Radio frequency circuit and control method therefor, radio frequency heating apparatus, device, and medium

Abstract

The present application discloses a radio frequency circuit and a control method therefor, a radio frequency heating apparatus, a device, and a medium. The control method comprises: controlling a radio frequency circuit to operate in a first state, the first state comprising an operating frequency point of a signal generation apparatus being a preset frequency point, and an output power of a power amplifier being a preset power, the preset power being less than a rated output power of the power amplifier; controlling the signal generation apparatus to traverse frequency points within a predetermined frequency band, and detecting a reflected power of the power amplifier in real time and obtaining a target frequency point corresponding to a minimum reflected power; and controlling the signal generation apparatus to operate at the target frequency point, and adjusting an attenuation value of an automatic level control apparatus, so that the output power of the power amplifier is the rated output power, and the attenuation value corresponding to the rated output power is a target attenuation value. By adjusting the attenuation value of the automatic level control apparatus without using an isolator, the power amplifier can output the rated power at different operating frequencies.

Description

A radio frequency circuit and its control method, a radio frequency heating device, equipment and medium

[0001] Cross-reference to related applications

[0002] This application claims priority to Chinese Patent Application No. 202411398939.8, filed on October 9, 2024, entitled "A Radio Frequency Circuit and Control Method Thereof, Radio Frequency Heating Device, Equipment and Medium", the entire contents of which are incorporated herein by reference. Technical Field

[0003] This application relates to the field of radio frequency heating technology, specifically to a radio frequency circuit and its control method, a radio frequency heating device, equipment, and medium. Background Technology

[0004] This section provides only background information relevant to this disclosure and is not necessarily prior art.

[0005] Radio frequency (RF) technology is often used in food processing and safety, such as using RF energy to directly heat food and using the thermal effect generated by RF energy to kill microorganisms in food.

[0006] In traditional radio frequency (RF) circuits, isolators are typically used to protect power amplifiers from damage caused by excessive reflected power. The main function of an isolator is to prevent reflected signals from returning to the power amplifier, thus avoiding damage. However, isolators are usually large and relatively expensive, and they also incur power losses during operation, reducing system efficiency. Summary of the Invention

[0007] The main objective of this invention is to provide a radio frequency (RF) circuit and its control method, an RF heating device, equipment, and medium that, without the need for an isolator, allows a power amplifier to output rated power at different operating frequencies by adjusting the attenuation value of an automatic level control device. This objective is achieved through the following technical solutions:

[0008] In a first aspect, this application proposes a control method for a radio frequency (RF) circuit, the RF circuit including a signal generating device, an automatic level control device, and a power amplifier. The signal generating device is used to provide an operating frequency to the automatic level control device, and the automatic level control device is used to provide an operating voltage to the power amplifier so that the power amplifier provides output power. The control method includes:

[0009] The radio frequency circuit is controlled to operate in a first state, wherein the operating frequency of the signal generator is a preset frequency and the output power of the power amplifier is a preset power, wherein the preset power is less than the rated output power of the power amplifier;

[0010] The signal generating device is controlled to traverse the frequency points within the predetermined frequency band, and the reflected power of the power amplifier is detected in real time to obtain the target frequency point corresponding to the minimum reflected power;

[0011] The signal generating device is controlled to operate at the target frequency, and the attenuation value of the automatic level control device is adjusted so that the output power of the power amplifier is the rated output power, and the attenuation value corresponding to the rated output power is the target attenuation value.

[0012] In some embodiments of this application, the method further includes: real-time detection of the reflected power of the power amplifier; and, when the reflected power of the power amplifier is greater than or equal to a reflected power threshold, adjusting the attenuation value of the automatic level control device so that the reflected power of the power amplifier is less than the reflected power threshold.

[0013] In some embodiments of this application, the method further includes: real-time detection of the operating temperature of the power amplifier; and, when the operating temperature of the power amplifier is greater than or equal to a temperature threshold, adjusting the attenuation value of the automatic level control device so that the operating temperature of the power amplifier is less than the temperature threshold.

[0014] In some embodiments of this application, the method further includes: real-time detection of the output power of the power amplifier; and, when the output power of the power amplifier is greater than or equal to a power threshold, adjusting the attenuation value of the automatic level control device so that the output power of the power amplifier is less than the power threshold, and the power threshold is greater than the rated output power.

[0015] In some embodiments of this application, the method further includes: cyclically executing the process of determining the target frequency and the target attenuation value at a preset frequency.

[0016] Secondly, this application proposes a radio frequency circuit, comprising: a signal generating device, an automatic level control device, a power amplifier, and a control unit. The signal generating device is used to provide an operating frequency to the automatic level control device, the automatic level control device is used to provide an operating voltage to the power amplifier to enable the power amplifier to provide output power, and the control unit is configured to:

[0017] The radio frequency circuit is controlled to operate in a first state, wherein the operating frequency of the signal generator is a preset frequency and the output power of the power amplifier is a preset power, wherein the preset power is less than the rated output power of the power amplifier;

[0018] The signal generating device is controlled to traverse the frequency points within the predetermined frequency band, and the reflected power of the power amplifier is detected in real time to obtain the target frequency point corresponding to the minimum reflected power;

[0019] The signal generating device is controlled to operate at the target frequency, and the attenuation value of the automatic level control device is adjusted so that the output power of the power amplifier is the rated output power, and the attenuation value corresponding to the rated output power is the target attenuation value.

[0020] In some embodiments of this application, the control unit is further configured to:

[0021] Real-time detection of the reflected power of the power amplifier;

[0022] When the reflected power of the power amplifier is greater than or equal to the reflected power threshold, the attenuation value of the automatic level control device is adjusted so that the reflected power of the power amplifier is less than the reflected power threshold.

[0023] In some embodiments of this application, the control unit is further configured to:

[0024] Real-time monitoring of the operating temperature of the power amplifier;

[0025] When the operating temperature of the power amplifier is greater than or equal to a temperature threshold, the attenuation value of the automatic level control device is adjusted so that the operating temperature of the power amplifier is less than the temperature threshold.

[0026] In some embodiments of this application, the control unit is further configured to:

[0027] Real-time detection of the output power of the power amplifier;

[0028] When the output power of the power amplifier is greater than or equal to the power threshold, the attenuation value of the automatic level control device is adjusted so that the output power of the power amplifier is less than the power threshold, and the power threshold is greater than the rated output power.

[0029] In some embodiments of this application, the control unit is further configured to:

[0030] The process of determining the target frequency and the target attenuation value is executed cyclically according to a preset frequency.

[0031] In some embodiments of this application, the control unit includes a control chip, a temperature detection device, and a power detection device. The control chip detects the operating temperature of the power amplifier through the temperature detection device and detects the output power of the power amplifier through the power detection device.

[0032] Secondly, this application proposes a heating, ventilation, and air conditioning (HVAC) system, including an outdoor unit as shown in any of the above technical solutions.

[0033] Thirdly, this application provides a radio frequency heating device, including the radio frequency circuit described in the second aspect, and further including a heating antenna, wherein the heating antenna is connected to the power output terminal of the power amplifier in the radio frequency circuit.

[0034] Fourthly, this application provides an apparatus including the radio frequency heating device described in the third aspect.

[0035] Fifthly, this application provides an electronic device, including: a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the computer program to implement the method described in the first aspect above.

[0036] In a sixth aspect, this application provides a computer-readable storage medium having computer-readable instructions stored thereon, which can be executed by a processor to implement the method described in the first aspect above. Attached Figure Description

[0037] Various other advantages and benefits will become apparent to those skilled in the art upon reading the following detailed description of preferred embodiments. The accompanying drawings are for illustrative purposes only and are not intended to limit the scope of this application. Furthermore, the same reference numerals denote the same parts throughout the drawings. In the drawings:

[0038] Figure 1 schematically shows a flowchart of a control method for a radio frequency circuit according to Embodiment 1 of this application;

[0039] Figure 2 schematically illustrates a radio frequency circuit diagram provided according to Embodiment 1 of this application;

[0040] Figure 3 schematically illustrates another radio frequency circuit diagram provided according to Embodiment 1 of this application;

[0041] Figure 4 schematically illustrates the structure of an electronic device according to Embodiment 1 of this application;

[0042] Figure 5 schematically illustrates a computer-readable storage medium provided according to Embodiment 1 of this application. Detailed Implementation

[0043] Exemplary embodiments of the present disclosure will now be described in more detail with reference to the accompanying drawings. While exemplary embodiments of the present disclosure are shown in the drawings, it should be understood that the present disclosure may be implemented in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the disclosure to those skilled in the art.

[0044] It should be understood that the terminology used herein is for the purpose of describing particular exemplary embodiments only and is not intended to be limiting. Unless the context clearly indicates otherwise, the singular forms “a,” “an,” and “described” as used herein may also include the plural forms. The terms “comprising,” “including,” “containing,” and “having” are inclusive and therefore indicate the presence of the stated features, steps, operations, elements, and / or components, but do not exclude the presence or addition of one or more other features, steps, operations, elements, components, and / or combinations thereof. The method steps, processes, and operations described herein are not construed as requiring them to be performed in a particular order described or illustrated unless the order of performance is explicitly indicated. It should also be understood that additional or alternative steps may be used.

[0045] Although terms such as first, second, third, etc., may be used in this document to describe multiple elements, components, regions, layers, and / or segments, these elements, components, regions, layers, and / or segments should not be limited by these terms. These terms may be used only to distinguish one element, component, region, layer, or segment from another. Unless the context clearly indicates otherwise, terms such as "first," "second," and other numerical terms used herein do not imply order or sequence. Therefore, the first element, component, region, layer, or segment discussed below may be referred to as the second element, component, region, layer, or segment without departing from the teachings of the exemplary embodiments.

[0046] For ease of description, spatial relative terms may be used in the text to describe the relationship of one element or feature relative to another element or feature, as shown in the figure. These relative terms include, for example, "inside," "outside," "middle," "outer," "below," "below," "above," "over," etc. Such spatial relative terms are intended to include different orientations of the device in use or operation, other than those depicted in the figure. For example, if the device in the figure is flipped, an element described as "below other elements or features" or "below other elements or features" would subsequently be oriented as "above other elements or features" or "above other elements or features." Therefore, the example term "below" can include both upper and lower orientations. The device may be otherwise oriented (rotated 90 degrees or in other directions), and the spatial relative descriptors used in the text will be interpreted accordingly.

[0047] Figure 1 illustrates a control method for a radio frequency circuit provided in an embodiment of this application. The radio frequency circuit includes a signal generating device, an automatic level control device, and a power amplifier. The signal generating device is used to provide an operating frequency to the automatic level control device, and the automatic level control device is used to provide an operating voltage to the power amplifier so that the power amplifier provides output power.

[0048] Based on the above-described radio frequency circuit, the control method includes the following steps:

[0049] Step 101: Control the radio frequency circuit to operate in a first state, wherein the first state includes the operating frequency of the signal generator being a preset frequency and the output power of the power amplifier being a preset power, wherein the preset power is less than the rated output power of the power amplifier;

[0050] Step 102: Control the signal generating device to traverse the frequency points within the predetermined frequency band and detect the reflected power of the power amplifier in real time to obtain the target frequency point corresponding to the minimum reflected power;

[0051] Step 103: Control the signal generating device to operate at the target frequency, and adjust the attenuation value of the automatic level control device so that the output power of the power amplifier is the rated output power, and the attenuation value corresponding to the rated output power is the target attenuation value.

[0052] First, the RF circuit operates in its initial state, where the operating frequency of the signal generator and the output power of the power amplifier are set to preset values. This preset ensures the circuit is in a known and controllable state upon startup, thus improving system stability. Next, the signal generator traverses frequencies within the predetermined band and monitors the reflected power of the power amplifier in real time. This process helps find the optimal target frequency—the frequency corresponding to the minimum reflected power—thereby optimizing signal transmission efficiency and quality. During operation, the attenuation value of the automatic level control device is adjusted to ensure the power amplifier operates at its rated output power at the target frequency. This ensures the power amplifier operates in optimal condition, further improving signal transmission efficiency and quality.

[0053] By adopting the technical solution of this disclosure, the target frequency and target attenuation value can be determined, thereby controlling the RF circuit to operate at the target frequency and target attenuation value. Since the target frequency corresponds to the minimum reflected power, when the RF circuit operates at the target frequency and target attenuation value, the reflected power of the RF circuit can be kept at the minimum reflected power, avoiding damage to the power amplifier due to excessive reflected power. Therefore, the RF circuit of this disclosure will not experience excessive reflected power during operation, and there is no need to add an isolator to protect the power amplifier. This not only avoids damage to the power amplifier, but also reduces the size and cost of the product.

[0054] In one possible implementation, the method further includes: real-time detection of the reflected power of the power amplifier; and, if the reflected power of the power amplifier is greater than or equal to a reflected power threshold, adjusting the attenuation value of the automatic level control device so that the reflected power of the power amplifier is less than the reflected power threshold. This prevents the reflected power of the radio frequency circuit from exceeding the reflected power threshold during operation, thus protecting the power amplifier from damage due to the reflected power exceeding the threshold.

[0055] The method also includes real-time detection of the reflected power of the power amplifier and adjustment of the attenuation value when the reflected power is greater than or equal to a preset threshold. This helps ensure that the reflected power of the system is always under control, reducing signal loss and system interference.

[0056] In one possible implementation, the method further includes: real-time detection of the operating temperature of the power amplifier; and, if the operating temperature of the power amplifier is greater than or equal to a temperature threshold, adjusting the attenuation value of the automatic level control device so that the operating temperature of the power amplifier is less than the temperature threshold.

[0057] By controlling the operating temperature of the power amplifier, damage caused by overheating can be prevented, as overheating can lead to signal distortion. Temperature control reduces this distortion, improving signal quality and overall system performance.

[0058] In one possible implementation, the method further includes: detecting the output power of the power amplifier in real time; and adjusting the attenuation value of the automatic level control device when the output power of the power amplifier is greater than or equal to a power threshold, such that the output power of the power amplifier is less than the power threshold, and the power threshold is greater than the rated output power.

[0059] During the operation of the power amplifier, its output power is monitored in real time to ensure it does not exceed the set power threshold, thus preventing hardware damage or overheating caused by prolonged high-load operation. These measures ensure that the power amplifier operates stably and efficiently under various operating conditions.

[0060] In one possible implementation, the method further includes: cyclically executing the process of determining the target frequency and the target attenuation value at a preset frequency.

[0061] By periodically re-evaluating and adjusting, the RF circuitry is ensured to always operate at the optimal frequency and attenuation value. By continuously optimizing the target frequency and attenuation value, the efficiency of the power amplifier can be improved.

[0062] Through dynamic adjustment and real-time monitoring, this control method improves the adaptability of the RF circuit to different operating conditions. Regardless of environmental changes or varying operational requirements, the system can quickly respond and adjust to its optimal state.

[0063] Based on the same technical concept, as shown in Figure 2, this application embodiment also provides a radio frequency circuit, including: a signal generating device, an automatic level control device, a power amplifier, and a control unit. The signal generating device is used to provide an operating frequency to the automatic level control device, the automatic level control device is used to provide an operating voltage to the power amplifier so that the power amplifier provides output power, and the control unit is configured to:

[0064] The radio frequency circuit is controlled to operate in a first state, wherein the operating frequency of the signal generator is a preset frequency and the output power of the power amplifier is a preset power, wherein the preset power is less than the rated output power of the power amplifier;

[0065] The signal generating device is controlled to traverse the frequency points within the predetermined frequency band, and the reflected power of the power amplifier is detected in real time to obtain the target frequency point corresponding to the minimum reflected power;

[0066] The signal generating device is controlled to operate at the target frequency, and the attenuation value of the automatic level control device is adjusted so that the output power of the power amplifier is the rated output power, and the attenuation value corresponding to the rated output power is the target attenuation value.

[0067] The signal generator can traverse different frequency points according to the control unit's instructions, improving the circuit's adaptability to different frequencies. The automatic level control device adjusts the attenuation value according to the control unit's instructions, ensuring that the power amplifier's output power reaches the rated value, thus improving power utilization. Under the management of the control unit, the power amplifier operates in an optimal state, improving the efficiency and performance of the entire RF circuit.

[0068] By detecting reflected power in real time and finding the target frequency point corresponding to the minimum reflected power, the circuit can operate with higher efficiency and reduce energy loss. By adjusting the attenuation value, the circuit can achieve the rated output power of the power amplifier, avoiding overload or underload problems.

[0069] In one possible implementation, the control unit is further configured to:

[0070] The reflected power of the power amplifier is detected in real time; if the reflected power of the power amplifier is greater than or equal to the reflected power threshold, the attenuation value of the automatic level control device is adjusted so that the reflected power of the power amplifier is less than the reflected power threshold.

[0071] By monitoring and adjusting the reflected power in real time, it is ensured to remain below a safe threshold, reducing signal distortion and system interference. The attenuation value is automatically adjusted in response to the real-time status of the power amplifier, ensuring optimal performance under various conditions.

[0072] In one possible implementation, the control unit is further configured to:

[0073] The operating temperature of the power amplifier is monitored in real time; if the operating temperature of the power amplifier is greater than or equal to a temperature threshold, the attenuation value of the automatic level control device is adjusted so that the operating temperature of the power amplifier is less than the temperature threshold.

[0074] The system monitors the power amplifier's temperature in real time and takes measures to reduce the temperature when it exceeds a threshold, preventing overheating damage and ensuring long-term stable operation. It automatically adjusts the attenuation value to respond to the power amplifier's real-time status, ensuring optimal performance under various conditions.

[0075] In one possible implementation, the control unit is further configured to:

[0076] The output power of the power amplifier is detected in real time; when the output power of the power amplifier is greater than or equal to a power threshold, the attenuation value of the automatic level control device is adjusted so that the output power of the power amplifier is less than the power threshold, and the power threshold is greater than the rated output power.

[0077] It controls the power amplifier's output power to not exceed a set threshold, protecting the hardware from damage even under high load conditions. It automatically adjusts the attenuation value in response to the power amplifier's real-time status, ensuring optimal performance under various conditions.

[0078] In one possible implementation, the control unit is further configured to: cyclically execute the process of determining the target frequency and the target attenuation value at a preset frequency.

[0079] The control unit automatically and cyclically executes the process of determining the target frequency and target attenuation value according to the preset frequency, ensuring that the radio frequency circuit always operates with optimal parameters.

[0080] In one possible implementation, the control unit includes a control chip, a temperature detection device, and a power detection device. The control chip detects the operating temperature of the power amplifier through the temperature detection device and detects the output power of the power amplifier through the power detection device.

[0081] The control unit integrates a control chip, a temperature detection device, and a power detection device, enabling comprehensive monitoring and control of the power amplifier. The temperature detection device allows the control unit to monitor the power amplifier's operating temperature in real time, promptly detecting overheating issues. The power detection device allows the control unit to monitor the power amplifier's output power in real time, ensuring it remains within safe limits.

[0082] The control method of the radio frequency circuit provided in the embodiments of this application will be described in detail below with reference to the accompanying drawings.

[0083] Figure 3 shows a schematic diagram of the radio frequency circuit structure provided in an embodiment of this application, specifically including the following devices:

[0084] Antenna System (Voltage Controlled Oscillator, VCO): Used to transmit radio frequency signals for polarized heating. It converts radio frequency energy into heat energy for defrosting and heating food. The VCO generates an adjustable frequency radio frequency signal, the frequency of which can be adjusted by a control voltage. The MCU adjusts the VCO frequency according to system requirements to find the optimal operating frequency. The main components of the signal are a crystal oscillator and a phase-locked loop (PLL). A crystal oscillator is an oscillator that uses the piezoelectric effect of a quartz crystal to generate a stable frequency. It is typically used to provide a stable clock signal for electronic devices. The output frequency of the crystal oscillator is fixed, for example, 26MHz. The desired frequency band is achieved by frequency multiplication (increasing the frequency of the input signal to an integer multiple) or frequency division (reducing the frequency of the input signal to an integer fraction). A phase-locked loop is an electronic circuit that locks onto the phase of an input signal and generates an output signal with the same or proportional frequency as the input signal. PLLs can be used for frequency synthesis, frequency modulation / demodulation, clock recovery, and many other applications.

[0085] In addition, the signal source can perform frequency hopping, allowing it to change arbitrarily within a frequency band. Frequency hopping is a communication technique that allows a signal to switch rapidly between multiple preset frequencies. This technique can improve the signal's anti-interference capability and security because it is difficult for an eavesdropper to predict which frequency the signal will be on. Frequency hopping is commonly used in military communications and some wireless communication standards, such as Bluetooth.

[0086] Automatic Level Control (ALC): Used to adjust output power in real time to address overheating, overpower, or excessive reflected power. When overheating or overpower occurs, the attenuation value is adjusted in real time to protect the system. The ALC system monitors the output signal level and automatically adjusts the gain or attenuation to maintain the signal within a certain range. If the output signal is too strong, the ALC system increases the attenuation value, reducing the signal output; if the signal is too weak, it decreases the attenuation value, increasing the signal output.

[0087] Power Amplifier (PA): Amplifies the signal generated by the signal generator to the rated power required by the system (e.g., 200W). The PA receives the signal from the VCO and amplifies it to the required power level (e.g., 200W). The output power of the PA is controlled by the MCU through the ALC system.

[0088] Signal generator RF output (RFout): Generates a continuous radio frequency (RF) signal. RFout is the system's output section, transmitting the RF signal, amplified by the PA and adjusted by the ALC, to the load (such as defrosted food). The RF energy is converted into heat energy at the load, achieving the purpose of defrosting or heating.

[0089] Microcontroller (MCU): Responsible for monitoring and controlling the entire system, including temperature detection and power detection.

[0090] AC-DC converter: Converts alternating current (AC) to direct current (DC) to provide a stable power supply for circuits.

[0091] AC input: The power input section of the system, which provides AC power.

[0092] Temperature detection device: monitors the operating temperature of the PA.

[0093] Power detection device: monitors the output power of the PA.

[0094] The MCU monitors the system status and controls the PA's output power via the ALC system. The VCO generates an adjustable frequency signal, and the MCU adjusts the frequency based on feedback to optimize system performance. The PA amplifies the VCO signal to the required power and outputs it through RFout. The system dynamically adjusts under the control of the MCU to adapt to different operating conditions and requirements.

[0095] The control method for the aforementioned radio frequency circuit specifically includes the following stages:

[0096] Phase 1: Initial Phase

[0097] When the system starts up, the VCO generates a signal, and the MCU controls it to operate at low power (e.g., 30W) to reduce thermal shock. The VCO adjusts the frequency, and the MCU adjusts the frequency based on feedback to optimize system performance and find the frequency point with the minimum reflected power.

[0098] The system iterates through different frequencies within the specified frequency band to find the frequency with the smallest S11 parameter value. A smaller S11 value indicates a lower ratio of reflected power to input power, resulting in better system matching. If the S11 value at the initial frequency is less than -8dB (a set threshold indicating sufficiently good system matching), a suitable starting frequency is considered found. Once the optimal S11 value is found, the system locks onto this frequency and then gradually increases the output power by adjusting the ALC (Automatic Level Control) attenuation value.

[0099] Phase Two: Frequency Locking and Power Boost

[0100] Once the optimal frequency is found, the system locks onto that frequency. The output power is then gradually increased to the rated power (e.g., 200W) via the ALC system, in increments of +5dB, +1dB, and +0.5dB.

[0101] Phase 3: Real-time monitoring of reflected power, temperature, and output power by the MCU:

[0102] The MCU monitors the reflected power in real time; if it is too high, the output power is reduced via the ALC system. The PA's operating temperature is also monitored in real time; if it exceeds a threshold, the output power is reduced via the ALC system. Finally, the output power is monitored in real time; if it exceeds a threshold, the output power is reduced via the ALC system.

[0103] Phase 4: Parameter Monitoring

[0104] S11 parameter monitoring: When the S11 value deteriorates, the system re-hops to find a new optimal frequency. Optimizing the S11 parameter ensures energy transfer efficiency and reduces reflections.

[0105] P r It is the reflected power, P i It is the input power.

[0106] The S11 parameter represents the ratio of reflected power to input power and is used to evaluate the matching degree of an antenna system. A smaller S11 value indicates lower reflected power and higher system efficiency. The S11 parameter is a very important indicator in radio frequency systems, typically used to describe the reflection characteristics of antennas or transmission line systems. The value of the S11 parameter is calculated by measuring the ratio of reflected power to input power, and is usually expressed in decibels (dB).

[0107] A deteriorating S11 value typically indicates increased reflected power: a larger S11 value (a smaller numerical value because decibels are negative) means an increased proportion of power reflected back to the source relative to the input power. This usually means reduced system efficiency, as more power is not being effectively utilized and is being reflected back. Poor impedance matching: In RF systems, ideal impedance matching means that all input power is delivered to the load, with no power reflected. A deteriorating S11 value may indicate poor impedance matching between system components, which could be due to component aging, temperature variations, mechanical vibration, or other environmental factors. System stability issues: A deteriorating S11 value can lead to system stability problems such as self-oscillation or signal distortion, which can affect system performance and reliability. Equipment damage risk: The prolonged presence of high reflected power can damage components in RF systems, especially power amplifiers, as they need to handle the additional power reflected back.

[0108] In radio frequency defrosting control systems, monitoring and timely adjustment of the S11 value is crucial for ensuring efficient and stable system operation. If the S11 value deteriorates below a certain threshold (e.g., below -8dB), the system may need to take measures such as reselecting the operating frequency or adjusting the ALC attenuation value to restore the system's matching and efficiency.

[0109] Phase 5: Readjustment and Optimization

[0110] After stable operation, the VCO frequency source is readjusted to find a new optimal frequency. Based on the new optimal frequency, the ALC attenuation value is readjusted to achieve rated power output.

[0111] The power increase increments are +5dB, +1dB, and +0.5dB in sequence, until the rated power of 200W is reached. This gradual increase helps the system stably adapt to higher power outputs while avoiding instability or damage caused by sudden power increases.

[0112] If the adjustment accuracy of the ALC attenuator is insufficient to accurately reach 200W, the system will fine-tune by adjusting the leakage voltage to ensure that the output power accurately reaches 200W.

[0113] During system operation, if the S11 value deteriorates (i.e., reflected power increases, and the S11 value drops below -8dB), the system will consider the current frequency unsuitable and require a new frequency selection. The system will re-hop frequencies, traversing the frequency band again to find a new optimal S11 value. After finding the new optimal value, the system will repeat the second step, readjusting the ALC attenuation value and gradually increasing the output power to 200W.

[0114] In summary, this application provides a radio frequency (RF) circuit and its control method, an RF heating device, an apparatus, and a medium. The RF circuit includes a signal generating device, an automatic level control device, and a power amplifier. The signal generating device provides an operating frequency to the automatic level control device, and the automatic level control device provides an operating voltage to the power amplifier to enable the power amplifier to provide output power. The control method includes: controlling the RF circuit to operate in a first state, wherein the first state includes the operating frequency of the signal generating device being a preset frequency and the output power of the power amplifier being a preset power, the preset power being less than the rated output power of the power amplifier; controlling the signal generating device to traverse frequency points within a predetermined frequency band and detecting the reflected power of the power amplifier in real time to obtain a target frequency point corresponding to the minimum reflected power; controlling the signal generating device to operate at the target frequency point and adjusting the attenuation value of the automatic level control device to make the output power of the power amplifier reach the rated output power, the attenuation value corresponding to the rated output power being the target attenuation value. Without the need for an isolator, by adjusting the attenuation value of the automatic level control device, the power amplifier can output rated power at different operating frequencies.

[0115] Based on the same technical concept, this application embodiment also provides a radio frequency heating device, including the above-mentioned radio frequency circuit, and further including a heating antenna, wherein the heating antenna is connected to the power output terminal of the power amplifier in the radio frequency circuit.

[0116] Based on the same technical concept, this application also provides a device, including the aforementioned radio frequency heating device. The device can be a refrigerator, microwave oven, or other device with a defrosting function.

[0117] This application also provides an electronic device corresponding to the method provided in the foregoing embodiments. Please refer to FIG4, which shows a diagram of an electronic device provided in some embodiments of this application. The electronic device 20 may include: a processor 200, a memory 201, a bus 202, and a communication interface 203. The processor 200, the communication interface 203, and the memory 201 are connected via the bus 202. The memory 201 stores a computer program that can run on the processor 200. When the processor 200 runs the computer program, it executes the method provided in any of the foregoing embodiments of this application.

[0118] The memory 201 may include high-speed random access memory (RAM) or non-volatile memory, such as at least one disk storage device. Communication between this system network element and at least one other network element is achieved through at least one physical port (which can be wired or wireless), such as the Internet, wide area network, local area network, or metropolitan area network.

[0119] Bus 202 can be an ISA bus, PCI bus, or EISA bus, etc. The bus can be divided into an address bus, a data bus, a control bus, etc. The memory 201 is used to store programs. After receiving an execution instruction, the processor 200 executes the program. The method disclosed in any of the foregoing embodiments of this application can be applied to the processor 200, or implemented by the processor 200.

[0120] The processor 200 may be an integrated circuit chip with signal processing capabilities. In implementation, each step of the above method can be completed by the integrated logic circuitry in the hardware of the processor 200 or by instructions in software form. The processor 200 may be a general-purpose processor, including a central processing unit (CPU), a network processor (NP), etc.; it may also be a digital signal processor (DSP), an application-specific integrated circuit (ASIC), an off-the-shelf programmable gate array (FPGA), or other programmable logic devices, discrete gate or transistor logic devices, or discrete hardware components. It can implement or execute the methods, steps, and logic block diagrams disclosed in the embodiments of this application. The general-purpose processor may be a microprocessor or any conventional processor. The steps of the methods disclosed in the embodiments of this application can be directly embodied in the execution of a hardware decoding processor, or executed by a combination of hardware and software modules in the decoding processor. The software modules may reside in random access memory, flash memory, read-only memory, programmable read-only memory, electrically erasable programmable memory, registers, or other mature storage media in the art. The storage medium is located in memory 201. The processor 200 reads the information in memory 201 and, in conjunction with its hardware, completes the steps of the above method.

[0121] The electronic devices and methods provided in the embodiments of this application are based on the same inventive concept and have the same beneficial effects as the methods they employ, operate, or implement.

[0122] This application also provides a computer-readable storage medium corresponding to the method provided in the foregoing embodiments. Please refer to FIG5, which shows a computer-readable storage medium 30, on which a computer program (i.e., a program product) is stored. When the computer program is run by a processor, it executes the method provided in any of the foregoing embodiments.

[0123] It should be noted that examples of the computer-readable storage medium may also 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 optical and magnetic storage media, which will not be elaborated here.

[0124] The computer-readable storage medium provided in the above embodiments of this application and the method provided in the embodiments of this application are based on the same inventive concept and have the same beneficial effects as the methods adopted, run or implemented by the applications stored therein.

[0125] The above description is merely a preferred embodiment of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. A control method for a radio frequency circuit, characterized in that, The radio frequency circuit includes a signal generator, an automatic level control device, and a power amplifier. The signal generator provides an operating frequency to the automatic level control device, and the automatic level control device provides an operating voltage to the power amplifier so that the power amplifier provides output power. The control method includes: The radio frequency circuit is controlled to operate in a first state, wherein the operating frequency of the signal generator is a preset frequency and the output power of the power amplifier is a preset power, wherein the preset power is less than the rated output power of the power amplifier; The signal generating device is controlled to traverse the frequency points within the predetermined frequency band, and the reflected power of the power amplifier is detected in real time to obtain the target frequency point corresponding to the minimum reflected power; The signal generating device is controlled to operate at the target frequency, and the attenuation value of the automatic level control device is adjusted so that the output power of the power amplifier is the rated output power, and the attenuation value corresponding to the rated output power is the target attenuation value.

2. The method as described in claim 1, characterized in that, The method further includes: Real-time detection of the reflected power of the power amplifier; When the reflected power of the power amplifier is greater than or equal to the reflected power threshold, the attenuation value of the automatic level control device is adjusted so that the reflected power of the power amplifier is less than the reflected power threshold.

3. The method as described in claim 1, characterized in that, The method further includes: Real-time monitoring of the operating temperature of the power amplifier; When the operating temperature of the power amplifier is greater than or equal to a temperature threshold, the attenuation value of the automatic level control device is adjusted so that the operating temperature of the power amplifier is less than the temperature threshold.

4. The method as described in claim 1, characterized in that, The method further includes: Real-time detection of the output power of the power amplifier; When the output power of the power amplifier is greater than or equal to the power threshold, the attenuation value of the automatic level control device is adjusted so that the output power of the power amplifier is less than the power threshold, and the power threshold is greater than the rated output power.

5. The method according to any one of claims 1-4, characterized in that, The method further includes: The process of determining the target frequency and the target attenuation value is executed cyclically according to a preset frequency.

6. A radio frequency circuit, characterized in that, include: The system includes a signal generator, an automatic level control device, a power amplifier, and a control unit. The signal generator provides an operating frequency to the automatic level control device, the automatic level control device provides an operating voltage to the power amplifier to enable the power amplifier to provide output power, and the control unit is configured to: The radio frequency circuit is controlled to operate in a first state, wherein the operating frequency of the signal generator is a preset frequency and the output power of the power amplifier is a preset power, wherein the preset power is less than the rated output power of the power amplifier; The signal generating device is controlled to traverse the frequency points within the predetermined frequency band, and the reflected power of the power amplifier is detected in real time to obtain the target frequency point corresponding to the minimum reflected power; The signal generating device is controlled to operate at the target frequency, and the attenuation value of the automatic level control device is adjusted so that the output power of the power amplifier is the rated output power, and the attenuation value corresponding to the rated output power is the target attenuation value.

7. The radio frequency circuit as described in claim 6, characterized in that, The control unit is also configured to: Real-time detection of the reflected power of the power amplifier; When the reflected power of the power amplifier is greater than or equal to the reflected power threshold, the attenuation value of the automatic level control device is adjusted so that the reflected power of the power amplifier is less than the reflected power threshold.

8. The radio frequency circuit as described in claim 6, characterized in that, The control unit is also configured to: Real-time monitoring of the operating temperature of the power amplifier; When the operating temperature of the power amplifier is greater than or equal to a temperature threshold, the attenuation value of the automatic level control device is adjusted so that the operating temperature of the power amplifier is less than the temperature threshold.

9. The radio frequency circuit as described in claim 6, characterized in that, The control unit is also configured to: Real-time detection of the output power of the power amplifier; When the output power of the power amplifier is greater than or equal to the power threshold, the attenuation value of the automatic level control device is adjusted so that the output power of the power amplifier is less than the power threshold, and the power threshold is greater than the rated output power.

10. The radio frequency circuit as described in any one of claims 6-9, characterized in that, The control unit is also configured to: The process of determining the target frequency and the target attenuation value is executed cyclically according to a preset frequency.

11. The radio frequency circuit as described in claim 6, characterized in that, The control unit includes a control chip, a temperature detection device, and a power detection device. The control chip detects the operating temperature of the power amplifier through the temperature detection device and detects the output power of the power amplifier through the power detection device.

12. A radio frequency heating device, characterized in that, The radio frequency circuit included in any one of claims 6-11 further includes a heating antenna, the heating antenna being connected to the power output terminal of the power amplifier in the radio frequency circuit.

13. A device, characterized in that, Includes the radio frequency heating device as described in claim 12.

14. An electronic device comprising: A memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that the processor executes the computer program to implement the method as claimed in any one of claims 1-5.

15. A computer-readable storage medium, characterized in that, It stores computer-readable instructions that can be executed by a processor to implement the method as described in any one of claims 1-5.

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