A radio frequency power AM external amplitude stabilizing device based on detector temperature control

Abstract

The application discloses a kind of based on detector temperature control radio frequency power AM external amplitude stabilizing device, including radio frequency output, temperature control circuit is carried out to the packaged detector before;Radio frequency output is carried out through signal source ALC mode, records the detector output voltage corresponding to target output power under open loop state of stable amplitude system;Signal source is switched to AM mode by being passed through, and the output voltage of direct current source is set according to the detector output voltage measured when open loop and starts stable amplitude system closed loop output, realizes the AM external amplitude control of radio frequency output power.The application effectively overcomes the problem that ALC mode can only solve signal source internal fluctuation, leading to poor stability of final output power, and significantly improves the defect that output voltage fluctuation and power cannot be long-term stable in traditional AM external stabilizing device due to the fact that thermistor seat is easily affected by temperature, further guarantees the stability of long-term output of radio frequency power.

Description

Technical Field

[0001] This invention relates to the field of semantic extraction research, and in particular to an external amplitude stabilization device for radio frequency power AM based on detector temperature control. Background Technology

[0002] Precise and stable radio frequency (RF) power output plays a crucial role in high-tech fields such as semiconductor manufacturing, medical devices, space communications, and radar systems. For example, in semiconductor plasma etching processes, RF power amplifiers need to provide continuous and stable kilowatt-level power output; any power fluctuations can damage wafers, causing significant economic losses. In medical applications, magnetic resonance imaging (MRI) equipment relies on high-peak-power RF pulses to generate precise atomic flip signals; power instability directly affects image quality and diagnostic safety. In space science and radar detection, stable RF power is fundamental to ensuring clear long-range signal transmission and accurate target identification and tracking. Therefore, achieving long-term, highly stable RF power output has always been a key technical challenge that industry and academia have been striving to solve.

[0003] In RF power control systems, ALC (Automatic Level Control) is a commonly used amplitude stabilization method within signal sources. ALC monitors and adjusts the output signal amplitude through an internal feedback loop, effectively suppressing internal fluctuations caused by temperature drift or component aging within the signal source. However, ALC monitoring points are typically located inside the signal source or at the output port, making it unable to detect and compensate for performance changes and losses caused by external components such as power amplifiers, transmission cables, couplers, and loads. In other words, ALC can only address the stability issue at the "source," and its control capability over the final output power of the entire signal chain has inherent limitations, potentially leading to insufficient output power stability in precision applications.

[0004] To overcome the limitations of ALC, AM (Amplitude Modulation) external amplitude stabilization technology has emerged. Traditional AM external amplitude stabilization devices couple a portion of the RF signal from the system's final output port, convert it into a DC voltage signal via a thermistor, and then compare this voltage with a highly stable DC reference source. The resulting error signal is fed back to the AM modulation port of the signal source, thus forming an external closed-loop control system. This system directly monitors and adjusts the final output power in real time, effectively compensating for amplitude fluctuations throughout the entire link from the signal source to the load, significantly improving the stability of the output power.

[0005] However, the performance of traditional AM external amplitude stabilization devices is largely limited by their core sensing device—the thermistor mount. While the thermistor mount can measure actual thermal power, its inherent temperature sensitivity is a major drawback. Changes in ambient temperature directly cause significant changes in the thermistor resistance, leading to output voltage drift. This drift can be mistakenly interpreted by the closed-loop system as a change in output power, triggering erroneous adjustments and introducing additional power instability. Therefore, in operating environments with large temperature variations or applications requiring extremely high long-term stability, traditional AM external amplitude stabilization devices based on thermistor mounts are insufficient. Thus, a novel AM external amplitude stabilization solution is needed that retains the advantage of direct monitoring of the final output power by external closed-loop control while fundamentally overcoming the inherent temperature sensitivity of traditional thermistor mounts. Exploring sensing devices with superior temperature characteristics and supplementing them with effective temperature control measures to suppress temperature drift has become an important technical path to improve the stability of RF power measurement and control. Therefore, an AM external amplitude stabilization device based on detector temperature control is proposed. Summary of the Invention

[0006] The purpose of this invention is to provide an external amplitude stabilization device for radio frequency power AM based on detector temperature control.

[0007] To achieve the above objectives, the present invention is implemented according to the following technical solution: This invention includes: Temperature control circuit, used to precisely control the temperature of the packaged detector before RF output; The signal source can switch between ALC and AM modes. In ALC mode, it outputs radio frequency signals to achieve open-loop operation of the amplitude stabilization system, and in AM mode, it receives amplitude feedback adjustment signals to achieve closed-loop amplitude stabilization. A DC source is used to set the output voltage based on the detector output voltage recorded in the open-loop state. The detection module includes a power meter and a DC meter, which are used to monitor the target output power and the corresponding detector output voltage in real time under open-loop conditions, respectively. The amplitude stabilization circuit is used to compare the detector output voltage with the DC source set voltage. After signal processing, it generates an amplitude feedback adjustment signal and transmits it to the AM port of the signal source to realize AM external amplitude stabilization control of the RF output power.

[0008] Furthermore, the temperature control circuit includes a temperature sensing unit, a signal conditioning unit, an error amplification and PI adjustment unit, and a power drive unit connected in sequence. The temperature sensing unit includes a Wheatstone bridge composed of a thermal resistor and an adjustable resistor, which converts temperature changes into a differential voltage signal. The signal conditioning unit uses an instrumentation amplifier to amplify the differential voltage signal and adjusts the amplification factor through a gain adjustment resistor. The error amplification and PI adjustment unit uses an operational amplifier to set the proportional gain and the integral time constant to adjust the temperature error. The power drive unit uses a power operational amplifier to drive the heating film and uses negative feedback to regulate and stabilize the internal temperature of the detector package.

[0009] Furthermore, the signal source achieves open-loop operation of the amplitude stabilization system in ALC mode, specifically including: the signal source outputs a radio frequency signal in ALC mode, which is amplified by a power amplifier and then split by a directional coupler, one path is transmitted to the load / calorimeter, and the other path is coupled to the detector; the power meter monitors and records the target output power value in real time, and the DC meter synchronously monitors and records the detector output voltage value corresponding to the power value, and the detector output voltage value is used as the basis for setting the DC source output voltage.

[0010] Furthermore, the amplitude stabilization circuit includes a signal differential amplifier unit, a PI adjustment unit, and a power amplifier unit connected in sequence; On the other hand, a radio frequency power AM external amplitude stabilization method based on detector temperature control is applied to the aforementioned device, the method comprising the following steps: Before the RF power output, activate the temperature control module to ensure the detector operates at a stable temperature. Open-loop calibration steps: Set the signal source to work in ALC mode and output an RF signal, and record the first voltage value output by the detector at the target output power; Closed-loop amplitude stabilization steps: a) Switch the signal source to AM mode and configure the external AM modulation parameters; b) Set the reference voltage output by the DC source to the first voltage value; c) Start the closed loop of the amplitude stabilization system, compare the real-time detector voltage output by the detector with the reference voltage in the amplitude stabilization circuit and adjust it with PI, generate a feedback signal and input it to the AM port of the signal source, dynamically adjust the RF output amplitude, and realize power amplitude stabilization of the external link.

[0011] Furthermore, the configuration of external AM modulation parameters includes: frequency ≥ 200MHz, amplitude ≥ 0dBm; setting the modulation depth to 50%, selecting the external AM source port, and setting the external AM source impedance to 600 ohms.

[0012] The beneficial effects of this invention are: This invention is an external amplitude stabilization device for radio frequency power AM based on detector temperature control. Compared with the prior art, this invention has the following technical advantages: This invention effectively overcomes the problem that ALC mode can only solve the internal fluctuations of the signal source, resulting in poor stability of the final output power. It also significantly improves the defects of traditional AM external radiance stabilizers, which suffer from output voltage fluctuations and power instability due to the thermistor base being easily affected by temperature. This further ensures the stability of long-term RF power output. Attached Figure Description

[0013] Figure 1 This is a schematic diagram of the detector temperature control circuit provided in an embodiment of the present invention; Figure 2 This is a schematic diagram of a preset signal source AM mode provided in an embodiment of the present invention; Figure 3 This is a schematic diagram of the AM external amplitude stabilization circuit provided in an embodiment of the present invention; Figure 4 This is a schematic diagram illustrating the working principle of an AM external radiation stabilization system based on detector temperature control, provided in an embodiment of the present invention. Figure 5 This is a diagram showing the resistance change of the internal temperature sensing resistor PT100 during a period of time after the temperature control circuit is turned on, as provided in an embodiment of the present invention. Detailed Implementation

[0014] The present invention will be further described below through specific embodiments. The illustrative embodiments and descriptions herein are used to explain the present invention, but are not intended to limit the present invention.

[0015] This invention includes: Temperature control circuit, used to precisely control the temperature of the packaged detector before RF output; The signal source can switch between ALC and AM modes. In ALC mode, it outputs radio frequency signals to achieve open-loop operation of the amplitude stabilization system, and in AM mode, it receives amplitude feedback adjustment signals to achieve closed-loop amplitude stabilization. A DC source is used to set the output voltage based on the detector output voltage recorded in the open-loop state. The detection module includes a power meter and a DC meter, which are used to monitor the target output power and the corresponding detector output voltage in real time under open-loop conditions, respectively. The amplitude stabilization circuit is used to compare the detector output voltage with the DC source set voltage. After signal processing, it generates an amplitude feedback adjustment signal and transmits it to the AM port of the signal source to realize AM external amplitude stabilization control of the RF output power.

[0016] like Figure 1As shown, the detector temperature control circuit is mainly used to accurately control the detector's operating temperature, ensuring a more stable voltage output under stable temperature conditions, thereby guaranteeing stable output RF power. The temperature control circuit is mainly divided into a power supply section, a temperature sensing and signal conditioning section, an error amplification and control section, and a power drive section. In the power supply section, an AC-DC power module is used to convert the 220V AC input into ±12V DC voltage, providing positive and negative power supplies for subsequent circuits. In the temperature sensing and signal conditioning section, a PT100 RTD (Resistant Temperature Detector) acts as the temperature sensing element, converting changes in ambient temperature into changes in resistance. Its resistance changes linearly with temperature, forming the basis for temperature measurement. The adjustable resistor P1 can be set to the resistance value corresponding to the target temperature. Resistors R1, R2, and R3, together with PT100 and P1, form a Wheatstone bridge circuit, converting changes in the PT100 resistance value into changes in voltage signals for processing by subsequent circuits. When the resistance value of the PT100 changes with temperature, the bridge circuit becomes unbalanced, resulting in a weak differential voltage signal output. The high-precision instrumentation amplifier U1 (AD620BNZ) amplifies this weak differential voltage signal from the Wheatstone bridge, bringing it to a level suitable for subsequent circuit processing. Resistor R4 acts as the gain adjustment resistor for U1 (AD620BNZ). By changing the value of R4, the amplification factor of U1 (AD620BNZ) can be adjusted using the following formula:

[0017] The amplification factor of U1 (AD620BNZ) in the current circuit can be calculated using this formula. Capacitors C1 and C2 are filter capacitors, whose main function is to filter out high-frequency noise in the input signal of U1 (AD620BNZ), preventing noise interference from causing errors in temperature signal measurement and improving signal purity. In the error amplification and control section, the high-precision operational amplifier U2 (OP07CP) further adjusts the PI parameter of the output signal of U1 (AD620BNZ), and the ratio of resistors R5 and R6 determines the proportional gain. ( =R6 / R5), by changing its resistance value, the controller's sensitivity to temperature deviation can be adjusted. Decreasing the value results in a slower response but also reduces the overshoot. Increasing the value of the integrating resistor R6, along with the integrating capacitors C7 and C8, constitutes the integrating circuit. The resistance and capacitance values ​​of R6 determine the integration time constant. The formula is:

[0018] A larger R6 value results in a longer integration time, weaker integration effect, and slower elimination of steady-state error. A smaller R6 value results in a shorter integration time, stronger integration effect, and faster elimination of steady-state error, but is prone to oscillation. A larger integrating capacitance results in a smoother integration effect, stable error elimination, but a slower speed. A smaller capacitance results in a faster integration effect but may cause system fluctuations. Furthermore, capacitors C3 and C4 are used to filter out high-frequency noise in the signal, ensuring the purity and stability of the temperature signal processed by U2 (OP07CP), providing a reliable signal basis for PI parameter adjustment. All components work together to ensure that U2 (OP07CP) can accurately regulate the temperature through PI control, maintaining a stable operating environment for the detector. In the power drive section, the power operational amplifier U3 (OPA548FKTWT) serves as the core of the power drive, receiving the temperature sensor signal processed by the error amplifier of the preceding stage U2 (OP07CP) to drive the heating element. The value of resistor R8 determines the current limiting magnitude, protecting the heating element and the U3 (OPA548FKTWT) amplifier. The formula is:

[0019] Resistors R7, R9, and R10, along with U10, form a feedback circuit to stabilize the output. Capacitors C5 and C6 filter high-frequency power supply noise from U10. Diode D1 provides a path for the reverse electromotive force when the heating element stops working. Heating elements 1 and 2 heat according to the power signal output by U3 (OPA548FKTWT) to regulate the ambient temperature of the detector. Specifically, when the circuit is working, PT100 senses temperature changes and causes the Wheatstone bridge to output a weak differential voltage signal. This signal is amplified by U1 (AD620BNZ), processed by U2 (OP07CP), and then input to U3 (OPA548FKTWT) for power amplification to drive the heating elements. The circuit automatically adjusts the heating element power through closed-loop control to maintain the detector within a suitable operating temperature range.

[0020] like Figure 2As shown, the setting logic and function of each parameter are as follows: ① Set frequency: Frequency>200>MHz; Set amplitude: Amplitude>0>dBm; This frequency value needs to match the operating frequency band of the detector and the signal source to ensure that the RF signal can be effectively captured by the detector and converted into a stable DC voltage signal, providing an accurate original signal basis for amplitude feedback adjustment, and avoiding the decrease in detection efficiency or signal distortion caused by frequency mismatch. The magnitude of the RF output power under AM external amplitude stabilization is completely determined by the output voltage of the DC voltage source. Selecting 0dBm as the initial value can avoid power amplifier overload or component damage caused by excessively high initial amplitude in sudden situations; ② Turn off ALC: Amplitude>ALCOFF; ALC (Automatic Level Control) is the internal amplitude stabilization mechanism of the signal source, which can only compensate for the fluctuation of the signal source itself and cannot cope with the loss changes of the external link. Turning off ALC can eliminate the interference of internal amplitude stabilization on the external closed loop, allowing the signal source to fully respond to the feedback adjustment signal of the AM external amplitude stabilization circuit, ensuring that the amplitude fluctuation of the external link can be effectively compensated. Enable AM: AM>AMON; This activates the amplitude modulation function of the signal source, allowing it to receive feedback adjustment signals from the external AM port. By changing the amplitude of the output RF signal, it cancels out amplitude drift in the link, achieving stable final output power. ③ Set modulation depth: AM>AMDepth>50%; This sets the modulation depth to 50%. The modulation depth determines the range of AM signal amplitude variation. A 50% setting achieves a balance between "adjustment sensitivity" and "signal stability." It ensures that when the detector detects an amplitude deviation, the signal source can quickly correct the deviation through a 50% amplitude adjustment range, while avoiding excessive signal amplitude fluctuations due to excessive modulation depth, which could cause system oscillations. Simultaneously, this depth matches the PI adjustment parameter of U2 (OP07CP) in the amplitude stabilization circuit, ensuring that the error signal can be efficiently converted into amplitude adjustment commands. ④ Select external port: AM>AMSource>Ext1 / 2; This specifies the external input source of the AM signal as the Ext1 / 2 port. This port is directly connected to the AM output port of the amplitude stabilization circuit to receive the amplitude feedback adjustment signal generated by the amplitude stabilization circuit; ⑤ External AM source impedance selection: More(1 / 2)>ExtImpedance>600ohm; Set the impedance matching value of the external AM source to 600Ω. This impedance value is consistent with the output impedance of the U6 (OPA551UA) power amplifier in the amplitude stabilization circuit and the transmission line impedance of the AM port, which can achieve impedance matching, reduce the reflection loss of the signal during transmission, ensure the stability of the amplitude and phase of the feedback adjustment signal, and avoid feedback signal attenuation or interference caused by impedance mismatch, thus affecting the amplitude stabilization accuracy.

[0021] like Figure 3As shown, the amplitude stabilization circuit is mainly divided into a power supply and conversion section, a signal input and conditioning section, an error amplification and processing section, and a power amplification and output section. In the power supply and conversion section, the AC-DC power module converts the 220V AC input into ±12V DC voltage. The 78L05 voltage regulator chip converts the input +12V voltage into a stable +5V voltage, and the 79L05 voltage regulator chip converts the -12V voltage into a stable -5V voltage, providing positive and negative power supplies for subsequent circuits. Capacitors C9, C10, C11, and C12 mainly serve a filtering function. On the one hand, they filter out high-frequency noise introduced by the power supply, ensuring the purity of the power supply and enabling the voltage regulator chip to output a stable voltage. On the other hand, they decouple the power supply pins of devices such as operational amplifiers, reducing power supply interference between devices. In the signal input and conditioning section, resistors R11 and R12 are connected to the detector output voltage and the DC source setting voltage to the input terminal of U4 (AD620BNZ), respectively, serving as current limiting protection to prevent excessive current from damaging the chip's input stage. At the same time, the equal resistance values ​​achieve input impedance matching, reducing common-mode noise interference. Resistor R13 serves as the gain adjustment resistor for U4 (AD620BNZ). By changing the value of R13, the amplification factor of U4 (AD620BNZ) can be adjusted. The formula is as follows:

[0022] The amplification factor of U4 (AD620BNZ) in the current circuit can be calculated using this formula. Capacitors C13 and C14 are filter capacitors, whose main function is to filter out high-frequency noise in the input signal of U4 (AD620BNZ), providing a clean signal and stable power supply for U4 (AD620BNZ) to ensure its high-precision differential amplification function; the signal amplification and processing section is the same as the temperature control circuit. The high-precision operational amplifier U5 (OP07CP) further adjusts the PI parameter of the output signal of U4 (AD620BNZ), and the ratio of resistors R14 and R15 determines the proportional gain. ( =R15 / R14), Increasing the amplitude will make the circuit more sensitive to AM signal amplitude deviation and speed up amplitude correction, but it can easily lead to overshoot or even oscillation in the system, thus disrupting the stability of the signal amplitude. Decreasing the value of the integrating resistor R15 results in a less responsive amplitude correction, which may not be able to promptly offset signal drift and affect the amplitude stabilization effect. The integrating resistor R15 and integrating capacitor C19 together form the integrating circuit; their resistance and capacitance values ​​determine the integration time constant. The formula is:

[0023] If the integration time is too long (e.g., the capacitance of C19 or the resistance of R15 increases), the integration effect will become smoother, and the speed of eliminating steady-state error of amplitude adjustment will be slower, which may lead to a small deviation in the signal amplitude for a long time. If the integration time is too short (e.g., the capacitance of C19 or the resistance of R15 decreases), the integration effect will be enhanced, and the speed of eliminating steady-state error will be faster, but it is easy to cause system fluctuations, or even over-adjustment. In addition, filter capacitor C15 can filter out high-frequency noise mixed in during the transmission of detector output voltage O1, avoiding noise interference that causes U5 (OP07CP) to misjudge amplitude deviation. Filter capacitor C16 is used to suppress high-frequency ripple and electromagnetic interference in the power supply circuit or signal path of U5 (OP07CP). Together, they provide a clean input signal and a stable working environment for PI regulation, reducing the impact of noise on regulation accuracy. In the power amplification and output section, power operational amplifier U6 (OPA551UA) receives the signal processed by U5 (OP07CP) and amplifies it to generate sufficient power to drive subsequent components related to RF amplitude control. Resistor R16 acts as a current limiter to prevent excessive current from damaging U6 (OPA551UA), and R17 is used to match the load and stabilize the output of U6 (OPA551UA). AM ports 1 and 2 in the AM port section serve as external interfaces related to RF signal amplitude control, connecting to RF circuits requiring amplitude stabilization control. The power signal output from U6 (OPA551UA) is applied to the external circuit through these ports to adjust the RF signal amplitude, thereby achieving amplitude stabilization. Specifically, during circuit operation, the detector outputs a voltage reflecting the RF output power, which, along with the DC source setting voltage, is input to the network composed of R11, R12, and R13. After conditioning, it enters U4 (AD620BNZ) for amplification. The amplified signal is further processed by U5 (OP07CP) and then input to U6 (OPA551UA) for power amplification. The power signal output from U6 (OPA551UA) is applied to the external RF control circuit through AM ports 1 / 2 to adjust the RF signal amplitude. Simultaneously, the power conversion section provides a stable ±5V power supply to the entire circuit, and the filter capacitors ensure the purity of the power supply and signal, ensuring stable circuit operation and ultimately achieving external AM amplitude stabilization control of the RF power.

[0024] like Figure 4As shown, the AM external amplitude stabilization system operates as follows: First, the temperature control circuit is activated to control the temperature of the detector and monitors the resistance change of the PT100 inside the detector's package in real time to ensure it operates in a stable temperature environment, thereby reducing the impact of temperature on the detector's output voltage. Then, the signal source outputs an RF signal, which is amplified by a power amplifier and split into two paths. One path is coupled to the detector through a directional coupler, while the other path continues to be transmitted and is absorbed by a load / calorimeter after passing through a subsequent directional coupler. The detector detects the coupled RF signal and records the detector output voltage corresponding to the target output power in the open-loop state using a DC meter. Next, during the debugging phase, the AM port of the amplitude stabilization circuit is connected to an oscilloscope through a three-way port to observe the AM signal waveform. If the amplitude stabilization loop is normal, the AM signal will not exhibit saturation. The signal source is then switched to AM mode, and the AM output port of the amplitude stabilization circuit is connected to the AM input port of the signal source to form a closed loop. Simultaneously, a DC source provides the amplitude stabilization circuit with the same voltage value as the detector output voltage measured in the open-loop state. The amplitude stabilization circuit receives the detector voltage and the DC source output voltage, compares and processes them, and then outputs an amplitude feedback adjustment signal to the AM port of the signal source to dynamically adjust the output amplitude. Simultaneously, the relevant signal is transmitted to an oscilloscope for waveform observation. At this point, the power probe couples the AM-stabilized RF signal output from the directional coupler to the power meter for real-time power measurement, ultimately completing the device's stable control of the RF signal amplitude and monitoring of related parameters.

[0025] Before the RF output, the temperature of the packaged detector is controlled by a temperature control circuit; Radio frequency output is performed using the signal source in ALC mode, and the detector output voltage corresponding to the target output power in the open-loop state of the amplitude stabilization system is recorded. By switching the signal source to AM mode, setting the DC source output voltage based on the detector output voltage measured in the open-loop state, and starting the closed-loop output of the amplitude stabilization system, AM external amplitude stabilization control of the RF output power is achieved.

[0026] In a radio frequency power AM external amplitude stabilization system based on detector temperature control, the detector temperature needs to be controlled by a temperature control circuit from before the AM external amplitude stabilization control is started until the entire control process. In this embodiment of the invention, the detector temperature control effect obtained by experiment is as follows: Figure 5The figure shows the resistance change of the PT100 temperature-sensing resistor inside the detector housing after the temperature control circuit has been turned on for a period of time. From the curve, we can see that in the initial stage, the PT100 resistance rises rapidly. This is because the temperature control system starts working, heating the detector and its surroundings, causing the PT100 resistance to increase with the temperature. As time progresses, after the resistance reaches a certain level, it quickly enters a relatively stable phase, fluctuating within a very small range, approximately ±0.02Ω, which corresponds to a temperature change of approximately ±0.05℃. This indicates that the temperature control circuit plays a good regulatory role, stabilizing the internal temperature of the detector housing within the target range, effectively suppressing large temperature fluctuations, ensuring the detector operates in a stable temperature environment, reducing the impact of temperature fluctuations on detection performance, and thus ensuring the long-term stability of the RF power output in the entire system.

[0027] After the temperature control circuit controls the temperature of the detector, the signal source outputs an RF signal in ALC mode, which is amplified to the target power level by the power amplifier, while simultaneously recording the corresponding detector output voltage. Then, the AM port of the amplitude stabilization circuit is connected to an oscilloscope for debugging via a three-way connector. After debugging, the signal source is switched to AM mode, and the AM output port of the amplitude stabilization circuit is connected to the AM input port of the signal source to form a closed loop, ensuring that the DC source output is consistent with the detector output voltage recorded in the open-loop state. The amplitude stabilization circuit receives the detector voltage and DC output voltage from the detector. After signal processing, it outputs an amplitude feedback adjustment signal to the AM port of the signal source to dynamically adjust its output amplitude, and simultaneously transmits relevant signals to the oscilloscope for waveform observation. At the same time, the power probe reads the amplitude-stabilized RF signal coupled out by the directional coupler in real time and transmits it to the power meter for real-time power measurement, ultimately completing the device's stable control of the RF signal amplitude and monitoring of related parameters.

[0028] The amplitude stabilization effect at different power levels, obtained through experimental calculations, provided by the embodiments of the present invention is shown in Table 1: ; Table 1 shows the experimental data of the amplitude stabilization effect of the RF power AM external amplitude stabilization device based on detector temperature control under different RF output power. A total of 9 sets of test results were recorded, covering three typical power levels: 9W, 30W, and 110W. Each level was tested repeatedly 3 times, and multiple data were continuously measured by the program for nearly 1 hour each time. The calculated data include the detector's average output voltage (V), average power (W), power repeatability (%), power change (W), and relative power change rate (%). At the 9W setting, the detector's average output voltage stabilized at approximately 1.941V-1.942V, with an average power of approximately 9.031W-9.061W. Power repeatability was approximately 0.07%-0.11%, power variation was approximately 0.037W-0.052W (less than 0.09W), and the relative power change rate was approximately 0.44%-0.55% (less than 1%). At the 30W setting, the detector's average output voltage stabilized at approximately 2.075V-2.077V, with an average power of approximately 30.029W-30.043W. Power repeatability... The power repeatability is approximately 0.05%-0.08%, the power variation is approximately 0.084W-0.142W (less than 0.3W), and the relative power change rate is approximately 0.27%-0.47% (less than 1%). At the 110W level, the detector's average output voltage is approximately 2.217V, the average power is approximately 110.865W-110.950W, the power repeatability is approximately 0.06%-0.08%, the power variation is approximately 0.440W-0.517W (less than 1.1W), and the relative power change rate is approximately 0.40%-0.47% (less than 1%). Overall, the data shows that regardless of the low, medium, or high power range, the detector output voltage remains highly stable, the average power variation is minimal, the power repeatability is excellent, and the relative power change rate is controlled within 1%. This fully verifies that the device, through the combination of detector temperature control and AM external amplitude stabilization technology, can effectively achieve high stability of long-term RF power output under different power levels and significantly suppress power fluctuations.

[0029] Those skilled in the art will understand that embodiments of this application can be provided as methods, systems, or computer program products. Therefore, this application can take the form of a completely hardware embodiment, a completely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, this application can take the form of a computer program product embodied on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0030] This application is described with reference to flowchart illustrations and / or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of this application. It will be understood that each block of the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, special-purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, generate instructions for implementing the flowchart... Figure 1 One or more processes and / or boxes Figure 1 A device that provides the functions specified in one or more boxes.

[0031] These computer program instructions may also be stored in a computer-readable storage medium that can direct a computer or other programmable data processing device to function in a particular manner, such that the instructions stored in the computer-readable storage medium produce an article of manufacture including instruction means, which are implemented in a process Figure 1 One or more processes and / or boxes Figure 1 The function specified in one or more boxes.

[0032] These computer program instructions may also be loaded onto a computer or other programmable data processing equipment to cause a series of operational steps to be performed on the computer or other programmable equipment to produce a computer-implemented process, thereby providing instructions that execute on the computer or other programmable equipment for implementing the process. Figure 1 One or more processes and / or boxes Figure 1 The steps of the function specified in one or more boxes.

[0033] In a typical configuration, a computing device includes one or more processors (CPU), input / output interfaces, network interfaces, and memory.

[0034] Memory may include non-persistent storage in computer-readable media, such as random access memory (RAM) and / or non-volatile memory, such as read-only memory (ROM) or flash RAM. Memory is an example of computer-readable media.

[0035] Computer-readable media include both permanent and non-permanent, removable and non-removable media that can store information by any method or technology. Information can be computer-readable instructions, data structures, modules of programs, or other data. Examples of computer storage media include, but are not limited to, phase-change memory (PRAM), static random access memory (SRAM), dynamic random access memory (DRAM), other types of random access memory (RAM), read-only memory (ROM), electrically erasable programmable read-only memory (EEPROM), flash memory or other memory technologies, CD-ROM, digital versatile optical disc (DVD) or other optical storage, magnetic tape, magnetic magnetic disk storage or other magnetic storage devices, or any other non-transferable medium that can be used to store information accessible by a computing device. As defined herein, computer-readable media does not include transient computer-readable media, such as modulated data signals and carrier waves.

[0036] It should also be noted that the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0037] Those skilled in the art will understand that embodiments of this application can be provided as methods, systems, or computer program products. Therefore, this application can take the form of a completely hardware embodiment, a completely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, this application can take the form of a computer program product embodied on one or more computer-usable storage media (including, but not limited to, disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0038] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A radio frequency power AM external amplitude stabilization device based on detector temperature control, characterized in that, include: Temperature control circuit, used to precisely control the temperature of the packaged detector before RF output; The signal source can switch between ALC and AM modes. In ALC mode, it outputs radio frequency signals to achieve open-loop operation of the amplitude stabilization system, and in AM mode, it receives amplitude feedback adjustment signals to achieve closed-loop amplitude stabilization. A DC source is used to set the output voltage based on the detector output voltage recorded in the open-loop state. The detection module includes a power meter and a DC meter, which are used to monitor the target output power and the corresponding detector output voltage in real time under open-loop conditions, respectively. The amplitude stabilization circuit compares the detector output voltage with the DC source set voltage, processes the signal to generate an amplitude feedback adjustment signal, and transmits it to the AM port of the signal source to achieve AM external amplitude stabilization control of the RF output power; The method of the device includes the following steps: Before the RF power output, activate the temperature control module to ensure the detector operates at a stable temperature. Open-loop calibration steps: Set the signal source to work in ALC mode and output an RF signal, and record the first voltage value output by the detector at the target output power; Closed-loop amplitude stabilization steps: a) Switch the signal source to AM mode and configure the external AM modulation parameters; b) Set the reference voltage output by the DC source to the first voltage value; c) Start the closed loop of the amplitude stabilization system, compare the real-time detector voltage output by the detector with the reference voltage in the amplitude stabilization circuit and adjust it with PI, generate a feedback signal and input it to the AM port of the signal source, dynamically adjust the RF output amplitude, and realize power amplitude stabilization of the external link.

2. The RF power AM external amplitude stabilization device based on detector temperature control according to claim 1, characterized in that, The temperature control circuit includes a temperature sensing unit, a signal conditioning unit, an error amplification and PI adjustment unit, and a power drive unit connected in sequence. The temperature sensing unit includes a Wheatstone bridge composed of a thermal resistor and an adjustable resistor, which converts temperature changes into a differential voltage signal. The signal conditioning unit uses an instrumentation amplifier to amplify the differential voltage signal and adjusts the amplification factor through a gain adjustment resistor. The error amplification and PI adjustment unit uses an operational amplifier to set the proportional gain and the integral time constant to adjust the temperature error. The power drive unit uses a power operational amplifier to drive the heating film and uses negative feedback to regulate and stabilize the internal temperature of the detector package.

3. The RF power AM external amplitude stabilization device based on detector temperature control according to claim 1, characterized in that, The signal source achieves open-loop operation of the amplitude stabilization system in ALC mode, specifically including: the signal source outputs a radio frequency signal in ALC mode, which is amplified by a power amplifier and then split by a directional coupler, one path is transmitted to the load / calorimeter, and the other path is coupled to the detector; the power meter monitors and records the target output power value in real time, and the DC meter synchronously monitors and records the detector output voltage value corresponding to the power value, and the detector output voltage value is used as the basis for setting the DC source output voltage.

4. The RF power AM external amplitude stabilization device based on detector temperature control according to claim 1, characterized in that, The amplitude stabilization circuit includes a signal differential amplifier unit, a PI adjustment unit, and a power amplifier unit connected in sequence.

5. The RF power AM external amplitude stabilization device based on detector temperature control according to claim 1, characterized in that, The configuration of external AM modulation parameters includes: frequency ≥ 200MHz, amplitude ≥ 0dBm; setting the modulation depth to 50%, selecting the external AM source port, and setting the external AM source impedance to 600 ohms.

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