Ultra-wideband high-performance radio frequency power amplifier based on gate-source nonlinearity

Abstract

The invention relates to an ultra-wideband high-performance radio frequency power amplifier based on gate source nonlinearity. One end of an SMA input connecting line is connected with a radio frequency signal source; the other end of the SMA input connecting line is connected with the input end of the input matching circuit; the output end of the input matching circuit is connected with the input end of the gate-source nonlinear control circuit; the output end of the gate-source nonlinear control circuit is connected with the gate of the power amplifier tube; the gate bias circuit is connected in parallel between the output end of the input matching circuit and the input end of the gate-source nonlinear control circuit; the drain electrode of the power amplifier tube is connected with the input end of the tuning circuit; the output end of the tuning circuit is connected with the input end of the output fundamental wave and harmonic wave matching circuit; the drain biasing circuit is connected in parallel between the output end of the tuning circuit and the input end of the output fundamental wave and harmonic wave matching circuit; the output end of the output fundamental wave and harmonic wave matching circuit is connected with one end of the SMA output connecting line; and the other end of the SMA output connecting line is a radio frequency signal output end. According to the invention, the ultra-wideband / multi-octave high-performance power amplifier is designed.

Description

Technical Field

[0001] The invention belongs to the field of communication technology, and in particular relates to an ultra-wideband high-performance radio frequency power amplifier based on gate-source nonlinearity. Background Art

[0002] RF power amplifiers are widely used in various fields. In satellite communications, RF PAs are used to amplify uplink signals to ensure that the signals can pass through the atmosphere, reach the satellite and maintain the stability of the communication link; in the Internet of Things, communication equipment needs to have good long-distance transmission capabilities and require ultra-long battery life; in wireless communications, RF power amplifiers are required to provide sufficient output power to meet specific communication standards and coverage, and need to amplify signals efficiently to reduce the heat dissipation pressure and power supply requirements of base stations. Regardless of the application field, the power and efficiency of RF power amplifiers are issues that are of great concern. If the input signal can be amplified to a certain level while obtaining sufficient efficiency, the overall performance of the system and the service life of the device will be improved. At the same time, with the increase in the application of RF circuits in broadband, more and more power modules are now required to achieve high efficiency and high power within a certain bandwidth, so high-performance broadband RF power amplifiers are very worthy of research.

[0003] The harmonic control amplifiers of the prior art, such as Class F and Class J amplifiers, have fixed fundamental and harmonic impedances, which limits their broadband realization. In order to solve this limitation, many continuous amplifiers have been proposed, such as continuous Class F amplifiers, continuous inverse Class F amplifiers, and continuous Class J amplifiers. However, since their second harmonic impedance still varies around the resistance circle, that is, the resistance is fixed and the reactance is variable, the impedance condition is still relatively harsh. The subsequently proposed extended continuous Class F amplifiers, extended continuous inverse Class F amplifiers, and extended continuous Class J amplifiers have the characteristics of variable resistance in their second harmonic impedance and fundamental impedance, further widening the impedance space. Since all the above-mentioned continuous amplifiers assume that the gate source has no nonlinear behavior, that is, all source harmonic impedances are short-circuited, which is impossible to achieve in broadband, and the second harmonic impedance of all the above-mentioned continuous amplifiers has no overlapping part with the fundamental impedance, it is theoretically impossible to achieve ultra-wideband and multi-octave amplifiers.

[0004] For example, the latest article "A Wideband High-Efficiency Continuous-Mode Class-GF-1 Power Amplifier With Second Harmonic Suppression" published by Hunan University scholar Huawei Wu in July 2024 reported a continuous inverse class F power amplifier with a controlled source second harmonic operating at 1.1 to 2 GHz. The power amplifier circuit structure given in the literature is as follows Figure 1As shown in the figure, the circuit consists of an input matching circuit, a gate bias circuit, a source second harmonic control circuit, a power amplifier transistor CGH40010F, a drain bias circuit, an output harmonic suppression circuit, and an output matching circuit. Based on the continuous inverse F-type theory, the author Huawei Wu analyzed the input nonlinearity γ and obtained a series of drain current waveforms, which were used to generate the impedance space of the power amplifier. By controlling the harmonics at the input and output ends, combined with the conjugate matching at the input end and the load line matching at the output end, power amplification was achieved. Figure 1 This is the circuit diagram of the power amplifier. Figure 2 is the impedance space diagram of the power amplifier, Figure 3 It is the large signal HB simulation diagram of the power amplifier.

[0005] The existing technical structure only performs gate-source nonlinear analysis on the continuous inverse F class power amplifier. The load impedance space obtained only expands the resistance part of the fundamental impedance, while the second harmonic still only expands the reactance component. The impedance space is still not wide enough, the matching difficulty is high, and it is difficult to achieve a larger bandwidth. It can be seen Figure 2 The impedance space of the fundamental impedance and the second harmonic impedance is far apart and has no overlap, which is impossible for the realization of ultra-wideband / cross-octave amplifiers, because the fundamental and second harmonic frequencies of cross-octave amplifiers will overlap, and it is impossible to achieve the matching of fundamental and second harmonic impedances at the same time for non-overlapping impedance space. The existing technical structure does not perfectly control the impedance of the second source harmonic, and there is mismatch behavior, which results in the amplifier efficiency still not being particularly high within the bandwidth of 0.9GHz, and the output power is low. Summary of the invention

[0006] In order to solve the problems existing in the background technology, the present invention discusses in detail the influence of the nonlinear factor γ and the resistive factor δ on the extended continuous F class and the distribution of its impedance space, and finds that the gate-source nonlinearity can expand the impedance space and improve the performance. Based on this, a new output fundamental wave and harmonic matching circuit is invented. Finally, the designed ultra-wideband power amplifier meets the theoretical basis and has the characteristics of high efficiency, high power and high gain.

[0007] In order to achieve the above technical objectives, the present invention provides the following technical solutions:

[0008] An ultra-wideband high-performance radio frequency power amplifier based on gate-source nonlinearity, comprising: an SMA input connection line, an input matching circuit, a gate bias circuit, a gate-source nonlinear control circuit, a power amplifier tube, a tuning circuit, a drain bias circuit, an output fundamental wave and harmonic matching circuit and an SMA output connection line;

[0009] One end of the SMA input connection line is connected to the radio frequency signal source; the other end of the SMA input connection line is connected to the input end of the input matching circuit;

[0010] The output end of the input matching circuit is connected to the input end of the gate-source nonlinear control circuit; the output end of the gate-source nonlinear control circuit is connected to the gate of the power amplifier tube;

[0011] The gate bias circuit is connected in parallel between the output end of the input matching circuit and the input end of the gate-source nonlinear control circuit;

[0012] The source of the power amplifier tube is grounded; the drain of the power amplifier tube is connected to the input end of the tuning circuit; the output end of the tuning circuit is connected to the input end of the output fundamental wave and harmonic matching circuit; the drain bias circuit is connected in parallel between the output end of the tuning circuit and the input end of the output fundamental wave and harmonic matching circuit; the output end of the output fundamental wave and harmonic matching circuit is connected to one end of the SMA output connecting line; the other end of the SMA output connecting line is the RF signal output end.

[0013] Preferably, the SMA input connection line and the SMA output connection line are formed by 50Ω microstrip lines.

[0014] Preferably, the input matching circuit includes: straight microstrip lines TL1~TL4 and a capacitor C1; one end of the capacitor C1 is connected to the input end of the input matching circuit; the other end of the capacitor C1 is connected to one end of the straight microstrip line TL1; the other end of the straight microstrip line TL1 is connected to one end of the straight microstrip line TL2; the other end of the straight microstrip line TL2 is connected to one end of the straight microstrip line TL3; the other end of the straight microstrip line TL3 is connected to one end of the straight microstrip line TL4; the other end of the straight microstrip line TL4 is connected to the output end of the input matching circuit.

[0015] Preferably, the gate-source nonlinear control circuit includes: straight microstrip lines TL6-TL7, a resistor R and a capacitor C2; one end of the straight microstrip line TL6 is connected to the input end of the gate-source nonlinear control circuit; the other end of the straight microstrip line TL6, one end of the resistor R and one end of the capacitor C2 are connected; the other end of the resistor R, the other end of the capacitor C2 and one end of the straight microstrip line TL7 are connected; the other end of the straight microstrip line TL7 is connected to the output end of the gate-source nonlinear control circuit.

[0016] Preferably, the gate bias circuit includes: a λ / 4 straight microstrip line TL5 and a capacitor C3; one end of the straight microstrip line TL5 is connected in parallel between the output end of the input matching circuit and the input end of the gate-source nonlinear control circuit; the other end of the straight microstrip line TL5 is connected to one end of the capacitor C3; the other end of the capacitor C3 is grounded.

[0017] Preferably, the tuning circuit includes: straight microstrip lines TL8, TL9, TL10 and TL11; the drain bias circuit includes: a straight microstrip line TL10 and a capacitor C4: one end of the straight microstrip line TL8 is connected to the input end of the tuning circuit; the other end of the straight microstrip line TL8 is connected to one end of the straight microstrip line TL9; the other end of the straight microstrip line TL9, one end of the straight microstrip line TL11 and the output end of the tuning circuit are connected; the load of the microstrip line TL11 is open; one end of the straight microstrip line TL10 is connected in parallel between the output end of the tuning circuit and the input end of the output fundamental wave and harmonic matching circuit; the other end of the straight microstrip line TL10 is connected to one end of the capacitor C4; the other end of the capacitor C4 is grounded.

[0018] Preferably, the output fundamental wave and harmonic matching circuit includes: straight microstrip lines TL12~TL17, capacitor C5, fan-shaped microstrip line MRSTUB1 and fan-shaped microstrip line MRSTUB2; one end of the straight microstrip line TL12 is connected to the input end of the output fundamental wave and harmonic matching circuit; the other end of the straight microstrip line TL12, one end of the straight microstrip line TL13 and one end of the straight microstrip line TL14 are connected; the other end of the straight microstrip line TL13 is connected to the fan-shaped microstrip line MRSTUB1; the other end of the straight microstrip line TL14, one end of the straight microstrip line TL15 and one end of the straight microstrip line TL16 are connected; the other end of the straight microstrip line TL15 is connected to the fan-shaped microstrip line MRSTUB2; the other end of the straight microstrip line TL16, one end of the straight microstrip line TL17 and one end of the capacitor C5 are connected; the other end of the straight microstrip line TL17 is open-circuited; the other end of the capacitor C5 is connected to the output end of the output fundamental wave and harmonic matching circuit.

[0019] The present invention has at least the following beneficial effects

[0020] The present invention combines gate-source nonlinearity with the extended continuous class F power amplifier theory, studies the influence of the nonlinear factor γ and the resistive factor δ on the power amplifier performance, and the Smith circle impedance distribution corresponding to the two factors, thereby more effectively utilizing the two factors to design a high-performance power amplifier; and finally verifies that the drain voltage and current of the designed power amplifier are in line with the gate-source nonlinear theory and the extended continuous class F theory, and reasonably controls the positive and negative of the nonlinear factor γ to expand the impedance space and improve the performance. The present invention designs a new output fundamental wave and harmonic matching circuit, uses the transmission zero introduced by series resonance to accelerate the process of the second harmonic moving to the Smith edge and uses a fan-shaped microstrip line to increase the bandwidth, and successfully designs an ultra-wideband / multi-octave high-performance power amplifier. The tuning circuit of the present invention utilizes the characteristics that the short-circuited microstrip line is equivalent to an inductor and the open-circuited microstrip line is equivalent to a capacitor, and can better tune the high and low frequency parts of the broadband second harmonic impedance to move to the high-performance area. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 This is a schematic diagram of the 1.1 to 2 GHz power amplifier circuit structure;

[0022] Figure 2 This is a schematic diagram of the impedance space of a 1.1 to 2 GHz power amplifier;

[0023] Figure 3 This is the large signal HB simulation diagram of 1.1 to 2 GHz power amplifier;

[0024] Figure 4 It is a schematic diagram of the overall circuit framework of the power amplifier of the present invention;

[0025] Figure 5 It is a schematic diagram of the overall circuit of the power amplifier of the present invention;

[0026] Figure 6 A schematic diagram of a circuit of an input matching circuit, a gate-source nonlinear control circuit and a gate bias circuit of the present invention;

[0027] Figure 7 A schematic diagram of a drain bias circuit, a tuning circuit, an output fundamental wave and a harmonic matching circuit of the present invention;

[0028] Figure 8 It is a schematic diagram of the impedance space of the extended class F power amplifier based on gate-source nonlinearity of the present invention;

[0029] Fig. 9 This is a large signal HB simulation diagram of the power amplifier of the present invention;

[0030] Fig.10 This is a time domain diagram of the drain voltage and current of the power amplifier of the present invention. DETAILED DESCRIPTION

[0031] The following describes the embodiments of the present invention by specific examples, and those skilled in the art can easily understand other advantages and effects of the present invention from the contents disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments, and the details in this specification can also be modified or changed in various ways based on different viewpoints and applications without departing from the spirit of the present invention. It should be noted that the illustrations provided in the following embodiments only illustrate the basic concept of the present invention in a schematic manner, and the following embodiments and features in the embodiments can be combined with each other without conflict.

[0032] Gate-source nonlinearity refers to the nonlinearity caused by the gate-source capacitance Cgs of the power amplifier transistor, which will apply a second harmonic voltage to the input ideal sinusoidal wave excitation, change the input voltage waveform reaching the intrinsic gate of the power amplifier tube, and then shape the drain current waveform through transconductance. This nonlinearity will change its half-sine waveform in the extended continuous class F power amplifier, thereby affecting the overlap between the drain current and the current waveform, thereby affecting the performance. The present invention finds that the gate-source nonlinear factor γ can expand the impedance space of the power amplifier and maintain or improve the performance of the power amplifier to a certain extent. The present invention conducts a detailed analysis of the nonlinear factor γ and the resistive factor δ and corresponds to their positions in the load impedance space. When the drain efficiency DE and the output power Pout can maintain a certain performance, the load impedance space is as follows: Figure 8 As shown, it can be seen that the fundamental impedance and the second harmonic impedance are almost completely overlapped, which provides a solid foundation for the ultra-wideband / multi-octave power amplifier of the present invention.

[0033] According to the research of the present invention, it is found that when the nonlinear factor γ is in the range of -1 to 1, the larger the nonlinear factor γ is, the better the power amplifier performance is. However, when the nonlinear factor γ is less than 0, the overlap of the second harmonic impedance and the fundamental impedance can be expanded. Moreover, when the resistive factor δ is in the range of 0 to 1, the smaller the resistive factor δ is, the better the power amplifier performance is. Therefore, a design idea of ​​0.5-3.1GHz ultra-wideband / multi-octave power amplifier can be conceived, in which the γ of 0.5Ghz-1.55GHz is less than 0 to provide the second harmonic impedance condition overlapping with the fundamental impedance, and the γ after 1.55GHz should be greater than 0 and the load second harmonic impedance should be moved to the edge of the Smith circle as much as possible to obtain a larger γ and a smaller δ.

[0034] Because the designed frequency band is in the microwave low frequency band, the loss of microstrip line in this frequency band is small, so the circuit is built with microstrip line. The invented ultra-wideband power amplifier includes microstrip line circuit, lumped elements and Rogers4350B dielectric substrate.

[0035] Embodiment 1, an ultra-wideband high-performance power amplifier based on gate-source nonlinearity, comprising a power amplifier branch, a power amplifier transistor CGH40010F and a dielectric plate Rogers4350B; the power amplifier branch sequentially comprises an SMA input connection line 1, an input matching circuit 2, a gate bias circuit 4, a gate-source nonlinear control circuit 3, a tuning circuit 6, a drain bias circuit 5, an output fundamental wave and harmonic matching circuit 7 and an SMA output connection line 8, Figure 4 It is the overall circuit framework diagram of the power amplifier of the present invention.

[0036] See also Figures 4 to 10The present invention provides an ultra-wideband high-performance radio frequency power amplifier based on gate-source nonlinearity, comprising: an SMA input connecting line, an input matching circuit, a gate bias circuit, a gate-source nonlinear control circuit, a power amplifier tube, a tuning circuit, a drain bias circuit, an output fundamental wave and harmonic matching circuit and an SMA output connecting line;

[0037] One end of the SMA input connection line is connected to the radio frequency signal source; the other end of the SMA input connection line is connected to the input end of the input matching circuit;

[0038] The output end of the input matching circuit is connected to the input end of the gate-source nonlinear control circuit; the output end of the gate-source nonlinear control circuit is connected to the gate of the power amplifier tube;

[0039] The gate bias circuit is connected in parallel between the output end of the input matching circuit and the input end of the gate-source nonlinear control circuit;

[0040] The source of the power amplifier tube is grounded; the drain of the power amplifier tube is connected to the input end of the tuning circuit; the output end of the tuning circuit is connected to the input end of the output fundamental wave and harmonic matching circuit; the drain bias circuit is connected in parallel between the output end of the tuning circuit and the input end of the output fundamental wave and harmonic matching circuit; the output end of the output fundamental wave and harmonic matching circuit is connected to one end of the SMA output connecting line; the other end of the SMA output connecting line is the RF signal output end.

[0041] See also Figure 4 and Figure 5 In this embodiment, the ultra-wideband / multi-octave power amplifier based on gate-source nonlinearity can achieve high-efficiency and high-gain power amplification. Its working principle is: the DC voltage supplies power to the power amplifier transistor through the gate bias circuit 4 and the drain bias circuit 5 to provide a suitable static operating point, and the RF input signal enters the amplifier circuit through the SMA input connection line 1. Since the input matching circuit 2 presents a conjugate impedance to the power amplifier tube, the maximum power transmission of the RF signal is achieved. In conjunction with the gate-source nonlinear control circuit 3, its intrinsic gate voltage is affected to shape the drain current. The tuning circuit 6 and the output fundamental and harmonic matching circuit 7 together provide the intrinsic current source plane. Figure 8 The appropriate fundamental and harmonic impedances are used to shape the drain voltage. At this time, the drain voltage and drain current are shaped as required to obtain the best performance, and the physical limitations of the transistor are taken into account to perform fundamental load line matching to maximize the voltage and current swings and increase the output power.

[0042] Preferably, the SMA input connection line and the SMA output connection line are formed by 50Ω microstrip lines to minimize the influence of the actual SMA welding on the input matching and output matching.

[0043] Preferably, the input matching circuit includes: straight microstrip lines TL1-TL4 and capacitor C1; one end of the capacitor C1 is connected to the input end of the input matching circuit; the other end of the capacitor C1 is connected to one end of the straight microstrip line TL1; the other end of the straight microstrip line TL1 is connected to one end of the straight microstrip line TL2; the other end of the straight microstrip line TL2 is connected to one end of the straight microstrip line TL3; the other end of the straight microstrip line TL3 is connected to one end of the straight microstrip line TL4; the other end of the straight microstrip line TL4 is connected to the output end of the input matching circuit. In this embodiment, the input matching circuit 2 is composed of straight microstrip lines TL1, TL2, TL3, TL4 and lumped element capacitor C1, the RF input signal enters from RFin, connected to the SMA input connection line, the SMA input connection line is connected to capacitor C1, capacitor C1 is connected to the straight microstrip line TL1, and then the straight microstrip lines TL2, TL3 and TL4 are connected in sequence. Capacitor C1 serves to isolate direct current, and the straight microstrip lines TL1, TL2, TL3 and TL4 serve to match the fundamental impedance to an impedance point conjugate with the input impedance of the transistor to achieve maximum power transmission.

[0044] Preferably, the gate-source nonlinear control circuit comprises: straight microstrip lines TL6-TL7, a resistor R and a capacitor C2; one end of the straight microstrip line TL6 is connected to the input end of the gate-source nonlinear control circuit; the other end of the straight microstrip line TL6, one end of the resistor R and one end of the capacitor C2 are connected; the other end of the resistor R, the other end of the capacitor C2 and one end of the straight microstrip line TL7 are connected; the other end of the straight microstrip line TL7 is connected to the output end of the gate-source nonlinear control circuit. In this embodiment, the gate-source nonlinear control circuit 3 is a circuit for tuning the source second harmonic impedance, adjusting the nonlinear factor γ to a required size to obtain a wider impedance space and a required drain current waveform. The gate-source nonlinear control circuit is composed of straight microstrip lines TL6, TL7, lumped element resistor R and capacitor C2. The left end of resistor R is connected to the upper right end of straight microstrip line TL6, the left end of capacitor C2 is connected to the lower right end of straight microstrip line TL6, the right end of resistor R is connected to the upper left end of straight microstrip line TL7, the right end of capacitor C2 is connected to the lower left end of straight microstrip line TL7, and then straight microstrip line TL7 is connected to the gate of power amplifier tube CGH40010F. Resistor R and capacitor C2 are responsible for adjusting the stability coefficient K of the power amplifier to be greater than 1, and straight microstrip lines TL6 and TL7 cooperate with input matching circuit 2 to adjust the nonlinear factor γ to the required size.

[0045] Preferably, the gate bias circuit comprises: a λ / 4 straight microstrip line TL5 and a capacitor C3; one end of the straight microstrip line TL5 is connected in parallel between the output end of the input matching circuit and the input end of the gate-source nonlinear control circuit; the other end of the straight microstrip line TL5 is connected to one end of the capacitor C3; the other end of the capacitor C3 is grounded. In this embodiment, the gate bias circuit 4 is composed of a λ / 4 straight microstrip line TL5 and a lumped element capacitor C3, C3 is a high Q capacitor resonating at 2.45GHz produced by Murata Company, to provide short-circuit impedance, which is transformed into an open-circuit impedance through the straight microstrip line TL5 to isolate the RF signal from the DC signal. Figure 6 It is a circuit diagram of an input matching circuit 2, a gate-source nonlinear control circuit 3 and a gate bias circuit 4.

[0046] Preferably, the tuning circuit 6 includes: straight microstrip lines TL8, TL9, TL10 and TL11; the drain bias circuit includes: a straight microstrip line TL10 and a capacitor C4: one end of the straight microstrip line TL8 is connected to the input end of the tuning circuit; the other end of the straight microstrip line TL8 is connected to one end of the straight microstrip line TL9; the other end of the straight microstrip line TL9, one end of the straight microstrip line TL11 and the output end of the tuning circuit are connected; the load of the microstrip line TL11 is open; one end of the straight microstrip line TL10 is connected in parallel between the output end of the tuning circuit and the input end of the output fundamental wave and harmonic matching circuit; the other end of the straight microstrip line TL10 is connected to one end of the capacitor C4; the other end of the capacitor C4 is grounded.

[0047] In this embodiment, the output fundamental wave and harmonic matching circuit 7 is composed of straight microstrip lines TL12, TL13, TL14, TL15, TL16, TL17, fan-shaped microstrip lines MRSTUB1, MRSUTB2 and lumped element capacitor C5. A series of straight microstrip line TL13 and fan-shaped microstrip line MRSTUB1 are connected in parallel between TL12 and TL14, and a series of straight microstrip line TL15 and fan-shaped microstrip line MRSTUB2 are connected in parallel between TL14 and TL16. This circuit cooperates with the tuning circuit 6 to match the fundamental wave impedance to Figure 4In the yellow area, the second harmonic impedance of 0.5GHz-1.55GHz reaches the overlap area of ​​yellow and gray, while the second harmonic of 1.55GHz-3.1GHz no longer overlaps with the fundamental wave, and is tuned to the edge of the Smith circle as much as possible to achieve higher performance. The series straight microstrip line TL13 and the fan-shaped microstrip line MRSTUB1, the series straight microstrip line TL15 and the fan-shaped microstrip line MRSTUB2 of the invented network introduce two transmission zeros at the second harmonic of 1.55-3.1GHz, so that the second harmonic impedance moves to the edge of the Smith circle more quickly, and due to the wideband characteristics of the fan-shaped microstrip line MRSTUB, the invented network has a wider bandwidth harmonic suppression and fundamental matching characteristics, and the capacitor C5 plays the role of isolating DC. The network makes full use of the principles in the technical solution, and utilizes the series resonance characteristics and the broadband characteristics of the fan-shaped line, which plays a role in promoting the realization of ultra-wideband high-performance power amplifiers.

[0048] Preferably, the output fundamental wave and harmonic matching circuit includes: straight microstrip lines TL12~TL17, capacitor C5, fan-shaped microstrip line MRSTUB1 and fan-shaped microstrip line MRSTUB2; one end of the straight microstrip line TL12 is connected to the input end of the output fundamental wave and harmonic matching circuit; the other end of the straight microstrip line TL12, one end of the straight microstrip line TL13 and one end of the straight microstrip line TL14 are connected; the other end of the straight microstrip line TL13 is connected to the fan-shaped microstrip line MRSTUB1; the other end of the straight microstrip line TL14, one end of the straight microstrip line TL15 and one end of the straight microstrip line TL16 are connected; the other end of the straight microstrip line TL15 is connected to the fan-shaped microstrip line MRSTUB2; the other end of the straight microstrip line TL16, one end of the straight microstrip line TL17 and one end of the capacitor C5 are connected; the other end of the straight microstrip line TL17 is open-circuited; the other end of the capacitor C5 is connected to the output end of the output fundamental wave and harmonic matching circuit.

[0049] The tuning circuit 6 is composed of straight microstrip lines TL8, TL9, TL10 and TL11. Since the impedance space in the technical solution is obtained for the current source plane, and the power amplifier tube is packaged, the impedance after the control of the network 7 and 8 is tuned to the impedance required by the current source plane by the tuning circuit 6. The straight microstrip line TL10 is terminated with a short-circuit capacitor C4, which can be equivalent to an inductor, and the straight microstrip line TL11 is terminated with an open circuit, which can be equivalent to a capacitor. The width and length of TL10 and TL11 are reasonably selected so that they can tune the low-frequency part and the high-frequency part of the second harmonic respectively, and then tune the fundamental wave and the second harmonic to the high-performance position of the impedance space through TL8 and TL9. Figure 7 It is a circuit diagram of a drain bias circuit 5, a tuning circuit 6, and an output fundamental wave and harmonic matching circuit 7.

[0050] The present invention designs an ultra-wideband high-performance RF power amplifier based on gate-source nonlinearity, combined with a new output fundamental wave and harmonic matching circuit, to achieve high power, high gain and high efficiency while expanding the bandwidth. The large signal electromagnetic simulation effect diagram at 0.5GHz-3.1GHz is shown in the figure below. Fig. 9 As shown, it can be seen that within the absolute bandwidth of 2.6GHz and the relative bandwidth of 144%, the drain efficiency DE is greater than 60.8%, the output power Pout is greater than 40.6dBm, and the large signal gain Gain is greater than 10.6dB. This achieves high power, high gain and high efficiency performance in ultra-wideband / multiple octaves, which is very meaningful. Compared with the latest literature "AWideband High-Efficiency Continuous-Mode Class-GF-1 Power Amplifier With Second Harmonic Suppression", which is also a microwave low-frequency band power amplifier, it also uses the theory of gate-source nonlinearity. Compared with this literature, the absolute bandwidth of the present invention is increased by 1.7GHz, the relative bandwidth is increased by 86%, and the bandwidth of this literature is less than one octave, while the present invention is multiple octaves; compared with the lowest simulated drain efficiency DE of this literature, it is increased by 0.8%, the saturated output power Pout is increased by 2.4dBm, and the large signal gain is also greater than 10dB. The drain voltage and drain current of the present invention conform to the gate-source nonlinear theory. In the range of 0.5 GHz to 1.55 GHz, γ < 0 is used to provide a load second harmonic overlapping with the fundamental wave, while γ > 0 after 1.55 GHz. The drain current and voltage waveforms at three frequencies of 1.0, 2.0 and 3.0 GHz are selected. It can be seen that the drain current has a double-sided peak at 1.0 GHz, which conforms to γ ​​< 0. The currents at 2.0 and 3.0 GHz are quasi-square waves, which conform to γ ​​> 0. Fig.10 shown.

[0051] In summary, the present invention combines gate-source nonlinearity with the extended continuous class F power amplifier theory, studies the influence of the nonlinear factor γ and the resistive factor δ on the power amplifier performance, and the Smith circle impedance distribution corresponding to the two factors, thereby more effectively utilizing the two factors to design a high-performance power amplifier; and finally verifies that the drain voltage and current of the designed power amplifier are in line with the gate-source nonlinear theory and the extended continuous class F theory, and reasonably controls the positive and negative of the nonlinear factor γ to expand the impedance space and improve the performance. The present invention designs a new output fundamental wave and harmonic matching circuit, uses the transmission zero introduced by series resonance to accelerate the process of the second harmonic moving to the Smith edge and uses the fan-shaped microstrip line to increase the bandwidth, and successfully designs an ultra-wideband / multi-octave high-performance power amplifier. The tuning circuit of the present invention utilizes the characteristics that the short-circuited microstrip line is equivalent to an inductor and the open-circuited microstrip line is equivalent to a capacitor, and can better tune the high and low frequency parts of the broadband second harmonic impedance to move to the high-performance area.

[0052] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solution of the present invention can be modified or replaced by equivalents without departing from the purpose and scope of the technical solution, which should be included in the scope of the claims of the present invention.

Claims

1. An ultra-wideband high-performance radio frequency power amplifier based on gate-source nonlinearity, characterized in that: include: SMA input connecting wire, input matching circuit, gate bias circuit, gate-source nonlinear control circuit, power amplifier tube, tuning circuit, drain bias circuit, output fundamental wave and harmonic matching circuit and SMA output connecting wire; One end of the SMA input connection line is connected to the radio frequency signal source; the other end of the SMA input connection line is connected to the input end of the input matching circuit; The output end of the input matching circuit is connected to the input end of the gate-source nonlinear control circuit; the output end of the gate-source nonlinear control circuit is connected to the gate of the power amplifier tube; The gate bias circuit is connected in parallel between the output end of the input matching circuit and the input end of the gate-source nonlinear control circuit; The source of the power amplifier tube is grounded; the drain of the power amplifier tube is connected to the input end of the tuning circuit; the output end of the tuning circuit is connected to the input end of the output fundamental wave and harmonic matching circuit; the drain bias circuit is connected in parallel between the output end of the tuning circuit and the input end of the output fundamental wave and harmonic matching circuit; the output end of the output fundamental wave and harmonic matching circuit is connected to one end of the SMA output connecting line; the other end of the SMA output connecting line is the RF signal output end.

2. The ultra-wideband high-performance RF power amplifier based on gate-source nonlinearity according to claim 1, characterized in that: The SMA input connection line and the SMA output connection line are formed by 50Ω microstrip lines.

3. The ultra-wideband high-performance RF power amplifier based on gate-source nonlinearity according to claim 1, characterized in that: The input matching circuit includes: straight microstrip lines TL1~TL4 and capacitor C1; one end of the capacitor C1 is connected to the input end of the input matching circuit; the other end of the capacitor C1 is connected to one end of the straight microstrip line TL1; the other end of the straight microstrip line TL1 is connected to one end of the straight microstrip line TL2; the other end of the straight microstrip line TL2 is connected to one end of the straight microstrip line TL3; the other end of the straight microstrip line TL3 is connected to one end of the straight microstrip line TL4; the other end of the straight microstrip line TL4 is connected to the output end of the input matching circuit.

4. The ultra-wideband high-performance RF power amplifier based on gate-source nonlinearity according to claim 1, characterized in that: The gate-source nonlinear control circuit includes: straight microstrip lines TL6-TL7, a resistor R and a capacitor C2; one end of the straight microstrip line TL6 is connected to the input end of the gate-source nonlinear control circuit; the other end of the straight microstrip line TL6, one end of the resistor R and one end of the capacitor C2 are connected; the other end of the resistor R, the other end of the capacitor C2 and one end of the straight microstrip line TL7 are connected; the other end of the straight microstrip line TL7 is connected to the output end of the gate-source nonlinear control circuit.

5. The ultra-wideband high-performance RF power amplifier based on gate-source nonlinearity according to claim 1, characterized in that: The gate bias circuit includes: a λ / 4 straight microstrip line TL5 and a capacitor C3; one end of the straight microstrip line TL5 is connected in parallel between the output end of the input matching circuit and the input end of the gate-source nonlinear control circuit; the other end of the straight microstrip line TL5 is connected to one end of the capacitor C3; the other end of the capacitor C3 is grounded.

6. The ultra-wideband high-performance RF power amplifier based on gate-source nonlinearity according to claim 1, characterized in that: The tuning circuit includes: straight microstrip lines TL8, TL9, TL10 and TL11; the drain bias circuit includes: straight microstrip line TL10 and capacitor C4: one end of the straight microstrip line TL8 is connected to the input end of the tuning circuit; the other end of the straight microstrip line TL8 is connected to one end of the straight microstrip line TL9; the other end of the straight microstrip line TL9, one end of the straight microstrip line TL11 and the output end of the tuning circuit are connected; the load of the microstrip line TL11 is open; one end of the straight microstrip line TL10 is connected in parallel between the output end of the tuning circuit and the input end of the output fundamental wave and harmonic matching circuit; the other end of the straight microstrip line TL10 is connected to one end of the capacitor C4; the other end of the capacitor C4 is grounded.

7. The ultra-wideband high-performance RF power amplifier based on gate-source nonlinearity according to claim 1, characterized in that: The output fundamental wave and harmonic matching circuit includes: straight microstrip lines TL12~TL17, capacitor C5, fan-shaped microstrip line MRSTUB1 and fan-shaped microstrip line MRSTUB2; one end of the straight microstrip line TL12 is connected to the input end of the output fundamental wave and harmonic matching circuit; the other end of the straight microstrip line TL12, one end of the straight microstrip line TL13 and one end of the straight microstrip line TL14 are connected; the other end of the straight microstrip line TL13 is connected to the fan-shaped microstrip line MRSTUB1; the other end of the straight microstrip line TL14, one end of the straight microstrip line TL15 and one end of the straight microstrip line TL16 are connected; the other end of the straight microstrip line TL15 is connected to the fan-shaped microstrip line MRSTUB2; the other end of the straight microstrip line TL16, one end of the straight microstrip line TL17 and one end of the capacitor C5 are connected; the other end of the straight microstrip line TL17 is open-circuited; the other end of the capacitor C5 is connected to the output end of the output fundamental wave and harmonic matching circuit.

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