Self-biased power amplifier circuit and self-resonant power amplifier circuit based on self-biasing

Abstract

This invention relates to a self-biased power amplifier circuit and a self-biased self-resonant power amplifier circuit, belonging to the field of radio frequency circuit technology. In this invention, the source of the power device is connected to a voltage divider module. The internal resistance of the power device and the voltage divider module divide the drain voltage. The voltage obtained across the voltage divider module serves as the source voltage. Since the gate of the power device is grounded, a negative voltage difference is formed between the gate and the source, providing voltage to the source of the power device and achieving self-biasing. Simultaneously, by designing a feedback resonant network composed of a fourth microstrip line, a coupling capacitor, a third microstrip line, an input capacitor, a first microstrip line, and a sixth microstrip line, the DC energy of the drain current is converted into a specific frequency radio frequency signal due to the feedback mechanism, even without an external periodic excitation signal. Part of this signal is coupled through the second and fourth microstrip lines and input to the feedback resonant network; the other part is output through the second microstrip line, the output capacitor, and the fifth microstrip line.

Description

Technical Field

[0001] This invention belongs to the field of radio frequency circuit technology, specifically relating to a self-biased circuit that enables the active transistor to form a voltage drop at its gate-source level as a negative voltage source and directly generate microwave signals through a feedback resonant network. Background Technology

[0002] In the field of power amplifier energy generation, traditional solutions typically rely on the coordinated operation of a signal source, a pre-amplifier module, and a power amplifier module. High-power output is achieved through multi-stage amplification, and an MCU (microcontroller unit) controller is used to manipulate a voltage-controlled oscillator (VCO) and a phase shifter to adjust the frequency and phase, ultimately achieving power synthesis. GaAs-based and GaN-based high-power devices generally require dual power supplies. The gate needs to be connected to a separate negative voltage source and stabilized before the drain can be energized. In practical applications, timing control circuits must be used to ensure the correct power-on and power-off sequence of the gate and drain voltages for proper operation; otherwise, device breakdown or burnout may occur. Such product designs suffer from problems such as a large number of components, complex circuitry, the need for multiple power supplies, large size, and high cost, significantly hindering low-cost and miniaturized engineering applications. Summary of the Invention

[0003] The purpose of this invention is to address the problems existing in the prior art by proposing a self-biased power amplifier circuit and a self-resonant power amplifier circuit based on self-biasing.

[0004] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0005] A self-biased power amplifier circuit includes a power device PA, a voltage divider module, a source AC grounding capacitor C8, an input capacitor C1, an output capacitor C4, a first drain bypass capacitor C5, a choke inductor L1, an input terminal Pin, an output terminal Pout, a ground terminal GND, and a power supply Vd, wherein the voltage divider module is a source DC voltage divider resistor R1.

[0006] The source S of the power device PA is connected to the voltage divider module R1, the drain D is connected to the power supply Vd through the choke inductor L1, the drain D is also connected to the output terminal Pout through the output capacitor C4, the gate G is connected to the ground terminal GND, the gate G is also connected to the input terminal Pin through the input capacitor C1, the choke inductor L1 is also connected to the ground terminal through the first drain bypass capacitor C5, and the source AC grounding capacitor C8 is connected in parallel with the voltage divider module, with one end connected to the source S of the power device PA and the other end grounded.

[0007] Furthermore, the power device PA is a gallium nitride device or a gallium arsenide device.

[0008] This invention provides a self-biased power amplifier circuit, wherein the source S of the power device PA is connected to the voltage divider module R1, and the internal resistance R of the power device PA is... ds And the voltage divider module R1 to the drain voltage V d Voltage division is performed, and the voltage across R1 is used as the source voltage V. S Because the gate of the power device PA is grounded (V G When the voltage is 0V, a negative voltage difference is formed between the gate and the source, providing voltage to the source of the power device PA. This achieves self-biasing. The resistance value of the voltage divider module R1 is determined based on the required negative bias voltage between the gate and source.

[0009] A self-biased self-resonant power amplifier circuit includes a power device PA, a voltage divider module, a source AC grounding capacitor C8, an input capacitor C1, an output capacitor C4, a first drain bypass capacitor C5, a choke inductor L1, a first microstrip line TL1, a second microstrip line TL2, a third microstrip line TL3, a fourth microstrip line TL4, a fifth microstrip line TL5, a sixth microstrip line TL6, a second drain bypass capacitor C6, a coupling capacitor C7, an output terminal Pout, a ground terminal GND, and a power supply Vd, wherein the voltage divider module is a source DC voltage divider resistor R1;

[0010] The source S of the power device PA is connected to the voltage divider module R1. The drain D is connected to the power supply Vd through the second microstrip line TL2 and the choke inductor L1. The drain D is also connected to the output terminal Pout through the second microstrip line TL2, the output capacitor C4, and the fifth microstrip line TL5. The gate G is connected to the ground GND through the first microstrip line TL1 and the sixth microstrip line TL6. The gate G is also connected to the ground GND through the first microstrip line TL1, the input capacitor C1, the third microstrip line TL3, the coupling capacitor C7, and the fourth microstrip line TL4. The choke inductor L1 is also connected to the ground through the first drain bypass capacitor C5 and the second drain bypass capacitor C6. The source AC grounding capacitor C8 is connected in parallel with the voltage divider module, with one end connected to the source S of the power device PA and the other end grounded.

[0011] This invention provides a self-biased self-resonant power amplifier circuit, wherein the source S of the power device PA is connected to the voltage divider module R1, and the internal resistance R of the power device PA is... ds And the voltage divider module R1 to the drain voltage V d Voltage division is performed, and the voltage across R1 is used as the source voltage V. S Because the gate of the power device PA is grounded (V G When the voltage is 0V, a negative voltage difference is formed between the gate and the source, providing voltage to the source of the power device PA. To achieve self-biasing;

[0012] The fourth microstrip line TL4, coupling capacitor C7, third microstrip line TL3, input capacitor C1, first microstrip line TL1, and sixth microstrip line TL6 form a feedback resonant network. Under the condition of no external periodic excitation signal, due to its own feedback mechanism, it converts the DC energy of the drain current into a radio frequency signal of a specific frequency, and obtains a stable radio frequency signal output.

[0013] The first microstrip line TL1 and the sixth microstrip line TL6 are connected to ground GND. By adjusting the lengths of the first microstrip line TL1 and the sixth microstrip line TL6, the input impedance matching of the power amplifier circuit is achieved. The second microstrip line TL2, the output capacitor C4, and the fifth microstrip line TL5 are connected to the output terminal. By adjusting the lengths of the second and fifth microstrip lines and the capacitance value of the output capacitor, the output impedance matching of the power amplifier circuit is achieved.

[0014] The first drain bypass capacitor C5 is connected between the choke inductor L1 and the ground terminal, and the second drain bypass capacitor C6 is connected between the choke inductor L1 and the ground terminal. By adjusting the capacitance values ​​of the first drain bypass capacitor C5 and the second drain bypass capacitor C6, the capacitor with the larger capacitance value is moved away from the second microstrip line TL2, and the capacitor with the smaller capacitance value is moved closer to the second microstrip line TL2. By minimizing the loop area of ​​the high-frequency signal generated by the power device PA itself, the influence of parasitic inductance in the power amplifier circuit is minimized, thereby achieving high-frequency decoupling.

[0015] Furthermore, by adjusting the lengths of the third microstrip line TL3 and the fourth microstrip line TL4, as well as the capacitance of the coupling capacitor C7, the frequency of the output signal of the self-resonant power amplifier circuit can be controlled.

[0016] Furthermore, the resistance value of the voltage divider module R1 is determined based on the negative gate-source bias voltage required for the self-resonant power amplifier circuit to operate, so as to provide an accurate self-bias voltage to the amplifier circuit. R1 = -Ugs / Ids, where Ids is the drain static operating current of the amplifier circuit and Ugs is the gate operating voltage corresponding to the drain static operating current of the power amplifier circuit being Ids under non-self-biased circuit conditions. Since the die material is a GaN transistor or a GaAs transistor normally open MOSFET, Ugs needs to be negative to turn it off and make it operate in the amplification region.

[0017] Furthermore, the fourth microstrip line TL4, coupling capacitor C7, third microstrip line TL3, input capacitor C1, first microstrip line TL1, and sixth microstrip line TL6 form a feedback resonant network. Without an external periodic excitation signal, due to its own feedback mechanism, the DC energy of the drain current is converted into a radio frequency (RF) signal of a specific frequency. Part of this RF signal, after being coupled between the second microstrip line TL2 and the fourth microstrip line TL4, serves as the input signal to the feedback resonant network formed by the fourth microstrip line TL4, coupling capacitor C7, third microstrip line TL3, input capacitor C1, first microstrip line TL1, and sixth microstrip line TL6, acting as the input to the power device PA. The other part of the RF signal is output through the second microstrip line TL2, output capacitor C4, and fifth microstrip line TL5. Specifically, the signal entering the feedback resonant network is amplified by the power device PA and then coupled again between the second microstrip line TL2 and the fourth microstrip line TL4 as the input to the power device PA, forming positive feedback and achieving stable signal output.

[0018] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0019] 1. This invention provides a self-biased self-resonant power amplifier circuit. The source of the power device is connected to a voltage divider module. The internal resistance of the power device and the voltage divider module divide the drain voltage. The voltage obtained across the voltage divider module serves as the source voltage. Since the gate of the power device is grounded, a negative voltage difference is formed between the gate and the source, providing voltage to the source of the power device and achieving self-biasing. This solves the problem of requiring multiple power supplies in traditional solutions, avoids the power supply sequence of adding the gate first and then the drain in multi-power supply systems, reduces complex timing and power supply circuits, simplifies the structure of the power amplifier circuit, reduces hardware complexity, and thus achieves low cost and miniaturization.

[0020] 2. This invention provides a self-biased self-resonant power amplifier circuit. By designing a feedback resonant network consisting of a fourth microstrip line, a coupling capacitor, a third microstrip line, an input capacitor, a first microstrip line, and a sixth microstrip line, the circuit converts the DC energy of the drain current into a radio frequency (RF) signal of a specific frequency due to its self-feedback mechanism, even without an external periodic excitation signal. A portion of this signal is coupled through the second and fourth microstrip lines and used as the input signal to the feedback resonant network. The remaining portion is output through the second microstrip line, the output capacitor, and the fifth microstrip line. The signal input to the feedback resonant network is amplified by a power device and then coupled again through the second and fourth microstrip lines to serve as the input to the power device, forming positive feedback and achieving stable RF signal output. Attached Figure Description

[0021] Figure 1 A schematic diagram of a self-biased power amplifier circuit provided for this invention;

[0022] Figure 2 The present invention provides a schematic diagram of a self-biased self-resonant power amplifier circuit. Detailed Implementation

[0023] The technical solution of the present invention will be described in detail below with reference to the accompanying drawings and embodiments.

[0024] Figure 1 The schematic diagram of a self-biased power amplifier circuit provided by the present invention includes a power device PA, a voltage divider module, a source AC grounding capacitor C8, an input capacitor C1, an output capacitor C4, a first drain bypass capacitor C5, a choke inductor L1, an input terminal Pin, an output terminal Pout, a ground terminal GND, and a power supply Vd, wherein the voltage divider module is a source DC voltage divider resistor R1.

[0025] The source S of the power device PA is connected to the voltage divider module R1, the drain D is connected to the power supply Vd through the choke inductor L1, the drain D is also connected to the output terminal Pout through the output capacitor C4, the gate G is connected to the ground terminal GND, the gate G is also connected to the input terminal Pin through the input capacitor C1, the choke inductor L1 is also connected to the ground terminal through the first drain bypass capacitor C5, and the source AC grounding capacitor C8 is connected in parallel with the voltage divider module, with one end connected to the source S of the power device PA and the other end grounded.

[0026] In the self-biased power amplifier circuit provided by this invention, the source S of the power device PA is connected to the voltage divider module R1, and the internal resistance R of the power device PA is... ds And the voltage divider module R1 to the drain voltage V d Voltage division is performed, and the voltage across R1 is used as the source voltage V. S Because the gate of the power device PA is grounded (V G When the voltage is 0V, a negative voltage difference is formed between the gate and the source, providing voltage to the source of the power device PA. This achieves self-biasing. The resistance value of the voltage divider module R1 is determined based on the required negative bias voltage between the gate and source.

[0027] In this circuit, the source AC grounding capacitor C8 connected in parallel across the voltage divider module R1 stores energy and reduces the RF energy attenuation caused by R1, thereby stabilizing the power amplifier circuit. The input capacitor C1 connected between the gate G and the input pin of the power device PA, and the output capacitor C4 connected between the drain D and the output Pout of the power device PA, serve as DC blocking capacitors for the input and output, respectively. The first drain bypass capacitor C5 connected between the choke inductor L1 and the ground GND is used to suppress low-frequency oscillations and enhance the stability of the power amplifier circuit. The choke inductor L1 connected between the drain of the power device PA and the first drain bypass capacitor C5 works together with the first drain bypass capacitor C5 to form a low-pass filter to isolate RF signals.

[0028] The power device PA can regulate the transmission and conversion of power, and can be selected as a gallium nitride (GaN) device or a gallium arsenide (GaAs) device.

[0029] Figure 2 The schematic diagram of a self-biased self-resonant power amplifier circuit provided by the present invention includes a power device PA, a voltage divider module, a source AC grounding capacitor C8, an input capacitor C1, an output capacitor C4, a first drain bypass capacitor C5, a choke inductor L1, a first microstrip line TL1, a second microstrip line TL2, a third microstrip line TL3, a fourth microstrip line TL4, a fifth microstrip line TL5, a sixth microstrip line TL6, a second drain bypass capacitor C6, a coupling capacitor C7, an output terminal Pout, a ground terminal GND, and a power supply Vd, wherein the voltage divider module is a source DC voltage divider resistor R1;

[0030] The source S of the power device PA is connected to the voltage divider module R1. The drain D is connected to the power supply Vd through the second microstrip line TL2 and the choke inductor L1. The drain D is also connected to the output terminal Pout through the second microstrip line TL2, the output capacitor C4, and the fifth microstrip line TL5. The gate G is connected to the ground GND through the first microstrip line TL1 and the sixth microstrip line TL6. The gate G is also connected to the ground GND through the first microstrip line TL1, the input capacitor C1, the third microstrip line TL3, the coupling capacitor C7, and the fourth microstrip line TL4. The choke inductor L1 is also connected to the ground through the first drain bypass capacitor C5 and the second drain bypass capacitor C6. The source AC grounding capacitor C8 is connected in parallel with the voltage divider module, with one end connected to the source S of the power device PA and the other end grounded.

[0031] This invention provides a self-biased self-resonant power amplifier circuit, wherein the source S of the power device PA is connected to the voltage divider module R1, and the internal resistance R of the power device PA is... ds And the voltage divider module R1 to the drain voltage V d Voltage division is performed, and the voltage across R1 is used as the source voltage V. S Because the gate of the power device PA is grounded (V G When the voltage is 0V, a negative voltage difference is formed between the gate and the source, providing voltage to the source of the power device PA. To achieve self-biasing;

[0032] The fourth microstrip line TL4, coupling capacitor C7, third microstrip line TL3, input capacitor C1, first microstrip line TL1, and sixth microstrip line TL6 form a feedback resonant network. Under the condition of no external periodic excitation signal, due to its own feedback mechanism, it converts the DC energy of the drain current into a radio frequency signal of a specific frequency, and obtains a stable radio frequency signal output.

[0033] The first microstrip line TL1 and the sixth microstrip line TL6 are connected to ground GND. By adjusting the lengths of the first microstrip line TL1 and the sixth microstrip line TL6, the input impedance matching of the power amplifier circuit is achieved. The second microstrip line TL2, the output capacitor C4, and the fifth microstrip line TL5 are connected to the output terminal. By adjusting the lengths of the second and fifth microstrip lines and the capacitance value of the output capacitor, the output impedance matching of the power amplifier circuit is achieved.

[0034] The first drain bypass capacitor C5 is connected between the choke inductor L1 and the ground terminal, and the second drain bypass capacitor C6 is connected between the choke inductor L1 and the ground terminal. By adjusting the capacitance values ​​of the first drain bypass capacitor C5 and the second drain bypass capacitor C6, the capacitor with the larger capacitance value is moved away from the second microstrip line TL2, and the capacitor with the smaller capacitance value is moved closer to the second microstrip line TL2. By minimizing the loop area of ​​the high-frequency signal generated by the power device PA itself, the influence of parasitic inductance in the power amplifier circuit is minimized, thereby achieving high-frequency decoupling.

[0035] Furthermore, by adjusting the lengths of the third microstrip line TL3 and the fourth microstrip line TL4, as well as the capacitance of the coupling capacitor C7, the frequency of the output signal of the self-resonant power amplifier circuit can be controlled.

[0036] Furthermore, the resistance value of the voltage divider module R1 is determined based on the negative gate-source bias voltage required for the self-resonant power amplifier circuit to operate, so as to provide an accurate self-bias voltage to the amplifier circuit. R1 = -Ugs / Ids, where Ids is the drain static operating current of the amplifier circuit and Ugs is the gate operating voltage corresponding to the drain static operating current of the power amplifier circuit being Ids under non-self-biased circuit conditions. Since the die material is a GaN transistor or a GaAs transistor normally open MOSFET, Ugs needs to be negative to turn it off and make it operate in the amplification region.

[0037] Furthermore, the fourth microstrip line TL4, coupling capacitor C7, third microstrip line TL3, input capacitor C1, first microstrip line TL1, and sixth microstrip line TL6 form a feedback resonant network. Without an external periodic excitation signal, due to its own feedback mechanism, the DC energy of the drain current is converted into a radio frequency (RF) signal of a specific frequency. Part of this RF signal, after being coupled between the second microstrip line TL2 and the fourth microstrip line TL4, serves as the input signal to the feedback resonant network formed by the fourth microstrip line TL4, coupling capacitor C7, third microstrip line TL3, input capacitor C1, first microstrip line TL1, and sixth microstrip line TL6, acting as the input to the power device PA. The other part of the RF signal is output through the second microstrip line TL2, output capacitor C4, and fifth microstrip line TL5. Specifically, the signal entering the feedback resonant network is amplified by the power device PA and then coupled again between the second microstrip line TL2 and the fourth microstrip line TL4 as the input to the power device PA, forming positive feedback and achieving stable signal output.

Claims

1. A self-biased self-resonant power amplifier circuit, characterized in that, It includes power devices, voltage divider modules, source AC grounding capacitors, input capacitors, output capacitors, first drain bypass capacitors, choke inductors, first microstrip lines, second microstrip lines, third microstrip lines, fourth microstrip lines, fifth microstrip lines, sixth microstrip lines, second drain bypass capacitors, coupling capacitors, output terminals, ground terminals, and power supplies, wherein the voltage divider modules are source DC voltage divider resistors; The source of the power device is connected to the voltage divider module, and the drain is connected to the power supply through the second microstrip line and the choke inductor. The drain is also connected to the output terminal through the second microstrip line, the output capacitor, and the fifth microstrip line. The gate is connected to the ground terminal through the first microstrip line and the sixth microstrip line. The gate is also connected to the ground terminal through the first microstrip line, the input capacitor, the third microstrip line, the coupling capacitor, and the fourth microstrip line. The choke inductor is also connected to the ground terminal through the first drain bypass capacitor and the second drain bypass capacitor. The source AC grounding capacitor is connected in parallel with the voltage divider module, with one end connected to the source of the power device and the other end grounded. The fourth microstrip line, coupling capacitor, third microstrip line, input capacitor, first microstrip line, and sixth microstrip line form a feedback resonant network. In the absence of an external periodic excitation signal, the DC energy of the drain current is converted into a radio frequency (RF) signal. Part of the RF signal is coupled through the second and fourth microstrip lines and used as an input signal to the feedback resonant network as the input to the power device. The other part of the RF signal is output through the second microstrip line, output capacitor, and fifth microstrip line. The signal entering the feedback resonant network is amplified by the power device and then coupled again through the second and fourth microstrip lines as the input to the power device, forming positive feedback and achieving stable signal output.

2. The self-biased self-resonant power amplifier circuit according to claim 1, characterized in that, Input impedance matching of the power amplifier circuit is achieved by adjusting the lengths of the first and sixth microstrip lines; output impedance matching of the power amplifier circuit is achieved by adjusting the lengths of the second and fifth microstrip lines and the capacitance value of the output capacitor.

3. The self-biased self-resonant power amplifier circuit according to claim 1, characterized in that, By adjusting the capacitance values ​​of the first drain bypass capacitor and the second drain bypass capacitor, the capacitor with the larger capacitance value is moved away from the second microstrip line, and the capacitor with the smaller capacitance value is moved closer to the second microstrip line, thereby achieving high-frequency decoupling.

4. The self-biased self-resonant power amplifier circuit according to claim 1, characterized in that, The frequency of the output signal of the self-resonant power amplifier circuit can be controlled by adjusting the lengths of the third and fourth microstrip lines and the capacitance of the coupling capacitor.

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