-order harmonics, and the fifth inductor L5 is used as a choke inductor, so that the fifth inductor L5 and the fourth capacitor C4 also constitute a trap circuit, so the overall circuit has a low impedance component to the second harmonic.

[0022] 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 during implementation, and the output matching module 103 in the embodiment of the present invention combines the circuit structure design of the second harmonic and the higher harmonic, which can achieve high bandwidth and strong practical applicability, and meet the higher harmonic suppression requirements of 3-7f0.

[0023] The embodiment of the present invention further provides a radio frequency power amplifier circuit 400, comprising a power amplifier 200, a bias circuit 300 and the power amplifier output matching circuit 100 as described above; The output end of the bias circuit 300 is connected to the input end of the power amplifier 200, and the output end of the power amplifier 200 is connected to the input end of the power amplifier output matching circuit 100; The output end of the bias circuit 300 is connected to the input end of the power amplifier 200 , and the bias circuit 300 is used to provide a stable bias current BIAS for the power amplifier.

[0024] The RF power amplifier circuit also includes an input matching circuit 500, the input end of the input matching circuit 500 is used to connect to an external RF signal RFin, the output end of the input matching circuit 500 is connected to the input end of the power amplifier 200, and the input matching circuit 500 is used to match the input impedance of the power amplifier 200.

[0025] The input matching circuit 500 includes an input capacitor Cin, a first end of the input capacitor Cin serves as an input end of the input matching circuit 500 , and a second end of the input capacitor Cin serves as an output end of the input matching circuit 500 .

[0026] It is understandable that the RF power amplifier circuit 400 provided in the embodiment of the present invention can have better impedance matching under high bandwidth based on the power amplifier output matching circuit 100 in the embodiment of the present invention, and its power amplifier output performance is better. Refer to the description in the above embodiment, which will not be repeated here.

[0027] The beneficial effect achieved by the present invention is that a power amplifier output matching circuit with multiple harmonic suppression function is proposed. In the circuit structure, the output matching module can match the impedance provided to the power amplifier to the impedance of the appropriate test to meet the bandwidth requirement, and suppress the second harmonic component through the improved structure formed by the second harmonic suppression module and the higher harmonic suppression module, while meeting the higher harmonic suppression requirements, thereby improving the fundamental impedance point position of the power amplifier and improving the performance of the power amplifier.

[0028] It should be noted that, in this article, the terms "include", "comprises" or any other variations thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, an element defined by the sentence "comprises a ..." does not exclude the existence of other identical elements in the process, method, article or device including the element.

[0029] The embodiments of the present invention are described above in conjunction with the accompanying drawings. What is disclosed is only the preferred embodiment of the present invention. However, the present invention is not limited to the above-mentioned specific implementation manner. The above-mentioned specific implementation manner is only illustrative rather than restrictive. Under the enlightenment of the present invention, ordinary technicians in this field can also make many forms and equivalent changes without departing from the scope of protection of the purpose of the present invention and the claims, all of which are within the protection 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 harmonic suppression module and an output matching module, wherein: The input end of the high-order harmonic suppression module is connected to the external power supply voltage, the output end of the high-order harmonic suppression module is used to be connected to the output end of the power amplifier, and the high-order harmonic suppression module is used to suppress the high-order harmonics of the power amplifier and improve the fundamental impedance point of the power amplifier; The input end of the second harmonic suppression module is used to be connected to the output end of the power amplifier, the output end of the second harmonic suppression module is grounded, and the second harmonic suppression module is used to suppress the second harmonic of the power amplifier; The input end of the output matching module is used to be connected to the output end of the power amplifier, the output end of the output matching module serves as the output end of the output matching circuit of the power amplifier, and the output matching module is used to match the output impedance of the power amplifier; the output end of the high-order harmonic suppression module, the input end of the second harmonic suppression module and the input end of the output matching module serve together as the input end of the output matching circuit of the power amplifier.

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 end of the first capacitor serves as the input end of the output matching module, and the second end of the first capacitor is respectively connected to the first end of the first inductor and the first end of the second inductor; The second end of the first inductor is grounded; The second end of the second inductor serves as the output end of the power amplifier output matching circuit to output a signal; The first end of the second capacitor is connected to the second end of the second inductor, and the second end of the second capacitor is connected to the first end of the third inductor; A 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 respectively connected to the first end of the fifth inductor and the first end of the third capacitor; The second end of the fifth inductor is connected to the external power supply voltage as the input end of the high-order harmonic suppression module; A 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 end of the fourth capacitor serves as the input end of the second harmonic suppression module, and the second end of the fourth capacitor is connected to the first end of the sixth inductor; The second end of the sixth inductor is grounded as the output end of the second harmonic suppression module.

5. A radio frequency power amplifier circuit, characterized in that: A power amplifier comprising a power amplifier, a bias circuit and a power amplifier output matching circuit as claimed in any one of claims 1 to 4; The output end of the bias circuit is connected to the input end of the power amplifier, and the output end of the power amplifier is connected to the input end of the power amplifier output matching circuit; The output end of the bias circuit is connected to the input end 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 RF power amplifier circuit also includes an input matching circuit, the input end of the input matching circuit is used to connect an external RF signal, the output end of the input matching circuit is connected to the input end of the power amplifier, and 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, a first end of the input capacitor serves as an input end of the input matching circuit, and a second end of the input capacitor serves as an output end of the input matching circuit.

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