Dual-loop amplitude stabilization system and method for electrical aging of RF / microwave devices under signal loading

Abstract

This invention provides a dual-closed-loop amplitude stabilization system and method for electrical curing of RF / microwave devices with signal loading. The system includes an RF / microwave signal source, an input ALC loop, a device under test (DUT) mounting station, an output ALC loop, an absorption load, and a main control unit. The RF / microwave signal source generates the initial excitation signal, which is then regulated and stabilized by the input ALC loop. The DUT is mounted at the mounting station, and the output ALC loop samples and stabilizes the output signal from the DUT. The absorption load absorbs the signal. The main control unit sets relevant parameters, receives alarm signals, and triggers corresponding actions. This invention achieves dual amplitude stabilization of the input and output signals during the electrical curing process of the RF / microwave device under test, improving the stability and accuracy of the curing test. It also allows for timely detection and handling of device failures, ensuring test safety and efficiency.

Description

Technical Field

[0001] This invention relates to the field of reliability screening and testing technology for radio frequency / microwave devices, and more specifically, to a dual closed-loop amplitude stabilization system and method for signal loading electrical aging of radio frequency / microwave devices. Background Technology

[0002] Electrical burning is a critical testing step for eliminating early failures in RF / microwave devices and assessing their long-term reliability. For medium- to high-power RF / microwave devices / components (such as power amplifiers, T / R modules, etc.), maintaining a constant amplitude of the RF / microwave signal applied to the device input (input amplitude stabilization) or monitoring and stabilizing the signal amplitude at the device output (output amplitude stabilization) during RF / microwave signal loading and burning under temperature and electrical stress is essential for ensuring consistent stress application and assessing the device's performance degradation trend.

[0003] However, in actual aging systems, several factors can cause signal amplitude fluctuations: a) Performance drift of the RF / microwave signal link: unstable output of the signal source itself, or gain drift of the external power amplifier due to temperature changes or aging, causing power fluctuations at the input end; b) Changes in device characteristics: During long-term aging, the parameters such as gain and insertion loss of the device under test (DUT) may change (e.g., gain compression or attenuation), causing the output power to be unstable under constant input, affecting the accurate judgment of device failure modes; c) Load pulling effect: Changes in the load matching state at the output end may also affect the output power of the device.

[0004] In existing technologies, the automatic level control (ALC) function built into the signal source is often used for amplitude stabilization. However, this can only compensate for fluctuations in the signal source itself and cannot compensate for drift in the power amplifier and subsequent links; or, as Figure 1 As shown, an open-loop control method is used to pre-select the control value of the digitally controlled / voltage-controlled attenuator stored in the main control unit, thereby adjusting the amplitude of the injected or output RF / microwave signal of the device under test. This open-loop method achieves amplitude adjustment, but it cannot achieve state monitoring and real-time input / output amplitude stabilization requirements during the test.

[0005] Furthermore, a single closed-loop control method cannot select or simultaneously perform input and output amplitude stabilization operating modes. It also cannot achieve precise and constant application of signal excitation stress during aging (constant input) or precise adjustment of signal excitation / bias voltage stress to meet the constant output test requirements of the test device, nor can it provide real-time monitoring / protection of the test device's status (constant output). Given the current practical need for multiple operating modes in test systems, sometimes input amplitude stabilization is required, sometimes output amplitude stabilization is required, and sometimes both are needed simultaneously.

[0006] Therefore, a dual closed-loop control system is needed that can achieve either input amplitude stabilization or output amplitude stabilization, or both simultaneously. Summary of the Invention

[0007] To address the shortcomings of existing technologies, the purpose of this invention is to provide a dual-closed-loop amplitude stabilization system for signal loading electrical aging of radio frequency / microwave devices.

[0008] A dual-closed-loop amplitude stabilization system for signal loading electrical aging of radio frequency / microwave devices, provided by the present invention, includes: Radio frequency / microwave signal source, used to generate raw radio frequency / microwave excitation signals; An input ALC loop is connected to the output of the radio frequency / microwave signal source to perform power adjustment and stabilization on the initial radio frequency / microwave excitation signal. The device under test (DUT) station has its input terminal connected to the output terminal of the input ALC loop, and is used to mount the RF / microwave device under test. The output ALC loop has its input terminal connected to the output terminal of the device under test station, and is used to sample and stabilize the output RF / microwave of the RF / microwave device under test. An absorption load, whose input terminal is connected to the output terminal of the ALC loop, is used to absorb radio frequency / microwave signals. The main control unit, connected to the control terminal of the radio frequency / microwave signal source, is used to set the operating frequency and initial power P0 of the link radio frequency / microwave excitation. The main control unit is connected to the control terminal of the input ALC loop and is used to set the input power pin of the RF / microwave device under test. The main control unit is also connected to the control terminal of the output ALC loop and is used to set the output RF / microwave amplitude of the RF / microwave device under test. The main control unit is connected to the alarm output terminals of the input ALC loop and the output ALC loop, and is used to trigger a system alarm, record the failure time of the RF / microwave device under test, or disconnect the power supply to the signal source, power amplifier, and RF / microwave device under test when an alarm signal is received from the input ALC loop or the output ALC loop.

[0009] Preferably, the input ALC loop includes: A voltage-controlled attenuator, the input of which is connected to the output of the radio frequency / microwave signal source, is controlled by a voltage-controlled signal Vctrl to adjust the amplitude of the original radio frequency / microwave excitation signal; A power amplifier, whose input is connected to the output of the voltage-controlled attenuator, is used to amplify the attenuated radio frequency / microwave excitation signal; The first directional coupler has its input terminal connected to the output terminal of the power amplifier, its through terminal connected to the input terminal of the device under test, and its coupling terminal outputting the first sampling signal Pdt1. The first detector has its input terminal connected to the coupling terminal of the first directional coupler, and is used to convert the first sampling signal Pdt1 into the first detection voltage Vdt1. The first comparison controller is connected to the output terminal of the first detector, the control terminal of the voltage-controlled attenuator, and the first alarm input terminal of the main control unit, respectively. The first comparison controller is used to compare the first detector voltage Vdt1 with the set first reference voltage Vref1, output a first control signal Vctrl1 to the control terminal of the voltage-controlled attenuator, and output an alarm signal Vw1 to the first alarm input terminal of the main control unit when the first detector voltage Vdt1 deviates from the first reference voltage Vref1 by more than a preset threshold.

[0010] Preferably, the output ALC loop includes: A high-power attenuator, the input of which is connected to the output of the device under test, is used to attenuate the output signal when the output power of the RF / microwave device under test is greater than a preset threshold. The second directional coupler has its input end connected to the output end of the high-power attenuator, its through end connected to the absorption load, and its coupling end outputting the second sampling signal Pdt2. The second detector is connected to the coupling end of the second directional coupler and is used to convert the second sampling signal Pdt2 into the second detection voltage Vdt2. The second comparison controller is connected to the output terminal of the second detector, the control terminal of the bias voltage power supply circuit, and the second alarm input terminal of the main control unit, respectively. The second comparison controller is used to compare the second detection voltage Vdt2 with the set second reference voltage Vref2, output the second control signal Vctrl2 to the control terminal of the bias voltage power supply circuit, and output the alarm signal Vw2 to the second alarm input terminal of the main control unit when the second detection voltage Vdt2 deviates from the second reference voltage Vref2 by more than a preset threshold. The bias voltage power supply circuit is connected to the output terminal of the second comparator controller, the gate voltage power supply terminal and the drain voltage power supply terminal of the RF / microwave device under test, respectively. The bias voltage power supply circuit is controlled by the second control signal Vctrl2 to adjust the output voltage Vd or Vg, thereby changing the amplitude of the RF / microwave signal output by the RF / microwave device under test.

[0011] Preferably, both the first comparator and the second comparator are analog proportional-integral-derivative controllers, or both are digital controllers that include an analog-to-digital converter module, a digital processing chip, and a digital-to-analog converter module.

[0012] Preferably, the attenuation amount of the high-power attenuator is determined based on the maximum output power of the RF / microwave device under test, and the attenuation amount satisfies that the signal power after attenuation by the high-power attenuator does not exceed the maximum withstand power of the second directional coupler and the second detector.

[0013] Preferably, the main control unit is used to set the first reference voltage Vref1 and the second reference voltage Vref2, and to receive the alarm signal Vw1 and the alarm signal Vw2.

[0014] Preferably, both the first directional coupler and the second directional coupler are broadband directional couplers.

[0015] This invention also provides a dual-closed-loop amplitude stabilization method for electrical aging of radio frequency / microwave device signals, based on the aforementioned dual-closed-loop amplitude stabilization system for electrical aging of radio frequency / microwave device signals, comprising the following steps: Device installation steps: Install the RF / microwave device under test at the device under test station; Mode determination steps: Determine the test operating mode, which is the input closed-loop amplitude stabilization mode, the output closed-loop amplitude stabilization mode, or the dual closed-loop amplitude stabilization mode; and simultaneously set the first reference voltage value Vref1 and the second reference voltage value Vref2. Signal source startup steps: Start the radio frequency / microwave signal source to generate an initial radio frequency excitation signal P0; Input amplitude stabilization steps: The initial RF excitation signal is sequentially attenuated by the voltage-controlled attenuator and amplified by the power amplifier in the input ALC loop. It is then sampled by the first directional coupler in the input ALC loop to obtain a first sampled signal Pdt1. The first sampled signal Pdt1 is converted into a first detected voltage Vdt1 by the first detector in the input ALC loop. The first comparator controller in the input ALC loop compares the first detected voltage Vdt1 with a first reference voltage Vref1, outputting a first control signal Vctrl1 to dynamically adjust the attenuation of the voltage-controlled attenuator until the first detected voltage Vdt1 and the first reference voltage Vref1 reach equilibrium. If the first detected voltage Vdt1 is within a preset threshold range, the amplified and stabilized signal is output to the tested RF / microwave device through the direct-through terminal of the first directional coupler. If the first detected voltage Vdt1 deviates from the first reference voltage Vref1 by more than a preset threshold, an alarm signal Vw1 is output through the first comparator controller. Output amplitude stabilization and monitoring steps: The output signal of the RF / microwave device under test is attenuated by the high-power attenuator of the output ALC loop, and sampled by the second directional coupler of the output ALC loop to obtain a second sampled signal Pdt2; the second detector of the output ALC loop converts the second sampled signal Pdt2 into a second detected voltage Vdt2; the second comparator controller of the output ALC loop compares the second detected voltage Vdt2 with the second reference voltage Vref2, and outputs a second control signal Vctrl2 to dynamically adjust the gate voltage Vg or drain voltage Vd of the bias voltage supply circuit of the output ALC loop until the second detected voltage Vdt2 and the second reference voltage Vref2 reach equilibrium; if the second detected voltage Vdt2 is within a preset threshold range, the stabilized signal is output to the absorption load through the through terminal of the second directional coupler; if the second detected voltage Vdt2 deviates from the second reference voltage Vref2 by more than the preset threshold, the second comparator controller outputs an alarm signal Vw2.

[0016] Preferably, the input stabilization step is continuously performed during system operation to compensate for power drift caused by the power amplifier and other link components.

[0017] Preferably, in the output stabilization and monitoring step, the alarm signal Vw2 is used to trigger a system alarm, record the failure time of the tested RF / microwave device, or jointly cut off the power supply to the RF / microwave signal source, power amplifier, and tested RF / microwave device.

[0018] Compared with the prior art, the present invention has the following beneficial effects: 1. This invention enables independent dual-loop control, taking into account both stress application and status monitoring. The input closed loop ensures that the RF stress applied to the device under test is highly stable and is not affected by signal source, power amplifier and link drift. The output closed loop monitors the device output power in real time, which can sensitively capture the performance degradation or sudden failure of the device during the aging process, and provide key data for reliability analysis.

[0019] 2. This invention can improve the effectiveness and consistency of aging tests. By inputting a stable amplitude, it ensures that each device bears the same electrical stress during batch aging, thereby improving the comparability and reliability of screening results.

[0020] 3. This invention can enhance the system's protection capabilities. Real-time monitoring at the output end can promptly detect abnormal output power (such as overpower or sudden power drop), triggering alarms or cutting off the input to prevent device damage or safety accidents.

[0021] 4. The present invention is highly adaptable. The combination of voltage-controlled attenuator and power amplifier in the input closed loop allows the system to flexibly adapt to the aging requirements of different power levels; the high-power attenuator at the output protects the expensive detection and sampling circuits when the power is high. Attached Figure Description

[0022] Other features, objects, and advantages of the present invention will become more apparent from the following detailed description of non-limiting embodiments with reference to the accompanying drawings: Figure 1 This is a diagram of the existing RF / microwave signal loading electrical aging test system architecture. Figure 2 This is a schematic diagram of the basic system architecture for the input & output dual closed-loop amplitude stabilization system used in the RF / microwave signal loading electrical aging test of the present invention; Figure 3 This is a schematic diagram of the input & output dual closed-loop amplitude stabilization system for RF / microwave signal loading electrical aging test as described in an embodiment of the present invention.

[0023] Explanation of reference numerals in the attached figures: 1. RF / microwave signal source; 2. Input ALC loop; 3. Test device and its test fixture; 4. Output ALC loop; 5. Absorption load; 6. Main control unit; 201. Voltage-controlled attenuator; 202. Power amplifier; 203. First directional coupler; 204. First detector; 205. First comparator controller; 206. Single-pole double-throw switch; 401. High-power attenuator; 402. Second directional coupler; 403. Second detector; 404. Detailed Implementation

[0024] The present invention will now be described in detail with reference to specific embodiments. These embodiments will help those skilled in the art to further understand the present invention, but do not limit the invention in any way. It should be noted that those skilled in the art can make several changes and improvements without departing from the concept of the present invention. These all fall within the protection scope of the present invention.

[0025] Example 1 like Figures 2 to 3 As shown, this embodiment provides a dual-closed-loop amplitude stabilization system for electrical aging of RF / microwave devices, including: an RF / microwave signal source 1, an input ALC loop 2, a device under test (DUT) station 3, an output ALC loop 4, an absorption load 5, and a main control unit 6. The components are connected via RF cables, control lines, and power supply lines to form a complete signal loading and amplitude stabilization link, achieving dual stable control of the input and output signal amplitudes during the electrical aging process of the RF / microwave device under test. RF / microwave devices refer to either RF devices or microwave devices.

[0026] The RF / microwave signal source 1 serves as the system's primary signal generation unit, generating a primary RF / microwave excitation signal with adjustable frequency and amplitude. Its operating frequency range covers the operating frequency band of the RF / microwave device under test (e.g., 1GHz~18GHz), and its output power range can be flexibly adjusted according to the rated input power of the device under test (e.g., -10dBm~+10dBm). The control terminal of the RF / microwave signal source 1 is connected to the main control unit 6, receiving control commands from the main control unit 6 to precisely set the operating frequency and initial power P0 of the initial excitation signal, providing a stable primary excitation signal for the entire system. The RF / microwave excitation signal refers to either an RF excitation signal or a microwave excitation signal.

[0027] The input ALC loop 2 serves as the core unit for input signal amplitude stabilization. Its input terminal is connected to the output terminal of the RF / microwave signal source 1, and its output terminal is connected to the input terminal of the device under test station 3. It is used to adjust the power and stabilize the original RF / microwave excitation signal with high precision, ensuring that the signal power Pin input to the device under test is always stable at the preset value, and compensating for the power fluctuations caused by component parameter drift in the input link.

[0028] Specifically, the input ALC loop 2 includes: a voltage-controlled attenuator 201, a power amplifier 202, a first directional coupler 203, a first detector 204, and a first comparator controller 205. These components are connected in series to form a closed-loop control link. The specific connection relationships and functions are as follows: Voltage-controlled attenuator 201: Its input terminal is connected to the output terminal of RF / microwave signal source 1, and its output terminal is connected to the input terminal of power amplifier 202. Its attenuation is controlled by the voltage-controlled signal Vctrl1 output by the first comparator controller 205, which can achieve continuous adjustable attenuation from 0 to 30dB. It is used to dynamically adjust the amplitude of the original RF / microwave excitation signal and is the core adjustment element of the input amplitude stabilization loop.

[0029] Power amplifier 202: Its input terminal is connected to the output terminal of voltage-controlled attenuator 201, and its output terminal is connected to the input terminal of the first directional coupler 203. It is used to amplify the power of the RF / microwave signal after attenuation by voltage-controlled attenuator 201 so that the signal power reaches the rated input power pin required by the device under test. Its amplification gain can be set according to the requirements of the device under test (e.g., 20dB~40dB) and has good linearity to avoid signal distortion.

[0030] First directional coupler 203: A broadband directional coupler is used, with the operating frequency band consistent with the RF / microwave signal source 1. Its input end is connected to the output end of the power amplifier 202, and its through end is connected to the input end of the device under test station 3. It is used to transmit the amplified signal to the device under test. Its coupling end is used to extract a portion of the signal as the first sampling signal Pdt1 (the sampling ratio can be set to 10dB~20dB) to realize real-time sampling of the signal power input to the device under test. The isolation of the directional coupler is ≥20dB to avoid interference of the sampling signal to the main link signal.

[0031] The first detector 204 has its input end connected to the coupling end of the first directional coupler 203 and its output end connected to the input end of the first comparator controller 205. It is used to convert the first sampling signal Pdt1 (RF / microwave signal) into the corresponding first detection voltage Vdt1 (DC voltage). The detection sensitivity is ≥0.1mV / dBm, ensuring the accurate conversion of the sampling signal and providing a reliable electrical signal basis for subsequent comparison control.

[0032] The first comparator controller 205, serving as the control core of the input ALC loop 2, is connected to the output of the first detector 204, the control terminal of the voltage-controlled attenuator 201, and the first alarm input terminal of the main control unit 6. It can employ an analog proportional-integral-derivative (PID) controller or a digital controller (including an analog-to-digital converter module, a digital processing chip, and a digital-to-analog converter module). Its core function is to compare the first detector voltage Vdt1 with the first reference voltage Vref1 set by the main control unit 6 in real time. It calculates the deviation using a PID algorithm and outputs a first control signal Vctrl1 to the control terminal of the voltage-controlled attenuator 201, dynamically adjusting the attenuation of the voltage-controlled attenuator 201 to balance the first detector voltage Vdt1 with the first reference voltage Vref1, thereby stabilizing the input signal power Pin. Simultaneously, when the first detector voltage Vdt1 deviates from the first reference voltage Vref1 by more than a preset threshold (e.g., ±0.5dB), the first comparator controller 205 immediately outputs an alarm signal Vw1 to the main control unit 6, triggering the system alarm and protection mechanism.

[0033] The device under test (DUT) station 3 serves as the mounting and securing unit for the RF / microwave device under test. Its input terminal is connected to the through-hole of the first directional coupler 203 in the input ALC loop 2, and its output terminal is connected to the input terminal of the output ALC loop 4. The station design is adaptable to different sizes and types of RF / microwave devices (such as surface mount and through-hole types), providing excellent RF connectivity and ensuring stable transmission of the input signal to the DUT, while also ensuring that the DUT's output signal is transmitted to the output ALC loop 4 without distortion. Furthermore, the DUT station 3 also provides a connection interface with the bias voltage supply circuit 405 to provide the gate voltage Vg and drain voltage Vd to the DUT.

[0034] The output ALC loop 4 serves as the core unit for output signal amplitude stabilization and monitoring. Its input terminal is connected to the output terminal of the device under test station 3, and its output terminal is connected to the input terminal of the absorption load 5. It is used to sample, attenuate, and stabilize the output RF / microwave signal of the device under test, while monitoring the output signal amplitude in real time to detect the failure state of the device under test in a timely manner.

[0035] Specifically, the output ALC loop 4 includes: a high-power attenuator 401, a second directional coupler 402, a second detector 403, a second comparator controller 404, and a bias voltage power supply circuit 405. These components are connected in series to form a closed-loop control link. The specific connection relationships and functions are as follows: High-power attenuator 401: Its input terminal is connected to the output terminal of station 3 of the device under test, and its output terminal is connected to the input terminal of the second directional coupler 402. Its attenuation is determined according to the maximum output power of the RF / microwave device under test (e.g., 20dB~50dB). Its core function is to attenuate the output signal when the output power of the device under test is too high, so as to ensure that the signal power after attenuation does not exceed the maximum withstand power of the second directional coupler 402 and the second detector 403 (e.g., +20dBm), and avoid damage to subsequent test components.

[0036] The second directional coupler 402 is a broadband directional coupler of the same specifications as the first directional coupler 203. Its input end is connected to the output end of the high-power attenuator 401, and its through end is connected to the absorption load 5. It is used to transmit the stabilized output signal to the absorption load 5 for absorption. Its coupling end is used to extract a portion of the signal as the second sampling signal Pdt2 (the sampling ratio is the same as that of the first directional coupler) to realize real-time sampling of the output signal power of the device under test. It also has an isolation of ≥20dB to avoid interference with the main link signal.

[0037] The second detector 403 has the same specifications as the first detector 204. Its input end is connected to the coupling end of the second directional coupler 402, and its output end is connected to the input end of the second comparator controller 404. It is used to convert the second sampling signal Pdt2 into the corresponding second detection voltage Vdt2 (DC voltage), ensuring the accurate conversion of the sampling signal and providing a reliable basis for the amplitude stabilization control of the output signal.

[0038] The second comparator controller 404, serving as the control core of the output ALC loop 4, is of the same type as the first comparator controller 205 (both are analog PID controllers or both are digital controllers). It is connected to the output terminal of the second detector 403, the control terminal of the bias voltage power supply circuit 405, and the second alarm input terminal of the main control unit 6. Its core function is to compare the second detector voltage Vdt2 with the second reference voltage Vref2 set by the main control unit 6 in real time, calculate the deviation through a PID algorithm, and output the second control signal Vctrl2 to the control terminal of the bias voltage power supply circuit 405 to dynamically adjust the output voltage (gate voltage Vg or drain voltage Vd) of the bias voltage power supply circuit 405. Simultaneously, when the second detector voltage Vdt2 deviates from the second reference voltage Vref2 by more than a preset threshold (e.g., ±0.5dB), it outputs an alarm signal Vw2 to the main control unit 6 to trigger the system alarm and protection mechanism.

[0039] The bias voltage supply circuit 405 is connected to the output terminal of the second comparator controller 404, the gate voltage supply terminal of the RF / microwave device under test, and the drain voltage supply terminal, respectively. It is the core adjustment element of the output amplitude stabilization loop. Its output voltage (gate voltage Vg, drain voltage Vd) can be continuously adjusted according to the second control signal Vctrl2 (e.g., Vg: -5V~0V, Vd: 5V~28V). Its working principle is: by adjusting the gate voltage Vg or drain voltage Vd of the device under test, the gain characteristics of the device under test are changed, thereby adjusting the amplitude of the RF / microwave signal output by the device under test, so that the second detector voltage Vdt2 and the second reference voltage Vref2 are balanced, thus stabilizing the output signal amplitude.

[0040] The absorption load 5 is a high-power RF absorption load. Its input end is connected to the through end of the second directional coupler 402 of the output ALC loop 4. It is used to completely absorb the RF / microwave signal after the output amplitude is stabilized, avoid signal reflection from interfering with the system link, and ensure the safety of the system operation. Its rated power is greater than or equal to the maximum output power of the device under test, and its VSWR is less than or equal to 1.2 to ensure the integrity of signal absorption.

[0041] The main control unit 6, as the core control and monitoring unit of the system, is implemented using a microcontroller, PLC, or industrial computer. It is connected via control lines to the control terminals of the RF / microwave signal source 1, the input ALC loop 2 (first comparator 205), the output ALC loop 4 (second comparator 404), the alarm output terminal of the input ALC loop 2 (first comparator 205), and the output ALC loop 4 (second comparator 404). Its core functions include: a. Parameter settings: Set the operating frequency and initial power P0 of the link RF / microwave excitation, set the input power Pin of the device under test (corresponding to the first reference voltage Vref1) and the output signal amplitude (corresponding to the second reference voltage Vref2), and set the alarm thresholds for the input and output signal amplitudes. b. Real-time monitoring: Real-time reception of alarm signal Vw1 output from input ALC loop 2 and alarm signal Vw2 output from output ALC loop 4, real-time acquisition of first detector voltage Vdt1 and second detector voltage Vdt2, and real-time display of system operating status (such as signal frequency, input power, output power, alarm status, etc.). c. Alarm and protection: When the Vw1 or Vw2 alarm signal is received, the system alarm is immediately triggered (such as audible and visual alarm), and the failure time of the tested RF / microwave device is recorded (accurate to milliseconds). It can also cut off the power supply to the RF / microwave signal source 1, power amplifier 202 and the tested RF / microwave device to prevent further damage to the tested device and test equipment. d. Data storage and export: Store key parameters during system operation (such as input power, output power, operating time, alarm information, etc.), support data export, and facilitate the analysis and archiving of test data.

[0042] This embodiment also provides a dual-closed-loop amplitude stabilization method for electrical aging of RF / microwave devices. Based on the above-mentioned dual-closed-loop amplitude stabilization system, the amplitude stabilization mode can be flexibly selected according to the test requirements to ensure the stability of the input and output signal amplitudes during the electrical aging test. The specific steps are as follows: Step S1: Device installation steps.

[0043] Accurately install the RF / microwave device under test (DUT) at DUT station 3, ensuring that the input terminal of the DUT is reliably connected to the through terminal of the first directional coupler 203 of the input ALC loop 2, and that the output terminal of the DUT is reliably connected to the input terminal of the high-power attenuator 401 of the output ALC loop 4. At the same time, connect the output terminal of the bias voltage power supply circuit 405 to the gate voltage power supply terminal and the drain voltage power supply terminal of the DUT. Check all connections to ensure that there are no loose connections or poor contacts, and avoid signal transmission distortion or power supply abnormalities.

[0044] Step S2: Pattern determination step.

[0045] The test operating mode is determined by the main control unit 6. There are three test operating modes: input closed-loop amplitude stabilization mode, output closed-loop amplitude stabilization mode, and dual closed-loop amplitude stabilization mode. The specific selection is determined according to the test requirements of the device under test. Input closed-loop amplitude stabilization mode: Only input ALC loop 2 is activated, and output ALC loop 4 is not working (bias voltage power supply circuit 405 outputs a fixed voltage), which is suitable for electrical aging tests that only need to ensure the stability of the input signal; Output closed-loop amplitude stabilization mode: Only the output ALC loop 4 is activated, and the input ALC loop 2 is not working (the attenuation of the voltage-controlled attenuator 201 is fixed). It is suitable for electrical aging tests that only need to ensure the stability of the output signal. Dual closed-loop amplitude stabilization mode: Simultaneously activate input ALC loop 2 and output ALC loop 4 to achieve dual amplitude stabilization of input and output signals. It is suitable for electrical aging tests with high requirements for signal amplitude stability (such as testing of high-precision power amplifiers, filters and other devices), and is also the preferred test mode of this invention.

[0046] Meanwhile, the main control unit 6 sets the first reference voltage value Vref1 and the second reference voltage value Vref2: the first reference voltage Vref1 corresponds to the rated input power Pin of the device under test, which is calculated based on Pin and the detection sensitivity of the first detector 204; the second reference voltage Vref2 corresponds to the rated output power of the device under test, which is calculated based on the rated output power of the device under test, the attenuation of the high-power attenuator 401, and the detection sensitivity of the second detector 403; and alarm thresholds (such as ±0.5dB) for the amplitude of the input and output signals are set at the same time.

[0047] Step S3: Signal source startup procedure.

[0048] The main control unit 6 sends a control command to start the radio frequency / microwave signal source 1, so that it generates the original radio frequency excitation signal according to the set operating frequency and initial power P0. The original signal is transmitted to the voltage-controlled attenuator 201 of the input ALC loop 2 via the radio frequency cable, ready to enter the amplitude stabilization adjustment stage.

[0049] Step S4: Input amplitude stabilization step.

[0050] This step is continuously performed during system operation to compensate for power drift in the power amplifier 202 and other components of the input link (such as RF cables and directional couplers) caused by factors such as temperature changes and aging, ensuring that the signal power input to the device under test remains stable at a preset value. The specific process is as follows: The original radio frequency excitation signal first enters the voltage-controlled attenuator 201. The voltage-controlled attenuator 201 adjusts the attenuation of the original signal according to the first control signal Vctrl1 output by the first comparator controller 205. The attenuated signal enters the power amplifier 202, which amplifies the signal so that the signal power reaches a level close to the rated input power Pin of the device under test. The amplified signal enters the first directional coupler 203. The through end of the first directional coupler 203 transmits the signal to the device under test at the device under test station 3. At the same time, the coupling end extracts part of the signal as the first sampling signal Pdt1. The first sampling signal Pdt1 enters the first detector 204, the first detector 204 converts the radio frequency / microwave signal into the first detection voltage Vdt1, and transmits Vdt1 to the first comparator controller 205; The first comparison controller 205 compares the first detection voltage Vdt1 with the first reference voltage Vref1 set by the main control unit 6 in real time, calculates the deviation between the two, processes the deviation through a PID algorithm, and outputs the first control signal Vctrl1 to the control terminal of the voltage-controlled attenuator 201. The voltage-controlled attenuator 201 dynamically adjusts its attenuation according to the first control signal Vctrl1 until the first detector voltage Vdt1 and the first reference voltage Vref1 reach a balance (the deviation is within the preset threshold range). At this time, the signal power Pin input to the device under test is stable at the preset value. If the first detection voltage Vdt1 deviates from the first reference voltage Vref1 by more than a preset threshold, it indicates that there is an abnormality in the input link (such as a power amplifier 202 failure, voltage-controlled attenuator 201 failure, etc.). The first comparator controller 205 immediately outputs an alarm signal Vw1 to the main control unit 6, triggering subsequent alarm and protection mechanisms.

[0051] Step S5: Output amplitude stabilization and monitoring steps.

[0052] This step is executed synchronously with the input amplitude stabilization step (in dual closed-loop mode) to compensate for changes in the output signal amplitude caused by the device under test (DUT) during its operation (such as heat generation or parameter drift), while simultaneously monitoring the DUT's operating status in real time. The specific process is as follows: After receiving a stable input signal, the device under test outputs an RF / microwave signal. This signal enters the high-power attenuator 401 of the output ALC loop 4. The high-power attenuator 401 attenuates the signal to ensure that the power of the attenuated signal does not exceed the maximum power of the second directional coupler 402 and the second detector 403. The attenuated signal enters the second directional coupler 402. The through end of the second directional coupler 402 transmits the signal to the absorption load 5 for absorption, while the coupling end extracts part of the signal as the second sampling signal Pdt2. The second sampling signal Pdt2 enters the second detector 403, which converts the radio frequency / microwave signal into the second detection voltage Vdt2 and transmits Vdt2 to the second comparator controller 404. The second comparison controller 404 compares the second detection voltage Vdt2 with the second reference voltage Vref2 set by the main control unit 6 in real time, calculates the deviation between the two, processes the deviation through a PID algorithm, and outputs the second control signal Vctrl2 to the control terminal of the bias voltage power supply circuit 405. The bias voltage power supply circuit 405 dynamically adjusts the gate voltage Vg or drain voltage Vd output to the device under test according to the second control signal Vctrl2, changes the gain characteristics of the device under test, and then adjusts the output signal amplitude of the device under test until the second detector voltage Vdt2 and the second reference voltage Vref2 reach a balance (the deviation is within the preset threshold range). At this time, the output signal amplitude of the device under test is stable at the preset value. If the second detection voltage Vdt2 deviates from the second reference voltage Vref2 by more than the preset threshold, it indicates that the device under test has failed (such as excessive gain attenuation, breakdown, etc.) or the output link is abnormal. The second comparator controller 404 immediately outputs an alarm signal Vw2 to the main control unit 6. Upon receiving the alarm signal Vw2, the main control unit 6 immediately triggers the system's audible and visual alarm, records the failure time of the device under test, and simultaneously cuts off the power supply to the RF / microwave signal source 1, power amplifier 202, and the device under test to prevent further damage to the device and equipment.

[0053] The core of this embodiment lies in the adoption of a dual closed-loop amplitude stabilization design of "input ALC loop + output ALC loop". Through two independent and cooperative closed-loop links, high-precision and stable control of the input and output signals is achieved respectively. At the same time, it has a complete alarm and protection mechanism. Its overall working principle is as follows: a. Dual-loop cooperative amplitude stabilization principle: Input ALC loop 2 compensates for parameter drift in the input link (RF signal source, voltage-controlled attenuator, power amplifier, etc.) to ensure stable signal power pin input to the device under test (DUT); output ALC loop 4 compensates for parameter drift in the DUT itself (such as gain changes caused by heat generation). By adjusting the bias voltage of the DUT, its output amplitude is changed to ensure stable output signal power. The two loops work independently and cooperate with each other, significantly improving the stability accuracy and response speed of signal amplitude compared to traditional single-loop amplitude stabilization systems, and effectively dealing with dual fluctuations from the input link and the DUT itself.

[0054] b. Amplitude Stabilization Mechanism: Both ALC loops employ PID control algorithms. The PID controller acquires the sampled signal (detector voltage) in real time, compares it with the preset reference voltage, calculates the deviation, and outputs a control signal through the synergistic action of proportional, integral, and derivative components. This dynamically adjusts the parameters of the regulating elements (voltage-controlled attenuator, bias voltage power supply circuit) to quickly eliminate the deviation and ensure signal amplitude stability. Specifically, the proportional component is used for rapid deviation response, the integral component for eliminating static deviation, and the derivative component for suppressing overshoot. The combination of these three components gives the closed-loop system good stability and response speed.

[0055] c. Alarm and Protection Principle: The system monitors the amplitude of input and output signals in real time through two comparison controllers. When the signal amplitude deviates from the preset threshold, an alarm signal is immediately output to the main control unit. The main control unit responds quickly, triggering an audible and visual alarm, recording the failure time, and cutting off the power supply to the relevant equipment, forming a complete closed loop of "monitoring-alarm-protection". This avoids damage to the device under test and the test equipment due to signal abnormalities, while ensuring the integrity of the test data (failure time recording).

[0056] d. Mode Adaptation Principle: The system supports three amplitude stabilization modes, which can be flexibly selected according to the test requirements of the device under test. The input closed-loop mode is suitable for scenarios with high requirements for input signal stability, the output closed-loop mode is suitable for scenarios with high requirements for output signal stability, and the dual closed-loop mode is suitable for high-precision test scenarios, which improves the versatility and adaptability of the system and can cover the electrical aging requirements of different types and specifications of RF / microwave devices.

[0057] Example 2 Those skilled in the art can understand this embodiment as a more specific description of Embodiment 1.

[0058] like Figures 2 to 3 As shown, this embodiment provides a dual closed-loop amplitude stabilization system for electrical aging of radio frequency / microwave devices by signal loading, including: radio frequency / microwave signal source 1, input ALC (automatic amplitude control) loop 2, device under test station 3, output ALC loop 4, absorption load 5, and main control unit 6.

[0059] RF / microwave signal source 1 generates the initial RF / microwave excitation signal. Input ALC (Automatic Amplitude Control) loop 2 is connected after RF / microwave signal source 1 to regulate and stabilize the initial RF / microwave excitation signal. Device under test (DUT) station 3 mounts the DUT, with its input connected to the output of input ALC loop 2. Output ALC loop 4 is connected after the output of DUT station 3 to sample and stabilize the output RF / microwave signal from the DUT. Absorption load 5 is connected after the output of output ALC loop 4 to absorb the RF / microwave signal, ensuring stable operation of the entire link.

[0060] The main control unit 6 is connected to the control terminal of the RF / microwave signal source 1 to set the operating frequency and initial power P0 of the link RF / microwave excitation, connected to the control terminal of the input ALC loop 2 to set the input power Pin of the device under test, connected to the control terminal of the output ALC loop 4 to set the output RF / microwave amplitude of the device under test, and connected to the alarm output terminals of the input ALC loop 2 and the output ALC loop 4 to trigger system alarm when an alarm signal is output, record the failure time of the device under test, or link to cut off the power supply of the signal source, power amplifier, and device under test; Furthermore, the input ALC loop 2 includes: a voltage-controlled attenuator 201, a power amplifier 202, a first directional coupler 203, a first detector 204, and a first comparator controller 205.

[0061] The input of voltage-controlled attenuator 201 is connected to signal source 1, and its amplitude is adjusted by the voltage-controlled signal Vctrl. Power amplifier 202 is connected after voltage-controlled attenuator 201 to amplify the attenuated signal. The input of first directional coupler 203 is connected to the output of power amplifier 202, its through-terminal is connected to the input of device under test station 3, and its coupling terminal outputs the first sampling signal Pdt1. First detector 204 is connected to the coupling terminal of first directional coupler 203 to convert the first sampling signal Pdt1 into a first detection voltage Vdt1.

[0062] The first comparison controller 205 is connected to the output terminal of the first detector 204, the control terminal of the voltage-controlled attenuator 201, and the first alarm input terminal of the main control unit 6, respectively. It is used to compare the first detector voltage Vdt1 with the set first reference voltage Vref1, output the first control signal Vctrl1 to the control terminal of the voltage-controlled attenuator 201, and output the alarm signal Vw1 to the first alarm input terminal of the main control unit 6 when the deviation exceeds the preset threshold.

[0063] Furthermore, the output ALC loop 4 includes: a high-power attenuator 401, a second directional coupler 402, a second detector 403, a second comparator 404, and a bias voltage power supply circuit 405.

[0064] The input of the high-power attenuator 401 is connected to the output of the device under test (DUT) station 3. This allows for signal attenuation even when the DUT outputs high power but the power is low. The input of the second directional coupler 402 is connected to the output of the high-power attenuator 401. Its direct-through terminal is used to connect to the aging load 5, and its coupling terminal outputs the second sampling signal Pdt2. The second detector 403 is connected to the coupling terminal of the second directional coupler 402 and converts the second sampling signal Pdt2 into a second detection voltage Vdt2. The second comparator 404 is connected to the output of the second detector 403, the control terminal of the bias voltage power supply circuit 405, and the second alarm input of the main control unit 6. It compares the second detection voltage Vdt2 with a set second reference voltage Vref2, outputs a first control signal Vctrl2 to the control terminal of the bias voltage power supply circuit 405, and outputs an alarm signal Vw2 to the second alarm input of the main control unit 6 when the deviation exceeds a preset threshold.

[0065] The bias voltage power supply circuit 405 is connected to the output terminal of the second comparator 404 and the gate voltage power supply terminal and the drain voltage power supply terminal of the device under test. The output Vd or Vg of the bias voltage power supply circuit 405 is adjusted by the voltage control signal Vctr2, which can be selected according to the test requirements, thereby changing the amplitude of the RF / microwave excitation signal output by the device under test.

[0066] Furthermore, the first comparator 205 and the second comparator 404 are analog proportional-integral-derivative controllers or digital controllers that include analog-to-digital conversion, digital processing chips and digital-to-analog conversion.

[0067] Furthermore, the attenuation of the high-power attenuator 401 does not need to be determined if the maximum output power of the device under test is not large, ensuring that the signal power after attenuation does not exceed the maximum withstand power of the second directional coupler 402 and the second detector 403.

[0068] Furthermore, the main control circuit 6 is connected to the first comparator controller 205 and the second comparator controller 404 to set the first reference voltage and the second reference voltage, and to receive alarm signals.

[0069] Furthermore, the first directional coupler 203 and the second directional coupler 402 are broadband directional couplers.

[0070] This embodiment also provides a dual-closed-loop amplitude stabilization method for electrical aging of RF / microwave device signals based on the above system, including the following steps: Step 1: Mount the device under test (DUT) onto the DUT and its test fixture 3; Step 2: Determine the test operating mode of input closed-loop amplitude stabilization / output closed-loop amplitude stabilization / dual closed-loop amplitude stabilization, and set the first reference voltage value Vref1 and the second reference voltage value Vref2; Step 3: Start signal source 1 to generate the initial radio frequency excitation signal P0; Input amplitude stabilization steps: The initial RF excitation signal is sampled by the first directional coupler 203 after passing through the voltage-controlled attenuator 201 and the power amplifier 202. The first detector 204 converts the sampled signal Pdt1 into a first detection voltage Vdt1. The first comparator controller 205 compares the first detection voltage Vdt1 with the first reference voltage Vref1 and outputs a first control signal Vctrl1 to dynamically adjust the attenuation of the voltage-controlled attenuator 201 until the first detection voltage Vdt1 and the first reference voltage Vref1 reach a balance. If the first detection voltage Vdt1 is within a preset threshold range, the signal is output to the device under test 3 through the direct-through terminal of the second directional coupler 402. If the first detection voltage Vdt1 deviates from the first reference voltage Vref1 by more than the preset threshold, the first comparator controller 205 outputs an alarm signal Vw1.

[0071] Output amplitude stabilization and monitoring steps: The output signal of the device under test is sampled by the second directional coupler 402 after the attenuation of the high-power attenuator 401 (which can be omitted if the attenuation power is not large). The second detector 403 converts the sampled signal Pdt2 into the second detection voltage Vdt2. The second comparator controller 404 compares the second detection voltage Vdt2 with the second reference voltage Vref2 and outputs the second control signal Vctrl2 to dynamically adjust the gate voltage Vg or drain voltage Vd of the bias voltage power supply circuit 405 until the second detection voltage Vdt2 and the second reference voltage Vref2 reach a balance. If the second detection voltage Vdt2 is within the preset threshold range, the signal is output to the load 5 through the direct-through terminal of the second directional coupler 402. If the second detection voltage Vdt2 deviates from the second reference voltage Vref2 by more than the preset threshold, the second comparator controller 404 outputs the alarm signal Vw2.

[0072] Furthermore, the input stabilization step continues during system operation to compensate for drift caused by the power amplifier 202 and other components in the link.

[0073] Furthermore, in the output stabilization and monitoring steps, the alarm signal is used to trigger system alarms, record the failure time of the device under test, or link to cut off the signal source, power amplifier, and power supply to the device under test.

[0074] Example 3 Those skilled in the art can understand this embodiment as a more specific description of Embodiment 1.

[0075] The purpose of this embodiment is to provide a dual closed-loop amplitude stabilization system and method for electrical aging of radio frequency / microwave devices, so as to solve the problems of unstable signal amplitude during the aging process and the inability to simultaneously ensure accurate application of input stress and monitoring of output status in the prior art.

[0076] This embodiment of a dual closed-loop amplitude stabilization system for signal loading electrical aging of radio frequency / microwave devices includes: Radio frequency / microwave signal sources are used to generate initial radio frequency excitation signals and typically need to have wideband output capabilities to achieve system versatility. An input ALC (Automatic Amplitude Control) loop is connected after the signal source to regulate and stabilize the power of the initial RF / microwave excitation signal and provide a constant amplitude input excitation to the device under test. The device under test and its test fixture are used to mount the RF / microwave device under test. Its input terminal is connected to the output of the input ALC loop, and its output terminal is connected to the output of the input closed-loop amplitude stabilization unit. The output ALC loop is connected to the output terminal of the test device and its test fixture. It is used to monitor the output signal of the test device and stabilize the output power. The output of the aging signal with constant amplitude is sent to the subsequent absorption load.

[0077] The absorption load is connected to the output end of the output ALC loop to absorb radio frequency / microwave signals and ensure stable operation of the entire link. The main control unit is connected to the control terminal of the RF / microwave signal source and is used to set the operating frequency and initial power (P0) of the link RF / microwave excitation. It is also connected to the control terminal of the input ALC loop and is used to set the input power Pin of the device under test. The control terminal of the output ALC loop is used to set the output RF / microwave amplitude of the device under test. The alarm output terminal of the input ALC loop and the output ALC loop is connected to the alarm output terminal and is used to trigger system alarm when an alarm signal is output, record the failure time of the device under test, or link to cut off the power supply of the signal source, power amplifier, and device under test. The input ALC loop includes: A voltage-controlled attenuator, the input of which is connected to the signal source, is controlled by a voltage-controlled signal to adjust the amplitude of the initial radio frequency excitation signal; A power amplifier, connected after the voltage-controlled attenuator, is used to amplify the attenuated signal to the required aging power; The first directional coupler has its input terminal connected to the output of the power amplifier, its through terminal connected to the input terminal of the device under test and its test fixture, and is used to feed the amplified excitation signal into the device under test. Its coupling terminal outputs the first sampling signal. The first detector is connected to the coupling end of the first directional coupler and is used to convert the first sampling signal into a first detection voltage; A first comparison controller is connected to the output of the first detector, the control terminal of the voltage-controlled attenuator, and the first reference voltage output and first alarm input terminals of the main control unit. It compares the first detected voltage with a set first reference voltage and outputs the first control signal to the voltage-controlled attenuator, forming a negative feedback closed loop to maintain a constant power supply to the input terminal of the device under test. When the first detected voltage deviates from the first reference voltage by more than a preset threshold, it determines that the device under test is over- or under-excited and outputs an alarm signal to the main control unit or records data.

[0078] The output ALC loop includes: A high-power attenuator (which may be omitted when the power is low) has its input terminal connected to the output terminal of the device under test and its test fixture, and is used to attenuate the output signal of the device under test to a power level that can be safely processed by the subsequent detection circuit. The second directional coupler has its input end connected to the output of the large attenuator, its through end connected to the aging load, and its coupling end outputting a second sampling signal; it is used to feed the output signal of the large attenuator into the aging absorption load and couple out the second sampling signal. The second detector is connected to the coupling end of the second directional coupler and is used to convert the second sampling signal into a second detection voltage; The second comparison controller is connected to the output terminal of the second detector, the control terminal of the bias voltage power supply circuit, the second reference voltage output terminal and the second alarm input terminal of the main control unit, respectively. It is used to compare the second detector voltage with the set second reference voltage and output the second control signal to the control terminal of the bias voltage power supply circuit. When the second detector voltage deviates from the second reference voltage by more than a preset threshold, it is determined that the performance of the device under test has drifted or failed, and an alarm signal is output to the main control unit or the data is recorded. The bias voltage power supply circuit is connected to the output terminal of the second comparator controller and the grid voltage power supply terminal and drain voltage power supply terminal of the device under test and its test fixture. It is controlled by the second voltage control signal to adjust the output drain voltage or grid voltage of the bias voltage power supply circuit (selectable according to test requirements), thereby changing the amplitude of the RF / microwave excitation signal output by the device under test.

[0079] Furthermore, in the input ALC loop, the first comparator controller is an analog proportional-integral-derivative controller or a digital controller that includes analog-to-digital conversion, digital processing chip and digital-to-analog conversion.

[0080] Furthermore, in the output ALC loop, the attenuation of the high-power attenuator is determined based on the maximum output power of the device under test, ensuring that the signal power after attenuation does not exceed the maximum power handling capacity of the second directional coupler and the second detector.

[0081] Furthermore, the system also includes a main control unit connected to the first comparison controller and the second comparison controller, used to set the first reference voltage and the second reference voltage, and to receive the alarm signal for real-time monitoring and data recording of the aging state.

[0082] Furthermore, the first and second directional couplers are broadband directional couplers, and their coupling degree is selected according to the signal power level to ensure that the detector operates in the linear region.

[0083] This invention also provides a dual-closed-loop amplitude stabilization method for electrical aging of radio frequency / microwave device signals based on the above system, comprising the following steps: Step 1: Install the device under test (DUT) to be aged onto the DUT and its test fixture, and connect the input and output links. Step 2: Determine the input amplitude stabilization / output amplitude stabilization / dual closed-loop amplitude stabilization test operating mode, and set the first reference voltage value (which corresponds to the expected amplitude stabilization power level applied to the input terminal of the device under test) and the second reference voltage value (which corresponds to the expected output power level of the device under test under normal operating conditions). Step 3: Start the signal source to generate the initial radio frequency excitation signal; Input amplitude stabilization steps: The original radio frequency excitation signal is sampled by the first directional coupler after passing through the voltage-controlled attenuator and the power amplifier, and the first detector converts the sampled signal into the first detection voltage. The first comparator controller compares the first detector voltage with the first reference voltage and outputs a first control signal to dynamically adjust the attenuation of the voltage-controlled attenuator. The adjustment process is repeated until the first detector voltage and the first reference voltage reach a balance, thereby providing a constant excitation power to the device under test at the input terminal. Output amplitude stabilization and monitoring steps: The output signal of the device under test is attenuated by a high-power attenuator (which may not be necessary if the power is low), and then sampled by the second directional coupler. The second detector converts the sampled signal into a second detection voltage. The second comparator controller compares the second detector voltage with the second reference voltage and outputs a second control signal to dynamically adjust the drain voltage or gate voltage output by the bias voltage power supply circuit. If the second detection voltage is within the preset threshold range, the device under test is determined to be working normally, and the signal is output to the load through the direct-through terminal of the second directional coupler; If the second detection voltage deviates from the second reference voltage by more than a preset threshold, the device under test is determined to be malfunctioning. The second comparator controller outputs an alarm signal to alert the operator or the main control unit records the failure event.

[0084] Example 4 Those skilled in the art can understand this embodiment as a more specific description of Embodiment 1.

[0085] like Figure 3 As shown, this embodiment provides a dual closed-loop amplitude stabilization system for signal loading electrical aging of radio frequency / microwave devices, including a signal source 1, an input ALC loop 2, a device under test and its test fixture 3, an output ALC loop 4, and an absorption load 5. The absorption load 5 is the aging load.

[0086] Signal source 1 is used to generate a radio frequency continuous wave or pulse modulated signal P0 with a specific frequency and basic power.

[0087] The input ALC loop 2 consists of a voltage-controlled attenuator 201, a power amplifier 202, a first directional coupler 203, a first detector 204, and a first comparator controller 205.

[0088] The RF input of voltage-controlled attenuator 201 is connected to signal source 1, and its control terminal is connected to the first comparator controller 205. The output of voltage-controlled attenuator 201 is connected to the input of power amplifier 202. Power amplifier 202 amplifies the RF / microwave signal P0 to the power level Pin required for aging. The input of first directional coupler 203 is connected to the output of power amplifier 202, and its through-hole is connected to the device under test (DUT) and its test fixture input on the DUT station 3 via a test cable. The coupling terminal of first directional coupler 203 is connected to the input of first detector 204. First detector 204 converts the RF sampling signal Pdt1 into a DC voltage Vdt1 proportional to the power and sends it to the first comparator controller 205.

[0089] The first comparator controller 205 (e.g., a circuit with a PID control algorithm) compares this voltage with a first reference voltage Vref1 provided by a high-precision DC reference source. If the detected voltage Vdt1 is lower than Vref1, the first comparator controller 205 outputs a control voltage Vctrl1 to decrease the attenuation of the voltage-controlled attenuator 201, and vice versa, thus forming a closed loop to ensure that the power Pin sent to the input terminal of the device under test is constant. Vref1 corresponds to the nominal output power of the device under test. As long as the second detected voltage is within a tolerance window (e.g., the voltage range corresponding to ±0.5dB) near Vref1, the system considers the device under test to be working normally. Once it exceeds this window, the first comparator controller 205 immediately outputs an alarm level signal Vw1 (e.g., TTL), or reports it to the main control unit 6 via the interface, indicating that the input power of the device is abnormal.

[0090] The device under test and its test fixture 3 are usually located in a heat sink (sometimes with temperature control function) or a high and low temperature chamber, used to fix and connect the device under test and provide the necessary DC bias.

[0091] The output ALC loop 4 consists of a high-power attenuator 401 (which can be omitted when the power is not high), a second directional coupler 402, a second detector 403, a second comparator controller 404, and a bias voltage power supply circuit 405.

[0092] The input of the high-power attenuator 401 is connected to the output of the device under test (DUT) and its test fixture 3. The attenuation of the high-power attenuator 401 (e.g., 30dB or 40dB) is sufficiently large to attenuate the highest power that the DUT might output (e.g., +40dBm) to a safe operating range for subsequent circuitry (e.g., below 0dBm). The attenuated signal enters the second directional coupler 402. The through-terminal of the second directional coupler 402 is connected to the annealed absorption load 5 (typically a power matching load), and its coupling terminal is connected to the second detector 403. The second detector 403 converts the sampled signal into a second detected voltage, which is then sent to the second comparator controller 404.

[0093] The second comparator controller 404 compares this voltage with the set second reference voltage Vref2. If the detected voltage Vdt2 is lower than Vref2, the second comparator controller 404 outputs a control voltage Vctrl2 to appropriately adjust the leakage voltage Vd or gate voltage Vg output by the bias voltage power supply circuit 405; otherwise, it increases the attenuation, thus forming a closed loop to ensure that the power Pout at the output terminal of the device under test is constant. Vref2 corresponds to the nominal output power of the device under test. As long as the second detected voltage is within a tolerance window (such as the voltage range corresponding to ±0.5dB) near Vref2, the system considers the device under test to be working normally. Once it exceeds this window, the second comparator controller 404 immediately outputs an alarm level signal (such as TTL) or reports it to the main control unit 6 through the interface, indicating that the output power of the device is abnormal.

[0094] The main control unit 6 connects to the first comparator 205 and the second comparator 404 (if they have digital interfaces) or other intelligent modules in the system via GPIB, LAN, or serial port for setting parameters, recording data, and unified alarm management. Multiple such dual closed-loop channels can work in parallel to achieve parallel and simultaneous signal loading electrical aging tests on multiple devices.

[0095] Based on the above system, this embodiment also provides a dual-closed-loop amplitude stabilization method, including: S1. Connect the system and install the DUT.

[0096] S2. Set Vref1 (corresponding to input power Pin) and Vref2 (corresponding to nominal output power Pout) and alarm thresholds ΔVw1 and ΔVw2 through the main control unit 6.

[0097] S3, Start signal source 1 and bias voltage power supply circuit (to power the device under test).

[0098] S4. Input closed-loop operation: The system automatically adjusts the voltage-controlled attenuator 201 to make the first detector voltage Vdet1 approach Vref1. After stabilization, the input power of the device under test is a constant value Pin.

[0099] S5. If |Vdet1 – Vref1| > ΔVw1, the excitation signal of the test device is determined to be abnormal, the failure time is recorded, and an alarm is triggered. If Vdet1 remains within the window, the test device continues aging until the preset aging time is reached. S6. Output monitoring: The second comparison controller 44 continuously compares Vdet2 and Vref2.

[0100] S7. If |Vdet2 – Vref2| > ΔVw2, the device under test is determined to be malfunctioning, the failure time is recorded, and an alarm is triggered. If Vdet2 remains within the window, the device under test continues aging until the preset aging time is reached.

[0101] This invention achieves dual amplitude stabilization of input and output signals during the electrical aging process of the tested RF / microwave device, improving the stability and accuracy of aging tests. At the same time, it can promptly detect and handle device failures, ensuring test safety and efficiency.

[0102] Specific embodiments of the present invention have been described above. It should be understood that the present invention is not limited to the specific embodiments described above, and those skilled in the art can make various changes or modifications within the scope of the claims, which do not affect the essence of the present invention. Unless otherwise specified, the embodiments and features described in this application can be arbitrarily combined with each other.

Claims

1. A dual-closed-loop amplitude stabilization system for signal loading electrical aging of radio frequency / microwave devices, characterized in that, include: Radio frequency / microwave signal source (1) is used to generate the original radio frequency / microwave excitation signal; The input ALC loop (2) is connected to the output of the radio frequency / microwave signal source (1) and is used to adjust and stabilize the power of the initial radio frequency / microwave excitation signal. The device under test station (3) has its input terminal connected to the output terminal of the input ALC loop (2) for mounting the RF / microwave device under test; The output ALC loop (4) is connected to the output of the device under test station (3) and is used to sample and stabilize the output RF / microwave of the device under test. The absorption load (5) has its input end connected to the output end of the ALC loop (4) and is used to absorb radio frequency / microwave signals. The main control unit (6) is connected to the control terminal of the radio frequency / microwave signal source (1) and is used to set the working frequency and initial power P0 of the link radio frequency / microwave excitation. The main control unit (6) is connected to the control terminal of the input ALC loop (2) and is used to set the input power Pin of the RF / microwave device under test; the main control unit (6) is connected to the control terminal of the output ALC loop (4) and is used to set the output RF / microwave amplitude of the RF / microwave device under test; the main control unit (6) is connected to the alarm output terminal of the input ALC loop (2) and the alarm output terminal of the output ALC loop (4) and is used to trigger a system alarm, record the failure time of the RF / microwave device under test, or cut off the power supply of the signal source, power amplifier and the RF / microwave device under test when receiving the alarm signal output by the input ALC loop (2) or the output ALC loop (4).

2. The dual closed-loop amplitude stabilization system for signal loading electrical aging of radio frequency / microwave devices according to claim 1, characterized in that, The input ALC loop (2) includes: A voltage-controlled attenuator (201) has its input end connected to the output end of the radio frequency / microwave signal source (1) and is controlled by the voltage control signal Vctrl to adjust the amplitude of the original radio frequency / microwave excitation signal; A power amplifier (202) is connected to the output of the voltage-controlled attenuator (201) for amplifying the attenuated radio frequency / microwave excitation signal. The first directional coupler (203) has its input end connected to the output end of the power amplifier (202), its through end connected to the input end of the device under test station (3), and its coupling end outputs the first sampling signal Pdt1; The first detector (204) has its input end connected to the coupling end of the first directional coupler (203) and is used to convert the first sampling signal Pdt1 into the first detection voltage Vdt1. The first comparison controller (205) is connected to the output terminal of the first detector (204), the control terminal of the voltage-controlled attenuator (201), and the first alarm input terminal of the main control unit (6), respectively. The first comparison controller (205) is used to compare the first detector voltage Vdt1 with the set first reference voltage Vref1, output the first control signal Vctrl1 to the control terminal of the voltage-controlled attenuator (201), and output the alarm signal Vw1 to the first alarm input terminal of the main control unit (6) when the first detector voltage Vdt1 deviates from the first reference voltage Vref1 by more than a preset threshold.

3. The dual closed-loop amplitude stabilization system for signal loading electrical aging of radio frequency / microwave devices according to claim 2, characterized in that, The output ALC loop (4) includes: A high-power attenuator (401) is connected to the output of the device under test station (3) and is used to attenuate the output signal when the output power of the RF / microwave device under test is greater than a preset threshold. The second directional coupler (402) has its input end connected to the output end of the high-power attenuator (401), its through end connected to the absorption load (5), and its coupling end outputting the second sampling signal Pdt2; The second detector (403) is connected to the coupling end of the second directional coupler (402) and is used to convert the second sampling signal Pdt2 into the second detection voltage Vdt2; The second comparison controller (404) is connected to the output terminal of the second detector (403), the control terminal of the bias voltage power supply circuit (405), and the second alarm input terminal of the main control unit (6), respectively. The second comparison controller (404) is used to compare the second detector voltage Vdt2 with the set second reference voltage Vref2, output the second control signal Vctrl2 to the control terminal of the bias voltage power supply circuit (405), and output the alarm signal Vw2 to the second alarm input terminal of the main control unit (6) when the second detector voltage Vdt2 deviates from the second reference voltage Vref2 by more than a preset threshold. The bias voltage power supply circuit (405) is connected to the output terminal of the second comparator controller (404), the gate voltage power supply terminal and the drain voltage power supply terminal of the RF / microwave device under test, respectively. The bias voltage power supply circuit (405) is controlled by the second control signal Vctrl2 to adjust the output voltage Vd or Vg, thereby changing the amplitude of the RF / microwave signal output by the RF / microwave device under test.

4. The dual closed-loop amplitude stabilization system for signal loading electrical aging of radio frequency / microwave devices according to claim 3, characterized in that, The first comparator (205) and the second comparator (404) are both analog proportional-integral-derivative controllers, or both are digital controllers that include an analog-to-digital converter module, a digital processing chip and a digital-to-analog converter module.

5. The dual closed-loop amplitude stabilization system for signal loading electrical aging of radio frequency / microwave devices according to claim 3, characterized in that, The attenuation of the high-power attenuator (401) is determined based on the maximum output power of the RF / microwave device under test, and the attenuation satisfies that the signal power after attenuation by the high-power attenuator (401) does not exceed the maximum withstand power of the second directional coupler (402) and the second detector (403).

6. The dual closed-loop amplitude stabilization system for signal loading electrical aging of radio frequency / microwave devices according to claim 3, characterized in that, The main control unit (6) is used to set the first reference voltage Vref1 and the second reference voltage Vref2, and to receive the alarm signal Vw1 and the alarm signal Vw2.

7. The dual closed-loop amplitude stabilization system for signal loading electrical aging of radio frequency / microwave devices according to claim 3, characterized in that, Both the first directional coupler (203) and the second directional coupler (402) are broadband directional couplers.

8. A dual-closed-loop amplitude stabilization method for signal loading electrical aging of radio frequency / microwave devices, characterized in that, The dual closed-loop amplitude stabilization system based on the signal loading electrical aging of the RF / microwave device according to any one of claims 1 to 7 includes the following steps: Device installation steps: Install the RF / microwave device under test at the device under test station (3); Mode determination steps: Determine the test operating mode, which is the input closed-loop amplitude stabilization mode, the output closed-loop amplitude stabilization mode, or the dual closed-loop amplitude stabilization mode; and simultaneously set the first reference voltage value Vref1 and the second reference voltage value Vref2. Signal source startup steps: Start the radio frequency / microwave signal source (1) to generate an initial radio frequency excitation signal P0; Input amplitude stabilization steps: The initial RF excitation signal is attenuated sequentially by the voltage-controlled attenuator (201) and amplified by the power amplifier (202) of the input ALC loop (2). It is then sampled by the first directional coupler (203) of the input ALC loop (2) to obtain a first sampled signal Pdt1. The first sampled signal Pdt1 is converted into a first detection voltage Vdt1 by the first detector (204) of the input ALC loop (2). The first detection voltage Vdt1 is then compared with... The first reference voltage Vref1 is compared, and the first control signal Vctrl1 is output to dynamically adjust the attenuation of the voltage-controlled attenuator (201) until the first detector voltage Vdt1 and the first reference voltage Vref1 are balanced; if the first detector voltage Vdt1 is within the preset threshold range, the amplified and stabilized signal is output to the tested RF / microwave device through the through terminal of the first directional coupler (203); if the first detector voltage Vdt1 deviates from the first reference voltage Vref1 by more than the preset threshold, the first comparator controller (205) outputs an alarm signal Vw1. Output amplitude stabilization and monitoring steps: The output signal of the RF / microwave device under test is attenuated by the high-power attenuator (401) of the output ALC loop (4), and sampled by the second directional coupler (402) of the output ALC loop (4) to obtain the second sampled signal Pdt2; the second sampled signal Pdt2 is converted into a second detection voltage Vdt2 by the second detector (403) of the output ALC loop (4); the second detection voltage Vdt2 is compared with the second reference voltage Vref2 by the second comparator (404) of the output ALC loop (4). The second control signal Vctrl2 is output to dynamically adjust the gate voltage Vg or drain voltage Vd of the bias voltage power supply circuit (405) of the output ALC loop (4) until the second detector voltage Vdt2 and the second reference voltage Vref2 reach a balance. If the second detector voltage Vdt2 is within the preset threshold range, the stabilized signal is output to the absorption load (5) through the through terminal of the second directional coupler (402). If the second detector voltage Vdt2 deviates from the second reference voltage Vref2 by more than the preset threshold, an alarm signal Vw2 is output through the second comparator controller (404).

9. The dual-closed-loop amplitude stabilization method for signal loading electrical aging of radio frequency / microwave devices according to claim 8, characterized in that, The input stabilization step is continuously performed during system operation to compensate for power drift caused by the power amplifier (202) and other components of the link.

10. The dual-closed-loop amplitude stabilization method for signal loading electrical aging of RF / microwave devices according to claim 8, characterized in that, In the output stabilization and monitoring steps, the alarm signal Vw2 is used to trigger a system alarm, record the failure time of the tested RF / microwave device, or link to cut off the power supply of the RF / microwave signal source (1), power amplifier (202), and the tested RF / microwave device.

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