System and method for testing trap effect of gallium nitride radio frequency device

Abstract

The invention provides a system and a method for testing a trap effect of a gallium nitride radio frequency device. According to the test system and method, a network analyzer is combined with a power amplifier to provide a high-power radio frequency pulse signal of a device in an actual working environment, and a first tuner and a second tuner are adopted to perform impedance tuning on an input end and an output end of the device, so that the high-power radio frequency pulse signal of the device can be tested under the actual working frequency and specific input and output impedance. According to the method, the trap effect of the gallium nitride radio frequency device is represented, the method has good accuracy and authenticity, guidance is provided for device research and development and power amplifier circuit design, and product updating and iteration are promoted.

Description

Technical Field

[0001] The present invention relates to the field of semiconductor testing technologies, and particularly relates to a testing system and method for trap effects of gallium nitride radio frequency devices. Background Art

[0002] As a third-generation semiconductor device, gallium nitride radio frequency devices have excellent high-frequency characteristics and are widely applicable to high-frequency communication fields, power electronics fields, etc. Among them, during the material growth and device fabrication processes of gallium nitride radio frequency devices, defects will inevitably be introduced. These defects will produce trap capture effects during device operation, causing frequency response delays, resulting in phenomena such as current collapse, radio frequency scattering, and gate delay, leading to device degradation and instability, and even device failure. Therefore, effectively characterizing the traps in gallium nitride radio frequency devices is of great significance for optimizing device design and improving its performance.

[0003] For example Figure 1 As shown, currently gallium nitride radio frequency devices are widely used as the core devices of 5G base station power amplifiers. To improve the modulation signal efficiency, 5G base station power amplifiers adopt the Doherty architecture. The core technology of this power amplifier architecture is the active load modulation technology, that is, under a large input signal power, the peak amplifier 102 performs load pulling on the main amplifier 101, so that the main amplifier 101 always operates on the optimal load path to achieve the best efficiency under the modulation signal. And to optimize the radio frequency gallium nitride radio frequency devices of this type of power amplifier, it is necessary to effectively characterize the trap effects under their actual working conditions. In this regard, the existing trap effect characterization is mainly achieved through a pulsed IV system. That is, a pulsed voltage is applied to the gallium nitride radio frequency device to be tested through this system, and the current responses under different voltage stresses and different pulse widths are recorded. However, the above method cannot characterize the radio frequency current response of gallium nitride radio frequency devices when applied in actual base station power amplifiers.

[0004] Therefore, there is an urgent need for a new testing method to characterize the trap effects of devices under high-power radio frequency pulse signals. Summary of the Invention

[0005] The purpose of the present invention is to provide a testing system and method for trap effects of gallium nitride radio frequency devices to solve the problem of how to accurately characterize the trap effects of gallium nitride radio frequency devices under high-power radio frequency pulse signals.

[0006] To solve the above technical problems, the present invention provides a testing system for trap effects of gallium nitride radio frequency devices, including:

[0007] A network analyzer, configured to provide radio frequency pulse signals and measure the power at the input end and output end of the gallium nitride radio frequency device;

[0008] A power amplifier, connected to the network analyzer, for receiving the radio frequency pulse signal and amplifying the power of the radio frequency pulse signal;

[0009] An isolator, connected to the power amplifier, for receiving the radio frequency pulse signal after power amplification and filtering out clutter; and enabling the radio frequency pulse signal to be transmitted unidirectionally to the first tuner;

[0010] A first tuner, respectively connected to the isolator and the input end of the gallium nitride radio frequency device, for tuning the input source impedance of the gallium nitride radio frequency device;

[0011] A second tuner, respectively connected to the output end of the gallium nitride radio frequency device and the load, for tuning the output load impedance of the gallium nitride radio frequency device;

[0012] An oscilloscope, for collecting the output current of the gallium nitride radio frequency device and obtaining a current recovery curve to characterize the trap effect of the gallium nitride radio frequency device.

[0013] Optionally, in the test system for the trap effect of the gallium nitride radio frequency device, couplers are respectively arranged in the first tuner and the second tuner and are connected to the network analyzer, for coupling the incident signal and the reflected signal at the input end and the output end of the gallium nitride radio frequency device to the network analyzer, so that the network analyzer measures the power at the input end and the output end of the gallium nitride radio frequency device.

[0014] Optionally, in the test system for the trap effect of the gallium nitride radio frequency device, probes are respectively arranged in the first tuner and the second tuner, for respectively tuning the input source impedance and the output load impedance of the gallium nitride radio frequency device.

[0015] Optionally, in the test system for the trap effect of the gallium nitride radio frequency device, the test system for the trap effect of the gallium nitride radio frequency device further includes: a first bias tee, a second bias tee and a power supply; wherein, the power supply is respectively connected to the first bias tee and the second bias tee, for respectively providing a DC bias voltage to the first bias tee and the second bias tee; and,

[0016] The first bias tee is respectively connected to the isolator and the first tuner, for providing the DC bias voltage to the input end of the gallium nitride radio frequency device; and the second bias tee is respectively connected to the second tuner and the load, for providing the DC bias voltage to the output end of the gallium nitride radio frequency device, so that the gallium nitride radio frequency device operates under the DC bias voltage.

[0017] Optionally, in the test system for the trap effect of the gallium nitride radio frequency device, the power supply includes a DC voltage or a pulsed power supply.

[0018] Optionally, in the test system for the trap effect of the gallium nitride radio frequency device, the test system for the trap effect of the gallium nitride radio frequency device further includes an attenuator; the attenuator is respectively connected to the load and the second bias tee, and is at least used to attenuate the output signal of the gallium nitride radio frequency device.

[0019] Optionally, in the test system for the trap effect of the gallium nitride radio frequency device, the gallium nitride radio frequency device includes a GaN HEMT device, and the gate of the GaN HEMT device is the input end, the drain of the GaN HEMT device is the output end, and the source of the GaN HEMT device is grounded.

[0020] Optionally, in the test system for the trap effect of the gallium nitride radio frequency device, the amount of current collapse in the current recovery curve is used to characterize the trap density of the gallium nitride radio frequency device; the recovery time in the current recovery curve is used to characterize the trap density and trap energy level of the gallium nitride radio frequency device.

[0021] Based on the same inventive concept, the present invention also provides a method for testing the trap effect of a gallium nitride radio frequency device, including:

[0022] Using a network analyzer to provide a radio frequency pulse signal to a power amplifier;

[0023] The power amplifier amplifies the radio frequency pulse signal and transmits the amplified radio frequency pulse signal to an isolator;

[0024] After filtering out clutter, the isolator transmits the radio frequency pulse signal unidirectionally to a first tuner;

[0025] The first tuner transmits the radio frequency pulse signal to the input end of the gallium nitride radio frequency device and tunes the source impedance of the input end of the gallium nitride radio frequency device;

[0026] The output signal generated at the output end of the gallium nitride radio frequency device is transmitted to a load through a second tuner; wherein, the second tuner tunes the load impedance of the output end of the gallium nitride radio frequency device; and at the same time, an oscilloscope is used to collect the output current of the gallium nitride radio frequency device and obtain a current recovery curve to characterize the trap effect of the gallium nitride radio frequency device.

[0027] Optionally, in the method for testing the trap effect of the gallium nitride radio frequency device, after the isolator filters out clutter, during the process of unidirectionally transmitting the radio frequency pulse signal to the first tuner, the radio frequency pulse signal is transmitted to the first bias tee through the isolator, and after adding a DC bias voltage through the first bias tee, it is transmitted to the first tuner; and,

[0028] During the process of the output signal generated at the output end of the gallium nitride radio frequency device being transmitted to the load through the second tuner, the output signal is transmitted to the second bias tee through the second tuner, and after adding the DC bias voltage through the second bias tee, it is transmitted to the load;

[0029] Among them, a power supply is used to provide the DC bias voltage to the first bias tee and the second bias tee respectively, so that the gallium nitride radio frequency device operates under the DC bias voltage.

[0030] In summary, the present invention provides a system and method for testing the trap effect of a gallium nitride radio frequency device. Compared with the prior art, the present invention uses a network analyzer combined with a power amplifier to provide a high-power radio frequency pulse signal under the actual working environment of the device, and uses a first tuner and a second tuner to perform impedance tuning on the input and output ends of the device, so as to be able to characterize the trap effect of the gallium nitride radio frequency device at the actual working frequency and specific input and output impedances, with better accuracy and authenticity, which is beneficial to providing guidance for device research and development and power amplifier circuit design, and promoting product update and iteration. Description of the Drawings

[0031] Those of ordinary skill in the art will understand that the provided drawings are used to better understand the present invention and do not constitute any limitation to the scope of the present invention.

[0032] Figure 1 is a schematic diagram of the Doherty architecture in the prior art.

[0033] Figure 2 is a schematic diagram of the framework structure of the system for testing the trap effect of a gallium nitride radio frequency device in an embodiment of the present invention.

[0034] Figure 3 is a schematic diagram of the structure of a GaN HEMT device in an embodiment of the present invention.

[0035] Figure 4 is a schematic diagram of a radio frequency pulse signal in an embodiment of the present invention.

[0036] Figure 5 is a current recovery curve diagram in an embodiment of the present invention.

[0037] Figure 6 is in an embodiment of the present invention Figure 5Partial enlarged view of the current recovery curve graph.

[0038] Figure 7 It is a flowchart of the test method for the trap effect of the gallium nitride radio frequency device in the embodiment of the present invention.

[0039] And, in the drawings:

[0040] 101 - Main amplifier; 102 - Peak amplifier;

[0041] 200 - Network analyzer; 201 - Power amplifier; 202 - Isolator; 203 - First tuner; 204 - Second tuner; 205 - Load; 206 - Oscilloscope; 207 - First bias tee; 208 - Second bias tee; 209 - Power supply; 210 - Attenuator;

[0042] 301 - Defects in the GaN buffer layer; 302 - Interface defects between the GaN buffer layer and the AlGaN layer; 303 - Defects in the AlGaN layer; 304 - Interface defects between the AlGaN layer and the passivation layer;

[0043] S - Source; G - Gate; D - Drain; RF - Radio frequency pulse signal. Detailed implementation manners

[0044] To make the objectives, advantages, and features of the present invention clearer, the following further describes the present invention in detail with reference to the accompanying drawings and specific embodiments. It should be noted that the accompanying drawings are all in a very simplified form and not drawn to scale, only for facilitating and clearly assisting in explaining the objectives of the embodiments of the present invention. In addition, the structures shown in the accompanying drawings are often part of the actual structures. In particular, the emphases to be shown in each drawing are different, and sometimes different scales are used. It should also be understood that unless otherwise specifically stated or indicated, the terms "first", "second", "third", etc. in the specification are only used to distinguish each component, element, step, etc. in the specification, rather than to represent the logical relationship or sequential relationship, etc. between each component, element, step.

[0045] Please refer to Figure 2, this embodiment provides a test system for the trap effect of a gallium nitride radio frequency device, including: a network analyzer 200, configured to provide a radio frequency pulse signal and measure the power at the input and output ends of the gallium nitride radio frequency device; a power amplifier 201, connected to the network analyzer 200, configured to receive the radio frequency pulse signal and amplify the power of the radio frequency pulse signal; an isolator 202, connected to the power amplifier 201, configured to receive the radio frequency pulse signal after power amplification and filter out clutter; and to enable the unidirectional transmission of the radio frequency pulse signal to a first tuner 203; the first tuner 203 is respectively connected to the isolator 202 and the input end of the gallium nitride radio frequency device, and is configured to tune the source impedance of the input end of the gallium nitride radio frequency device; a second tuner 204 is respectively connected to the output end of the gallium nitride radio frequency device and a load 205, and is configured to tune the load impedance of the output end of the gallium nitride radio frequency device; an oscilloscope 206 is configured to collect the output current of the gallium nitride radio frequency device and obtain a current recovery curve to characterize the trap effect of the gallium nitride radio frequency device.

[0046] It can be seen that the test system provided in this embodiment uses the network analyzer 200 and the power amplifier 201 to provide a high-power radio frequency pulse signal under the actual working environment of the device, and uses the first tuner 203 and the second tuner 204 to tune the impedances of the input and output ends of the device. Therefore, it is possible to characterize the trap effect of the gallium nitride radio frequency device at the actual working frequency and specific impedance, with better accuracy and authenticity, which is beneficial to providing guidance for device research and development and power amplifier circuit design, and accelerating the product development process.

[0047] The following combines the attached Figures 2 to 7 Specifically describe the test system for the trap effect of the gallium nitride radio frequency device provided in this embodiment.

[0048] It should be noted that the trap effect of a gallium nitride radio frequency device refers to that due to the limitations of device material growth and epitaxial preparation processes, there will inevitably be defects inside it. These defects will act as traps to capture the internal carriers, resulting in a decline in device performance. Please refer to Figure 3 , taking the GaN HEMT device as an example, when the device is working, the defects 301 in the GaN buffer layer, the interface defects 302 between the GaN buffer layer and the AlGaN layer, the defects 303 in the AlGaN layer, and the interface defects 304 between the AlGaN layer and the passivation layer will all trap and capture carriers, thereby delaying the device frequency response, causing phenomena such as current collapse and gate delay, and leading to the degradation or even failure of the device. Therefore, the test system for the trap effect of the gallium nitride radio frequency device provided in this embodiment is intended to accurately measure the true situation of the trap effect of the gallium nitride radio frequency device in the actual working environment, so as to optimize and update the gallium nitride radio frequency device.

[0049] Please continue to refer to Figure 2 ,The test system for the trap effect of the gallium nitride radio frequency device provided in this embodiment includes: a network analyzer 200, a power amplifier 201, an isolator 202, a first tuner 203 (Tuner), a second tuner 204 (Tuner), an oscilloscope 206, a first bias tee 207 (Bias Tee), a second bias tee 208 (Bias Tee), and a power supply 209. Specifically, as Figure 4 shown, the network analyzer 200 is used to provide a radio frequency pulse signal RF. Among them, the network analyzer 200 has a built-in source to generate a specified frequency signal, and through its internal pulse modulator, it can generate the modulated radio frequency pulse signal RF. And, the network analyzer 200 is also used to measure the power at the input end and the output end of the gallium nitride radio frequency device through its built-in receiver to ensure the characteristic test of the trap effect at a specific power of the device.

[0050] The power amplifier 201 and the isolator 202 are sequentially connected to the signal output end of the network analyzer 200. And the power amplifier 201 is used to amplify the power of the received radio frequency pulse signal RF to reach the power required for the specified operating point of the device. The isolator 202 is used on the one hand to achieve the unidirectional transmission of the radio frequency pulse signal RF to avoid damaging the pre-stage power amplifier 201 due to signal reflection, and on the other hand, the isolator 202 can also have a built-in filtering function to filter out clutter and improve the test accuracy.

[0051] The power supply 209 is respectively connected to the first bias tee 207 and the second bias tee 208, and is used to provide DC bias voltages to the first bias tee 207 and the second bias tee 208 respectively. And, the first bias tee 207 is respectively connected to the isolator 202 and the first tuner 203; the second bias tee 208 is respectively connected to the second tuner 204 and the load 205. It can be understood that the first bias tee 207 and the second bias tee 208 are intended to add the DC bias voltage to the input end and the output end of the gallium nitride radio frequency device to provide a suitable static operating point. Among them, the power supply 209 can be a DC voltage or a pulse power supply; preferably a pulse power supply.

[0052] Optionally, the gallium nitride radio frequency device includes but is not limited to a GaN HEMT device. And when the gallium nitride radio frequency device is the GaN HEMT device, the gate G of the GaN HEMT device is the input end, the drain D of the GaN HEMT device is the output end, and the source S of the GaN HEMT device is grounded.

[0053] Furthermore, a first tuner 203 is also provided between the input end of the gallium nitride radio frequency device and the first bias tee 207; and, a second tuner 204 is also provided between the output end of the gallium nitride radio frequency device and the second bias tee 208. It should be noted that both the first tuner 203 and the second tuner 204 are internally provided with couplers, and the two couplers are respectively connected to the network analyzer 200. Their function is to couple the incident signals and reflection signals at the input end and output end of the gallium nitride radio frequency device to the receiver built in the network analyzer 200, so that the receiver built in the network analyzer 200 can measure the power at the input end and output end of the gallium nitride radio frequency device. In addition, probes are respectively provided in the first tuner 203 and the second tuner 204, which are used to tune the source impedance at the input end and the load impedance at the output end of the gallium nitride radio frequency device respectively, so as to simulate the actual working state of the gallium nitride radio frequency device. Based on this, the trap effect of the gallium nitride radio frequency device under actual specified working conditions can be characterized. For example, in the Doherty architecture adopted by the power amplifier in a 5G base station, the main amplifier has been under the load pulling of the peak amplifier, and the load pulling of the peak amplifier will directly affect the impedance variation at both ends of the main amplifier. Therefore, the test system provided in this embodiment can generate a radio frequency pulse signal RF with a specified frequency through the network analyzer 200 and the power amplifier 201, and combine the first tuner 203 and the second tuner 204 to accurately tune the impedance at both ends of the device, and then the trap effect of the gallium nitride radio frequency device under actual specified working conditions can be characterized, effectively improving the measurement accuracy. In other examples, by tuning the impedance at both ends of the device, the output current recovery situation at impedance points such as maximum output power, maximum drain efficiency, and power back-off can also be obtained.

[0054] Meanwhile, during the test, an oscilloscope 206 is used to collect the output current at the output end of the gallium nitride radio frequency device and obtain a current recovery curve to characterize the trap effect of the gallium nitride radio frequency device. For example, by using a radio frequency pulse signal RF with a pulse width of 100 μS and a duty cycle of 0.1%, testing the GaN HEMT device according to the test system provided in this embodiment, Figure 5 and Figure 6 the current recovery curve shown can be obtained. Among them, Figure 6 is Figure 5 a partial enlarged view of. And according to Figure 6From the current recovery curves corresponding to a saturated power back-off of 6 dB, a saturated power back-off of 3 dB, and a saturated output power Psat as shown, a recovery time of approximately 60 ms and a current collapse ratio of approximately 28.6% can be obtained. It should be noted that in this field, the current collapse amount in the current recovery curve can be used to characterize the trap density of the gallium nitride radio frequency device. The recovery time in the current recovery curve can be used to characterize the trap density and trap energy level of the gallium nitride radio frequency device. If the recovery time is too long, the memory effect caused by the traps will be more significant, making it difficult to accurately model Digital Pre-Distortion (DPD), thereby reducing the linearization effect of DPD.

[0055] Furthermore, the test system for the trap effect of the gallium nitride radio frequency device further includes an attenuator 210, and the attenuator 210 is respectively connected to the load 205 and the second bias tee 208. Among them, the attenuator 210 is used to attenuate the output signal of the gallium nitride radio frequency device to avoid damaging the load 205 due to excessive power. The load 205 is used to absorb the output signal of the gallium nitride radio frequency device after attenuation, reduce signal reflection, and protect the front-end link. Exemplarily, the resistance value of the load 205 is 50 Ω.

[0056] As can be seen from the above, the test system for the trap effect of the gallium nitride radio frequency device provided in this embodiment uses a network analyzer 200 in combination with a power amplifier 201 to provide a radio frequency pulse signal, and uses a first tuner 203 and a second tuner 204 to tune the impedance at the input and output ends of the device, so as to obtain the trap effect characterization data of the gallium nitride radio frequency device under specific impedance, with better accuracy. And by adjusting the radio frequency pulse signal and the corresponding impedance, the trap effect of the gallium nitride radio frequency device under different input power levels, different source and load impedance conditions can be obtained, which is beneficial to providing guidance for device research and development and power amplifier circuit design, and accelerating the product research and development process.

[0057] Based on the same concept, this embodiment also provides a test method for the trap effect of a gallium nitride radio frequency device. Please refer to Figure 2 and Figure 7 , the test method uses the above-mentioned test system for the trap effect of the gallium nitride radio frequency device, and includes:

[0058] Step S10: Use a network analyzer 200 to provide a radio frequency pulse signal to a power amplifier 201.

[0059] Step S20: The power amplifier 201 amplifies the radio frequency pulse signal and transmits the amplified radio frequency pulse signal to the isolator 202.

[0060] Step S30: After the isolator 202 filters out the clutter, it unidirectionally transmits the RF pulse signal to the first tuner 203.

[0061] Specifically, the RF pulse signal first passes through the power amplifier 201 for power amplification, then passes through the isolator 202 to filter out the clutter and prevent the reflected signal from entering the preamplifier, so that the RF pulse signal is unidirectionally transmitted to the first bias tee 207 and the first tuner 203. Among them, the first bias tee 207 and the second bias tee 208 in the test system are used to apply the DC bias voltage supplied by the power supply 209 to the input end and the output end of the gallium nitride RF device respectively; that is, the gate G and the drain D of the GaN HEMT device, so that the gallium nitride RF device operates under specified DC bias conditions.

[0062] Step S40: The first tuner 203 transmits the RF pulse signal to the input end of the gallium nitride RF device and tunes the input end source impedance of the gallium nitride RF device.

[0063] Step S50: The output signal generated at the output end of the gallium nitride RF device is transmitted to the load 205 through the second tuner 204; among them, the second tuner 204 tunes the output end load impedance of the gallium nitride RF device; and at the same time, an oscilloscope 206 is used to collect the output current of the gallium nitride RF device and obtain the current recovery curve to characterize the trap effect of the gallium nitride RF device.

[0064] It can be understood that the first tuner 203 and the second tuner 204 are used to tune the impedance at both ends of the gallium nitride RF device to achieve impedance tuning. And the first tuner 203 and the second tuner 204 achieve the tuning of specific impedance according to different combinations of the positions of different probes inside them, so as to further ensure the characterization of the trap effect of the gallium nitride RF device under the actual specified working conditions, effectively improving the measurement accuracy.

[0065] Furthermore, before performing the test method for the trap effect of the gallium nitride RF device, the equipment system needs to be calibrated. Exemplarily, first turn on the equipment and confirm the interconnection, and then calibrate the test system. The calibration process of the test system generally includes: coaxial calibration of the input port Port1 and the output port Port2, reflection system test, TRL calibration, tuner calibration, and receiver calibration. Secondly, perform system configuration, and after the configuration is completed, use a calibration chip for system verification. If the verification is incorrect, re-calibrate the test system. If the verification is correct, the test method for the trap effect of the gallium nitride RF device can be executed. Finally, save and process the data after the test.

[0066] In summary, for the test system and method for the trap effect of the gallium nitride radio frequency device provided in this embodiment, the network analyzer 200 is combined with the power amplifier 201 to provide radio frequency pulse signals under the actual working environment of the device, and the first tuner 203 and the second tuner 204 are used to tune the impedance of the input and output ends of the device. Therefore, the trap effect of the gallium nitride radio frequency device can be characterized at the actual working frequency and specific impedance, with better accuracy and authenticity, which is beneficial to providing guidance for device research and development and power amplifier circuit design, and promoting product update and iteration.

[0067] In addition, it should also be recognized that although the present invention has been disclosed above with preferred embodiments, the above embodiments are not intended to limit the present invention. For any person skilled in the art, without departing from the scope of the technical solution of the present invention, many possible changes and modifications can be made to the technical solution of the present invention by using the technical content disclosed above, or modified into equivalent embodiments with equivalent changes. Therefore, any simple modification, equivalent change and modification made to the above embodiments according to the technical essence of the present invention without departing from the content of the technical solution of the present invention still belong to the scope of protection of the technical solution of the present invention.

Claims

1. A test system for the trap effect of a gallium nitride radio frequency device, characterized in that: include: Network analyzer, used to provide RF pulse signals and measure the power at the input and output of GaN RF devices; A power amplifier connected to the network analyzer, used to receive the radio frequency pulse signal and amplify the power of the radio frequency pulse signal; an isolator connected to the power amplifier, used to receive the power-amplified RF pulse signal and filter out clutter; and to enable the RF pulse signal to be unidirectionally transmitted to the first tuner; A first tuner is connected to the isolator and the input end of the gallium nitride radio frequency device respectively, and is used to tune the input end source impedance of the gallium nitride radio frequency device; A second tuner is connected to the output end and the load of the GaN RF device respectively, and is used to tune the output end load impedance of the GaN RF device; An oscilloscope is used to collect the output current of the GaN RF device and obtain a current recovery curve to characterize the trap effect of the GaN RF device.

2. The test system for the trapping effect of gallium nitride radio frequency devices according to claim 1, characterized in that: The first tuner and the second tuner are respectively provided with couplers, and are connected to the network analyzer, for coupling the incident signal and the reflected signal at the input end and the output end of the gallium nitride radio frequency device to the network analyzer, so that the network analyzer measures the power at the input end and the output end of the gallium nitride radio frequency device.

3. The test system for the trapping effect of GaN radio frequency devices according to claim 1, characterized in that: The first tuner and the second tuner are respectively provided with probes for respectively tuning the input end source impedance and the output end load impedance of the gallium nitride radio frequency device.

4. The test system for the trapping effect of a GaN radio frequency device according to claim 1, characterized in that: The test system for the trap effect of the GaN radio frequency device further includes: a first bias tee, a second bias tee and a power supply; wherein the power supply is connected to the first bias tee and the second bias tee respectively, and is used to provide a DC bias voltage to the first bias tee and the second bias tee respectively; and, The first bias tee is connected to the isolator and the first tuner respectively, and is used to provide the DC bias to the input end of the gallium nitride RF device; and the second bias tee is connected to the second tuner and the load respectively, and is used to provide the DC bias to the output end of the gallium nitride RF device, so that the gallium nitride RF device operates under the DC bias.

5. The test system for the trapping effect of gallium nitride radio frequency devices according to claim 4, characterized in that: The power supply includes a direct current voltage or a pulse power supply.

6. The test system for the trapping effect of a GaN radio frequency device according to claim 4, characterized in that: The test system for the trap effect of the GaN radio frequency device also includes an attenuator; the attenuator is respectively connected to the load and the second bias tee, and is at least used to attenuate the output signal of the GaN radio frequency device.

7. The test system for the trapping effect of GaN radio frequency devices according to claim 1, characterized in that: The gallium nitride radio frequency device includes a GaN HEMT device, wherein the gate of the GaN HEMT device is the input end, the drain of the GaN HEMT device is the output end, and the source of the GaN HEMT device is grounded.

8. The test system for the trapping effect of a gallium nitride radio frequency device according to any one of claims 1 to 7, characterized in that: The current collapse amount in the current recovery curve is used to characterize the trap density of the gallium nitride radio frequency device; and the recovery time in the current recovery curve is used to characterize the trap density and trap energy level of the gallium nitride radio frequency device.

9. A method for testing the trap effect of a gallium nitride radio frequency device, characterized in that: A test system for the trap effect of a gallium nitride radio frequency device according to any one of claims 1 to 8, and comprising: A network analyzer is used to provide a radio frequency pulse signal to a power amplifier; The power amplifier amplifies the radio frequency pulse signal and transmits the amplified radio frequency pulse signal to the isolator; After filtering out clutter, the isolator transmits the radio frequency pulse signal unidirectionally to the first tuner; The first tuner transmits the RF pulse signal to the input end of the GaN RF device and tunes the input end source impedance of the GaN RF device; The output signal generated at the output end of the GaN RF device is transmitted to the load via a second tuner; wherein the second tuner tunes the output end load impedance of the GaN RF device; and, at the same time, an oscilloscope is used to collect the output current of the GaN RF device and obtain a current recovery curve to characterize the trap effect of the GaN RF device.

10. The method for testing the trap effect of a gallium nitride radio frequency device according to claim 9, characterized in that: In the process of unidirectionally transmitting the RF pulse signal to the first tuner after the isolator filters out clutter, the RF pulse signal is transmitted to the first bias tee through the isolator, and after the DC bias is increased by the first bias tee, it is transmitted to the first tuner; as well as, In the process of transmitting the output signal generated at the output end of the gallium nitride radio frequency device to the load via the second tuner, the output signal is transmitted to the second bias tee via the second tuner, and after the DC bias is increased by the second bias tee, it is transmitted to the load; Wherein, a power supply is used to provide the DC bias voltage to the first bias tee and the second bias tee respectively, so that the gallium nitride radio frequency device operates under the DC bias voltage.

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