Gate-source nonlinear power amplifier applied to microwave wireless energy transmission

Abstract

The invention relates to a gate source nonlinear power amplifier applied to microwave wireless energy transmission. 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 network is connected with the input end of the gate-source nonlinear control circuit; the gate bias circuit is connected in parallel between the output end of the input matching network and 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 source electrode of the power amplifier tube is grounded; the drain electrode of the power amplifier tube is connected with the input end of the parasitic compensation circuit; the output end of the parasitic compensation circuit is connected with the input end of the output matching network; the drain bias circuit and the output harmonic suppression circuit are connected in parallel between the output end of the parasitic compensation circuit and the input end of the output matching network; the output end of the output matching network 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.

Description

Technical Field

[0001] The invention belongs to the field of communication technology, and in particular relates to a gate-source nonlinear power amplifier applied to microwave wireless energy transmission. Background Art

[0002] RF Power Amplifier (RF PA) is a key component in RF microwave systems. Its main function is to efficiently amplify low-power RF signals to a sufficient power level so that they can be effectively radiated through antennas. It plays an indispensable role in the field of microwave wireless power transmission (MWPT) and has great application potential in narrowband Internet, mobile communication base stations, wireless LANs, satellite communications, radio stations and radar systems.

[0003] In the field of microwave wireless energy transmission, the RF power amplifier is responsible for converting electrical energy into high-frequency electromagnetic waves, thereby realizing wireless energy transmission. Power and efficiency are the main performance indicators for judging wireless energy transmission modules. As the main energy-consuming component in wireless energy transmission, the efficiency of the power amplifier has an important impact on the performance and energy consumption of the entire system. Low efficiency means that more energy is converted into heat instead of being used to amplify signals, which will increase energy consumption and shorten battery life; insufficient power means limited transmission distance and insufficient energy transmission capacity, and may lead to reduced system reliability. Therefore, it is expected that the RF power amplifier used in wireless energy transmission has high performance with high efficiency and high output power. Traditional linear RF power amplifiers such as Class A and Class AB have relatively low efficiency, while traditional switching and harmonic tuning amplifiers such as Class F power amplifiers have improved efficiency, but the output power may be relatively low when achieving high efficiency.

[0004] For example, Mohammad Jamshidi, a scholar at the University of Pilsen in West Bohemia, published an article titled "Using an ANN Approach to Estimate Output Power and PAE of AModified Class-F Power Amplifier" reporting a Class F power amplifier operating at 900MHz. The power amplifier circuit structure given in the literature is as follows: Figure 1 As shown in FIG. 1 , the circuit consists of an input matching circuit (TL1, TL2, and TL3), a gate bias circuit (TL4 and TL5), a power amplifier transistor, a drain bias circuit (TL6 and TL7), an output harmonic suppression circuit (TL10), and an output matching circuit (TL8 and TL9). The power amplifier uses the output waveform engineering theory and achieves the open-circuit and short-circuit harmonic impedance requirements of the package surface through harmonic control at the output end, and realizes power amplification by combining the conjugate matching at the input end and the load line matching at the output end. Figure 2 This is the large signal HB simulation effect diagram of the circuit. Figure 3 This is the time domain diagram of the drain voltage and current waveform of the power amplifier. The gate-source end of this structure only performs conjugate matching of the fundamental wave, and does not pay attention to the impact of the nonlinearity of the gate-source end on the performance of the Class F power amplifier, which will cause the performance of the single-frequency power amplifier to be degraded to a large extent, which is not conducive to achieving high power and high efficiency of the power amplifier. At the same time, although the above power amplifier has achieved good performance, it does not conform to the proposed theory. Figure 3 In the process, since the harmonic suppression is aimed at the packaging plane of the transistor, the drain voltage waveform does not present the square wave shape of the Class F power amplifier, which leads to an increase in the product of the drain voltage and the traditional half-sinusoidal drain current waveform, that is, an increase in DC loss, resulting in a decrease in efficiency. Summary of the invention

[0005] In order to solve the problems existing in the background technology, the present invention utilizes the gate-source nonlinearity theory and combines it with the class F power amplifier theory to innovatively design a narrowband power amplifier operating at 2.45 GHz to maximize the performance of combining high power and high efficiency, so as to improve the energy transmission capacity of the wireless energy transmission system, the battery life and the reliability of the system. At the same time, the drain terminal voltage and current waveform conforms to the gate-source nonlinearity and class F power amplifier theory.

[0006] In order to achieve the above technical objectives, the present invention provides the following technical solution, a gate-source nonlinear power amplifier applied to microwave wireless energy transmission, comprising:

[0007] SMA input connecting wire, input matching circuit, gate bias circuit, gate-source nonlinear control circuit, power amplifier tube, parasitic compensation circuit, drain bias circuit, output harmonic suppression circuit, output matching circuit and SMA output connecting wire;

[0008] 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 network is connected to the input end of the gate-source nonlinear control circuit; the gate bias circuit is connected in parallel between the output end of the input matching network and the input end of the gate-source nonlinear control circuit;

[0009] The output terminal of the gate-source nonlinear control circuit is connected to the gate of the power amplifier tube; the source of the power amplifier tube is grounded;

[0010] The drain of the power amplifier tube is connected to the input end of the parasitic compensation circuit, and the output end of the parasitic compensation circuit is connected to the input end of the output matching network;

[0011] The drain bias circuit and the output harmonic suppression circuit are connected in parallel between the output end of the parasitic compensation circuit and the input end of the output matching network;

[0012] The output end of the output matching network 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 both formed by 50Ω microstrip lines.

[0014] Preferably, the input matching circuit includes: straight microstrip lines TL1~TL4, a resistor R and a capacitor C1; one end of the straight microstrip line TL1, one end of the straight microstrip line TL2 and one end of the straight microstrip line TL3 are connected; the other end of the straight microstrip line TL2 is open-circuited; the other end of the straight microstrip line TL1 is connected to the input end of the input matching circuit; the other end of the straight microstrip line TL3, one end of the resistor R and one end of the capacitor C1 are connected; the other end of the resistor R, the other end of the capacitor C1 and one end of the straight microstrip line TL4 are connected; 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 line branches TL6~TL8; one end of the straight microstrip line TL6, one end of the straight microstrip line TL7 and one end of the straight microstrip line TL8 are connected; the other 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 TL8 is connected to the output end of the gate-source nonlinear control circuit; the other end of the straight microstrip line TL7 is open-circuited.

[0016] Preferably, the gate bias circuit comprises: a λ / 4 straight microstrip line TL5 and a capacitor C2; one end of the capacitor C2 is grounded; the other end of the capacitor C2 is connected to one end of the straight microstrip line TL5; the other end of the straight microstrip line TL5 is connected in parallel between the output end of the input matching network and the input end of the gate-source nonlinear control circuit.

[0017] Preferably, the drain bias circuit includes: a fan-shaped microstrip line MRSTUB2 resonating at 4.9 GHz, a straight microstrip line TL11 and a capacitor C3; one end of the capacitor C3 is grounded, and the other end of the capacitor C3, one end of the straight microstrip line TL11 and the fan-shaped microstrip line MRSTUB2 are connected; the other end of the microstrip line TL11 is connected in parallel between the output end of the parasitic compensation circuit and the input end of the output matching network.

[0018] Preferably, the parasitic compensation circuit includes: straight microstrip lines TL9~TL10 and a fan-shaped microstrip line MRSTUB1; one end of the straight microstrip line TL9, one end of the straight microstrip line TL10 and the fan-shaped microstrip line MRSTUB1 are connected; the other end of the straight microstrip line TL9 is connected to the input end of the parasitic compensation circuit; the other end of the straight microstrip line TL10 is connected to the output end of the parasitic compensation circuit.

[0019] Preferably, the output harmonic suppression circuit comprises: a straight microstrip line TL12, one end of the straight microstrip line TL12 is connected in parallel between the output end of the parasitic compensation circuit and the input end of the output matching network, and the other end of the straight microstrip line TL12 is open-circuited.

[0020] Preferably, the output matching circuit includes: straight microstrip lines TL13~TL15, and tapered microstrip lines TAPER1~TAPER2; one end of the straight microstrip line TL13 is connected to the wide end of the tapered microstrip line TAPER1; the narrow end of the tapered microstrip line TAPER1 is connected to one end of the straight microstrip line TL14; the other end of the straight microstrip line TL14 is connected to the wide end of the tapered microstrip line TAPER2; the narrow end of the tapered microstrip line TAPER2 is connected to one end of the straight microstrip line TL15.

[0021] The present invention has at least the following beneficial effects

[0022] The present invention combines gate-source nonlinearity with the theory of class F power amplifiers, and innovatively applies it to the design practice of narrowband power amplifiers; the drain current is shaped into a quasi-square wave waveform by using a gate-source nonlinear control circuit, and the degree of overlap with the square wave voltage of the class F power amplifier is significantly reduced, thereby improving the output power and power added efficiency, so as to be better used in wireless energy transmission. The present invention mixes lumped and distributed parameters, and designs a drain bias circuit to reduce the harmonic impedance offset caused by actual welding errors and thus affect the output efficiency, and due to this hybrid design, the microstrip can be folded to reduce the size in the vertical direction. The output matching circuit of the present invention combines a straight microstrip line with a tapered microstrip line to reduce the reflection caused by the direct connection of the straight microstrip line to improve the output power and gain. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 This is the circuit structure diagram of the 900MHz power amplifier;

[0024] Figure 2 This is the simulation effect diagram of HB power amplifier at 900MHz;

[0025] Figure 3 This is the time domain diagram of the drain voltage and current of the 900MHz power amplifier;

[0026] Figure 4It is a schematic diagram of the overall circuit framework of the present invention;

[0027] Figure 5 The overall circuit diagram of the present invention is

[0028] Figure 6 A circuit diagram of input matching, gate-source nonlinear control and gate biasing of the present invention;

[0029] Figure 7 A circuit diagram of drain bias, parasitic compensation, harmonic suppression and output matching of the present invention;

[0030] Figure 8 This is a large signal electromagnetic simulation effect diagram of the gate-source nonlinear power amplifier of the present invention;

[0031] Fig. 9 It is a time domain diagram of the drain voltage and current of the gate-source nonlinear power amplifier of the present invention. DETAILED DESCRIPTION

[0032] 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.

[0033] The gate-source end of the prior art structure only performs conjugate matching of the fundamental wave, but does not pay attention to the impact of the nonlinearity of the gate-source end on the performance of the Class F power amplifier, which will cause the performance of the single-frequency power amplifier to be greatly degraded, which is not conducive to achieving high power and high efficiency of the power amplifier.

[0034] Although the power amplifier of the prior art has achieved good performance, it does not conform to the proposed theory. Figure 3 In the process, since the harmonic suppression is aimed at the packaging plane of the transistor, the drain voltage waveform does not present the square wave shape of the Class F power amplifier, which leads to an increase in the product of the drain voltage and the traditional half-sinusoidal drain current waveform, that is, an increase in DC loss, resulting in a decrease in efficiency.

[0035] The present invention utilizes the gate-source nonlinearity theory and combines it with the class F power amplifier theory to innovatively design a narrowband power amplifier operating at 2.45 GHz to maximize the performance of combining high power and high efficiency, so as to improve the energy transmission capacity of the wireless energy transmission system, the battery life and the reliability of the system. At the same time, the drain terminal voltage and current waveforms conform to the gate-source nonlinearity and class F power amplifier theory.

[0036] See also Figures 4 to 9 The present invention provides a gate-source nonlinear power amplifier for microwave wireless energy transmission, comprising:

[0037] SMA input connecting wire, input matching circuit, gate bias circuit, gate-source nonlinear control circuit, power amplifier tube, parasitic compensation circuit, drain bias circuit, output harmonic suppression circuit, output matching circuit and SMA output connecting wire;

[0038] 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 network is connected to the input end of the gate-source nonlinear control circuit; the gate bias circuit is connected in parallel between the output end of the input matching network and the input end of the gate-source nonlinear control circuit;

[0039] The output terminal of the gate-source nonlinear control circuit is connected to the gate of the power amplifier tube; the source of the power amplifier tube is grounded;

[0040] The drain of the power amplifier tube is connected to the input end of the parasitic compensation circuit, and the output end of the parasitic compensation circuit is connected to the input end of the output matching network;

[0041] The drain bias circuit and the output harmonic suppression circuit are connected in parallel between the output end of the parasitic compensation circuit and the input end of the output matching network;

[0042] The output end of the output matching network 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.

[0043] See also Figure 4 and Figure 5In this embodiment, 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 the semi-sine waveform of the traditional class F power amplifier in the class F power amplifier, thereby affecting the overlap between the drain current and the current waveform, thereby affecting the performance. Gate-source nonlinearity has both positive and negative effects. By tuning the source second harmonic impedance, the gate-source nonlinearity can be controlled to improve the performance to a certain extent. Because the designed frequency band is in the low-frequency band of microwaves, the microstrip line has a small loss in this frequency band, so a microstrip line is used to build the circuit. The invented power amplifier includes: a microstrip line circuit and a Rogers4350B dielectric substrate. A high-power and high-efficiency power amplifier based on gate-source nonlinearity comprises: a power amplifier branch, a power amplifier transistor CG2H40010F and a dielectric plate; the power amplifier branch sequentially comprises an SMA input connection line 1, an input matching circuit 2, a gate-source nonlinear control circuit 3, a gate bias circuit 4, a drain bias circuit 5, a parasitic compensation circuit 6, an output harmonic suppression circuit 7, an output matching circuit 8 and an SMA output connection line 9, Figure 4 The figure is the overall circuit structure diagram of the power amplifier. The class F power amplifier based on gate-source nonlinearity can achieve high-performance 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. 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 parasitic compensation network 6 and the output harmonic suppression circuit 7 provide suitable short-circuit and open-circuit harmonic impedances for the intrinsic current source plane to shape the drain voltage. At this time, both the drain voltage and the drain current are shaped to reduce DC losses and improve amplification efficiency. The output matching 8 takes into account the physical limitations of the transistor to perform load line matching to maximize the voltage and current swings and increase the output power.

[0044] Preferably, the SMA input connection line and the SMA output connection line are both formed by 50Ω microstrip lines to minimize the impact of the SMA on input matching and output matching during actual welding.

[0045] See also Figure 6Preferably, the input matching circuit includes: straight microstrip lines TL1~TL4, a resistor R and a capacitor C1; one end of the straight microstrip line TL1, one end of the straight microstrip line TL2 and one end of the straight microstrip line TL3 are connected; the other end of the straight microstrip line TL2 is open-circuited; the other end of the straight microstrip line TL1 is connected to the input end of the input matching circuit; the other end of the straight microstrip line TL3, one end of the resistor R and one end of the capacitor C1 are connected; the other end of the resistor R, the other end of the capacitor C1 and one end of the straight microstrip line TL4 are connected; the other end of the straight microstrip line TL4 is connected to the output end of the input matching circuit.

[0046] In this embodiment, the straight microstrip lines TL1-TL4 play the role of matching the fundamental impedance to the impedance point conjugate with the input impedance of the power amplifier tube to achieve maximum power transmission. At the same time, the lumped elements R and C1 are used to stabilize the amplifier circuit and also match the fundamental impedance.

[0047] Preferably, the gate-source nonlinear control circuit includes: straight microstrip line branches TL6~TL8; one end of the straight microstrip line TL6, one end of the straight microstrip line TL7 and one end of the straight microstrip line TL8 are connected; the other 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 TL8 is connected to the output end of the gate-source nonlinear control circuit; the other end of the straight microstrip line TL7 is open-circuited.

[0048] In this embodiment, the gate-source nonlinear control circuit 3 is a new type of nonlinear control circuit, that is, the source second harmonic impedance is tuned to shape the drain current waveform into a quasi-square wave shape. The gate-source end of the traditional circuit simply controls the second harmonic impedance to the short-circuit point or does not control the second harmonic impedance, which may lead to degradation of the power amplifier performance. The gate-source nonlinear control circuit is composed of TL6, TL7 and TL8, wherein TL7 moves the second source harmonic impedance to the vicinity of the short-circuit point, and then tunes the source second harmonic impedance through TL6 and TL8 to make the nonlinear factor greater than 0, shaping the drain current waveform into a quasi-square wave shape, and the nonlinear control circuit will further optimize the fundamental impedance.

[0049] Preferably, the gate bias circuit comprises: a λ / 4 straight microstrip line TL5 and a capacitor C2; one end of the capacitor C2 is grounded; the other end of the capacitor C2 is connected to one end of the straight microstrip line TL5; the other end of the straight microstrip line TL5 is connected in parallel between the output end of the input matching network and the input end of the gate-source nonlinear control circuit.

[0050] In this embodiment, the gate bias circuit 4 is composed of a transmission line TL5 and a lumped element C2. C2 is a high-Q capacitor resonating at 2.45 GHz produced by Murata Corporation to provide short-circuit impedance, which is transformed into open-circuit impedance through the transmission line TL5 to isolate RF signals from DC signals. Figure 5 It is a circuit diagram of the input matching circuit 2, the gate-source nonlinear control circuit 3 and the gate bias circuit 4.

[0051] Preferably, the drain bias circuit includes: a fan-shaped microstrip line MRSTUB2 resonating at 4.9 GHz, a straight microstrip line TL11 and a capacitor C3; one end of the capacitor C3 is grounded, and the other end of the capacitor C3, one end of the straight microstrip line TL11 and the fan-shaped microstrip line MRSTUB2 are connected; the other end of the microstrip line TL11 is connected in parallel between the output end of the parasitic compensation circuit and the input end of the output matching network.

[0052] In this embodiment, the drain bias circuit 5 is composed of a new type of distributed and lumped mixed parameters to achieve the functions of harmonic suppression and isolation of RF and DC signals at the same time. On the one hand, since the lumped parameter capacitor model may deviate from the actual one and the manual welding of the capacitor may cause harmonic impedance offset, thereby causing the wrong shaping of the drain voltage waveform, this invention uses the advantage of distributed parameters without welding to make the fan-shaped microstrip line MRSTUB2 resonate at 4.9GHz, and transform the second harmonic impedance into a short circuit through TL11; on the other hand, because a filter capacitor will also be designed near the DC power supply, isolating the RF signal from the DC signal only requires a relatively large impedance, and does not require a perfect open circuit point, and the size of the fan-shaped microstrip line resonating at 2.45GHz will be much larger than MRSTUB2, which is not conducive to the folding of the TL11 microstrip line, so the lumped element C3 is selected to provide the impedance near the short circuit point, which is transformed into an open circuit impedance through TL11 to isolate the RF signal from the DC signal. This drain bias circuit can not only isolate the RF signal from the DC signal, but also suppress the second harmonic impedance, and can greatly reduce the vertical size of the circuit by folding TL11.

[0053] Preferably, the parasitic compensation circuit includes: straight microstrip lines TL9~TL10 and a fan-shaped microstrip line MRSTUB1; one end of the straight microstrip line TL9, one end of the straight microstrip line TL10 and the fan-shaped microstrip line MRSTUB1 are connected; the other end of the straight microstrip line TL9 is connected to the input end of the parasitic compensation circuit; the other end of the straight microstrip line TL10 is connected to the output end of the parasitic compensation circuit.

[0054] The parasitic compensation circuit 6 is composed of a mixture of novel straight microstrip lines TL9 and TL10 and a fan-shaped microstrip line MRSTUB1. The overall circuit is in a "T" shape to achieve the second harmonic short circuit and the third harmonic open circuit of the intrinsic current source plane.

[0055] Preferably, the output harmonic suppression circuit comprises: a straight microstrip line TL12, one end of which is connected in parallel between the output end of the parasitic compensation circuit and the input end of the output matching circuit, and the other end of the straight microstrip line TL12 is open-circuited. The harmonic suppression circuit 7 is composed of TL12 to suppress the third harmonic impedance.

[0056] Preferably, the output matching circuit includes: straight microstrip lines TL13~TL15, and tapered microstrip lines TAPER1~TAPER2; one end of the straight microstrip line TL13 is connected to the wide end of the tapered microstrip line TAPER1; the narrow end of the tapered microstrip line TAPER1 is connected to one end of the straight microstrip line TL14; the other end of the straight microstrip line TL14 is connected to the wide end of the tapered microstrip line TAPER2; the narrow end of the tapered microstrip line TAPER2 is connected to one end of the straight microstrip line TL15.

[0057] The output matching circuit 8 is composed of straight microstrip lines TL13, TL14 and TL15 and tapered microstrip lines TAPER1 and TAPER2. Because the widths of the straight microstrip lines are different, that is, the impedances are different, direct connection may cause signal reflection due to impedance discontinuity. Connecting the straight microstrip lines with tapered microstrip lines can reduce such reflection and participate in the matching of fundamental impedance. Figure 7 It is a circuit diagram of a drain bias circuit 5, a parasitic compensation circuit 6, a harmonic suppression circuit 7 and an output matching circuit 8.

[0058] This invention proposes a high-power and high-efficiency power amplifier for wireless energy transmission. Combining gate-source nonlinear theory and Class F power amplifier theory, this invention innovatively designs a narrowband power amplifier. Compared with traditional narrowband power amplifiers and broadband power amplifiers, this invention maximizes the output power and conversion efficiency of the target frequency. The large signal electromagnetic simulation effect diagram at 2.45GHz is shown in the figure below. Figure 8As shown, it can be seen that in the large input range of 23dBm (0.2W)-35dBm (3.16W), the output power is greater than 40dBm (10W), and when the input power is 28.5dBm (0.7W), the output power is amplified to 41.8dBm (15.1W), and the power added efficiency (PAE) at this time is 75.1%, which achieves high power and high efficiency performance, and has a good large signal gain. Compared with the simulation effect of the F-class power amplifier literature "Usingan ANN Approach to Estimate Output Power and PAE of AModified Class-F Power Amplifier" in the same microwave low-frequency band, the saturated power is increased by more than 10dBm, and the PAE at this time is increased by 7%. The drain voltage of the present invention is a square wave, and the drain current is a quasi-square wave, and the overlap between the two is very small, which is consistent with the theory of square wave voltage and quasi-square wave current with gate-source nonlinear factor greater than 0 of the F-class power amplifier, indicating that the new theory of the present invention is combined and applied to the practice of narrow-band power amplifiers and can be used to design high-power and high-efficiency amplifiers. The time domain diagram is shown in FIG. Fig. 9 As shown in the figure, compared with the literature "Using an ANN Approach to Estimate Output Power and PAE of AModified Class-F Power Amplifier", the waveform results are more consistent with the theory, and the degree of overlap is reduced.

[0059] In summary, the present invention combines gate-source nonlinearity with the theory of class F power amplifiers, and innovatively applies it to the design practice of narrowband power amplifiers; the gate-source nonlinear control circuit is used to shape the drain current into a quasi-square wave waveform, and the degree of overlap with the square wave voltage of the class F power amplifier is significantly reduced, thereby improving the output power and power added efficiency, so as to be better used in wireless energy transmission. The present invention mixes lumped and distributed parameters, and designs a drain bias circuit to reduce the harmonic impedance offset caused by actual welding errors and thus affect the output efficiency, and due to this hybrid design, the microstrip can be folded to reduce the size in the vertical direction. The output matching circuit of the present invention combines a straight microstrip line with a tapered microstrip line to reduce the reflection caused by the direct connection of the straight microstrip line to improve the output power and gain.

[0060] 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. A gate-source nonlinear power amplifier for microwave wireless energy transmission, characterized in that: include: SMA input connecting wire, input matching circuit, gate bias circuit, gate-source nonlinear control circuit, power amplifier tube, parasitic compensation circuit, drain bias circuit, output harmonic suppression circuit, output 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 network is connected to the input end of the gate-source nonlinear control circuit; the gate bias circuit is connected in parallel between the output end of the input matching network and the input end of the gate-source nonlinear control circuit; The output terminal of the gate-source nonlinear control circuit is connected to the gate of the power amplifier tube; the source of the power amplifier tube is grounded; The drain of the power amplifier tube is connected to the input end of the parasitic compensation circuit, and the output end of the parasitic compensation circuit is connected to the input end of the output matching network; The drain bias circuit and the output harmonic suppression circuit are connected in parallel between the output end of the parasitic compensation circuit and the input end of the output matching network; The output end of the output matching network 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. A gate-source nonlinear power amplifier for microwave wireless energy transmission according to claim 1, characterized in that: The SMA input connection line and the SMA output connection line are both formed by 50Ω microstrip lines.

3. The gate-source nonlinear power amplifier for microwave wireless energy transmission according to claim 1, characterized in that: The input matching circuit includes: straight microstrip lines TL1~TL4, a resistor R and a capacitor C1; one end of the straight microstrip line TL1, one end of the straight microstrip line TL2 and one end of the straight microstrip line TL3 are connected; the other end of the straight microstrip line TL2 is open-circuited; the other end of the straight microstrip line TL1 is connected to the input end of the input matching circuit; the other end of the straight microstrip line TL3, one end of the resistor R and one end of the capacitor C1 are connected; the other end of the resistor R, the other end of the capacitor C1 and one end of the straight microstrip line TL4 are connected; the other end of the straight microstrip line TL4 is connected to the output end of the input matching circuit.

4. The gate-source nonlinear power amplifier for microwave wireless energy transmission according to claim 1, characterized in that: The gate-source nonlinear control circuit includes: straight microstrip line branches TL6~TL8; one end of the straight microstrip line TL6, one end of the straight microstrip line TL7 and one end of the straight microstrip line TL8 are connected; the other 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 TL8 is connected to the output end of the gate-source nonlinear control circuit; the other end of the straight microstrip line TL7 is open-circuited.

5. The gate-source nonlinear power amplifier for microwave wireless energy transmission according to claim 1, characterized in that: The gate bias circuit includes: a λ / 4 straight microstrip line TL5 and a capacitor C2; one end of the capacitor C2 is grounded; the other end of the capacitor C2 is connected to one end of the straight microstrip line TL5; the other end of the straight microstrip line TL5 is connected in parallel between the output end of the input matching network and the input end of the gate-source nonlinear control circuit.

6. The gate-source nonlinear power amplifier for microwave wireless energy transmission according to claim 1, characterized in that: The drain bias circuit includes: a fan-shaped microstrip line MRSTUB2 resonating at 4.9 GHz, a straight microstrip line TL11 and a capacitor C3; one end of the capacitor C3 is grounded, and the other end of the capacitor C3, one end of the straight microstrip line TL11 and the fan-shaped microstrip line MRSTUB2 are connected; the other end of the microstrip line TL11 is connected in parallel between the output end of the parasitic compensation circuit and the input end of the output matching network.

7. The gate-source nonlinear power amplifier for microwave wireless energy transmission according to claim 1, characterized in that: The parasitic compensation circuit includes: straight microstrip lines TL9~TL10 and a fan-shaped microstrip line MRSTUB1; one end of the straight microstrip line TL9, one end of the straight microstrip line TL10 and the fan-shaped microstrip line MRSTUB1 are connected; the other end of the straight microstrip line TL9 is connected to the input end of the parasitic compensation circuit; the other end of the straight microstrip line TL10 is connected to the output end of the parasitic compensation circuit.

8. The gate-source nonlinear power amplifier for microwave wireless energy transmission according to claim 1, characterized in that: The output harmonic suppression circuit includes: a straight microstrip line TL12, one end of the straight microstrip line TL12 is connected in parallel between the output end of the parasitic compensation circuit and the input end of the output matching circuit, and the other end of the straight microstrip line TL12 is open-circuited.

9. The gate-source nonlinear power amplifier for microwave wireless energy transmission according to claim 1, characterized in that: The output matching circuit includes: straight microstrip lines TL13~TL15, and tapered microstrip lines TAPER1~TAPER2; one end of the straight microstrip line TL13 is connected to the wide end of the tapered microstrip line TAPER1; the narrow end of the tapered microstrip line TAPER1 is connected to one end of the straight microstrip line TL14; the other end of the straight microstrip line TL14 is connected to the wide end of the tapered microstrip line TAPER2; the narrow end of the tapered microstrip line TAPER2 is connected to one end of the straight microstrip line TL15.

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