A method for wireless digital microphone signal interference suppression

Abstract

The application discloses a wireless digital microphone signal interference suppression method and relates to the technical field of wireless data.The application continuously monitors a feed port reflection coefficient in real time, calculates a standing wave ratio, extracts a periodic standing wave ratio valley frequency, and then accurately identifies a single jump amplitude and an accumulated drift direction through a frequency drift tracking comparison unit; a detuning classification model is called, whether the single jump variable exceeds a jump threshold value and the accumulated drift direction and a result threshold value are used to accurately distinguish two typical interference sources, namely, non-continuous detuning caused by discrete droplets or progressive detuning caused by continuous film loading; and the transmission stability and anti-interference capability of the microphone under a complex use environment are further improved.

Description

Technical Field

[0001] This invention relates to the field of wireless data technology, specifically to a method for suppressing interference in wireless digital microphone signals. Background Technology

[0002] In the field of wireless communication equipment, wireless digital microphones are core tools for stage performances and live events. Their signal stability and anti-interference capabilities directly affect sound quality and user experience, making them extremely important. With the increasing complexity of performance environments, microphone signal interference suppression technology has become a crucial element in ensuring sound quality, especially in the use of headset microphones, where addressing the impact of external factors on signal transmission is particularly urgent.

[0003] Currently, while many solutions attempt to reduce interference by improving hardware design or adding protective measures, these methods often overlook the dynamic impact of external environmental changes on the internal matching state of the device. Particularly for the external antenna portion of headset microphones, existing technologies focus more on protecting against single environmental factors, failing to adequately consider the complex performance under the superposition of multiple interference factors, resulting in significant potential risks to signal stability in practical use. Focusing on specific technical challenges, impedance mismatch in external antennas after sweat penetration becomes a major hurdle. Sweat, as a conductive liquid, alters the dielectric environment around the antenna, thereby interfering with signal transmission stability. More complexly, the uneven distribution of sweat directly determines the varying degrees of interference. When the amount of sweat is small, the droplets are scattered in critical areas of the antenna, leading to unpredictable fluctuations in the signal matching state; conversely, when the amount of sweat increases and forms a uniform coverage, the interference may exhibit a certain regularity. This random interference caused by uneven distribution greatly increases the difficulty of signal correction. Taking stage performances as an example, during intense performances, actors' sweat may drip irregularly onto the microphone antenna connection, causing intermittent signal transmission and even sound quality distortion. Especially during crucial performance segments, signal instability can directly affect the audience's auditory experience, leading to irreversible consequences.

[0004] Therefore, how to effectively identify and dynamically adjust the random mismatch of antenna impedance matching under conditions of uneven sweat distribution has become a key issue in ensuring the stability of wireless microphone signals and the performance effect. Summary of the Invention

[0005] To address the shortcomings of existing technologies, this invention provides a method for suppressing interference in wireless digital microphone signals, thus solving the problems mentioned in the background section.

[0006] To achieve the above objectives, the present invention provides the following technical solution: A method for suppressing interference in wireless digital microphone signals, the method comprising: S101, obtain the reflection coefficient of each frequency point of the feed port, and perform multiple adjustments on the adjustable impedance matching network according to the reflection coefficient, wherein the adjustable impedance matching network includes varactor diodes and switching elements; S102, based on the adjusted adjustable impedance matching network, re-acquire the reflection coefficient, determine the valley frequency drift, determine the offset direction, obtain the adjustment step value by proportional mapping, and apply it to the varactor diode in the adjusted adjustable impedance matching network. S103, construct the initial drift sequence, calculate the periodic change as the single jump variable, accumulate it within the time window and perform a direction consistency judgment to obtain the direction judgment result, including validity and invalidity; S104, call the preset detuning classification model, analyze the jump trend of the single jump variable, compare it with the jump threshold, and determine the droplet initiation factor if it exceeds the threshold. S105, if not exceeded, use the direction determination result to verify and identify the type of detuning, including droplet initiation factors, uniform sweat penetration and normal interference; S106, extract the compensation amount from the preset impedance compensation lookup table according to the detuning category, determine the compensation method according to the detuning category and the compensation amount, the compensation method includes fast tracking compensation amount and steady-state compensation amount, and obtain the compensation method determination result; S107, Based on the compensation method, adjust the actual capacitive reactance and actual inductive reactance of the varactor diode in the adjustable impedance matching network to suppress interference from the wireless digital microphone signal.

[0007] Preferably, the reflection coefficients at each frequency point of the feed port are obtained, and the adjustable impedance matching network is adjusted multiple times based on the reflection coefficients, including: In the antenna feed area, a continuous frequency scan is performed in the preset working frequency band by the VSWR sweep frequency sampling unit, and the reflection coefficient of each frequency point is obtained from the feed port after the impedance is adjusted by the adjustable impedance matching network. Based on the reflection coefficient, the standing wave ratio is calculated, and the impedance in the adjustable impedance matching network is initially adjusted according to the standing wave ratio. The adjustable impedance matching network includes varactor diodes and switching elements. For the initially adjusted adjustable impedance matching network, the new VSWR value is recalculated. If the new VSWR value exceeds the preset VSWR threshold condition, the adjustment amount of the varactor diode control voltage is calculated based on the deviation between the new VSWR value and the target VSWR value using a proportional-integral control algorithm. The corresponding control voltage is then applied to the varactor diode in the adjustable impedance matching network to obtain the adjusted adjustable impedance matching network, thus completing the modification of the impedance matching state.

[0008] Preferably, based on the adjusted adjustable impedance matching network, the reflection coefficient is re-acquired, the valley frequency drift is determined, the offset direction is judged, and an adjustment step value is obtained by proportional mapping and applied to the varactor diode, including: For the readjusted adjustable impedance matching network, the new VSWR value is recalculated to obtain the current period VSWR curve; Extract the minimum standing wave ratio (SWR) value and its corresponding frequency point from the current period's standing wave ratio (SWR) curve to determine the current period's valley frequency. The valley frequency of the current period is compared with the valley frequency recorded in the previous period to obtain the valley frequency drift. A preset directional threshold is set, which includes a positive threshold and a negative threshold. If the valley frequency drift is greater than the positive threshold, the valley is determined to be shifted to a higher frequency direction. If the valley frequency drift is less than the negative threshold, the valley is determined to be shifted to a lower frequency direction. Based on the absolute value of the valley frequency drift, the adjustment step value of the varactor diode control voltage is determined by a proportional mapping method. Based on the adjustment step value and the determined offset direction, the adjusted amount is obtained and applied to the varactor diode in the readjusted adjustable impedance matching network to complete the impedance correction operation for this cycle.

[0009] Preferably, an initial drift sequence is constructed, the periodic change is calculated as a single jump variable, accumulated within a time window, and a direction consistency judgment is performed to obtain the direction determination result, including validity and invalidity, including: Based on the impedance correction operation completed in this cycle, the initial drift sequence is obtained based on the valley frequency drift. Extract the periodic change in the valley frequency drift between two adjacent sampling periods based on the initial drift sequence; The valley frequency drift is accumulated within a preset continuous time window to obtain the accumulated result. The periodic change is used as a single jump variable, and the cumulative result is compared with the direction of all single jump variables within a preset continuous time window. If the direction is consistent and the absolute value of the cumulative result exceeds the preset result threshold, the validity of the cumulative drift direction is confirmed. If the direction is consistent and the absolute value of the cumulative result exceeds the preset result threshold, the invalidity of the cumulative drift direction is confirmed. Combining validity and invalidity yields the direction determination result.

[0010] Preferably, a preset detuning classification model is invoked to analyze the jump trend of a single jump variable, and this trend is compared with a jump threshold. If the threshold is exceeded, the droplet initiation factor is determined, including: By acquiring signal data from multiple consecutive sampling points within the antenna feed area, and then performing absolute value calculation on the single jump variable followed by difference calculation, the jump amplitude value is obtained. The detuning category is obtained by comparing the jump amplitude value with the preset jump threshold. If the jump amplitude value exceeds the jump threshold, discrete droplet distribution data and electromagnetic reflection deviation data are extracted from the signal data to determine the droplet initiation factors.

[0011] Preferably, if the deviation does not exceed the limit, the direction determination result is used for verification to identify the type of detuning, including droplet-initiating factors, uniform sweat penetration, and normal interference, including: If the jump amplitude value does not exceed the jump threshold, the direction determination result is used for verification to supplement the detuning category. The specific supplementary content is as follows: If the direction determination result is valid, it can be determined that there is a type of detuning caused by continuous thin film loading in the antenna feed point area, and the continuous detuning caused by uniform sweat penetration can be obtained. If the direction determination result is invalid, it means that the current drift is neither caused by droplet initiation factors nor by continuous detuning caused by uniform sweat penetration, and is therefore considered normal interference. By combining droplet-initiating factors, uniform sweat penetration, and normal interference, a detuning category is obtained.

[0012] Preferably, the compensation amount is extracted from a preset impedance compensation lookup table according to the detuning category. The compensation method is determined based on the detuning category and the compensation amount. The compensation methods include fast tracking compensation and steady-state compensation. The compensation method determination result includes: Based on the detuning category, the compensation value is extracted from the preset impedance compensation lookup table to obtain the compensation value result; Based on the detuning category, the category parameter is obtained. The compensation method type result is obtained by correlating and comparing the compensation amount value result with the category parameter, including steady-state compensation type and fast tracking type. When the compensation method type is fast tracking, the fast tracking compensation amount is used to dynamically adjust the impedance to obtain the tracking adjustment result. The steady-state maintenance parameters are obtained based on the detuning category. The compensation method is determined by combining the tracking adjustment results with the steady-state maintenance parameters.

[0013] Preferably, based on the compensation method, the actual capacitive reactance and actual inductive reactance in the adjustable impedance matching network are driven and adjusted to suppress interference from the wireless digital microphone signal, including: Based on the compensation method, obtain the current operating frequency of the wireless digital microphone, and look up the preset impedance matching reference table based on the operating frequency to obtain the corresponding target capacitive reactance and target inductive reactance. The target capacitive reactance value is compared with the actual capacitive reactance value of the current varactor diode. If the actual capacitive reactance value deviates from the target capacitive reactance value, the capacitive reactance deviation is calculated. The variable capacitor adjustment unit is driven by the capacitive reactance deviation to adjust the capacitance value of the varactor diode and obtain the updated capacitive reactance value. The target inductive reactance value is compared with the actual inductive reactance value of the current inductor. If the actual inductive reactance value deviates from the target inductive reactance value, the inductive reactance deviation is calculated. The inductance value is adjusted by using the inductance deviation to drive the inductor element adjustment unit, thereby obtaining the updated inductance value. The updated capacitive reactance and updated inductive reactance work together on the readjusted adjustable impedance matching network to process interference from the wireless digital microphone signal.

[0014] The above-described solution of the present invention has at least the following beneficial effects: To address the unique operational scenario where sweat, saliva, and other bodily fluids create discrete droplets or continuous thin-film loading at the external antenna feed port of a wireless digital microphone, leading to discontinuous impedance jumps or slow, continuous drifts and consequently deteriorating VSWR and increased signal interference, this invention continuously monitors the reflection coefficient of the feed port in real time and calculates the VSWR. It extracts the VSWR valley frequencies for each cycle and uses a frequency drift tracking and comparison unit to accurately identify the amplitude of a single jump and the direction of cumulative drift. A detuning classification model is then invoked to accurately distinguish between two typical interference sources: discontinuous detuning caused by discrete droplets and gradual detuning caused by continuous thin-film loading, based on whether the single jump exceeds a threshold and the direction of cumulative drift relative to the threshold. The corresponding compensation amount is then extracted from an impedance compensation lookup table based on the detuning category, and either fast tracking compensation or steady-state compensation is used to drive the variable capacitors and inductors in the adjustable impedance matching network. This achieves precise dynamic adjustment of capacitive and inductive reactance, effectively suppressing signal interference caused by bodily fluid loading. This invention further improves the transmission stability and anti-interference capability of the microphone in complex operating environments. Attached Figure Description

[0015] Figure 1 This is a block diagram of the method of the present invention; Figure 2 This is a schematic diagram illustrating the direction determination of the present invention; Figure 3 This is a schematic diagram illustrating the compensation categories of the present invention. Detailed Implementation

[0016] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0017] Example 1 Please refer to Figures 1 to 3 This invention provides a method for suppressing interference in wireless digital microphone signals, the method comprising: S101, obtain the reflection coefficient of each frequency point of the feed port, and perform multiple adjustments on the adjustable impedance matching network according to the reflection coefficient, wherein the adjustable impedance matching network includes varactor diodes and switching elements; S102, based on the adjusted adjustable impedance matching network, re-acquire the reflection coefficient, determine the valley frequency drift, determine the offset direction, obtain the adjustment step value by proportional mapping, and apply it to the varactor diode in the adjusted adjustable impedance matching network. S103, construct the initial drift sequence, calculate the periodic change as the single jump variable, accumulate it within the time window and perform a direction consistency judgment to obtain the direction judgment result, including validity and invalidity; S104, call the preset detuning classification model, analyze the jump trend of the single jump variable, compare it (single jump variable) with the jump threshold, and determine the droplet initiation factor if it exceeds the threshold. S105, if not exceeded, use the direction determination result to verify and identify the type of detuning, including droplet initiation factors, uniform sweat penetration and normal interference; S106, extract the compensation amount from the preset impedance compensation lookup table according to the detuning category, determine the compensation method according to the detuning category and the compensation amount, the compensation method includes fast tracking compensation amount and steady-state compensation amount, and obtain the compensation method determination result; S107, Based on the compensation method, adjust the actual capacitive reactance and actual inductive reactance of the varactor diode in the adjustable impedance matching network to suppress interference from the wireless digital microphone signal.

[0018] In this embodiment, by employing step-by-step, precise impedance adjustment and detuning classification, the impedance detuning problem caused by sweat interference in the external antenna of a headset wireless digital microphone is effectively solved, significantly improving the stability and anti-interference capability of signal transmission. The logic is as follows: First, the adjustable impedance matching network is initially calibrated and periodically corrected through S101-S102 to lay a stable foundation; then, through S103-S105, three detuning categories—discrete droplets, uniform sweat penetration, and normal interference—are precisely distinguished to avoid misjudgment and ineffective compensation; finally, through S106-S107, the compensation method is specifically determined and the capacitive and inductive reactances are adjusted to achieve precise interference suppression.

[0019] For example, if sweat drips onto the antenna feed point as discrete droplets during an actor's performance, this invention can quickly identify the droplet-causing factor through S104 and promptly correct the impedance using rapid tracking compensation. If the sweat evenly permeates and forms a thin film, it can be identified through S105 and the matching can be maintained with a steady-state compensation. Even if there is minor normal interference, it will not blindly adjust, ensuring both the timeliness and accuracy of compensation and avoiding signal fluctuations caused by over-adjustment. This ensures clear microphone sound quality and stable transmission, meeting the needs of high-intensity usage scenarios such as stage performances.

[0020] All thresholds in this invention can be obtained using the mean-standard deviation method.

[0021] Specifically, in one embodiment, a VSWR (Standard Vibration Ratio) sweep sampling unit is located in the feed port region of the external antenna to monitor and optimize the antenna's impedance matching performance. This unit includes an RF signal generator and a reflection measurement module, which enable continuous frequency scanning of a preset operating frequency band.

[0022] For example, in the antenna system of a wireless communication base station, the scanning unit can be integrated near the feed port to ensure that the scanning process does not interfere with normal signal transmission. Furthermore, the determination of the preset operating frequency band is based on the antenna design specifications.

[0023] The specific steps of S101 include: in the antenna feed point area, a continuous frequency scan is performed in the preset working frequency band through the standing wave ratio sweep sampling unit, and the reflection coefficient of each frequency point after the impedance is adjusted by the adjustable impedance matching network is obtained from the feed port; the coefficient represents the ratio of the amplitude of the incident signal to the reflected signal at the feed port, and its magnitude directly reflects the degree of signal reflection. The smaller the magnitude, the less the reflection and the better the impedance matching effect. It is used to calculate the standing wave ratio and determine the antenna impedance matching status.

[0024] The antenna feed area is the connection area between the external antenna of the wireless digital microphone and the signal transmission line. It is also a critical area where sweat can easily penetrate and impedance can easily become detuned. The feed port is the input and output interface for the antenna to receive and transmit radio frequency signals, and it is a key node for signal transmission and impedance matching. The reflection coefficient at each frequency point is captured by a directional coupler; a directional coupler is a device used to separate incident and reflected signals. The VSWR sweep sampling unit is a hardware unit deployed in the feed port area, consisting of an RF signal generator, a reflection measurement module, a microcontroller, etc., used to monitor and optimize the impedance matching performance of the antenna; Based on the reflection coefficient, the standing wave ratio (VSWR) is calculated, and the impedance within the adjustable impedance matching network is initially adjusted according to the VSWR. The purpose is to quickly correct the detuned impedance towards matching, laying the foundation for subsequent fine-tuning. The adjustable impedance matching network includes varactor diodes and switching elements. Standing wave ratio is obtained through the formula The value is ≥1, and the closer the value is to 1, the less signal reflection at the feed port and the better the impedance matching between the antenna and the transmission line; conversely, the larger the value, the more severe the reflection and the more obvious the impedance mismatch. Its core function is to serve as a quantitative indicator for judging the antenna impedance matching status, providing data for the subsequent dynamic adjustment of the adjustable impedance matching network. The standing wave ratio, This represents the magnitude of the reflection coefficient. An adjustable impedance matching network is an RF circuit network composed of varactor diodes and switching elements. It is deployed between the microphone feed port and the antenna. Its core function is to dynamically adjust its own impedance to match the input impedance of the antenna with the characteristic impedance of the transmission line, thereby reducing signal reflection.

[0025] For the initially adjusted adjustable impedance matching network, a new scan is performed to obtain the new reflection coefficient, and the new VSWR value is calculated. If the new VSWR value exceeds the preset VSWR threshold, the adjustment amount of the varactor diode control voltage is calculated using a proportional-integral control algorithm based on the deviation between the new VSWR value and the target VSWR value. The specific formula is as follows: ,in This is the adjustment amount of the control voltage for the varactor diode. This is a proportional coefficient, calibrated according to hardware characteristics. This is the deviation between the new standing wave ratio and the target standing wave ratio. The integral coefficient is calibrated based on the system response speed. The integral time is used; and the control voltage corresponding to the adjustment amount is applied to the varactor diode in the adjustable impedance matching network to obtain the adjusted adjustable impedance matching network, so as to complete the modification of the impedance matching state and effectively suppress signal interference caused by factors such as sweat; the specific steps are as follows: first, the adjustment amount of the control voltage of the varactor diode is calculated by the proportional-integral control algorithm; the control voltage applied across the varactor diode is adjusted according to the adjustment amount; the change of the control voltage will change the equivalent capacitance value of the varactor diode, and thus change the overall equivalent impedance of the adjustable impedance matching network; the change of the network impedance will change the reflection coefficient of the feed port; the change of the reflection coefficient will further lead to the change of the standing wave ratio; finally, the impedance matching state of the antenna will change from detuned to matched, thus completing the modification of the impedance matching state.

[0026] The target VSWR is a pre-set threshold value based on the performance requirements of the wireless digital microphone and the antenna design specifications. It is the ultimate target for impedance matching adjustment and is generally taken to be close to 1. For example, 1.2 to 1.8 represents that the antenna is in an ideal impedance matching state. The deviation is the numerical difference between the new VSWR and the target VSWR, which reflects the degree of impedance mismatch.

[0027] The control voltage of a varactor diode is an external voltage applied across the varactor diode to change its equivalent capacitance value, and it is a key variable for controlling the parameters of the varactor diode. The adjustment amount refers to the voltage value that needs to be increased or decreased to make the varactor diode reach the target equivalent capacitance value. The acquisition process is as follows: First, the deviation of the standing wave ratio is used as the input variable of the algorithm. The algorithm first gives the real-time voltage adjustment ratio based on the magnitude of the deviation through the proportional element, and then accumulates the historical deviation through the integral element to eliminate the static deviation. The two work together to calculate the accurate control voltage adjustment amount of the varactor diode. Specifically, the VSWR sweep sampling unit first obtains the reflection coefficient of each frequency point through continuous frequency scanning and calculates the VSWR value. Using the VSWR value as the core judgment basis, the adjustable impedance matching network is initially adjusted: first, based on the magnitude of the VSWR value, the initial adjustment direction and approximate adjustment range of the varactor diodes and switching elements in the network are determined, and the corresponding parameters of the elements are changed to modify the network impedance. After the initial adjustment is completed, a continuous frequency scan is performed on the adjusted network again to reacquire the reflection coefficients of each frequency point and calculate the new standing wave ratio (SWR). Then, it is determined whether the new SWR meets the preset threshold condition. If it does not exceed the threshold, the current adjustment is completed. If it exceeds the threshold, the precise adjustment amount is calculated through the proportional-integral control algorithm to perform a second fine adjustment on the network. Then, the scanning, calculation, and judgment are repeated until the SWR meets the preset threshold.

[0028] In this embodiment, precise impedance matching adjustment effectively solves the problems of impedance detuning and signal interference caused by factors such as sweat in wireless digital microphones, significantly improving signal transmission stability and sound quality. The logic is as follows: first, the feed point reflection coefficient and VSWR are obtained through a VSWR sweep sampling unit; then, the VSWR and reflection coefficient are calculated; finally, a proportional-integral algorithm is used to calculate the control voltage adjustment amount, driving the varactor diode to change its capacitance value, thereby adjusting the network impedance until the VSWR reaches the acceptable threshold.

[0029] For example, when actors perform with microphones, sweat can seep into the antenna feed point, causing an increase in the standing wave ratio (VSWR) and signal distortion. This solution can capture changes in the reflection coefficient through frequency sweep sampling. After calculating the deviation, it precisely adjusts the varactor diode control voltage and corrects the network impedance to bring the VSWR back to the acceptable range, avoiding signal interruption or distortion. The entire process requires no complex calculations, responds quickly, and can handle interference from sweat and other sources in real time, ensuring that the microphone maintains clear and stable signal transmission in performances and other scenarios, meeting practical usage requirements.

[0030] Specifically, step S102 includes: recalculating the new VSWR value for the readjusted adjustable impedance matching network to obtain the current period VSWR curve; this curve is a continuous curve obtained by fitting the VSWR values ​​corresponding to all scanned frequency points with frequency as the horizontal axis and VSWR value as the vertical axis after completing a full-band continuous scan within the entire preset working frequency band. It is used to help the system find the optimal impedance matching position in the entire frequency band under the current network. Extract the minimum VSWR value and the corresponding frequency point from the current period VSWR curve to determine the current period valley frequency. This valley frequency is used to mark the frequency position with the best impedance matching effect in the entire working frequency band under the current adjustable impedance matching network. By tracking the change of this position, the system can sense the slow drift trend of impedance. Because factors such as sweat penetration and environmental temperature drift will cause the impedance to change slowly, the position of this optimal matching point will also slowly shift. Tracking it can correct the slow detuning in advance and avoid the detuning from accumulating to the point of affecting the operation.

[0031] The current cycle valley frequency is compared with the valley frequency recorded in the previous cycle. The frequency difference between the two is calculated to obtain the valley frequency drift, which represents the degree of deviation of the optimal matching point and provides a basis for subsequent impedance fine-tuning.

[0032] A preset directional threshold is set, which includes a positive threshold and a negative threshold. If the valley frequency drift is greater than the positive threshold, the valley is determined to be shifted to a higher frequency direction. If the valley frequency drift is less than the negative threshold, the valley is determined to be shifted to a lower frequency direction. Specifically, the positive and negative thresholds are dead-zone thresholds preset by the system to filter out minute drift noise. The positive threshold is a positive frequency value, such as +2MHz, representing the trigger threshold for the valley value to shift towards higher frequencies; the negative threshold is a negative frequency value, such as -2MHz, representing the trigger threshold for the valley value to shift towards lower frequencies. They are used to prevent the system from making ineffective adjustments to measurement noise and minor normal fluctuations. If the drift is very small, between the positive and negative thresholds, it means that this is just a normal measurement error or a negligible minor fluctuation, and no adjustment is needed. Only when the drift exceeds these two thresholds does it mean that a perceptible impedance drift has occurred, and adjustment needs to be triggered.

[0033] Based on the absolute value of the valley frequency drift, the adjustment step value of the varactor diode control voltage is determined by proportional mapping. This step value is the adjustment range of the varactor diode control voltage within this cycle. It is the single adjustment amount of this fine-tuning and its function is to control the adjustment range each time to avoid overshoot due to excessive adjustment at one time, while ensuring that the adjustment range matches the drift range, so as to pull the drift valley value back to the normal position.

[0034] Specifically, proportional mapping is a linear conversion method. The system pre-calibrates the linear proportional relationship between frequency drift and voltage adjustment based on the characteristics of the varactor diode and the parameters of the impedance network. By converting the magnitude of the offset into the corresponding voltage adjustment step size according to this pre-calibrated proportional relationship, for example, if the pre-calibration is that every 1MHz of frequency drift corresponds to a 0.1V voltage adjustment, then a 3MHz offset corresponds to an adjustment step of 0.3V. This process is proportional mapping, which linearly converts the frequency drift into the voltage adjustment, ensuring that the larger the drift, the larger the adjustment, thus achieving precise corresponding adjustment.

[0035] Based on the adjustment step value and the determined offset direction (e.g., offset towards higher frequencies), the adjusted amount is obtained and applied to the varactor diode in the readjusted adjustable impedance matching network, completing the impedance correction operation for this cycle. This cycle's impedance correction operation includes S101 for immediate adjustment in case of sudden large detuning and S102 for tracking and fine-tuning of slow drift, ensuring the long-term stability of the impedance matching.

[0036] Specifically, if the frequency drifts towards higher frequencies, the control voltage is decreased; if it drifts towards lower frequencies, the control voltage is increased. The calculated voltage adjustment is applied to the varactor diode in the adjustable impedance matching network to change its equivalent capacitance value, thereby achieving impedance correction.

[0037] The above implementation process, by accurately capturing the valley frequency drift, determining the consistency of the drift direction, and quantifying the cumulative drift, achieves accurate identification of continuous detuning caused by sweat penetration, etc., and avoids confusing the interference of discrete droplets with uniform sweat. Meanwhile, the clear step-by-step process ensures that each step is supported by data, which not only enables accurate differentiation of detuning types but also provides a clear basis for subsequent impedance compensation, effectively avoiding ineffective adjustments, ensuring the stability of signal transmission, adapting to the actual use needs of scenarios such as vehicle antennas, and the operation process is clear, feasible, and in line with actual application scenarios.

[0038] Specifically: Step S103 includes: based on the impedance correction operation completed in this cycle, obtaining the initial drift sequence based on the valley frequency drift; The initial drift sequence is a sequence of valley frequency drift values ​​collected continuously by the frequency drift tracking and comparison unit within multiple sampling periods, which provides a continuous historical data basis for subsequent trend statistics. In one implementation, the sampling period can be set to a fixed interval, such as once per second, to accommodate real-time monitoring requirements.

[0039] The method extracts the periodic change in the valley frequency drift between two adjacent sampling periods based on the initial drift sequence. This change measures the amplitude of the drift between two adjacent periods, used to determine whether the current drift is a steady, slow change or a sudden, anomalous jump. It should be noted that this extraction method emphasizes periodic comparison to ensure the accuracy of the jump amplitude is within 0.1 Hz, thus supporting subsequent anomaly detection.

[0040] Within a preset continuous time window, the valley frequency drift is accumulated to obtain the accumulated result. At the same time, the direction is determined by the positive or negative sign of the accumulated result. This is used to determine the severity of the drift and decide whether to make a fine adjustment or trigger a larger impedance adjustment. The periodic change is used as a single jump variable, and the cumulative result is compared with the direction of all single jump variables within a preset continuous time window. If the direction is consistent and the absolute value of the cumulative result exceeds a preset threshold, the validity of the cumulative drift direction is confirmed. That is, the cumulative drift direction is real and reliable, not a false trend caused by noise or random fluctuations, and can be used as a real drift. If the condition of consistent direction and the absolute value of the cumulative result exceeding the preset threshold does not hold, the invalidity of the cumulative drift direction is confirmed. Combining validity and invalidity yields the direction determination result. This result is used to subsequently determine the type of current detuning. All thresholds can be obtained using the mean-standard deviation method.

[0041] By continuously collecting the valley frequency drift over multiple sampling periods, an initial drift sequence is formed, providing continuous and complete historical data support for subsequent trend analysis. This avoids misjudgments caused by deviations in data from a single period and ensures that subsequent analysis has a reliable data foundation.

[0042] By calculating the drift changes between adjacent sampling periods, it is possible to clearly distinguish between slow, steady drift and sudden jumps, and quickly identify the differences between discrete droplets and uniform sweat, avoiding misjudging normal fluctuations as effective detuning.

[0043] By accumulating and calculating the drift amount and verifying the consistency of direction, continuous and stable drift trends can be accurately identified, random minor fluctuations can be eliminated, and it can be ensured that only real and continuous detuning is responded to, thus avoiding ineffective adjustments.

[0044] By verifying the consistency of the drift direction and the threshold of the accumulated results, it is possible to accurately distinguish between uniform sweat detuning that requires compensation and normal fluctuations that do not require treatment. This avoids misjudging occasional, irregular drifts as detuning that requires compensation, reduces ineffective operations, and lowers equipment wear and tear.

[0045] Clear valid / invalid determination results provide a direct basis for subsequent mistuning type identification, ensuring that subsequent compensation operations can accurately match the mistuning type and avoid the problem of using the wrong compensation method.

[0046] This step, through standardized sequence acquisition, variation analysis, and direction verification, achieves accurate identification of the slow-varying detuning of uniform sweat penetration, eliminates accidental fluctuations and invalid interference, and provides an accurate basis for subsequent targeted adjustments. It not only ensures the accuracy of anti-interference but also avoids the problems of over-adjustment or under-adjustment, while reducing unnecessary equipment wear and tear and ensuring the stability of overall signal transmission.

[0047] Specifically, the steps in S104 include: acquiring signal data from multiple consecutive sampling points within the antenna feed area, calculating the absolute value of the single jump variable, and then performing difference calculation to obtain the jump amplitude value; this jump amplitude value is the difference between the single jump variable of the current period and the previous period, and its purpose is to distinguish the type of detuning: because the droplet falling on the feed point is a sudden event that will cause an instantaneous change in impedance, while the normal slow drift and noise change amplitudes are very small.

[0048] Signal data is a collective term for all state detection data collected by the system in this area. It provides a complete data source for determining the type of detuning. It includes at least valley frequency drift, cycle-by-cycle change, capacitance detection data, optical detection data, radio frequency signal reflection coefficient, received signal strength, and VSWR change data, which are used to comprehensively determine the state of the feed point area.

[0049] The detuning category is determined by comparing the jump amplitude value with the preset jump threshold. If the jump amplitude value exceeds the jump threshold, it indicates that there is a discontinuous detuning caused by discrete droplets in the antenna feed point area. Discrete droplet distribution data and electromagnetic reflection deviation data are then extracted from the signal data to determine the droplet initiating factor. The droplet initiating factor is a discrete droplet that falls on the feed point. This independent small droplet changes the dielectric properties of the feed point area, which in turn leads to a sudden change in impedance. This droplet is the root cause of this detuning, hence the name droplet initiating factor.

[0050] Specifically, the pre-defined detuning classification model refers to an algorithmic framework trained on historical data, used to identify abnormal changes in signal parameters in an antenna system. Specifically, this model employs a support vector machine or neural network structure. It takes real-time signal sequence data from the antenna feed area as input, internally extracts transition points, calculates amplitude values, filters noise interference, and then outputs a probability distribution of the detuning type. In the field of antenna communication, such as in base station antenna maintenance scenarios, the pre-defined process of this model includes collecting sample data under normal and detuned conditions, performing feature extraction and training to adapt to signal fluctuations under different weather conditions.

[0051] Discontinuous detuning refers to intermittent impedance mismatch caused by droplets, rather than continuous, uniformly distributed interference. Uniform sweat penetration emphasizes continuous, slowly varying detuning. The jump threshold is used to distinguish between sudden changes and normal changes. This judgment does not distinguish whether the cumulative drift is valid and is the first step in detuning classification: if the jump amplitude exceeds the jump threshold, it means that a sudden and large impedance jump has occurred, which is not a normal slow drift. It is likely that something suddenly hit the feed point, such as a drop of sweat suddenly falling on it; if it does not exceed the jump threshold, it means that it is a normal slow change. At this time, the previously obtained direction determination result will be used to determine whether it is a smooth slow drift, that is, continuous detuning caused by uniform sweat penetration. Once the jump amplitude exceeds the jump threshold and a sudden detuning is confirmed, droplet-related verification will be carried out, as detailed below: First, two feature data are extracted: discrete droplet distribution data and electromagnetic reflection deviation data. The discrete droplet distribution data is detected by a capacitance or optical sensor in the feed point area, showing the droplet distribution in that area. This data is used to determine whether there are independent, discrete small droplets on the feed point, rather than uniform sweat penetration. The electromagnetic reflection deviation data refers to the deviation of the radio frequency signal reflection from the normal state. Because the dielectric constant of droplets is different from that of air, it can cause a sudden and large abnormal deviation in electromagnetic reflection. This deviation is the feature we want to extract.

[0052] Next, the droplet-inducing factor is determined. Based on these two data points, it is determined whether the cause of this sudden detuning is a droplet: if discrete droplets are detected and electromagnetic reflection also shows a corresponding abnormal deviation, it indicates that the cause of this detuning is a droplet, that is, a sweat droplet falling on the feed point.

[0053] The final conclusion is that there is a discontinuous detuning caused by discrete droplets in the antenna feed point area. That is, the current detuning is caused by individual sweat droplets falling on the feed point, resulting in a sudden and discontinuous impedance detuning. It is not caused by slowly seeping uniform sweat, nor by other interference.

[0054] This step obtains signal data from multiple sampling points of the antenna feed point, calculates the absolute value, and processes the difference to obtain the jump amplitude value. Combined with the preset jump threshold, it can accurately distinguish between discontinuous detuning caused by discrete droplets and continuous detuning caused by uniform sweat, thus avoiding misjudgment.

[0055] By extracting discrete droplet distribution data and electromagnetic reflection deviation data, the droplet-inducing factors can be accurately determined. Simultaneously, by comparing the jump amplitude with the jump threshold, discontinuous and continuous detuning can be precisely identified, eliminating normal interference. This solves the problem of traditional methods being unable to distinguish between sweat and droplet interference, and accurately locates the cause of detuning, providing a reliable basis for subsequent targeted compensation, effectively avoiding misjudgments, improving signal transmission stability, reducing invalid operations, ensuring the accuracy and efficiency of interference suppression, providing precise data support for subsequent impedance adjustment, and guaranteeing the stable operation of the overall system.

[0056] Specifically, the steps in S105 include: if the jump amplitude value does not exceed the jump threshold, then the direction determination result is used for verification to supplement the detuning category. The specific supplementary content is as follows: If the direction determination result is valid, it can be determined that there is a type of detuning caused by continuous thin film loading in the antenna feed point area, and the continuous detuning caused by uniform sweat penetration can be obtained. If the direction determination result is invalid, it means that the current drift is neither caused by droplet-induced factors, i.e., sudden droplet detuning, nor by continuous detuning caused by uniform sweat penetration. It is a normal small fluctuation or temporary interference that does not need to be dealt with. It is only necessary to maintain the current impedance state and continue the sampling and monitoring of the next cycle. Therefore, it is a normal interference. Continuous thin-film loading is a technical term in the radio frequency (RF) field. Essentially, it refers to the uniform penetration of sweat. A continuous thin film means that as sweat slowly and evenly penetrates the metal surface of the antenna feed point, it forms a continuous, uniform thin liquid film on the surface, much like the smooth water film formed when you smear water on glass—not individual, discrete water droplets. Loading, in RF terms, refers to the process of covering the feed point or antenna surface with an additional dielectric material, changing its dielectric constant and thus its impedance. Because the dielectric constant of this liquid film is completely different from that of air, it's equivalent to adding an extra dielectric material to the feed point, altering its electrical characteristics.

[0057] Normal interference includes: normal measurement noise: slight errors are inevitable during sampling, causing drift to fluctuate, but the amplitude is very small and will not affect impedance matching or signal transmission; slight environmental temperature drift: slight fluctuations in ambient temperature cause slight changes in impedance, but the amplitude is very small, will not accumulate, and will not cause the VSWR to exceed the standard; temporary minor interference: for example, a user lightly touching the antenna causes a slight temporary change in impedance, but it recovers quickly and will not accumulate. Abnormal interference includes droplet-induced factors and uniform sweat penetration; By combining droplet-initiating factors, uniform sweat penetration, and normal interference, a detuning category is obtained.

[0058] The beneficial effect of this step is that, through clear judgment logic, it accurately distinguishes different types of detuning, avoiding misjudgments and invalid operations. By verifying the direction judgment results, it can accurately distinguish between continuous detuning caused by uniform sweat, sudden detuning caused by discrete droplets, and normal minor fluctuations, preventing normal interference from being misjudged as detuning requiring action.

[0059] Meanwhile, the differences between continuous thin-film loading and sudden droplet detuning are clearly defined to avoid using the wrong compensation method; the criteria for judging normal interference are clarified to avoid over-adjustment and save equipment power consumption.

[0060] Its core value lies in accurately identifying different types of detuning, providing a basis for subsequent targeted compensation, ensuring that only real and necessary detunings are adjusted, avoiding both missing effective detunings and preventing ineffective adjustments, thus ensuring stable signal transmission and improving overall anti-interference capabilities.

[0061] Once the detuning classification model determines that the antenna feed point region is affected by either continuous thin-film loading or discrete droplet loading, the system immediately switches to the impedance compensation stage and performs corresponding compensation operations based on the specific detuning category. Specifically, step S106 includes: extracting the compensation value from a preset impedance compensation lookup table according to the detuning category to obtain the compensation value result; The compensation value, or the compensation result, is the amount of impedance adjustment required for the corresponding detuning category. For example, a 1V voltage adjustment corresponds to droplet detuning, or a 0.2V fine adjustment corresponds to uniform sweat. Its function is to tell the system how much adjustment is needed to bring the detuned impedance back to normal.

[0062] The preset impedance compensation lookup table is a set of mapping relationships built in advance based on a large amount of historical monitoring data and simulation experiments. Each row records the impedance offset value and recommended compensation value corresponding to different detuning categories. In one embodiment, the impedance compensation lookup table is constructed as follows: A mapping relationship between detuning categories and compensation amounts is established using historical monitoring data and simulation experiments. The lookup table structure is a two-dimensional array, with row indices representing detuning category codes, and columns containing detuning characteristic parameters, impedance offset values, fast tracking compensation amounts, and steady-state compensation amounts. The detuning category codes include 1 for continuous thin-film loading and 2 for discrete droplet loading. For example, for continuous thin-film loading (category code 1), the corresponding fast tracking compensation is 0.3 units / cycle, and the steady-state compensation is 0.1 units / cycle; for discrete droplet loading (category code 2), the corresponding fast tracking compensation is 0.5 units / cycle, and the steady-state compensation is 0.05 units / cycle. Specifically, the compensation unit is microliters, representing the minute volume compensation value of media addition / deposition within a single process cycle; in quality control scenarios, milligrams are used as the standard unit of measurement.

[0063] The system retrieves the corresponding compensation value from a lookup table based on the category code output by the mistuning classification model. Furthermore, the extraction of the compensation value is achieved through a simple query.

[0064] For example, in the scenario of a communication base station antenna, if it is determined to be a continuous thin film loading type, the model directly locates the corresponding row in the table and retrieves the pre-stored compensation value. This value represents the impedance matching offset that needs to be adjusted in order to restore the stability of the signal parameters. Preferably, the system determines the compensation method into two categories based on the type of detuning and the extracted compensation amount.

[0065] It should be noted that the rapid tracking compensation is suitable for cumulative effects that require immediate response. It quickly offsets the gradual impedance changes caused by the thin film by gradually applying compensation over a short period of time. The steady-state compensation, on the other hand, focuses on subsequent maintenance and ensures long-term balance through continuous correction with smaller amplitudes.

[0066] In one possible implementation, for the case of continuous thin-film loading in the feed area of ​​an outdoor 5G base station, when the compensation amount is 0.8 units, the system first applies a fast tracking compensation amount for three cycles at a rate of 0.2 units per cycle, and then switches to a steady-state compensation amount, continuously adjusting at a rate of 0.05 units per cycle until the compensation amount is reached. This phased approach ensures a smooth transition from detection to recovery.

[0067] Understandably, the lookup table's preset process involves matching historical drift data with actual impedance test results one by one. For example, for moisture film loading in high humidity environments, the table has specially set up entries biased towards positive compensation to adapt to the upward drift characteristics of signal parameters.

[0068] The category parameter is obtained based on the detuning category. The compensation method type is determined by comparing the compensation value with the category parameter, including steady-state compensation and rapid tracking compensation. Specifically, the compensation value and category parameter are correlated and matched. For example, if the category parameter for droplets is sudden and the compensation amount is large, the compensation belongs to the rapid tracking type. If it is uniform sweat, the category parameter is slowly changing and the compensation amount is small, the compensation belongs to the steady-state compensation type. The compensation method type result obtained in this process is used to determine whether the current compensation is rapid tracking or steady-state. This serves as the basis for subsequent adjustments, determining the appropriate rhythm for impedance adjustment.

[0069] Category parameters are the inherent attribute parameters of each detuning category, which are also stored in the lookup table in advance. For example, the parameters of the droplet category are sudden, large change, and need for rapid response, while the parameters of uniform sweat are slow change, small change, and need for steady-state maintenance. Its function is to distinguish whether the detuning needs to be compensated quickly or steadily. Based on the detuning category, the corresponding parameters of this category are directly extracted from the lookup table.

[0070] When the compensation method type is fast tracking, the fast tracking compensation amount is used to dynamically adjust the impedance to obtain the tracking adjustment result. Specifically, the control voltage of the varactor diode can be adjusted to the corresponding amplitude in one go, or if necessary, the switching element can be switched to adjust the network topology to instantly pull back the detuned impedance. The whole process is in milliseconds and there is no delay.

[0071] The rapid tracking compensation amount is a fast adjustment amount for sudden, large-amplitude detuning. It is the compensation amount corresponding to the droplet detuning extracted from the lookup table. It is used to quickly bring back the sudden large detuning because the droplet detuning is instantaneous and must be corrected quickly, otherwise the signal will be interrupted.

[0072] The tracking adjustment result is the new impedance state obtained after a rapid adjustment. For example, after the adjustment, the VSWR returns to the normal range and the valley value returns to the target position. It is used to lay the foundation for subsequent steady-state adjustment.

[0073] The steady-state maintenance parameters are obtained based on the detuning category. By combining the tracking adjustment results with the steady-state maintenance parameters, the compensation method is determined. Specifically, after completing the rapid adjustment and obtaining the tracking adjustment results, the adjusted state is stabilized by combining the steady-state maintenance parameters. For example, after the rapid adjustment brings back the large detuning, we use small steady-state steps to slowly make subsequent fine adjustments to maintain the impedance in the optimal state for a long time without frequent fluctuations. This process yields the compensation method determination result.

[0074] Steady-state maintenance parameters are pre-set parameters used to maintain long-term steady-state operation for the slow-varying detuning of uniform sweat. These parameters include the maximum step size for each fine-tuning, the adjustment interval, and the target VSWR for steady-state operation. These parameters are extracted from a lookup table based on the detuning category and are used to avoid over-adjustment, prevent impedance fluctuations, and ensure long-term stability.

[0075] By using a pre-defined impedance compensation lookup table, precise compensation for different types of detuning is achieved, avoiding signal instability caused by blind adjustments. The corresponding compensation amount is extracted based on the detuning category to clarify the adjustment range. Then, by comparing the category parameters with the compensation amount, the system accurately distinguishes between fast tracking and steady-state compensation methods, adapting to different detuning scenarios.

[0076] Rapid tracking compensation can quickly correct sudden detuning and avoid signal interruption; steady-state compensation can maintain long-term matching and prevent over-adjustment. The phased compensation strategy not only solves the sudden detuning caused by discrete droplets, but also adapts to the slow detuning caused by uniform sweat penetration, ensuring stable signal transmission, avoiding ineffective adjustments, reducing equipment wear, adapting to various practical application scenarios, and improving overall anti-interference capability.

[0077] Specifically: The specific steps of S107 include: according to the compensation method, obtaining the current operating frequency of the wireless digital microphone, querying the preset impedance matching reference table according to the operating frequency, and obtaining the corresponding target capacitive reactance value and target inductive reactance value; The operating frequency is the radio frequency currently used by the wireless digital microphone, which is read directly from the system's radio frequency chip register.

[0078] The preset impedance matching reference table is a comparison table formed during the product development stage by measuring the optimal matching parameters of the antenna and the adjustable impedance matching network point by point in the entire operating frequency band using a vector network analyzer, and pre-storing the optimal target capacitive reactance value and target inductive reactance value corresponding to each operating frequency point.

[0079] The target capacitive reactance value is compared with the actual capacitive reactance value of the current varactor diode. If the actual capacitive reactance value deviates from the target capacitive reactance value, the capacitive reactance deviation is calculated. The formula for calculating the actual capacitive reactance of a varactor diode is as follows: ,in This is the actual capacitive reactance value of the varactor diode, specifically obtained by reading the current state after the compensation method is determined and before adjustment. Pi For the operating frequency point, This is the current capacitance value; The capacitive reactance deviation is the difference between the target capacitive reactance value and the actual capacitive reactance value. It reflects how much adjustment is needed to bring the capacitive reactance to the target value. The variable capacitor adjustment unit is driven by the capacitive reactance deviation to adjust the capacitance value of the varactor diode and obtain the updated capacitive reactance value. The variable capacitor adjustment unit is the unit that controls the varactor diode. It is used to output a control voltage to the varactor diode. Based on the capacitive reactance deviation, it calculates how much control voltage needs to be adjusted, and then outputs this voltage adjustment amount to the varactor diode to adjust its capacitance value. As the capacitance changes, the capacitive reactance also changes, and finally, the updated equivalent capacitive reactance value is obtained, which is the adjusted capacitive reactance value, so that it just reaches the target value.

[0080] The updated capacitive reactance value is the new capacitive reactance that will ultimately be sent to the adjustable impedance matching network for actual use. It is used to correct the capacitive reactance of the variable capacitor from the old value that deviated from the matching to the optimal target value at the current operating frequency, so that the entire impedance network can achieve impedance matching again and eliminate signal interference caused by sweat or droplets.

[0081] The target inductive reactance value is compared with the actual inductive reactance value of the current inductor. If the actual inductive reactance value deviates from the target inductive reactance value, the inductive reactance deviation is calculated. Inductors adjust their inductance by switching them with switching elements; they are components used to adjust inductive reactance. The current actual inductive reactance value of the inductor is the inductive reactance value before adjustment, and its calculation formula is: ,in This represents the actual inductive reactance of the current inductor. This is the current inductance value; The inductive impedance deviation is the difference between the target inductive impedance value and the actual inductive impedance value, which reflects how much inductive impedance needs to be adjusted. The inductance value is adjusted by using the inductance deviation to drive the inductor element adjustment unit, thereby obtaining the updated inductance value. The inductor element adjustment unit is used to adjust the inductance. If it is a switching inductor, it will switch the switch and connect the inductor of the corresponding size to the circuit. If it is an adjustable inductor, it will adjust the inductor parameters to adjust the inductance value to the target value, and finally obtain the updated equivalent inductive reactance value, which is the adjusted inductive reactance value, just to achieve our goal.

[0082] The capacitance value of a varactor diode is the capacitance of the capacitor, and the unit is pF; the inductance value of an inductor is the inductance of the inductor, and the unit is nH. These are the basic parameters of the components, which determine the magnitude of capacitive reactance and inductive reactance.

[0083] The updated inductive reactance value, together with the updated equivalent capacitive reactance, constitutes a relatively optimal impedance matching condition at the current operating frequency, correcting the impedance detuning of the antenna feed point caused by factors such as sweat and droplets, and suppressing interference with the wireless digital microphone signal.

[0084] By applying the updated capacitive and inductive reactance values ​​together to the readjusted adjustable impedance matching network, interference from the wireless digital microphone signal is processed. This is equivalent to adjusting the parameters of the capacitors and inductors to relatively optimal values ​​for the current operating frequency, ensuring that the impedance of the entire impedance network perfectly matches the impedance of the antenna and transmission line, thus canceling out the previous detuning. This negates the impedance changes caused by sweat, suppressing signal interference and completing the entire calibration process.

[0085] This step directly obtains the target capacitive reactance and target inductive reactance by reading the current operating frequency and consulting the preset impedance matching reference table, ensuring the accuracy and reliability of the impedance adjustment benchmark based on the measured calibration data.

[0086] By comparing the actual capacitive and inductive reactance with the target values, the deviation is calculated and used to drive the varactor diode and inductor adjustment unit respectively, dynamically correcting the capacitance and inductance values ​​to form updated equivalent capacitive and inductive reactance. The updated parameters work synergistically with the adjustable impedance matching network, enabling the antenna and transmission line to quickly restore impedance matching and effectively eliminating impedance shifts and signal reflections caused by sweat and discrete droplets.

[0087] The execution process is complete and precisely adjusted, balancing rapid response and steady-state performance. It can significantly suppress radio frequency interference and ensure stable signal and reliable transmission of wireless digital microphones in complex usage scenarios.

[0088] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A method for suppressing interference in wireless digital microphone signals, characterized in that, The method includes: S101, obtain the reflection coefficient of each frequency point of the feed port, and perform multiple adjustments on the adjustable impedance matching network according to the reflection coefficient, wherein the adjustable impedance matching network includes varactor diodes and switching elements; S102, based on the adjusted adjustable impedance matching network, re-acquire the reflection coefficient, determine the valley frequency drift, determine the offset direction, obtain the adjustment step value by proportional mapping, and apply it to the varactor diode in the adjusted adjustable impedance matching network. S103, construct the initial drift sequence, calculate the periodic change as the single jump variable, accumulate it within the time window and perform a direction consistency judgment to obtain the direction judgment result, including validity and invalidity; S104, call the preset detuning classification model, analyze the jump trend of the single jump variable, compare it with the jump threshold, and determine the droplet initiation factor if it exceeds the threshold. S105, if not exceeded, use the direction determination result to verify and identify the type of detuning, including droplet initiation factors, uniform sweat penetration and normal interference; S106, extract the compensation amount from the preset impedance compensation lookup table according to the detuning category, and determine the compensation method according to the detuning category and the compensation amount. The compensation methods include fast tracking compensation amount and steady-state compensation amount. S107, Based on the compensation method, adjust the actual capacitive reactance and actual inductive reactance of the varactor diode in the adjustable impedance matching network to suppress interference from the wireless digital microphone signal.

2. The method for suppressing interference in a wireless digital microphone signal according to claim 1, characterized in that, Obtain the reflection coefficient at each frequency point of the feed port, and perform multiple adjustments to the adjustable impedance matching network based on the reflection coefficient, including: In the antenna feed area, a continuous frequency scan is performed in the preset working frequency band by the VSWR sweep frequency sampling unit, and the reflection coefficient of each frequency point is obtained from the feed port after the impedance is adjusted by the adjustable impedance matching network. Based on the reflection coefficient, the standing wave ratio is calculated, and the impedance in the adjustable impedance matching network is initially adjusted according to the standing wave ratio. For the initially adjusted adjustable impedance matching network, the new VSWR value is recalculated. If the new VSWR value exceeds the preset VSWR threshold, the adjustment amount of the varactor diode control voltage is calculated based on the deviation between the new VSWR value and the target VSWR value using a proportional-integral control algorithm. The corresponding control voltage is then applied to the varactor diode in the adjustable impedance matching network to obtain the adjusted adjustable impedance matching network, thus completing the modification of the impedance matching state.

3. The method for suppressing interference in a wireless digital microphone signal according to claim 2, characterized in that, Based on the adjusted adjustable impedance matching network, the reflection coefficient is re-acquired, the valley frequency drift is determined, the offset direction is judged, and the adjustment step value is obtained by proportional mapping and applied to the varactor diode in the adjusted adjustable impedance matching network, including: For the readjusted adjustable impedance matching network, the new VSWR value is recalculated to obtain the current period VSWR curve; Extract the minimum standing wave ratio (SWR) value and its corresponding frequency point from the current period's standing wave ratio (SWR) curve to determine the current period's valley frequency. The valley frequency of the current period is compared with the valley frequency recorded in the previous period to obtain the valley frequency drift. A preset directional threshold is set, which includes a positive threshold and a negative threshold. If the valley frequency drift is greater than the positive threshold, the valley is determined to be shifted to a higher frequency direction. If the valley frequency drift is less than the negative threshold, the valley is determined to be shifted to a lower frequency direction. Based on the absolute value of the valley frequency drift, the adjustment step value of the varactor diode control voltage is determined by a proportional mapping method. Based on the adjustment step value and the determined offset direction, the adjusted amount is obtained and applied to the varactor diode in the readjusted adjustable impedance matching network to complete the impedance correction operation for this cycle.

4. The method for suppressing interference in a wireless digital microphone signal according to claim 1, characterized in that, An initial drift sequence is constructed, and the periodic change is calculated as a single jump variable. These changes are accumulated within a time window, and a direction consistency judgment is performed to obtain the direction determination result, including validity and invalidity. Based on the impedance correction operation completed in this cycle, the initial drift sequence is obtained based on the valley frequency drift. Extract the periodic change in the valley frequency drift between two adjacent sampling periods based on the initial drift sequence; The valley frequency drift is accumulated within a preset continuous time window to obtain the accumulated result. The periodic change is used as a single jump variable, and the cumulative result is compared with the direction of all single jump variables within a preset continuous time window. If the direction is consistent and the absolute value of the cumulative result exceeds the preset result threshold, the validity of the cumulative drift direction is confirmed. If the direction is consistent and the absolute value of the cumulative result exceeds the preset result threshold, the invalidity of the cumulative drift direction is confirmed. Combining validity and invalidity yields the direction determination result.

5. The method for suppressing interference in a wireless digital microphone signal according to claim 4, characterized in that, The pre-defined detuning classification model is invoked to analyze the jump trend of a single jump variable, and compared with a jump threshold. If the threshold is exceeded, the droplet initiation factors are identified, including: By acquiring signal data from multiple consecutive sampling points within the antenna feed area, and then performing absolute value calculation on the single jump variable followed by difference calculation, the jump amplitude value is obtained. The detuning category is obtained by comparing the jump amplitude value with the preset jump threshold. If the jump amplitude value exceeds the jump threshold, discrete droplet distribution data and electromagnetic reflection deviation data are extracted from the signal data to determine the droplet initiation factors.

6. The method for suppressing interference in a wireless digital microphone signal according to claim 5, characterized in that, If the deviation does not exceed the limit, the direction determination result is used for verification to identify the type of detuning, including droplet-initiating factors, uniform sweat penetration, and normal interference, including: If the jump amplitude value does not exceed the jump threshold, the direction determination result is used for verification to supplement the detuning category. The specific supplementary content is as follows: If the direction determination result is valid, it can be determined that there is a type of detuning caused by continuous thin film loading in the antenna feed area, and the continuous detuning caused by uniform sweat penetration can be obtained. If the direction determination result is invalid, it means that the current drift is neither caused by droplet initiation factors nor by continuous detuning caused by uniform sweat penetration, and is therefore considered normal interference. By combining droplet-inducing factors, uniform sweat penetration, and normal interference, a detuning category is obtained.

7. The method for suppressing interference in a wireless digital microphone signal according to claim 1, characterized in that, The compensation amount is extracted from a preset impedance compensation lookup table based on the detuning category. The compensation method is determined based on the detuning category and the compensation amount. Compensation methods include fast tracking compensation and steady-state compensation, including: Based on the detuning category, the compensation value is extracted from the preset impedance compensation lookup table to obtain the compensation value result; Based on the detuning category, the category parameter is obtained. The compensation method type result is obtained by correlating and comparing the compensation amount value result with the category parameter, including steady-state compensation type and fast tracking type. When the compensation method type is fast tracking, the fast tracking compensation amount is used to dynamically adjust the impedance to obtain the tracking adjustment result. The steady-state maintenance parameters are obtained based on the detuning category, and the compensation method is obtained by combining the tracking adjustment results with the steady-state maintenance parameters.

8. The method for suppressing interference in a wireless digital microphone signal according to claim 7, characterized in that, Based on a compensation method, the actual capacitive reactance and actual inductive reactance in the adjustable impedance matching network are adjusted to suppress interference from wireless digital microphone signals, including: Based on the compensation method, obtain the current operating frequency of the wireless digital microphone, and look up the preset impedance matching reference table based on the operating frequency to obtain the corresponding target capacitive reactance and target inductive reactance. The target capacitive reactance value is compared with the actual capacitive reactance value of the current varactor diode. If the actual capacitive reactance value deviates from the target capacitive reactance value, the capacitive reactance deviation is calculated. The variable capacitor adjustment unit is driven by the capacitive reactance deviation to adjust the capacitance value of the varactor diode and obtain the updated capacitive reactance value. The target inductive reactance value is compared with the actual inductive reactance value of the current inductor. If the actual inductive reactance value deviates from the target inductive reactance value, the inductive reactance deviation is calculated. The inductance value is adjusted by using the inductance deviation to drive the inductor element adjustment unit, thereby obtaining the updated inductance value. The updated capacitive reactance and updated inductive reactance work together on the readjusted adjustable impedance matching network to process interference from the wireless digital microphone signal.

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