A C-band broadband high-power GaN radio frequency power amplifier

Abstract

This invention provides a C-band broadband high-power GaN RF power amplifier, comprising an external matching input network, an input pre-matching network, a GaN chip parallel network, a pre-matching output network, and an external matching output network. The external matching input network is electrically connected to the input pre-matching network. The GaN chip parallel network is electrically connected to both the input pre-matching network and the pre-matching output network. The pre-matching output network is electrically connected to the external matching output network. This invention reduces the external matching area of ​​the RF power amplifier, resulting in a compact and simple structure that simplifies the design process for similar power amplifiers. Its high efficiency and small size make this invention promising for applications in communications, radar systems, and unmanned aerial vehicles (UAVs).

Description

Technical Field

[0001] This invention belongs to the technical field of power amplifiers, and specifically relates to a C-band broadband high-power GaN radio frequency power amplifier. Background Technology

[0002] C-band power amplifiers are core components of communication and radar systems. With the development of scatter communication technology, the requirements for the transmission power of C-band communication systems are becoming increasingly higher. High power requirements, wide bandwidth, and high efficiency directly determine the quality of communication.

[0003] In existing technologies, traditional C-band high-power GaN amplifiers have relatively low impedance, resulting in a large peripheral PCB matching area and high losses, making it difficult to achieve broadband performance. Summary of the Invention

[0004] To address the aforementioned technical problems, this invention provides a C-band broadband high-power GaN RF power amplifier, thereby overcoming the shortcomings of the prior art.

[0005] This invention provides a C-band broadband high-power GaN RF power amplifier, comprising an external matching input network, an input pre-matching network, a GaN chip parallel network, a pre-matching output network, and an external matching output network; The external matching input network is electrically connected to the input pre-matching network, the GaN chip parallel network is electrically connected to the input pre-matching network and the pre-matching output network respectively, and the pre-matching output network is electrically connected to the external matching output network; The external matching input network is used to connect the RFin radio frequency signal and suppress even-order harmonic signals and perform total reflection of the fundamental signal. The input pre-matching network is used to suppress harmonics in the processed RFin radio frequency signal. The GaN chip parallel network is used to increase power. The pre-matching output network is used to increase the die impedance and suppress higher-order harmonics. The external matching output network is used for higher-order harmonic suppression and fundamental open circuit.

[0006] Compared with the prior art, the beneficial effects of the present invention are: the internal matching initially raises the impedance, the external matching multi-section matching achieves full-band matching to 50Ω, the quarter-wavelength line improves the efficiency of the RF power amplifier, the external matching area of ​​the RF power amplifier is reduced, the structure is compact and simple, simplifying the design process of similar power amplifiers, and the high efficiency and small size make the present invention have important application prospects in communication, radar systems and drones.

[0007] Furthermore, the external matching input network includes a first 50Ω line, a first DC blocking capacitor, a first matching section, two first quarter-wavelength line circuits, and two first filter circuits. The first 50Ω line is electrically connected to the first matching section through the first DC blocking capacitor, and the two first filter circuits are respectively connected to the first matching section through the two first quarter-wavelength line circuits.

[0008] Furthermore, the first 50Ω line is used to connect the RFin radio frequency signal, and the first matching section is electrically connected to the input pre-matching network.

[0009] Furthermore, the input pre-matching network includes an input pin and a first LCL low-pass network. The input pin is electrically connected to the external matching input network and the first LCL low-pass network, respectively. The first LCL low-pass network is electrically connected to the GaN chip parallel network.

[0010] Furthermore, the GaN chip parallel network includes two sets of dies, which are electrically connected. One set of dies is electrically connected to the input pre-matching network, and the other set of dies is electrically connected to the pre-matching output network.

[0011] Furthermore, the total grid width of the two sets of dies is 24 mm.

[0012] Furthermore, the pre-matched output network includes a second LCL low-pass network and an output pin. The second LCL low-pass network is electrically connected to the parallel network of the GaN chip, and the second LCL low-pass network is electrically connected to the externally matched output network through the output pin.

[0013] Furthermore, the external matching output network includes a second 50Ω line, a second DC blocking capacitor, a second matching section, two second quarter-wavelength line circuits, and two second filter circuits. The second 50Ω line is electrically connected to the second matching section through the second DC blocking capacitor, and the two second filter circuits are respectively connected to the second matching section through the two second quarter-wavelength line circuits.

[0014] Furthermore, the second matching section is electrically connected to the pre-matched output network, and the second 50Ω line is connected to RFOUT.

[0015] Furthermore, the second matching section employs a multi-section T-shaped section. Attached Figure Description

[0016] To more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0017] Figure 1 This is a schematic diagram of the structure of the C-band broadband high-power GaN RF power amplifier in an embodiment of the present invention; Figure 2 This is a schematic diagram of the circuit structure of the C-band broadband high-power GaN RF power amplifier in an embodiment of the present invention.

[0018] Explanation of key component symbols: 10. External matching input network; 11. First 50Ω line; 12. First DC blocking capacitor; 13. First matching section; 14. First quarter-wavelength line circuit; 15. First filter circuit; 20. Input pre-matching network; 21. Input pin; 22. First LCL low-pass network; 30. GaN chip parallel network; 31. Die; 40. Pre-matched output network; 41. Second LCL low-pass network; 42. Output pin; 50. External matching output network; 51. Second 50Ω line; 52. Second DC blocking capacitor; 53. Second matching section; 54. Second quarter-wavelength line circuit; 55. Second filter circuit; 60, RFin; 70, RFout.

[0019] The embodiments of the present invention will be further described below with reference to the accompanying drawings. Detailed Implementation

[0020] To facilitate understanding of the present invention, a more complete description will be given below with reference to the accompanying drawings. Several embodiments of the invention are illustrated in the drawings. However, the invention can be implemented in many different forms and is not limited to the embodiments described herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete.

[0021] It should be noted that when a component is said to be "fixed to" another component, it can be directly on the other component or there may be an intervening component. When a component is said to be "connected to" another component, it can be directly connected to the other component or there may be an intervening component. The terms "vertical," "horizontal," "left," "right," and similar expressions used in this document are for illustrative purposes only.

[0022] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. The terminology used herein in the description of the invention is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

[0023] Please see Figure 1 The figure shows a C-band broadband high-power GaN RF power amplifier in an embodiment of the present invention, including an external matching input network 10, an input pre-matching network 20, a GaN chip parallel network 30, a pre-matching output network 40, and an external matching output network 50.

[0024] The external matching input network 10 is electrically connected to the input pre-matching network 20. The GaN chip parallel network 30 is electrically connected to the input pre-matching network 20 and the pre-matching output network 40, respectively. The pre-matching output network 40 is electrically connected to the external matching output network 50. The external matching input network 10 is used to connect the RFin60 radio frequency signal and suppress even-order harmonic signals and perform total reflection of the fundamental signal. The input pre-matching network 20 is used to suppress harmonics in the processed RFin60 radio frequency signal. The GaN chip parallel network 30 is used to increase power. The pre-matching output network 40 is used to increase the impedance of the die 31 and suppress higher-order harmonics. The external matching output network 50 is used for higher-order harmonic suppression and fundamental open circuit.

[0025] Specifically, in this embodiment, the external matching input network 10 includes a first 50Ω line 11, a first DC blocking capacitor 12, a first matching section 13, two first quarter-wavelength line circuits 14, and two first filter circuits 15. The first 50Ω line 11 is electrically connected to the first matching section 13 through the first DC blocking capacitor 12. The two first filter circuits 15 are respectively connected to the first matching section 13 through the two first quarter-wavelength line circuits 14. The first 50Ω line 11 is used to connect to the RFin60 radio frequency signal. The first matching section 13 is electrically connected to the input pre-matching network 20.

[0026] It should be noted that the first 50Ω line 11 is used to connect the RFin60 radio frequency signal; the first DC blocking capacitor 12 is used to isolate DC current and prevent current from flowing into RFin60 and causing a short circuit; the first matching section 13 mainly serves as an impedance transformer, transforming the 50Ω impedance at RFin60 into an input pre-matched conjugate impedance; the first quarter-wavelength line circuit 14 is used to suppress even harmonic signals of the input signal and to perform total reflection of the fundamental signal. The first quarter-wavelength line circuit 14 has a narrow circuit width to provide high impedance. The first filter circuit 15 is used to remove the influence of DC power supply on the radio frequency signal. The first filter circuit 15 and the first quarter-wavelength line circuit 14 form a power supply circuit to provide the gate voltage to the power transistor.

[0027] Specifically, in this embodiment, the input pre-matching network 20 includes an input pin 21 and a first LCL low-pass network 22. The input pin 21 is electrically connected to the external matching input network 10 and the first LCL low-pass network 22, respectively. The first LCL low-pass network 22 is electrically connected to the GaN chip parallel network 30.

[0028] It should be noted that input pin 21 originates from the inherent structure of the power transistor's input terminal and contains parasitic capacitance and inductance. The first LCL low-pass network 22 serves two purposes: first, it further transforms the output impedance of the external matching input network 10 to a smaller value. Due to the larger dielectric constant of the internal matching capacitor, its impedance transformation amplitude is greater, thus achieving impedance conjugate matching at the GaN die input terminal. Second, it provides high-order harmonic suppression; the inductive reactance of the inductor is... , Indicates the imaginary part. Represents pi (π). This represents the inductance; the impedance of an inductor is... ,in, The fundamental frequency. When the radio frequency signal is... At that time, The impedance is relatively large, so the signal passes through the first LCL low-pass network 22. When the RF signal is 2... Or 3 Even at higher harmonics, The value is close to 0Ω, which can effectively transmit high-order harmonics to the ground, thereby achieving the purpose of harmonic suppression.

[0029] Specifically, in this embodiment, the GaN chip parallel network 30 includes two sets of dies 31, which are electrically connected. One set of dies 31 is electrically connected to the input pre-matching network 20, and the other set of dies 31 is electrically connected to the pre-matching output network 40. The total gate width of the two sets of dies 31 is 24mm.

[0030] It should be noted that the GaN die 31 works by converting DC energy into AC energy. Its benefits are twofold: first, it doubles the power output; second, the two 24mm total gate width dies 31 have better heat dissipation than a single 48mm total gate width die 31.

[0031] Specifically, in this embodiment, the pre-matched output network 40 includes a second LCL low-pass network 41 and an output pin 42. The second LCL low-pass network 41 is electrically connected to the GaN chip parallel network 30, and the second LCL low-pass network 41 is electrically connected to the externally matched output network 50 through the output pin 42.

[0032] It should be noted that the second LCL low-pass network 41 serves to initially increase the impedance of the GaN die 31 and suppress high-order harmonics; the output pin 42 is from the output end of the die and also includes parasitic capacitance and parasitic inductance.

[0033] Specifically, in this embodiment, the external matching output network 50 includes a second 50Ω line 51, a second DC blocking capacitor 52, a second matching section 53, two second quarter-wavelength line circuits 54, and two second filter circuits 55. The second 50Ω line 51 is electrically connected to the second matching section 53 through the second DC blocking capacitor 52. The two second filter circuits 55 are respectively connected to the second matching section 53 through the two second quarter-wavelength line circuits 54. The second matching section 53 is electrically connected to the pre-matched output network 40. The second 50Ω line 51 is connected to RFOUT. The second matching section 53 adopts a multi-section T-shaped section.

[0034] It should be noted that the second matching section 53 of the multi-section T-type junction is used to match the impedance of the output pin 42 to around 50Ω throughout the entire frequency band; the second quarter-wavelength line circuit 54 is used to suppress high-order harmonics and open the fundamental frequency of the output signal; the second filter circuit 55 is used to remove the influence of the DC power supply on the RF signal. The second filter circuit 55 and the second quarter-wavelength line circuit 54 form a drain DC circuit to provide drain voltage to the power transistor. Both the first DC blocking capacitor 12 and the second DC blocking capacitor 52 block DC current.

[0035] It is worth noting that the C-band broadband high-power GaN RF power amplifier in this embodiment operates at a frequency of 4.8~6GHz, has a saturated output power of 200W, and a drain efficiency of 50%. The RF power amplifier consists of two parts: a pre-matched power transistor and an external matching circuit board. The pre-matched power transistor internally uses two GaNHEMT chips with a total gate width of 24mm connected in parallel. The input matching network inside the transistor adopts an LCL T-type architecture. This matching method increases the input impedance of the pre-matched power transistor. The output also uses an LCL T-type architecture to increase the output impedance. Appropriate L and C values ​​are used to make the increased input and output impedance values ​​more concentrated, reducing the area of ​​the external matching and lowering the impedance matching difficulty. On the external matching circuit board, there are multiple trapezoidal sections on the input and output matching sections to achieve broadband impedance matching. The input and output power supply microstrip lines use a 1 / 4 wavelength line harmonic suppression structure and a DC filter structure. When the transmission line length is 1 / 4 of the signal wavelength, the relationship between the input impedance and the load impedance is: ; in, Indicates input impedance. The characteristic impedance of the matching circuit. This indicates the load impedance. Since a capacitor is connected in parallel at the port of the 1 / 4 wavelength line near the DC terminal, thus... The value is close to 0 ohms, therefore Since the value is infinitely large, the connection between the RF circuit and the power supply arm forms an open circuit, preventing the RF signal from leaking out. Similarly, it can be deduced that at a frequency of 2fo, the connection between the RF circuit and the power supply arm forms a short circuit, allowing the second harmonic signal to be output, thereby improving the fundamental signal.

[0036] Additionally, please refer to the circuit schematic of the C-band broadband high-power GaN RF power amplifier in this embodiment of the invention. Figure 2 TL1-TL28 are microstrip line structures using high-frequency microwave board materials; C1 and C14 are DC blocking capacitors, surface-mount high-Q capacitors; C6-C9 are RF power transistor internal matching capacitors, bipolar planar capacitors made of high-dielectric-constant ceramic material; C3, C5, C11, and C13 are filter capacitors; C2, C4, C10, and C12 are bias capacitors, surface-mount capacitors; R1 and R2 are gate stabilizing resistors, surface-mount resistors; L1-L4 are pre-matched input inductors, and L5-L8 are pre-matched output inductors, using gold wire inductors. G1 and G2 are the same type of 24mm GaN chip. Figure 2From left to right, the circuit can be divided into the following parts: TL1, C1, and TL2 form the DC blocking current circuit at the input terminal; TL3, TL4, TL5, TL6, TL7, TL10, TL11, and TL12 form the input matching circuit; the input pins are the bridge connecting the external matching PCB and the internal matching PCB. R1, TL8, and C2 form the upper half of the gate bias circuit. TL8 is a quarter-wavelength line at 5.5G with a width of 0.5mm and a high characteristic impedance. R2, TL13, and C4 form the lower half of the gate bias circuit. TL14 and C5 form the lower half of the gate filter circuit. L1, C6, and L2 form the upper half low-pass matching network. L3, C7, and L4 form the lower half low-pass matching network. G1 and G2 form a parallel structure of the GaN chip, with the gate and drain interconnected to reduce the effect of phase difference. L5, C8, and L6 form the upper half output low-pass matching network, and L7, C9, and L8 form the lower half output low-pass matching network. The output pin is the bridge connecting the pre-matched output network and the externally matched output network. TL15, TL16, TL19-TL23, and TL26 form the external matching output matching section; TL17 and C10 form the upper half drain bias circuit; TL18 and C11 form the upper half filter circuit; TL24 and C12 form the lower half drain bias circuit; TL25 and C13 form the lower half drain filter circuit. TL27, C14, and TL28 form the output DC blocking circuit; the power supply uses separate power supplies for the upper and lower chips, with a gate voltage of -3.2V and a drain voltage of 28V.

[0037] In summary, the C-band broadband high-power GaN RF power amplifier in the above embodiments of the present invention utilizes internal matching to initially raise the impedance, and external matching with multiple matching sections to achieve full-band matching to 50Ω. The quarter-wavelength line improves the efficiency of the RF power amplifier, reduces the external matching area of ​​the RF power amplifier, and has a compact and simple structure, simplifying the design process of similar power amplifiers. Its high efficiency and small size make the present invention have important application prospects in communications, radar systems, and UAVs.

[0038] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0039] The embodiments described above are merely illustrative of several implementations of the present invention, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the invention patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these all fall within the protection scope of the present invention. Therefore, the protection scope of this invention patent should be determined by the appended claims.

Claims

1. A C-band wideband high-power GaN radio frequency power amplifier, characterized in that, This includes an external matching input network, an input pre-matching network, a GaN chip parallel network, a pre-matching output network, and an external matching output network. The external matching input network is electrically connected to the input pre-matching network, the GaN chip parallel network is electrically connected to the input pre-matching network and the pre-matching output network respectively, and the pre-matching output network is electrically connected to the external matching output network; The external matching input network is used to connect the RFin radio frequency signal and suppress even-order harmonic signals and perform total reflection of the fundamental signal. The input pre-matching network is used to suppress harmonics in the processed RFin radio frequency signal. The GaN chip parallel network is used to increase power. The pre-matching output network is used to increase the die impedance and suppress higher-order harmonics. The external matching output network is used for higher-order harmonic suppression and fundamental open circuit.

2. The C-band broadband high-power GaN RF power amplifier according to claim 1, characterized in that, The external matching input network includes a first 50Ω line, a first DC blocking capacitor, a first matching section, two first quarter-wavelength line circuits, and two first filter circuits. The first 50Ω line is electrically connected to the first matching section through the first DC blocking capacitor, and the two first filter circuits are respectively connected to the first matching section through the two first quarter-wavelength line circuits.

3. The C-band broadband high-power GaN RF power amplifier according to claim 2, characterized in that, The first 50Ω line is used to connect the RFin radio frequency signal, and the first matching section is electrically connected to the input pre-matching network.

4. The C-band broadband high-power GaN RF power amplifier according to claim 1, characterized in that, The input pre-matching network includes an input pin and a first LCL low-pass network. The input pin is electrically connected to the external matching input network and the first LCL low-pass network, respectively. The first LCL low-pass network is electrically connected to the GaN chip parallel network.

5. The C-band broadband high-power GaN RF power amplifier according to claim 1, characterized in that, The GaN chip parallel network includes two sets of dies, which are electrically connected. One set of dies is electrically connected to the input pre-matching network, and the other set of dies is electrically connected to the pre-matching output network.

6. The C-band broadband high-power GaN RF power amplifier according to claim 5, characterized in that, The total grid width of the two sets of dies is 24 mm.

7. The C-band broadband high-power GaN RF power amplifier according to claim 1, characterized in that, The pre-matched output network includes a second LCL low-pass network and an output pin. The second LCL low-pass network is electrically connected to the parallel network of the GaN chip, and the second LCL low-pass network is electrically connected to the externally matched output network through the output pin.

8. The C-band broadband high-power GaN RF power amplifier according to claim 1, characterized in that, The external matching output network includes a second 50Ω line, a second DC blocking capacitor, a second matching section, two second quarter-wavelength line circuits, and two second filter circuits. The second 50Ω line is electrically connected to the second matching section through the second DC blocking capacitor, and the two second filter circuits are respectively connected to the second matching section through the two second quarter-wavelength line circuits.

9. The C-band broadband high-power GaN RF power amplifier according to claim 8, characterized in that, The second matching section is electrically connected to the pre-matched output network, and the second 50Ω line is connected to RFOUT.

10. The C-band broadband high-power GaN RF power amplifier according to claim 8, characterized in that, The second matching section uses a multi-section T-shaped section.

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