A radio frequency power amplifier power supply circuit with bidirectional current drive

Abstract

The utility model relates to radio frequency power amplifier technical field, concretely relates to a radio frequency power amplifier power supply circuit with bidirectional current drive, including two -way negative voltage protection circuit, second circuit, third circuit, fourth circuit, fifth circuit and sixth circuit, two -way negative voltage protection circuit is used for monitoring main road grid negative voltage Vgs main and peak value grid negative voltage Vgs peak, and is turned off drain electrode power VDS when any road negative voltage loss, second circuit is used for 50V direct current voltage to 12V, third circuit is used for 12V direct current voltage to 5V, fourth circuit is used for direct current 5V conversion direct current 5V, fifth circuit is used for direct current 5V conversion direct current 5.8V, sixth circuit is used for direct current 5V to direct current 2.5V, and increases bidirectional current drive ability, and the power supply of main road grid negative voltage Vgs main. The problem that the existing DC / DC negative voltage chip negative voltage adjustment is complex, current carrying capacity is insufficient and lacks bidirectional current drive ability has been solved.

Description

Technical Field

[0001] This utility model relates to the field of radio frequency power amplifier technology, and in particular to a power supply circuit for a radio frequency power amplifier with bidirectional current drive. Background Technology

[0002] Radio frequency (RF) power amplifiers are widely used in broadcasting, television, communications, military, medical, aviation, and aerospace industries. Their core function is to amplify the input RF signal to the required power level. With the rapid development of wireless communication technology, the performance requirements of RF power amplifiers are increasing, especially in terms of output power, efficiency, and linearity. Currently, the process technology for RF power amplifiers has evolved from early gallium arsenide (GaAs) to silicon-based LDMOS (Laterally Diffused Metal-Oxide Semiconductor) and gallium nitride (GaN) processes. Among these, gallium nitride transistors, due to their high output power, wide operating bandwidth, and high efficiency, are gradually becoming the preferred choice for high-frequency, high-power applications.

[0003] In gallium nitride transistor power amplifiers, the performance of the power supply circuit directly affects the overall performance of the amplifier. To support peak-to-average power ratio (PAPR) signals and improve efficiency, a Doherty power amplification structure with predistortion correction is typically employed. However, this structure places higher demands on the power supply circuit, especially requiring a stable and controllable power supply for the gate main bias (Vgs-main) and gate peak bias (Vgs-peak). Specifically, the gate main bias needs to have bidirectional current drive capability to ensure a stable quiescent operating point even when the power amplifier output is saturated, thereby guaranteeing high linearity and high efficiency.

[0004] Currently, commercially available DC / DC negative voltage converter chips generally suffer from the following drawbacks: Complex negative voltage adjustment: Traditional circuits use fixed resistors to adjust the negative voltage, making the debugging process cumbersome and difficult to quickly adjust the operating point, increasing debugging time and cost. Insufficient current carrying capacity: Existing π-type filters often use multilayer chip inductors, which have weak carrying capacity and are prone to voltage drop under high current conditions, leading to quiescent operating point drift and affecting the efficiency and linearity of the power amplifier. Lack of bidirectional current drive capability: Existing negative voltage converter chips are mostly unidirectional current driven. When the gate main circuit negative voltage is reverse biased, it cannot effectively maintain voltage stability, resulting in a decrease in main circuit output power, deterioration of linearity, and limiting the full performance of gallium nitride transistors. To address these issues, a new type of RF power amplifier power supply circuit is urgently needed that simplifies negative voltage adjustment, enhances current carrying capacity, and achieves bidirectional current drive, thereby providing a stable and reliable operating power supply for gallium nitride transistor power amplifiers and meeting the high efficiency and high linearity requirements of modern communication systems. Utility Model Content

[0005] The purpose of this invention is to provide a power supply circuit for an RF power amplifier with bidirectional current drive, which solves the problems of complex negative voltage adjustment, insufficient current carrying capacity, and lack of bidirectional current drive capability of existing DC / DC negative voltage chips.

[0006] To achieve the above objectives, this utility model provides a power supply circuit for a radio frequency power amplifier with bidirectional current drive, including a dual-channel negative voltage protection circuit, a second circuit, a third circuit, a fourth circuit, a fifth circuit, and a sixth circuit. The dual-channel negative voltage protection circuit is connected to the second circuit, the second circuit is connected to the third circuit, the third circuit is connected to the fourth circuit and the fifth circuit respectively, and the fourth circuit is connected to the sixth circuit.

[0007] The dual-path negative voltage protection circuit is used to monitor the main gate negative voltage Vgs-main and the peak gate negative voltage Vgs-peak, and to shut off the drain power supply VDS when either negative voltage is lost.

[0008] The second circuit is used to regulate the 50V DC voltage to 12V;

[0009] The third circuit is used to regulate the 12V DC voltage to 5V;

[0010] The fourth circuit is used to convert DC 5V to DC -5V;

[0011] The fifth circuit is used to convert DC 5V to DC -5.8V;

[0012] The sixth circuit is used to regulate DC-5V to DC-2.5V and increase bidirectional current drive capability, and to supply power to the main gate negative voltage Vgs-main.

[0013] The dual-path negative voltage protection circuit includes transistors Q2, Q4, and Q5, diodes D1 and D6, a P-channel MOSFET Q6, resistors R4, R5, R6, R9, and R10, and a filter capacitor C2.

[0014] The main gate negative voltage Vgs-main is connected to one end of diode D6, and the other end of diode D6 is connected to resistors R9, R4, R6, R10, P-channel MOSFET Q6, filter capacitor C2 and transistor Q5.

[0015] One end of transistor Q5 is connected to transistors Q2 and Q4;

[0016] One end of diode D1 is connected to resistor R4 and transistor Q2;

[0017] One end of transistor Q2 is connected to resistor R6 and transistor Q4;

[0018] One end of resistor R5 is connected to resistor R10 and P-channel MOSFET Q6, and the other end of resistor R5 is connected to transistor Q4.

[0019] One end of the P-channel MOSFET Q6 is connected to the filter capacitor C2, and the other end of the P-channel MOSFET Q6 is connected to the drain power supply VDS.

[0020] The second circuit includes a three-terminal voltage regulator U1, a filter capacitor C1, and a filter capacitor C3. The first terminal of the three-terminal voltage regulator U1 is connected to the filter capacitors C1 and C2, and the third terminal of the three-terminal voltage regulator U1 is connected to the filter capacitor C3.

[0021] The third circuit includes a three-terminal voltage regulator U2, a filter capacitor C4, a filter capacitor C5, and a filter capacitor C19. The first terminal of the three-terminal voltage regulator U2 is connected to the filter capacitors C4, C5, and C3, and the third terminal of the three-terminal voltage regulator U2 is connected to the filter capacitor C19.

[0022] The fourth circuit includes a negative voltage converter U4, capacitors C10, C12, and C14, and resistors R8, R11, and R12.

[0023] The first terminal of the negative voltage converter U4 is connected to capacitor C10 and filter capacitor C19;

[0024] The second terminal of the negative voltage converter U4 is connected to capacitor C12;

[0025] The fourth terminal of the negative voltage converter U4 is connected to capacitor C12; the fifth terminal of the negative voltage converter U4 is connected to resistor R11 and capacitor C14.

[0026] The sixth terminal of the negative voltage converter U4 is connected to capacitor C10 and resistor R8;

[0027] The seventh terminal of the voltage converter U4 is connected to resistors R8 and R12;

[0028] Resistor R12 is connected to resistor R11.

[0029] The fifth circuit includes a negative voltage converter U3, capacitors C7, C8, C9, C11, C18, C20, and C21, resistors R1 and R2, inductors L2, L3, and L4, diode D3, and adjustable potentiometer RP2.

[0030] The first terminal of the negative voltage converter U3 is connected to inductor L3 and capacitor C9;

[0031] The third terminal of the negative voltage converter U3 is connected to resistor R1, capacitor C8 and resistor R2;

[0032] The fourth terminal of the negative voltage converter U3 is connected to capacitor C7, inductor L3, capacitor C19, and capacitor C10;

[0033] The fifth terminal of the negative voltage converter U3 is connected to the fourth terminal of the negative voltage converter U3, capacitor C7, inductor L3, capacitor C19, and capacitor C10.

[0034] One end of capacitor C9 is connected to diode D3 and inductor L2;

[0035] One end of capacitor C8 is connected to resistor R2, and the other end of capacitor C8 is connected to inductor L2, capacitor C21 and adjustable potentiometer RP2.

[0036] One end of the adjustable potentiometer RP2 is connected to the resistor R2, and the other end of the adjustable potentiometer RP2 is connected to the capacitors C21 and C20, the inductor L4, and the capacitor C18.

[0037] One end of inductor L4 is connected to capacitor C11.

[0038] The sixth circuit includes an operational amplifier U5, capacitors C15, C17, C13, and C16, resistors R13, R14, R30, R31, and R32, an inductor L1, an N-channel JFETQ3, a P-channel JFETQ1, and an adjustable potentiometer RP1.

[0039] The negative terminal of operational amplifier U5 is connected to resistors R14 and R13, the positive terminal of operational amplifier U5 is connected to resistors R32 and R31, one end of operational amplifier U5 is connected to resistor R31, capacitor C17, capacitor C15, P-channel JFETQ1 and capacitor C14, and the other end of operational amplifier U5 is connected to N-channel JFETQ3 and P-channel JFETQ1.

[0040] The N-channel JFETQ3 is connected to the adjustable potentiometer RP1, capacitor C16 and inductor L1.

[0041] Adjustable potentiometer RP1 is connected to resistor R14;

[0042] Inductor L1 is connected to capacitor C13 and resistor R30.

[0043] This invention discloses a power supply circuit for a radio frequency power amplifier with bidirectional current drive. It improves the negative voltage adjustment method, replacing the previous cumbersome method of adjusting the negative voltage using a fixed resistor with a fixed resistor and an adjustable potentiometer. This pre-locks the negative voltage within a calculated range, requiring only fine-tuning of the potentiometer during use, saving significant debugging time. The inductor in the π-type filter is replaced with a surface-mount power inductor instead of a multilayer chip inductor, increasing the filter's load-carrying capacity and preventing voltage drop across the inductor when the current is too high. A bidirectional current drive circuit is designed after the commonly used negative voltage conversion chip, perfectly solving the problem of the chip's inability to drive bidirectional current. This also addresses the issue of gallium nitride transistor power amplifiers experiencing reduced output capability and unsatisfactory linearity in saturation conditions, laying the technical groundwork for the large-scale application of gallium nitride transistor power amplifiers in industries such as broadcasting, television, communications, military, medical, aviation, and aerospace. Currently, this technology has been applied in small batches to terrestrial digital television and aerospace products. After nearly a year of operation with several hundred sets of products, the bidirectional current-driven RF power amplifier power amplifier power supply circuit provides a stable and reliable operating state for the gallium nitride transistor power amplifier. Through regular inspections and after-sales statistics, the reliability of the power amplifier has been significantly improved after adopting this invention, with user satisfaction approaching 100%. Compared to before this invention, it has reduced a significant amount of after-sales time and costs, indirectly increasing the company's profit margin and laying the foundation for the company's healthy development. Attached Figure Description

[0044] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the accompanying drawings used in the description of the embodiments or the prior art will be briefly introduced below.

[0045] Figure 1 This is the schematic diagram of the dual-channel negative voltage protection circuit of this utility model.

[0046] Figure 2 This is the second circuit schematic diagram of this utility model.

[0047] Figure 3 This is the third circuit schematic diagram of this utility model.

[0048] Figure 4 This is the fourth circuit schematic diagram of this utility model.

[0049] Figure 5 This is the fifth circuit schematic diagram of this utility model.

[0050] Figure 6 This is the sixth circuit schematic diagram of this utility model.

[0051] Figure 7This is a schematic diagram of the power supply circuit for a radio frequency power amplifier with bidirectional current drive according to this utility model. Detailed Implementation

[0052] The embodiments of the present invention are described in detail below. Examples of the embodiments are shown in the accompanying drawings. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain the present invention, but should not be construed as limiting the present invention.

[0053] Please see Figures 1 to 7 ,in, Figure 1 This is the schematic diagram of the dual-channel negative voltage protection circuit of this utility model. Figure 2 This is the second circuit schematic diagram of this utility model. Figure 3 This is the third circuit schematic diagram of this utility model. Figure 4 This is the fourth circuit schematic diagram of this utility model. Figure 5 This is the fifth circuit schematic diagram of this utility model. Figure 6 This is the sixth circuit schematic diagram of this utility model. Figure 7 This is a schematic diagram of the power supply circuit for a radio frequency power amplifier with bidirectional current drive according to this utility model.

[0054] This utility model provides a power supply circuit for a radio frequency power amplifier with bidirectional current drive, including a dual negative voltage protection circuit, a second circuit, a third circuit, a fourth circuit, a fifth circuit, and a sixth circuit.

[0055] In this specific embodiment, the dual-path negative pressure protection circuit is connected to the second circuit, the second circuit is connected to the third circuit, the third circuit is connected to the fourth circuit and the fifth circuit respectively, and the fourth circuit is connected to the sixth circuit;

[0056] The dual-path negative voltage protection circuit is used to monitor the main gate negative voltage Vgs-main and the peak gate negative voltage Vgs-peak, and to shut off the drain power supply VDS when either negative voltage is lost.

[0057] The second circuit is used to regulate the 50V DC voltage to 12V;

[0058] The third circuit is used to regulate the 12V DC voltage to 5V;

[0059] The fourth circuit is used to convert DC 5V to DC -5V;

[0060] The fifth circuit is used to convert DC 5V to DC -5.8V;

[0061] The sixth circuit is used to regulate DC-5V to DC-2.5V and increase bidirectional current drive capability, and to supply power to the main gate negative voltage Vgs-main.

[0062] This circuit primarily provides a stable and reliable power supply for a gallium nitride transistor (GaN) RF power amplifier based on the Doherty circuit design (a circuit structure that improves operating efficiency). It mainly includes the drain power supply VDS, peak voltage Vgs-peak, and main voltage Vgs-main. The dual-channel negative voltage protection circuit primarily monitors the two negative voltages in real time; if either negative voltage is lost, it immediately shuts off the DC 50V, resulting in no output from VDS. The second circuit primarily regulates the DC 50V to DC 12V. The third circuit primarily regulates the DC 12V to DC 5V. The fourth circuit primarily converts DC 5V to DC -5V. Although this circuit can directly step down to DC -2.5V to power the GaN transistor's main voltage Vgs-main, it lacks bidirectional current drive capability, and the voltage is often unstable during operation, affecting power output. Therefore, the fourth circuit cannot be used directly. The fifth circuit primarily converts DC 5V to DC -5.8V. The circuit primarily powers the peak voltage Vgs-peak of the gallium nitride transistor. Since Vgs-peak has a low current carrying capacity and does not require bidirectional current drive, it can be directly powered. However, simply providing power to Vgs-peak is insufficient for the gallium nitride transistor to operate (Vgs-main and Vgs-peak need to be stably powered first, and then VDS can provide the operating power). The sixth circuit's main function is to regulate DC-5V to DC-2.5V and increase bidirectional current drive capability, completely resolving the unstable power supply problem of the fourth circuit. This allows the RF power amplifier to operate stably, maximizing its output capability and optimal performance.

[0063] The dual-path negative voltage protection circuit includes transistors Q2, Q4, and Q5, diodes D1 and D6, a P-channel MOSFET Q6, resistors R4, R5, R6, R9, and R10, and a filter capacitor C2. The main gate negative voltage Vgs-main is connected to one end of diode D6, and the other end of diode D6 is connected to resistors R9, R4, R6, and R10, the P-channel MOSFET Q6, the filter capacitor C2, and the transistors. Q5 is connected; one end of transistor Q5 is connected to transistors Q2 and Q4; one end of diode D1 is connected to resistor R4 and transistor Q2; one end of transistor Q2 is connected to resistor R6 and transistor Q4; one end of resistor R5 is connected to resistor R10 and P-channel MOSFET Q6, and the other end of resistor R5 is connected to transistor Q4; one end of P-channel MOSFET Q6 is connected to filter capacitor C2, and the other end of P-channel MOSFET Q6 is connected to drain power supply VDS.

[0064] The dual-path negative voltage protection circuit mainly consists of three NPN transistors Q2, Q4, and Q5, two Zener diodes D1 and D6, one P-channel MOSFET (Metal-Oxide-Semiconductor Field-Effect Transistor) Q6, five resistors R4, R5, R6, R9, and R10, and a filter capacitor C2. Under normal conditions, a DC 50V voltage is input from the Vi_50V port, and a DC -2.5V voltage is input from Vgs-main. After being regulated by the 2.5V Zener diode D6, the voltage will become approximately 0V. Since Q5 has no forward bias, it remains in the off state, so its collector C remains high. A DC -5.8V voltage is input from Vgs-peak. After being regulated by the 5.6V Zener diode D1, the voltage will become approximately -0.2V. Since Q2 has no forward bias, it remains in the off state, so its collector C remains high. After Q4 is turned on by the forward bias voltage from resistor R6, the voltage divider circuit composed of R5 and R10 sends a DC 40V voltage to the gate G of the P-channel MOSFET (Metal-Oxide-Semiconductor Field-Effect Transistor) Q6. At this time, VGS is approximately -10V, Q6 starts to conduct, and the VDS port outputs a DC 50V voltage. When the DC -2.5V input to Vgs-main is lost, a high voltage will appear at the base B of Q5, turning Q5 on, pulling down the high voltage at the base of Q4, causing Q4 to turn off. After Q4 turns off, Q6 will also immediately turn off, shutting off the VDS output, thus achieving Vgs-main negative voltage loss protection. When the DC-5.8V input to Vgs-peak is lost, a high voltage will appear at the base (B) of Q2, turning Q2 on. This pulls down the high voltage at the base of Q4, causing Q4 to turn off. After Q4 turns off, Q6 will also immediately turn off, shutting off the VDS output, thus achieving Vgs-peak negative voltage loss protection. The key to this circuit is that the states of the collectors (C) of Q5 and Q2 can control the on / off state of Q6, achieving dual-path negative voltage protection.

[0065] Secondly, the second circuit includes a three-terminal voltage regulator U1, a filter capacitor C1 and a filter capacitor C3. The first terminal of the three-terminal voltage regulator U1 is connected to the filter capacitors C1 and C2, and the third terminal of the three-terminal voltage regulator U1 is connected to the filter capacitor C3.

[0066] The second circuit mainly consists of a three-terminal regulator U1 and two filter capacitors C1 and C3. The input voltage of 50V is input from the Vi_50V port. After being regulated by the three-terminal regulator U1, a constant 12V voltage is output from the Vo_12.0V port.

[0067] Meanwhile, the third circuit includes a three-terminal voltage regulator U2, filter capacitors C4, C5, and C19. The first terminal of the three-terminal voltage regulator U2 is connected to filter capacitors C4, C5, and C3, and the third terminal of the three-terminal voltage regulator U2 is connected to filter capacitor C19.

[0068] The third circuit mainly consists of a three-terminal voltage regulator U2 and three filter capacitors C4, C5, and C19. The 12V voltage generated by the second circuit is input from the Vo_12.0V port, and after being regulated by the three-terminal voltage regulator U2, a constant 5V voltage is output from the Vo_5.0V port.

[0069] Additionally, the fourth circuit includes a negative voltage converter U4, capacitors C10, C12, and C14, and resistors R8, R11, and R12. The first terminal of the negative voltage converter U4 is connected to capacitor C10 and filter capacitor C19; the second terminal of the negative voltage converter U4 is connected to capacitor C12; the fourth terminal of the negative voltage converter U4 is connected to capacitor C12; the fifth terminal of the negative voltage converter U4 is connected to resistor R11 and capacitor C14; the sixth terminal of the negative voltage converter U4 is connected to capacitor C10 and resistor R8; the seventh terminal of the negative voltage converter U4 is connected to resistors R8 and R12; and resistor R12 is connected to resistor R11.

[0070] The fourth circuit mainly consists of a negative voltage converter U4, three capacitors C10, C12, and C14, and three resistors R8, R11, and R12. The 5V voltage generated by the third circuit is input from the Vo_5.0V port. After negative voltage conversion, a constant -5V voltage is output from the Vo_-5.0V port. Due to the negative voltage converter U4, the -5V voltage at this time only has unidirectional current driving capability.

[0071] Meanwhile, the fifth circuit includes a negative voltage converter U3, capacitors C7, C8, C9, C11, C18, C20, and C21, resistors R1 and R2, inductors L2, L3, and L4, diode D3, and adjustable potentiometer RP2; the first terminal of the negative voltage converter U3 is connected to inductor L3 and capacitor C9; the third terminal of the negative voltage converter U3 is connected to resistors R1, C8, and R2; and the fourth terminal of the negative voltage converter U3 is connected to capacitors C7 and L3, and capacitors C19 and C10. Connect the fifth terminal of the negative voltage converter U3 to the fourth terminal of the negative voltage converter U3, capacitor C7, inductor L3, capacitor C19, and capacitor C10; connect one end of capacitor C9 to diode D3 and inductor L2; connect one end of capacitor C8 to resistor R2, and connect the other end of capacitor C8 to inductor L2, capacitor C21, and adjustable potentiometer RP2; connect one end of adjustable potentiometer RP2 to resistor R2, and connect the other end of adjustable potentiometer RP2 to capacitor C21, capacitor C20, inductor L4, and capacitor C18; connect one end of inductor L4 to capacitor C11.

[0072] The fifth circuit mainly consists of a negative voltage converter U3, seven capacitors C7, C8, C9, C11, C18, C20, and C21, two resistors R1 and R2, three inductors L2, L3, and L4, one diode D3, and one adjustable potentiometer RP2. The 5V voltage generated by the third circuit is input from the Vo_5.0V port. After negative voltage conversion, a constant -5.8V voltage is output from the Vgs-peak port. Due to the negative voltage converter U3, the -5.8V voltage at this time only has unidirectional current driving capability.

[0073] Finally, the sixth circuit includes operational amplifier U5, capacitors C15, C17, C13, and C16, resistors R13, R14, R30, R31, and R32, inductor L1, N-channel JFETQ3, P-channel JFETQ1, and adjustable potentiometer RP1. The negative terminal of operational amplifier U5 is connected to resistors R14 and R13, and the positive terminal of operational amplifier U5 is connected to resistors R32 and R31. One end of operational amplifier U5 is connected to resistor R31, capacitors C17 and C15, P-channel JFETQ1, and capacitor C14, and the other end of operational amplifier U5 is connected to N-channel JFETQ3 and P-channel JFETQ1. N-channel JFETQ3 is connected to adjustable potentiometer RP1, capacitor C16, and inductor L1. Adjustable potentiometer RP1 is connected to resistor R14. Inductor L1 is connected to capacitor C13 and resistor R30.

[0074] The sixth circuit mainly consists of an operational amplifier U5, four capacitors C15, C17, C13, and C16, five resistors R13, R14, R30, R31, and R32, an inductor L1, an N-channel JFET (Junction Field-Effect Transistor) Q3, a P-channel JFET (Junction Field-Effect Transistor) Q1, and an adjustable potentiometer RP1. First, a -5V voltage is input from the Vo_-5.0V port. After being filtered by capacitors C15 and C17, the power supply is input to the GND pin of operational amplifier U5. The VCC pin of operational amplifier U5 is grounded, allowing U5 to operate under negative voltage. The reference voltage of -0.455V generated by the voltage divider of R31 and R32 is sent to the + pin of operational amplifier U5. One end of R13 is connected to the - pin of operational amplifier U5, and the other end is connected to ground. R14 and RP1 form a negative feedback resistor, with one end connected to the - pin of operational amplifier U5 and the other end connected to the common output terminal of Q1 and Q3. Since RP1 is 1... With a 0KΩ potentiometer, the maximum amplification factor of operational amplifier U5 is 6.3 times (1+53KΩ / 10KΩ), and the minimum is 5.3 times (1+43KΩ / 10KΩ). Therefore, the maximum output voltage at the common output terminal of Q1 and Q3 is -2.41V (-0.455V×5.3), and the minimum output voltage is -2.87V (-0.455V×6.3). The -2.5V output voltage required by Vgs-main is exactly between -2.41V and -2.87V. By fine-tuning potentiometer RP1, the voltage can be quickly adjusted to the required value. The π-type filter, consisting of L1 and capacitors C13 and C16, primarily filters out stray signals and power supply ripple, resulting in a cleaner power output. L1 is replaced with a surface-mount power inductor instead of a multilayer chip inductor, increasing its current handling capacity and load-carrying ability. Even with excessively high current, it ensures no voltage drop, keeping the output voltage constant. Resistor R30 to ground eliminates floating voltage in the circuit, making the DC negative voltage output from Vgs-main more stable and smooth. This ensures the gallium nitride transistor power amplifier always operates in a stable power supply environment, maintaining the amplifier's efficiency and linearity. Q1 and Q3 form a bidirectional current drive circuit. When current flows from resistor R30 to operational amplifier U5, the current flows through the P-channel JFET (Junction Field-Effect Transistor) Q1 to operational amplifier U5. When current flows from operational amplifier U5 to resistor R30, the current flows through the N-channel JFET (Junction Field-Effect Transistor) Q3 to resistor R30. The larger the current that U5, Q1, and Q3 can withstand, the stronger their load-carrying capacity. In actual use, the appropriate model can be selected according to the required current.This circuit perfectly achieves bidirectional current drive capability. Even if the negative voltage of the gate main circuit reverses and becomes a positive gate current, it will not cause the negative voltage of the gate main circuit to decrease, thus not affecting the main circuit output power capability or the linearity index, providing a guarantee for the widespread use of gallium nitride transistor power amplifiers.

[0075] Using the bidirectional current-driven RF power amplifier power supply circuit of this embodiment, as can be seen from the principle block diagrams of the fourth and fifth circuits, commonly used negative voltage converters can only drive current in one direction. When the output power of the gallium nitride transistor power amplifier is saturated, Vgs-main needs to provide bidirectional current drive capability to ensure the power amplifier's high peak power output capability and excellent linearity. To solve this problem, the newly designed sixth circuit can effectively address this challenge, allowing the gallium nitride transistor power amplifier to provide excellent performance at any time. The second circuit converts the input DC50V power supply to DC12V power supply through a DC / DC converter to provide operating power for the third circuit; the third circuit again converts the input DC12V power supply to DC5V power supply through a DC / DC converter to provide operating power for the fourth and fifth circuits; after the DC5V power supply is input, the fifth circuit processes it through the negative voltage converter U3 to generate a DC-5.8V power supply, providing operating power for the peak voltage Vgs-peak of the gallium nitride transistor. The fourth circuit, after receiving a DC 5V power input, processes the output through a negative voltage converter U4 to generate a DC-5.0V power supply, providing operating power for the sixth circuit. The sixth circuit, using a novel circuit design, stabilizes the output power at approximately DC-2.5V and provides bidirectional current drive capability, ensuring a stable operating power supply for the main voltage Vgs-main of the gallium nitride transistor. Once the power supplies generated by the fifth and sixth circuits (DC-5.8V and DC-2.5V respectively) are functioning normally, the dual negative voltage protection circuit of the first circuit turns on the MOSFET Q6, providing a DC 50V operating power supply to the drain VDS of the gallium nitride transistor. Thus, the gallium nitride transistor RF power amplifier based on the Doherty circuit design (a circuit structure that improves operating efficiency) completes all its power supply requirements.

[0076] This invention innovates upon common power amplifier power supply circuits. Firstly, it improves the negative voltage adjustment method, replacing the cumbersome approach of adjusting the negative voltage with a fixed resistor with a fixed resistor and an adjustable potentiometer. This pre-locks the negative voltage within a calculated range, requiring only fine-tuning of the potentiometer during use, saving significant debugging time. Secondly, it replaces the multilayer chip inductor in the π-type filter with a surface-mount power inductor, increasing the filter's load-carrying capacity and preventing voltage drop across the inductor when current is excessive. Thirdly, it incorporates a bidirectional current-driven circuit after the commonly used negative voltage converter chip, perfectly solving the problem of bidirectional current driving capability in negative voltage converter chips. This addresses the issue of gallium nitride transistor power amplifiers experiencing reduced output capability and unmet linearity requirements in saturation conditions, paving the way for the large-scale application of gallium nitride transistor power amplifiers in industries such as broadcasting, television, communications, military, medical, aviation, and aerospace.

[0077] Currently, this technology has been applied in small batches to terrestrial digital television and aerospace products. After nearly a year of operation with several hundred sets of products, the bidirectional current-driven RF power amplifier power amplifier power supply circuit provides a stable and reliable operating state for the gallium nitride transistor power amplifier. Through regular inspections and after-sales statistics, the reliability of the power amplifier has been significantly improved after adopting this invention, with user satisfaction approaching 100%. Compared to before this invention, it has reduced a significant amount of after-sales time and costs, indirectly increasing the company's profit margin and laying the foundation for the company's healthy development.

[0078] The above-disclosed embodiments are merely one or more preferred embodiments of this application and should not be construed as limiting the scope of this application. Those skilled in the art can understand that all or part of the processes for implementing the above embodiments and equivalent changes made in accordance with the claims of this application still fall within the scope of this application.

Claims

1. A power supply circuit for a radio frequency power amplifier with bidirectional current drive, characterized in that, It includes a dual-circuit negative pressure protection circuit, a second circuit, a third circuit, a fourth circuit, a fifth circuit, and a sixth circuit. The dual-circuit negative pressure protection circuit is connected to the second circuit, the second circuit is connected to the third circuit, the third circuit is connected to the fourth circuit and the fifth circuit respectively, and the fourth circuit is connected to the sixth circuit. The dual-path negative voltage protection circuit is used to monitor the main gate negative voltage Vgs-main and the peak gate negative voltage Vgs-peak, and to shut off the drain power supply VDS when either negative voltage is lost. The second circuit is used to regulate the 50V DC voltage to 12V; The third circuit is used to regulate the 12V DC voltage to 5V; The fourth circuit is used to convert DC 5V to DC -5V; The fifth circuit is used to convert DC 5V to DC -5.8V; The sixth circuit is used to regulate DC-5V to DC-2.5V and increase bidirectional current drive capability, and to supply power to the main gate negative voltage Vgs-main.

2. The power supply circuit for the radio frequency power amplifier with bidirectional current drive as described in claim 1, characterized in that, The dual-channel negative voltage protection circuit includes transistors Q2, Q4, and Q5, diodes D1 and D6, a P-channel MOSFET Q6, resistors R4, R5, R6, R9, and R10, and a filter capacitor C2. The main gate negative voltage Vgs-main is connected to one end of diode D6, and the other end of diode D6 is connected to resistors R9, R4, R6, R10, P-channel MOSFET Q6, filter capacitor C2 and transistor Q5. One end of transistor Q5 is connected to transistors Q2 and Q4; One end of diode D1 is connected to resistor R4 and transistor Q2; One end of transistor Q2 is connected to resistor R6 and transistor Q4; One end of resistor R5 is connected to resistor R10 and P-channel MOSFET Q6, and the other end of resistor R5 is connected to transistor Q4. One end of the P-channel MOSFET Q6 is connected to the filter capacitor C2, and the other end of the P-channel MOSFET Q6 is connected to the drain power supply VDS.

3. The power supply circuit for the radio frequency power amplifier with bidirectional current drive as described in claim 2, characterized in that, The second circuit includes a three-terminal voltage regulator U1, a filter capacitor C1, and a filter capacitor C3. The first terminal of the three-terminal voltage regulator U1 is connected to the filter capacitors C1 and C2, and the third terminal of the three-terminal voltage regulator U1 is connected to the filter capacitor C3.

4. The power supply circuit for the radio frequency power amplifier with bidirectional current drive as described in claim 3, characterized in that, The third circuit includes a three-terminal voltage regulator U2, filter capacitors C4, C5, and C19. The first terminal of the three-terminal voltage regulator U2 is connected to filter capacitors C4, C5, and C3, and the third terminal of the three-terminal voltage regulator U2 is connected to filter capacitor C19.

5. The power supply circuit for the radio frequency power amplifier with bidirectional current drive as described in claim 4, characterized in that, The fourth circuit includes a negative voltage converter U4, capacitors C10, C12, and C14, and resistors R8, R11, and R12. The first terminal of the negative voltage converter U4 is connected to capacitor C10 and filter capacitor C19; The second terminal of the negative voltage converter U4 is connected to capacitor C12; The fourth terminal of the negative voltage converter U4 is connected to capacitor C12; the fifth terminal of the negative voltage converter U4 is connected to resistor R11 and capacitor C14. The sixth terminal of the negative voltage converter U4 is connected to capacitor C10 and resistor R8; The seventh terminal of the voltage converter U4 is connected to resistors R8 and R12; Resistor R12 is connected to resistor R11.

6. The power supply circuit for the radio frequency power amplifier with bidirectional current drive as described in claim 5, characterized in that, The fifth circuit includes a negative voltage converter U3, capacitors C7, C8, C9, C11, C18, C20, and C21, resistors R1 and R2, inductors L2, L3, and L4, diode D3, and adjustable potentiometer RP2. The first terminal of the negative voltage converter U3 is connected to inductor L3 and capacitor C9; The third terminal of the negative voltage converter U3 is connected to resistor R1, capacitor C8 and resistor R2; The fourth terminal of the negative voltage converter U3 is connected to capacitor C7, inductor L3, capacitor C19, and capacitor C10; The fifth terminal of the negative voltage converter U3 is connected to the fourth terminal of the negative voltage converter U3, capacitor C7, inductor L3, capacitor C19, and capacitor C10. One end of capacitor C9 is connected to diode D3 and inductor L2; One end of capacitor C8 is connected to resistor R2, and the other end of capacitor C8 is connected to inductor L2, capacitor C21 and adjustable potentiometer RP2. One end of the adjustable potentiometer RP2 is connected to the resistor R2, and the other end of the adjustable potentiometer RP2 is connected to the capacitors C21 and C20, the inductor L4, and the capacitor C18. One end of inductor L4 is connected to capacitor C11.

7. The power supply circuit for a radio frequency power amplifier with bidirectional current drive as described in claim 6, characterized in that, The sixth circuit includes an operational amplifier U5, capacitors C15, C17, C13, and C16, resistors R13, R14, R30, R31, and R32, an inductor L1, an N-channel JFETQ3, a P-channel JFETQ1, and an adjustable potentiometer RP1. The negative terminal of operational amplifier U5 is connected to resistors R14 and R13, the positive terminal of operational amplifier U5 is connected to resistors R32 and R31, one end of operational amplifier U5 is connected to resistor R31, capacitor C17, capacitor C15, P-channel JFETQ1 and capacitor C14, and the other end of operational amplifier U5 is connected to N-channel JFETQ3 and P-channel JFETQ1. The N-channel JFETQ3 is connected to the adjustable potentiometer RP1, capacitor C16 and inductor L1. Adjustable potentiometer RP1 is connected to resistor R14; Inductor L1 is connected to capacitor C13 and resistor R30.

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