A power-on and alarm protection circuit for a gallium nitride power amplifier

Abstract

The invention discloses a power-on and alarm protection circuit for a gallium nitride power amplifier, which is composed of a power-on delay circuit, a detection and alarm circuit and a DC-DC conversion circuit; the detection and alarm circuit comprises a detection and alarm circuit for power, current and temperature and a negative voltage alarm circuit, wherein the outputs of the alarm circuits for power, current, temperature and negative pressure are directly connected in parallel in a line-AND manner to form an alarm signal output, and the circuit is simple and easy to expand; the alarm signal is connected to the reset input terminal of the power-on delay circuit, thereby realizing the combination of the alarm protection circuit and the power-on delay circuit; the power-on delay circuit adopts a delay trigger chip, and the alarm protection time is automatically extended, which is beneficial to the protection of the power amplifier tube, and the alarm protection is self-recovering; the circuit is entirely implemented by hardware, does not require software control, has a fast response speed, and has a reliable protection function, and can meet the basic requirements of a miniaturized power amplifier.

Description

Technical Field

[0001] The present invention relates to the technical field of power amplifiers, and in particular to a power-on and alarm protection circuit for a gallium nitride power amplifier. Background Art

[0002] GaN (gallium nitride) power amplifier devices belong to the third generation of semiconductor power devices. They have the advantages of high voltage resistance, high power density, high junction temperature, low thermal resistance, large input and output resistance, small capacitance, and simple broadband matching. They are being increasingly used in the fields of wireless communications and electronic countermeasures.

[0003] The GaN power amplifier is an enhancement-mode device. When the gate-source voltage is zero, the device is fully turned on. When the gate-source voltage drops to a certain negative value, the device is completely turned off. There are power-on timing requirements during operation, that is, the gate negative bias voltage must be applied first, and then the drain power supply voltage must be applied. Incorrect timing will burn out the power amplifier tube.

[0004] GaN power amplifiers are relatively expensive and fragile devices. When designing power amplifiers, it is necessary to consider how to protect the power amplifier tubes to avoid power amplifier failure or malfunction caused by overvoltage, overtemperature, overcurrent, and overload.

[0005] At present, GaN power amplifiers are generally designed with power-on timing circuits and some protection circuits, such as temperature protection, current protection, power protection, negative voltage protection, overvoltage protection, undervoltage protection and other protections. The power-on timing circuit is independent of the protection circuit, and the protection function requires software participation. Software control is required to complete parameter collection, comparison and judgment, output control and other operations. Software control is required to complete alarm protection self-recovery. The response speed is slow and the circuit is complex, which is not conducive to the miniaturization of the power amplifier.

[0006] Based on the above defects and shortcomings, it is necessary to improve the existing technology and design a power-on and alarm protection circuit for a gallium nitride power amplifier. Summary of the invention

[0007] The main technical problem solved by the present invention is to provide a power-on and alarm protection circuit for a gallium nitride power amplifier, which has a power-on circuit and current, temperature, power, and negative voltage protection circuits, and the outputs of the alarm protection circuit are directly connected in parallel, the power-on circuit is combined with the protection circuit, the circuit is entirely implemented by hardware, the protection function can be self-recovering, the circuit is simple, the protection function is reliable, and it is easy to expand, which is conducive to the miniaturization of the power amplifier.

[0008] In order to solve the above technical problems, a technical solution adopted by the present invention is: to provide a power-on and alarm protection circuit for a gallium nitride power amplifier, comprising a power-on delay circuit, a detection and alarm circuit and a DC-DC conversion circuit, wherein a first input end of the power-on delay circuit is connected to an external DC power supply as a power input end, a second input end of the power-on delay circuit is connected to an alarm output signal of the detection and alarm circuit as a reset end, an output end of the power-on delay circuit is connected to a drain power supply circuit of a gallium nitride power device, and the power-on delay circuit is configured such that when the voltage of the power input end reaches a certain threshold and there is no signal at the reset end, the voltage of the output end starts to rise and reaches the voltage of the power input end after a time T, otherwise the voltage of the output end remains at 0V;

[0009] The detection and alarm circuit includes a power detection circuit, a power alarm circuit, a current detection circuit, a current alarm circuit, a temperature detection circuit, a temperature alarm circuit and a negative pressure alarm circuit. The input terminals of the power, current and temperature alarm circuits are connected to the output terminals of the corresponding detection circuits. The output terminals of the power alarm circuit, the current alarm circuit, the temperature alarm circuit and the negative pressure alarm circuit are connected in parallel in a wired-AND manner to form an alarm signal output. The detection and alarm circuit is configured to convert the detected physical quantity into a DC voltage. When the DC voltage exceeds a set threshold, the hardware comparator is triggered to reverse and generate an alarm signal.

[0010] The input end of the DC-DC conversion circuit is connected to an external DC power supply to convert the external DC power supply into a positive voltage +Vs output and a negative voltage -Vs output; the positive voltage +Vs output is used to power the power-on delay circuit and the detection and alarm circuit; the negative voltage -Vs output is used to power the bias network of the gallium nitride power device.

[0011] Preferably, the power-on delay circuit is composed of a delay trigger, a drive circuit and an electronic switch circuit; the delay trigger includes a power input terminal, a reset terminal and an output terminal, and is configured such that when the power input terminal voltage is higher than a threshold and there is no signal at the reset terminal, the output terminal flips after a delay of T, otherwise the output terminal remains unchanged;

[0012] The output end of the delay trigger is connected to the input end of the driving circuit, and is output from the output end after the driving circuit enhances the driving capability;

[0013] The output end of the driving circuit is connected to the control end of the electronic switch circuit to control the closing of the electronic switch. When the electronic switch is closed, the input end and the output end of the power-on delay circuit are externally connected.

[0014] Preferably, the power detection circuit is composed of a power sampling circuit, an attenuation network and a detection network; the power sampling circuit is composed of a directional coupler or a circulator, and is configured to obtain a portion of the power in a certain proportion from the output signal of the gallium nitride power amplifier to the sampling output end; the sampling output end is connected to the input end of the attenuation network, and the attenuation network is composed of a discrete network or an integrated network, which reduces the power attenuation of the input sampling signal; the output of the attenuation network is connected to the detection network, and the detection network is composed of a linear power detection circuit or a logarithmic power detection circuit, which converts the input RF signal into a DC voltage output.

[0015] Preferably, the current detection circuit is composed of a current detection chip, and the detection output voltage is linearly related to the passing current.

[0016] Preferably, the temperature detection circuit is composed of a temperature detection chip, and the detection output voltage is linearly related to the detection temperature.

[0017] Preferably, the power alarm circuit, current alarm circuit and temperature alarm circuit are respectively composed of a comparator and a voltage-dividing resistor network, and the comparator output structure is an OC or OE structure; the voltage-dividing resistor network is composed of resistor 1 and resistor 2 connected in series between the power supply VCC and the ground, and the connection point of resistor 1 and resistor 2 is connected to the positive input terminal of the comparator; the negative input terminal of the comparator is connected to the output of each detection circuit.

[0018] Preferably, the negative voltage alarm circuit is composed of a comparator, two voltage-dividing resistor networks and a clamping diode, and the comparator output structure is an OC or OE structure; the voltage-dividing resistor network 1 is composed of resistor 1 and resistor 2 connected in series between the power supply VCC and the ground, and the connection point of resistor 1 and resistor 2 is connected to the positive input terminal of the comparator; the voltage-dividing resistor network 2 is composed of resistor 3 and resistor 4 connected in series between the power supply VCC and the negative power supply -Vs, and the connection point of resistor 3 and resistor 4 is connected to the negative input terminal of the comparator; the cathode of the clamping diode is connected to the negative input terminal of the comparator, and the positive electrode is grounded.

[0019] Preferably, the electronic switch circuit comprises a P-channel MOS tube, the source of the electronic switch circuit is connected to the power input terminal, the gate is connected to the output terminal of the drive circuit (12) as the control terminal of the electronic switch, and the drain is connected to the drain circuit of the power amplifier tube as the power output terminal.

[0020] Preferably, the driving circuit (12) comprises an NPN transistor or an N-channel MOS tube; the base of the NPN transistor or the gate of the N-channel MOS tube is connected to the output end of the delay trigger; the collector of the NPN transistor or the drain of the N-channel MOS tube is connected to the control end of the electronic switch circuit as the output end; the emitter of the NPN transistor or the source of the N-channel MOS tube is grounded.

[0021] Preferably, the output of the delay trigger of the power-on delay circuit is output as an alarm signal of the power amplifier.

[0022] Compared with the prior art, the present invention has the following beneficial effects:

[0023] The alarm detection outputs are directly connected in parallel, the circuit is simple and easy to expand;

[0024] The power-on circuit is combined with the alarm protection circuit, and the circuit is simple; the reset delay trigger chip is adopted, and it has a self-recovery function after the alarm is eliminated;

[0025] The circuit is entirely implemented by hardware, without the need for software control, has a fast response speed, reliable protection functions, and can meet the basic needs of miniaturized power amplifiers. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 The present invention is a block diagram of a power-on and alarm protection circuit for a gallium nitride power amplifier.

[0027] Figure 2 The figure is a detailed block diagram of a power-on and alarm protection circuit for a gallium nitride power amplifier.

[0028] Figure 3 The present invention is a block diagram of a power detection circuit for a power-on and alarm protection circuit of a gallium nitride power amplifier.

[0029] Figure 4 A circuit diagram of an embodiment of a power-on and alarm protection circuit for a gallium nitride power amplifier.

[0030] Among them, 1. power-on delay circuit, 11. delay trigger, 12. drive circuit, 13. electronic switch circuit;

[0031] 2. Detection and alarm circuit, 21. Power detection circuit, 211. Power sampling circuit, 212. Attenuation network, 213. Detection network, 22. Power alarm circuit, 23. Current detection circuit, 24. Current alarm circuit, 25. Temperature detection circuit, 26. Temperature alarm circuit, 27. Negative pressure alarm circuit;

[0032] 3. DC-DC conversion circuit. DETAILED DESCRIPTION

[0033] The preferred embodiments of the present invention are described in detail below in conjunction with the accompanying drawings so that the advantages and features of the invention can be more easily understood by those skilled in the art, thereby making a clearer and more definite definition of the protection scope of the present invention.

[0034] See also Figures 1 to 4 , the embodiment of the present invention includes:

[0035] A power-on and alarm protection circuit for a gallium nitride power amplifier, the power-on and alarm protection circuit for a gallium nitride power amplifier comprising a delay trigger 11, a drive circuit 12 and an electronic switch circuit 13, a power detection circuit 21, a power alarm circuit 22, a current detection circuit 23, a current alarm circuit 24, a temperature detection circuit 25, a temperature alarm circuit 26, a negative voltage alarm circuit 27 and a DC-DC conversion circuit 3.

[0036] The delay trigger 11, the drive circuit 12 and the electronic switch circuit 13 constitute a power-on delay circuit 1. The output end of the delay trigger 11 is connected to the input end of the drive circuit 12, and the output end is output after the drive circuit 12 enhances the driving capability; the output end of the drive circuit 12 is connected to the control end of the electronic switch circuit 13 to control the closing of the electronic switch. When the electronic switch is closed, the input end and the output end of the power-on delay circuit 1 are externally connected.

[0037] The power detection circuit 21, the power alarm circuit 22, the current detection circuit 23, the current alarm circuit 24, the temperature detection circuit 25, the temperature alarm circuit 26 and the negative pressure alarm circuit 27 constitute a detection and alarm circuit 2. The output ends of the power alarm circuit 22, the current alarm circuit 24, the temperature alarm circuit 26 and the negative pressure alarm circuit 27 are connected in parallel in a line-AND manner to form an alarm signal output. The detection and alarm circuit 2 is configured to convert the detected physical quantity into a DC voltage. When the DC voltage exceeds a set threshold, it triggers the hardware comparator to reverse and generate an alarm signal.

[0038] The first input end of the power-on delay circuit 1 is connected to the external DC power supply as a power input end, the second input end of the power-on delay circuit 1 is connected to the alarm output signal of the detection and alarm circuit 2 as a reset end, and the output end of the power-on delay circuit 1 is connected to the drain power supply circuit of the gallium nitride power device. The power-on delay circuit 1 is configured so that when the voltage of the power input end reaches a certain threshold and there is no signal at the reset end, the voltage of the output end starts to rise and reaches the voltage of the power input end after a time T (generally on the order of hundreds of milliseconds), otherwise the voltage of the output end remains at 0V.

[0039] The power detection circuit 21 is composed of a power sampling circuit 211, an attenuation network 212 and a detection network 213; the power sampling circuit 211 is composed of a directional coupler or a circulator W1, the circulator W1 is used to detect the reflected power at the output end of the power amplifier, and the power sampling circuit 211 is configured to obtain a portion of the power at a certain ratio from the output signal of the gallium nitride power amplifier to the sampling output end; the sampling output end is connected to the input end of the attenuation network 212, the attenuation network 212 is composed of a discrete network or an integrated network, and the power attenuation of the input sampling signal is reduced. The integrated network An attenuator R4 is used, and the attenuation of the attenuator R4 is 30dB; the output of the attenuation network 212 is connected to the detection network 213, and the detection network 213 is composed of a linear power detection circuit or a logarithmic power detection circuit, wherein the linear power detection circuit is composed of a detector V2, a resistor R6 and a capacitor C2, and the output end of the detector V2 is connected in parallel to the resistor R6 and the capacitor C2 to the ground. The model of the detector V2 is HSMS-2825, and the detected voltage value is linearly related to the voltage value of the reflected power. The detection network 213 converts the input RF signal into a DC voltage output.

[0040] The current detection circuit 23 is composed of a current detection chip, and the detection output voltage is linearly related to the current passing through. The current detection chip adopts a current sensor N5, and the current sensor N5 model is CC6902SO-10A. The current detection range is 0-10A, and the output voltage is linearly related to the current passing through, and the relationship is V=2.5+0.2×I.

[0041] The temperature detection circuit 25 is composed of a temperature detection chip, and the detection output voltage is linearly related to the detection temperature. The temperature detection chip uses a temperature sensor N6, and the temperature sensor N6 model is CT7035BKR. The output voltage is linearly related to the temperature, and the relationship is V=0.6+0.01×T.

[0042] The power alarm circuit 22 is composed of a comparator N1 and a voltage-dividing resistor network. Here, the voltage-dividing resistor network is composed of a resistor R1 and a resistor R2 connected in series, with both ends connected to the ground and the power supply VCC respectively. The common end of the resistor R1 and the resistor R2 is connected to the non-inverting input end of the comparator N1. The comparator type N1 is SGM8709, and its output structure is an open collector type. When the detected reflected power exceeds the comparison threshold value, the comparator N1 output is low resistance.

[0043] The temperature alarm circuit 26 is composed of a comparator N2 and a voltage-dividing resistor network. Here, the voltage-dividing resistor network is composed of a resistor R11 and a resistor R12 connected in series, with both ends connected to the ground and the power supply VCC respectively, and the common end is connected to the non-inverting input end of the comparator N2. The comparator N2 model is SGM8709, and its output structure is an open collector type. When the temperature is higher than 90°C, the comparator N2 output is low resistance.

[0044] The current alarm circuit 24 is composed of a comparator N4 and a voltage-dividing resistor network R15 and R16. Here, the voltage-dividing resistor network is composed of resistors R15 and R16 connected in series, with both ends connected to the ground and the power supply VCC respectively, and the common end is connected to the non-inverting input of the comparator N4. The comparator N4 model is SGM8709, and its output structure is an open collector type. When the current is higher than 5A, the comparator N4 output is low resistance.

[0045] The negative input terminals of the comparators of the power alarm circuit 22 , the current alarm circuit 24 and the temperature alarm circuit 26 are connected to the output terminals of the corresponding power detection circuit 21 , the current detection circuit 23 and the temperature detection circuit 25 .

[0046] The negative voltage alarm circuit 27 is composed of a comparator N3, two voltage-dividing resistor networks and a clamping diode V4. The output structure of the comparator N3 is an OC or OE structure. The model of the comparator N3 is SGM8709, and its output structure is an open collector type. When the voltage of the -6.5V power supply is higher than -6V, the comparator output is low resistance; a voltage-dividing resistor network is composed of a resistor R17 and a resistor R18 connected in series between the power supply VCC and the ground, and the connection point of the resistor R17 and the resistor R18 is connected to the positive input terminal of the comparator N3; another voltage-dividing resistor network is composed of a resistor R19 and a resistor R20 connected in series between the power supply VCC and the negative power supply -Vs, and the connection point of the resistor R19 and the resistor R20 is connected to the negative input terminal of the comparator N3; the cathode of the clamping diode V4 is connected to the negative input terminal of the comparator N3, and the positive electrode is grounded.

[0047] The output of the delay trigger 11 is used as the alarm signal output of the power amplifier. The delay trigger 11 is composed of a reset chip N7. The reset chip N7 model is SGM811, has a manual reset input pin, an internal weak pull-up, and a power-on delay time of 150mS. The delay trigger 11 includes a power input terminal, a reset terminal and an output terminal. It is configured that when the power input terminal voltage is higher than the threshold and there is no signal at the reset terminal, the output terminal flips after a delay of T, otherwise the output terminal remains unchanged.

[0048] The driving circuit 12 is composed of a transistor V3 and a resistor R9. The transistor V3 is of model 2N5551. One end of the resistor R9 is connected to the base of the transistor V3. The resistor R9 is connected to the output end of the reset chip N7. The collector of the transistor V3 is the output end connected to the control end of the electronic switch circuit 13, and the emitter of the transistor V3 is grounded.

[0049] The electronic switch circuit 13 is composed of a transistor V1, a resistor R5 and a resistor R8. The transistor V1 model is NCE60P82K. The resistor R5 is connected in parallel between the gate and source of the transistor V1. One end of the resistor R8 is connected to the gate of the transistor V1. The source of the transistor V1 is connected to the power input end. The gate of the transistor V1 is connected to the resistor R8 and then connected to the output end of the drive circuit 12, i.e., the collector of the transistor V3, as the control end of the electronic switch. The drain of the transistor V3 is connected to the drain circuit of the power amplifier tube as the power output end.

[0050] The input end of the DC-DC conversion circuit 3 is connected to the external DC power supply, and the external DC power supply is converted into a positive voltage +Vs output and a negative voltage -Vs output; the positive voltage +Vs output is used to power the power-on delay circuit 1 and the detection and alarm circuit 2; the negative voltage -Vs output is used to power the bias network of the gallium nitride power device. The DC-DC conversion circuit 3 includes a switch module N8 (model K78U24-300), a switch module N9 (model K7805MT-500), and a switch module N10 (model K78X6MT-500), and the output voltages are 24V, 5V, and -6.5V, respectively.

[0051] The input end of the switch module N8 is connected in parallel with the capacitor C5 to the ground, and the output end is connected in parallel with the capacitor C6 to the ground. The input end of the switch module N9 is connected in parallel with the capacitor C7 to the ground, and the output end is connected in parallel with the capacitor C8 to the ground. The input end of the switch module N10 is connected in parallel with the capacitor C9 to the ground, and the output end is connected in series with the inductor L1. The output end of the inductor L1 is connected in parallel with the capacitor C10 to the ground.

[0052] The -6.5V power supply output by the switch module N10 is supplied to the gate circuit of the GaN amplifier tube, and the 48V power supply output by the electronic switch circuit 13 is connected to the drain power supply circuit of the GaN amplifier tube.

[0053] When the amplifier power is powered on, the -6.5V power supply is established first, and after a delay of 150mS, the electronic switch circuit 13 connects to the 48V power supply, meeting the power-on timing requirements of the gallium nitride amplifier tube.

[0054] The outputs of the power alarm circuit 22, the current alarm circuit 23, the temperature alarm circuit 24, and the negative pressure alarm circuit 27 are directly connected in parallel and connected to the manual reset input of the delay trigger 11. When any alarm occurs, the manual reset pin is pulled low, causing a manual reset, causing the electronic switch circuit 13 to shut off the 48V power supply for up to 150mS. When the alarm is eliminated, the delay trigger 11 outputs a high level, and the electronic switch circuit 13 reconnects the 48V power supply, realizing the protection self-recovery function.

[0055] The output of the delay trigger 11 can be used as an alarm signal output of the power amplifier, and a low level indicates that an alarm occurs in the amplifier.

[0056] The invention discloses a power-on and alarm protection circuit for a gallium nitride power amplifier, which comprises a power-on circuit and current, temperature, power and negative voltage protection circuits, and the outputs of the alarm protection circuits are directly connected in parallel, the power-on circuit is combined with the protection circuit, the circuit is entirely implemented by hardware, the protection function can be self-recovering, the circuit is simple, the protection function is reliable, and it is easy to expand, which is conducive to the miniaturization of the power amplifier.

[0057] The above descriptions are merely embodiments of the present invention and are not intended to limit the patent scope of the present invention. Any equivalent structure or equivalent process transformation made using the contents of the present invention specification and drawings, or directly or indirectly applied in other related technical fields, are also included in the patent protection scope of the present invention.

Claims

1. A power-on and alarm protection circuit for a gallium nitride power amplifier, characterized in that: The invention comprises a power-on delay circuit (1), a detection and alarm circuit (2) and a DC-DC conversion circuit (3); the first input end of the power-on delay circuit (1) is connected to an external DC power supply as a power input end; the second input end of the power-on delay circuit (1) is connected to an alarm output signal of the detection and alarm circuit (2) as a reset end; the output end of the power-on delay circuit (1) is connected to a drain power supply circuit of a gallium nitride power device; the power-on delay circuit (1) is configured such that when the voltage at the power input end reaches a certain threshold and there is no signal at the reset end, the voltage at the output end starts to rise and reaches the voltage at the power input end after a time T; otherwise, the voltage at the output end remains at 0V; The detection and alarm circuit (2) comprises a power detection circuit (21), a power alarm circuit (22), a current detection circuit (23), a current alarm circuit (24), a temperature detection circuit (25), a temperature alarm circuit (26) and a negative pressure alarm circuit (27); the input ends of the power, current and temperature alarm circuits are connected to the outputs of the corresponding detection circuits; the output ends of the power alarm circuit (22), the current alarm circuit (24), the temperature alarm circuit (26) and the negative pressure alarm circuit (27) are connected in parallel in a wired-AND manner to form an alarm signal output; the detection and alarm circuit (2) is configured to convert the detected physical quantity into a direct current voltage; when the direct current voltage exceeds a set threshold, the hardware comparator is triggered to invert and generate an alarm signal; The input end of the DC-DC conversion circuit (3) is connected to an external DC power supply to convert the external DC power supply into a positive voltage +Vs output and a negative voltage -Vs output; the positive voltage +Vs output is used to supply power to the power-on delay circuit (1) and the detection and alarm circuit (2); and the negative voltage -Vs output is used to supply power to a bias network of a gallium nitride power device.

2. The power-on and alarm protection circuit for a gallium nitride power amplifier according to claim 1, characterized in that: The power-on delay circuit (1) is composed of a delay trigger (11), a drive circuit (12) and an electronic switch circuit (13); the delay trigger (11) comprises a power input terminal, a reset terminal and an output terminal, and is configured such that when the voltage of the power input terminal is higher than a threshold and there is no signal at the reset terminal, the output terminal flips after a delay of T, otherwise the output terminal remains unchanged; The output end of the delay trigger (11) is connected to the input end of the drive circuit (12), and is output from the output end after the drive circuit (12) enhances the driving capability; The output end of the drive circuit (12) is connected to the control end of the electronic switch circuit (13) to control the closing of the electronic switch. When the electronic switch is closed, the input end and the output end of the power-on delay circuit (1) are externally connected.

3. The power-on and alarm protection circuit for a gallium nitride power amplifier according to claim 1, characterized in that: The power detection circuit (21) is composed of a power sampling circuit (211), an attenuation network (212) and a detection network (213); the power sampling circuit (211) is composed of a directional coupler or a circulator, and is configured to obtain a portion of power from the output signal of the gallium nitride power amplifier at a certain ratio to a sampling output end; the sampling output end is connected to the input end of the attenuation network (212), and the attenuation network (212) is composed of a discrete network or an integrated network, and reduces the power attenuation of the input sampling signal; the output of the attenuation network (212) is connected to the detection network (213), and the detection network (213) is composed of a linear power detection circuit or a logarithmic power detection circuit, and converts the input radio frequency signal into a DC voltage output.

4. The power-on and alarm protection circuit for a gallium nitride power amplifier according to claim 1, characterized in that: The current detection circuit (23) is composed of a current detection chip, and the detection output voltage is linearly related to the passing current.

5. The power-on and alarm protection circuit for a gallium nitride power amplifier according to claim 1, characterized in that: The temperature detection circuit (25) is composed of a temperature detection chip, and the detection output voltage is in a linear relationship with the detection temperature.

6. The power-on and alarm protection circuit for a gallium nitride power amplifier according to claim 1, characterized in that: The power alarm circuit (22), the current alarm circuit (24) and the temperature alarm circuit (26) are respectively composed of a comparator and a voltage-dividing resistor network, and the output structure of the comparator is an OC or OE structure; the voltage-dividing resistor network is composed of a resistor 1 and a resistor 2 connected in series between a power supply VCC and a ground, and the connection point of the resistor 1 and the resistor 2 is connected to the positive input terminal of the comparator; and the negative input terminal of the comparator is connected to the output of each detection circuit.

7. The power-on and alarm protection circuit for a gallium nitride power amplifier according to claim 1, characterized in that: The negative voltage alarm circuit (27) is composed of a comparator, two voltage-dividing resistor networks and a clamping diode, and the comparator output structure is an OC or OE structure; the voltage-dividing resistor network 1 is composed of resistors 1 and 2 connected in series between a power supply VCC and a ground, and the connection point of resistors 1 and 2 is connected to the positive input terminal of the comparator; the voltage-dividing resistor network 2 is composed of resistors 3 and 4 connected in series between a power supply VCC and a negative power supply -Vs, and the connection point of resistors 3 and 4 is connected to the negative input terminal of the comparator; the cathode of the clamping diode is connected to the negative input terminal of the comparator, and the positive electrode is grounded.

8. The power-on and alarm protection circuit for a gallium nitride power amplifier according to claim 2, characterized in that: The electronic switch circuit (13) comprises a P-channel MOS tube, the source of the electronic switch circuit (13) is connected to the power input terminal, the gate as the control terminal of the electronic switch is connected to the output terminal of the drive circuit (12), and the drain as the power output terminal is connected to the drain circuit of the power amplifier tube.

9. The power-on and alarm protection circuit for a gallium nitride power amplifier according to claim 2, characterized in that: The driving circuit (12) comprises an NPN transistor or an N-channel MOS tube; the base of the NPN transistor or the gate of the N-channel MOS tube is connected to the output end of the delay trigger (11); the collector of the NPN transistor or the drain of the N-channel MOS tube is connected to the control end of the electronic switch circuit (13) as the output end; the emitter of the NPN transistor or the source of the N-channel MOS tube is grounded.

10. The power-on and alarm protection circuit for a gallium nitride power amplifier according to claim 2, characterized in that: The output of the delay trigger (11) of the power-on delay circuit (1) is output as an alarm signal of the power amplifier.

Images