Tuning method of multi-band radio frequency antenna and wireless antenna system
Through the division of reference frequency bands and interference frequency bands and the determination of tuning parameters, the problems of high hardware complexity and long tuning time during multi-band RF antenna tuning are solved, and hardware simplification and tuning efficiency are improved.
Patent Information
- Application Number
- CN202510888833.4
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-06-30
- Publication Date
- 2025-07-29
- Estimated Expiration
- Not applicable · inactive patent
AI Technical Summary
In the prior art, when tuning multi-band RF antennas, matching networks need to be independently designed for each frequency band, resulting in complex hardware structure and long tuning time.
Through the classification of reference frequency bands and interference frequency bands based on radio frequency signals, the interference signal type is determined and the tuning parameters are calculated. The optimal value is determined through field search and the tuning process is performed using the same matching network.
It reduces the complexity of RF signal processing hardware, reduces the invalid search time, significantly reduces the complexity and tuning time of the hardware, and is suitable for dynamically changing electromagnetic environments.
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Figure CN120389226A_ABST
Abstract
Description
Technical Field
[0001] The present invention relates to the field of wireless communication technologies, and particularly to a tuning method for a multi-band radio frequency antenna and a wireless antenna system. Background Art
[0002] A multi-band radio frequency antenna refers to an antenna system that can effectively operate within two or more different radio frequency bands. With the rapid development of 5G communication, satellite communication, and Internet of Things technologies, multi-band radio frequency antennas have become the core components for realizing wide-spectrum communication. Such antennas can operate within a wide range from very low frequencies to microwave frequencies and can adapt to the frequency band requirements of different communication protocols (such as NB-IoT, 5GNR, Wi-Fi6E).
[0003] Due to the significant differences in electromagnetic characteristics between each frequency band, radio frequency signals in different frequency bands are prone to interfere with each other. Therefore, it is necessary to perform tuning processing on the radio frequency signals. However, in the prior art, when tuning, a matching network needs to be independently designed for each frequency band, resulting in a relatively complex hardware structure and a long tuning time. Summary of the Invention
[0004] In view of this, the purpose of the present invention is to provide a tuning method for a multi-band radio frequency antenna and a wireless antenna system, which solves the problem that when tuning a multi-band radio frequency antenna, a matching network needs to be independently designed for each frequency band, resulting in a relatively complex hardware structure and a long tuning time.
[0005] In a first aspect, the present application provides a tuning method for a multi-band radio frequency antenna, including: Determining a reference frequency band and an interference frequency band of the radio frequency signal based on the target operating frequency band of the radio frequency signal; Determining an interference signal corresponding to the interference frequency band and confirming the signal type of the interference signal according to the interference characteristics of the interference signal; Determining a tuning parameter of the interference frequency band relative to the reference frequency band based on the signal type of the interference signal; Determining a search space corresponding to the tuning parameter, using the search space corresponding to the tuning parameter as a reference center, determining the optimal value of the tuning parameter through domain search, and performing tuning processing on the radio frequency signal based on the optimal value of the tuning parameter.
[0006] Optionally, the determining a reference frequency band and an interference frequency band of the radio frequency signal based on the target operating frequency band of the radio frequency signal specifically includes: Performing a frequency sweep on the radio frequency signal to obtain the power spectral density distribution of the radio frequency signal; Based on the power spectral density distribution, dividing the radio frequency signal into continuous sub-band units according to power characteristics; Determine the power variance of each of the sub - band units, record the sub - band units whose power variances are within the range of the target power variance as the reference bands, and record the sub - band units whose power variances are outside the range of the target power variance as the interference bands.
[0007] Optionally, the signal types of the interference signals include narrow - band interference, multipath fading interference, and wide - band noise interference.
[0008] Optionally, the confirmation of the signal type of the interference signal according to the interference characteristics of the interference signal specifically includes: When the frequency offset of the interference signal is less than a preset nominal frequency threshold, the period stability of the continuous sine wave of the waveform feature is greater than a preset stability threshold, there are sudden spikes in the baseline of the bit error rate, and there is a significant peak in the power spectral density at the peak power frequency point, determine that the signal type of the interference signal is narrow - band interference; and / or When the number of peaks of the waveform feature of the interference signal is greater than a preset quantity threshold, the power variance is greater than a preset maximum variance threshold, the bit error rate has periodic fluctuations, and the frequency offset is random and less than a preset nominal frequency threshold, determine that the signal type of the interference signal is multipath fading interference; and / or When the 3dB bandwidth of the interference signal is greater than a preset bandwidth threshold, the waveform feature is a Gaussian distributed random signal, the frequency offset continuously increases and is greater than the maximum frequency threshold, and the power variance is less than a preset minimum variance threshold, determine that the signal type of the interference signal is wide - band noise interference.
[0009] Optionally, the determination of the tuning parameters of the interference band relative to the reference band based on the signal type of the interference signal specifically includes: If the signal type of the interference signal is narrow - band interference, the tuning parameters include the inductance compensation amount and the capacitance compensation amount, and the calculation formulas for the inductance compensation amount and the capacitance compensation amount are:
[0010]
[0011] wherein, the is the inductance compensation amount of the adjustable inductor ; the is the capacitance compensation amount; the is the characteristic impedance of the transmission line; the is the center frequency of the narrow - band interference signal; the is the real part of the equivalent impedance of the RF antenna; the is the operating frequency of the reference band; the is the initial value of the adjustable inductor .
[0012] Optionally, determining the tuning parameter of the interference frequency band relative to the reference frequency band based on the signal type of the interference signal specifically includes: If the signal type of the interference signal is multipath fading interference, the tuning parameter includes a capacitance correction amount, and the calculation formula for the capacitance correction amount is:
[0013] Wherein, the is the capacitance correction amount; the is the operating frequency of the reference frequency band; the is the initial value of the inductor; the is the phase offset, ; the is the multipath time delay difference; the is the effective dielectric constant.
[0014] Optionally, determining the tuning parameter of the interference frequency band relative to the reference frequency band based on the signal type of the interference signal specifically includes: If the signal type of the interference signal is wideband noise interference, the tuning parameter includes a microstrip line length adjustment amount, and the calculation formula for the microstrip line length adjustment amount is:
[0015] Wherein, the is the microstrip line length adjustment amount; the is the speed of light constant, ; the is the multipath time delay difference; the is the phase offset, ; the is the multipath time delay difference; the is the effective dielectric constant; the is the operating frequency of the reference frequency band.
[0016] Optionally, taking the search space corresponding to the tuning parameter as the reference center and determining the optimal value of the tuning parameter through domain search specifically includes: Based on a preset search step size, taking the search space corresponding to the tuning parameter as the reference center, determining the domain space of the search space; the tuning parameter of the domain space is determined according to the tuning parameter of the reference center and the search step size; Based on the reflection coefficient, bit error rate, and inter-subcarrier interference power of each domain space, determining the fitness of each domain space, and selecting the domain space with the minimum fitness as the new reference center; If the fitness of the domain space corresponding to the reference center reaches the fitness threshold, determine that the tuning parameter corresponding to the reference center is the optimal value.
[0017] Optionally, the search space is defined according to the parameters of the tuning element; before determining the domain space of the search space with the search space corresponding to the tuning parameter as the reference center, it further includes: If the signal type of the interference signal is broadband noise interference, introduce a random frequency offset, and define the search space based on the frequency offset and the parameters of the tuning element.
[0018] In a second aspect, the present application provides a wireless antenna system, including a processor and a memory; wherein, the memory stores a computer program, and the computer program is used to be loaded and executed by the processor for the tuning method of the multi-band radio frequency antenna as described in any one of the first aspects.
[0019] In the tuning method of the multi-band radio frequency antenna and the wireless antenna system of this embodiment, by dividing the reference frequency band and the interference frequency band to reuse the same matching network, the complexity of the radio frequency signal processing hardware is reduced, the optimal parameter adjustment direction is selected according to the signal type of the interference signal, the ineffective search time is reduced, and the multi-band tuning problem is transformed into a single-band optimization problem. While maintaining the tuning accuracy, the hardware complexity and tuning time are significantly reduced, which is especially suitable for a dynamically changing electromagnetic environment. BRIEF DESCRIPTION OF THE DRAWINGS
[0020] To more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings required to be used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of the present invention, and therefore should not be regarded as limiting the scope. For those of ordinary skill in the art, other related drawings can be obtained based on these drawings without creative efforts.
[0021] Figure 1 It is a schematic structural diagram of a tuning unit of a wireless antenna system provided by an embodiment of the present application.
[0022] Figure 2 It is a schematic flow diagram of a tuning method of a multi-band radio frequency antenna provided by an embodiment of the present application.
[0023] Figure 3 It is a schematic structural diagram of an electronic device provided by an embodiment of the present application. DETAILED DESCRIPTION OF THE EMBODIMENTS
[0024] Specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all embodiments. All other embodiments obtained by those of ordinary skill in the art based on the description of the present invention without creative efforts shall fall within the scope of protection of the present invention.
[0025] In the description of the present invention, unless otherwise clearly defined and limited, terms such as "arranged", "installed", "connected", etc. shall be understood in a broad sense. For example, it may be a fixed connection, a detachable connection, or an integral connection; it may be a mechanical connection or an electrical connection; it may be directly connected or indirectly connected through an intermediate medium. For those of ordinary skill in the art, the specific meanings of the above terms can be understood according to specific situations.
[0026] The orientation or positional relationship indicated by terms such as "upper", "lower", "left", "right", "front", "rear", "top", "bottom", "inner", "outer", etc. is based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship in which the product of the invention is usually placed during use. It is only for the convenience of description and simplification of the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation of the present invention.
[0027] Terms such as "first", "second", "third", etc. are only used to distinguish elements with similar attributes, rather than indicating or implying relative importance or a specific order.
[0028] The term "comprising", "including" or any other variant thereof is intended to cover non-exclusive inclusion. In addition to including the listed elements, it may also include other elements not specifically listed.
[0029] Figure 1 It is a schematic structural diagram of the tuning unit of the wireless antenna system of this embodiment, which is equipped with a very low frequency module, a radio frequency module, and a hybrid conditioning module. The very low frequency module is equipped with an anti-Γ type impedance matching network, where L1 and L2 are adjustable inductors, and C1 and C2 are capacitors. The capacitance value in the impedance matching network is changed by switch switching. The parallel connection of C1 and L2 can achieve continuous adjustment of the capacitance. The radio frequency section integrates a microelectromechanical system variable inductor and a varactor diode, and uses a distributed parameter design to match the microstrip line. The hybrid conditioning unit realizes the conversion between lumped parameters and distributed parameters through an impedance transformation network, and supports full-band coverage from 20 kHz to 6 GHz.
[0030] The very low frequency module builds a 24 kHz simulation scenario, with a characteristic impedance of 50 Ω in the very low frequency band, an equivalent resistance of 30 Ω and a reactance of 20 Ω for the antenna; the radio frequency module constructs a 5.2 GHz microstrip line matching network, and simultaneously injects a 24.5 kHz narrowband interference and a 5.1 - 5.3 GHz broadband noise, and sets the radio frequency section to use a dielectric substrate with a dielectric constant of 4.4 and a thickness of 0.8 mm.
[0031] As Figure 2 shown, this embodiment provides a tuning method for a multi - band radio frequency antenna, including: Step S10: Determine the reference frequency band and the interference frequency band of the radio frequency signal based on the target operating frequency band of the radio frequency signal; Step S20: Determine the interference signal corresponding to the interference frequency band, and confirm the signal type of the interference signal according to the interference characteristics of the interference signal; Step S30: Determine the tuning parameter of the interference frequency band relative to the reference frequency band based on the signal type of the interference signal; Step S40: Determine the search space corresponding to the tuning parameter, take the search space corresponding to the tuning parameter as the reference center, determine the optimal value of the tuning parameter through domain search, and perform tuning processing on the radio frequency signal based on the optimal value of the tuning parameter.
[0032] In the tuning method of the multi - band radio frequency antenna of this embodiment, by dividing the reference frequency band and the interference frequency band to reuse the same matching network, the complexity of the processing hardware of the radio frequency signal is reduced. Selecting the optimal parameter adjustment direction according to the signal type of the interference signal reduces the invalid search time, and transforms the multi - band tuning problem into a single - band optimization problem. While maintaining the tuning accuracy, it significantly reduces the hardware complexity and tuning time, and is especially suitable for a dynamically changing electromagnetic environment.
[0033] Step S10: Determine the reference frequency band and the interference frequency band of the radio frequency signal based on the target operating frequency band of the radio frequency signal.
[0034] The target operating frequency band refers to the complete frequency range that the radio frequency antenna needs to cover according to service requirements, including one or more sub - bands. For example, the target operating frequency band of a 5G base station includes [3.3 GHz, 3.6 GHz] or [24.25 GHz, 29.5 GHz]. For another example, the target operating frequency band of satellite communication includes the L - band of 1.5 - 2.7 GHz, the S - band of 2.31 - 2.36 GHz, etc.
[0035] The reference frequency band is the core communication frequency band selected from the target operating frequency band and serves as the reference for the tuning algorithm. The reference frequency band has the lowest interference level, the highest service priority, and the most stable channel quality. For example, when the target operating frequency band is [20 kHz, 30 kHz], the reference frequency band can be [23 kHz, 25 kHz] with the least interference.
[0036] The interference frequency band refers to the sub-frequency band of electromagnetic interference that interferes with the normal operation of the reference frequency band. Its interference signal will cause the communication quality to decline and needs to be suppressed or avoided through the tuning algorithm.
[0037] Determining the reference frequency band and the interference frequency band of the radio frequency signal based on the radio frequency signal specifically includes: performing a frequency sweep on the radio frequency signal to obtain the power spectral density distribution of the radio frequency signal; based on the power spectral density distribution, dividing the radio frequency signal into continuous sub-frequency band units according to the power characteristics; determining the power variance of each sub-frequency band unit, recording the sub-frequency band units with the power variance within the range of the target power variance as the reference frequency band, and recording the sub-frequency band units with the power variance outside the range of the target power variance as the interference frequency band.
[0038] The power spectral density distribution is used to describe the distribution of the radio frequency signal power on the frequency axis and can reflect the concentration degree of the signal energy at different frequency points. The spectrum analyzer can be used to receive and measure the power at each frequency point. When performing a frequency sweep, first set the frequency sweep range as the target operating frequency band , then determine the frequency resolution , where and are the minimum frequency band and the maximum frequency band respectively, is the number of sampling points, and finally, signals are transmitted at each frequency point in turn to measure the power at each frequency point , and fitting the power at each frequency point can obtain the power spectral density distribution. If the power spectral density distribution is relatively flat, it indicates the existence of white noise; if the power spectral density distribution has a spike-like tip, it indicates the existence of narrowband interference; if the power spectral density distribution has a fluctuating structure, it indicates the existence of multipath fading interference.
[0039] The power characteristic refers to the characteristic used to characterize the statistical characteristics and variation laws of the signal power, including the average power, the power fluctuation range, and the power change rate. When dividing the sub-frequency band units, first divide the frequency band of the radio frequency signal into multiple sub-units with equal bandwidths, and the sub-units with similar average power, similar power fluctuation ranges, and similar and connected power change rates can be divided into continuous sub-frequency band units.
[0040] Power variance is a statistic used to measure the degree of power fluctuation within a sub-band. Generally, the smaller the power variance, the more stable the power is, and it may be a reference band; while the larger the power variance, the more severe the power fluctuation is, and it may be an interference band. The power variance is calculated as follows: , is the power variance, N is the number of frequency points in the sub-band unit, The first The power of each frequency point, is the average power of the sub-band unit.
[0041] By dividing the frequency band into reference and interference bands, the core matching network only needs to be designed for the reference band, and parameter mapping can be used to adapt to other bands, reducing hardware costs. For the interference band, there is no need to tune each band independently, significantly reducing tuning time. Through power characteristic analysis and frequency band classification mechanisms, high-quality communication bands and interference areas can be automatically identified, providing an accurate basis for subsequent tuning parameter generation, achieving efficient adaptive tuning of multi-band RF antennas.
[0042] Step S20: determining an interference signal corresponding to the interference frequency band, and confirming a signal type of the interference signal according to an interference feature of the interference signal.
[0043] Interference signals are signals that electromagnetically interfere with normal RF communications within the target operating frequency band. Their power or spectral characteristics can degrade the quality of received RF signals. Interference signatures describe the characteristics of interference signals and can be used to distinguish different types of interference. Interference signatures typically include center frequency, bandwidth, power spectral density, waveform characteristics, pulse width, and bit error rate.
[0044] The signal types of the interference signal include narrowband interference, multipath fading interference and broadband noise interference.
[0045] The bandwidth of narrowband interference is significantly smaller than the system bandwidth, and the energy is usually concentrated at a specific frequency point. Its waveform is periodic or quasi-periodic and lasts for a long time. When the frequency offset of the interference signal is less than the preset nominal frequency threshold, the periodic stability of the continuous sine wave of the waveform characteristic is greater than the preset stability threshold, there is a sudden spike in the baseline of the bit error rate, and there is a significant peak in the power spectrum density at the peak power frequency point, the signal type of the interference signal is determined to be narrowband interference. Frequency offset refers to the difference between the center frequency of the interference signal and the nominal frequency of the system. The nominal frequency threshold is usually 100Hz (can also be modified as needed). The periodic stability of the continuous sine wave of the waveform characteristic can be determined by the stability factor. The calculation formula of the stability factor is , where N is the number of cycles of the sine wave, For the cycles, is the average period, is the total period of the sub - frequency band unit, and the stability threshold is 0.01. The bit error rate refers to the bit error rate level of the system without interference. Narrow - band interference will cause sudden spikes in the bit error rate near the baseline. Narrow - band interference has a significant peak at the peak power frequency point, and its peak bandwidth is usually less than 0.1 times the bandwidth of the wireless antenna system.
[0046] Multipath fading interference refers to the interference caused by the radio frequency signal reaching the receiving end through multiple paths, resulting in time - delay spread due to the difference in path lengths. It shows frequency - selective fading, and deep fading valleys appear in the power spectrum. When the number of peaks in the waveform characteristics of the interference signal is greater than a preset quantity threshold, the power variance is greater than a preset maximum variance threshold, the bit error rate has periodic fluctuations, and the frequency offset is random and less than a preset nominal frequency threshold, it is determined that the signal type of the interference signal is multipath fading interference. During multipath propagation, the superposition of signals from different paths will cause multiple local peaks in the waveform. The more peaks there are, the more paths may be involved in the superposition, and the waveform after multipath superposition may have multiple irregular peaks such as saw - teeth. In multipath fading, the phases of the signals on each path change randomly, resulting in significant fluctuations in the power of the superimposed signal, and the power variance is higher than the normal level. Due to the time - varying nature of multipath fading, the signal - to - noise ratio of the received signal will change periodically, resulting in regular high - and - low fluctuations in the bit error rate. The frequency offset in multipath fading is usually caused by the Doppler effect or path changes, showing small frequency fluctuations without a fixed pattern, and the offset is generally less than the nominal frequency threshold of the wireless antenna system.
[0047] Wide - band noise interference refers to the interference whose bandwidth covers the entire or most of the system frequency band, and its power spectral density is approximately flat. When the 3dB bandwidth of the interference signal is greater than a preset bandwidth threshold, the waveform characteristics are Gaussian - distributed random signals, the frequency offset continuously increases and is greater than the maximum frequency threshold, and the power variance is less than a preset minimum variance threshold, it is determined that the signal type of the interference signal is wide - band noise interference. The 3dB bandwidth refers to the frequency range corresponding to when the signal power spectral density drops to half of the peak power, which is used to quantify the effective bandwidth of the signal. The bandwidth threshold is usually more than 50% of the bandwidth of the wireless antenna system. When the amplitude of the waveform characteristics follows a Gaussian distribution and its signal kurtosis is approximately equal to 3 and the skewness is approximately equal to 0, it can be determined as a Gaussian - distributed random signal. If the slope of the frequency offset of the interference signal is positive and exceeds the threshold, it is determined to be continuously increasing. The maximum frequency threshold is 100KHz (which can be set by itself according to the system nominal frequency and requirements). Since the power of wide - band noise interference fluctuates less in the time domain, while the power variance of multipath interference is large, its minimum variance threshold is usually 10% of the power variance of narrow - band interference.
[0048] Judging the signal type of the interference signal through multiple features can improve the accuracy of the determination of the interference signal category, which is convenient for subsequent targeted tuning to ensure the stability of the radio frequency signal. It can be understood that if there are multiple interference signals in the radio frequency signal and narrowband interference and broadband noise interference exist at the same time, the narrowband interference needs to be filtered out first, and then the characteristics of the broadband noise interference are analyzed.
[0049] Step S30: Determine the tuning parameter of the interference frequency band relative to the reference frequency band based on the signal type of the interference signal.
[0050] For different types of interference signals, their tuning parameters are different. Based on the identified signal type of the interference signal, calculating the tuning parameter specifically can facilitate eliminating or suppressing the influence of the interference frequency band in a short time, and only activating the tuning circuit in the interference frequency band can reduce the system power consumption and hardware complexity.
[0051] The determining the tuning parameter of the interference frequency band relative to the reference frequency band based on the signal type of the interference signal specifically includes: if the signal type of the interference signal is narrowband interference, the tuning parameter includes an inductance compensation amount and a capacitance compensation amount, and the calculation formulas for the inductance compensation amount and the capacitance compensation amount are:
[0052]
[0053] Among them, the is the inductance compensation amount of the tunable inductor ; the is the capacitance compensation amount; the is the characteristic impedance of the transmission line; the is the center frequency of the narrowband interference signal; the is the real part of the equivalent impedance of the radio frequency antenna; the is the operating frequency of the reference frequency band; the is the initial value of the tunable inductor .
[0054] Since the core feature of narrowband interference is that the energy is concentrated at a specific frequency point (i.e., the center frequency is ), and the bandwidth is much smaller than the system bandwidth. To suppress narrowband interference, it is necessary to adjust the resonance characteristics of the anti-Γ type impedance matching network to make the circuit impedance at the interference frequency not match the signal transmission path, thereby attenuating the interference signal. Inductors and capacitors are key components that make up the resonant circuit, and changes in their parameters will directly affect the resonant frequency and impedance characteristics of the circuit. Therefore, the tuning parameters select the inductance compensation amount ΔL1 and the capacitance compensation amount ΔC1 to accurately suppress the fixed frequency characteristics of narrowband interference.
[0055] The inductance compensation amount changes the resonant frequency of the circuit by adjusting the inductance value, so that it is far from the center frequency where interference exists. . For example, if is higher than , the inductance is increased to lower the resonant frequency, so that the circuit at the interference frequency presents a capacitive impedance, which is mismatched with the impedance of the RF antenna, thereby attenuating the interference signal; conversely, if is lower than , the inductance is decreased to increase the resonant frequency.
[0056] The capacitance compensation amount and the inductance compensation amount need to be adjusted synergistically to ensure that the resonant frequency of the circuit accurately matches the suppression requirement. When the total inductance becomes L2 + ΔL1, the capacitance value needs to be adjusted by ΔC1 to make the resonant frequency of the circuit far from the center frequency . For example, if the inductance increases, the capacitance needs to be correspondingly decreased to maintain or change the resonant frequency; conversely, if the inductance decreases, the capacitance needs to be increased.
[0057] Determining the tuning parameter of the interference band relative to the reference band based on the signal type of the interference signal specifically includes: if the signal type of the interference signal is multipath fading interference, the tuning parameter includes a capacitance correction amount, and the calculation formula of the capacitance correction amount is:
[0058] wherein, the is the capacitance correction amount; the is the operating frequency of the reference band; the is the initial inductance value; the is the phase offset amount, ; the is the multipath time delay difference; the is the effective dielectric constant.
[0059] Multipath fading interference is that the RF signal propagates through multiple paths, resulting in a time delay difference, which in turn causes a phase offset, and finally causes frequency selective fading. At this time, the phase difference needs to be compensated by adjusting the capacitance value of the capacitor. Since the capacitor and the inductor jointly determine the phase characteristics in the resonant circuit, adjusting the capacitor can change the resonant frequency and phase response of the circuit, thereby canceling the phase difference of the multipath signals, making the RF signals of different paths in-phase superimposed at the receiving end, reducing the fading effect, and increasing the signal power.
[0060] Determining the tuning parameter of the interference band relative to the reference band based on the signal type of the interference signal specifically includes: if the signal type of the interference signal is broadband noise interference, the tuning parameter includes a microstrip line length adjustment amount, and the calculation formula of the microstrip line length adjustment amount is:
[0061] Among them, the is the adjustment amount of the microstrip line length; the is the speed of light constant, ; the is the multipath time delay difference; the is the phase offset amount, ; the is the multipath time delay difference; the is the effective dielectric constant; the is the operating frequency of the reference frequency band.
[0062] The core feature of broadband noise interference is that the bandwidth covers the entire frequency band or most of the frequency band of the system, and the power spectral density is approximately flat. This type of interference will cause phase offset and multipath time delay difference in the signal during transmission. As a key transmission line component in the radio frequency circuit, the physical length of the microstrip line directly affects the propagation phase and impedance matching of the signal.
[0063] By adjusting the length of the microstrip line, the phase difference of the signals arriving from different paths can be reduced, and the signal distortion caused by the multipath effect can be reduced, which is especially suitable for the wide-spectrum phase offset problem under broadband noise interference. The length of the strip line affects its characteristic impedance and input impedance. Adjusting the length can reduce signal reflection in a wide frequency band, thereby reducing the coupling efficiency of the interference signal. Without complex feedback control, it is suitable for real-time anti-interference scenarios.
[0064] Step S40: Determine the search space corresponding to the tuning parameter, use the search space corresponding to the tuning parameter as the reference center, determine the optimal value of the tuning parameter through neighborhood search, and perform tuning processing on the radio frequency signal based on the optimal value of the tuning parameter.
[0065] The search space refers to the set of possible value ranges of the tuning parameter, that is, according to the physical constraints of the system, design specifications, and interference characteristics, a feasible solution interval is set for tuning parameters such as inductance compensation amount, capacitance correction amount, and microstrip line length adjustment amount.
[0066] When defining the reference center, the tuning parameter can be directly used as the search space, and is used as the minimum step size to search for the neighborhood space near the reference center, and whether the tuning parameter in the neighborhood space is the optimal value is analyzed.
[0067] The method of using the search space corresponding to the tuning parameter as the reference center and determining the optimal value of the tuning parameter through neighborhood search specifically includes: Based on a preset search step size, taking the search space corresponding to the tuning parameter as the reference center, determine the neighborhood space of the search space; the tuning parameter of the neighborhood space is determined according to the tuning parameter of the reference center and the search step size; Determine the fitness of each neighborhood space based on the reflection coefficient, bit error rate, and inter-carrier interference power of each neighborhood space, and select the neighborhood space with the minimum fitness as the new reference center; If the fitness of the neighborhood space corresponding to the reference center reaches the fitness threshold, determine the tuning parameter corresponding to the reference center as the optimal value.
[0068] The neighborhood space is a local search range formed by expanding in the parameter dimension with the search space of the current tuning parameter as the reference center. It is a local range of possible values of the tuning parameter and is used to approximate the optimal solution in iterative search. Multiple parameter combinations can be formed above, below, to the left, to the right, and diagonally of the reference center to form eight neighborhood spaces.
[0069] Reflection coefficient Used to measure the reflection degree of the interference signal. The smaller its value, the higher the transmission efficiency. Its calculation formula is , where is the load impedance, is the characteristic impedance of the transmission line.
[0070] The bit error rate BER represents the probability of data transmission errors. The lower its value, the higher the signal reliability. The bit error rate of the interference signal can be actually detected by a bit error rate tester.
[0071] Inter-carrier interference power Reflects the degree of signal distortion in the system. The smaller its value, the smaller the interference effect. The inter-carrier interference power of the k th sub-carrier on the m th sub-carrier can be expressed as , where is the frequency offset of the interference signal, is the period of the sub-carrier.
[0072] Fitness Is a comprehensive index used to measure the influence of the tuning parameter in the neighborhood space on the system performance. Its calculation formula is , where , and are weight coefficients.
[0073] Gradually approach the optimal value of the tuning parameter through domain search, which can be dynamically adjusted according to different signal types of interference signals such as narrowband interference and multipath fading, improving the tuning pertinence. Moreover, without prior knowledge of the precise characteristics of the interference, the optimal parameters can be automatically matched through iterative search. It is applicable to a dynamically changing interference environment. Based on local domain search rather than global traversal, the computational amount can be reduced, the efficiency of radio frequency signal tuning can be improved, and it is suitable for real-time processing of radio frequency signals.
[0074] In one embodiment, the search space is defined according to the parameters of the tuning element. Before determining the domain space of the search space with the search space corresponding to the tuning parameter as the reference center, it further includes: if the signal type of the interference signal is broadband noise interference, a random frequency offset is introduced, and the search space is defined based on the frequency offset and the parameters of the tuning element.
[0075] The frequency offset refers to the random deviation of the center frequency of the signal relative to the nominal frequency, usually caused by oscillator instability, Doppler effect or environmental interference. In the broadband noise interference scenario, the frequency offset has randomness and time-variability, manifested as the overall translation of the signal spectrum.
[0076] When the signal type of the interference signal is broadband noise, an additional frequency offset needs to be introduced as a search dimension, so that the search space can dynamically adapt to the time-varying characteristics of the interference, expanding the search space from a two-dimensional space to a three-dimensional space, and the domain space can be increased to twenty-six, thereby improving the robustness of the tuning parameter. In addition, the change in the length of the microstrip line will affect the resonant frequency, and the frequency offset will cause a change in the phase response. Microstrip line length compensation is required. By introducing the frequency offset, the microstrip line length can be jointly adjusted.
[0077] In summary, in the tuning method of the multi-band radio frequency antenna in this embodiment, on the one hand, by dividing the reference frequency band and the interference frequency band to reuse the same matching network, the complexity of the radio frequency signal processing hardware is reduced. The optimal parameter adjustment direction is selected according to the signal type of the interference signal, the invalid search time is reduced, and the multi-band tuning problem is transformed into a single-band optimization problem. While maintaining the tuning accuracy, the hardware complexity and tuning time are significantly reduced, especially suitable for a dynamically changing electromagnetic environment. On the other hand, gradually approach the optimal value of the tuning parameter through domain search, which can be dynamically adjusted according to different signal types of interference signals such as narrowband interference and multipath fading, improving the tuning pertinence. Moreover, without prior knowledge of the precise characteristics of the interference, the optimal parameters can be automatically matched through iterative search. It is applicable to a dynamically changing interference environment. Based on local domain search rather than global traversal, the computational amount can be reduced, the efficiency of radio frequency signal tuning can be improved, and it is suitable for real-time processing of radio frequency signals.
[0078] Based on the same inventive concept as the above embodiments, this embodiment also provides a wireless antenna system, including a processor and a memory; wherein, the memory stores a computer program, and the computer program is used to be loaded and executed by the processor to perform the tuning method of the multi-band radio frequency antenna as described above.
[0079] As Figure 3 shown, based on the same inventive concept as the above embodiments, this embodiment also provides a computer-readable storage medium, and the computer-readable storage medium stores instructions, and the instructions are used to be loaded and executed by a processor to perform the tuning method of the multi-band radio frequency antenna as described above.
[0080] In the embodiments of the mobile terminal and the computer-readable storage medium provided in this application, all the technical features of each embodiment of the above control method are included, and the extended and explanatory content of the specification is basically the same as that of each embodiment of the above method, and will not be repeated here.
[0081] This application embodiment also provides a computer program product, and the computer program product includes computer program code. When the computer program code runs on a computer, it causes the computer to execute the methods in the above various possible implementation manners.
[0082] This application embodiment also provides a chip, including a memory and a processor. The memory is used to store a computer program, and the processor is used to call and run the computer program from the memory, so that the device equipped with the chip executes the methods in the above various possible implementation manners.
[0083] The serial numbers of the above embodiments of this application are only for description and do not represent the advantages or disadvantages of the embodiments.
[0084] In this application, for the description of the same or similar term concepts, technical solutions and / or application scenarios, generally only the first occurrence is described in detail. When it appears repeatedly later, for the sake of brevity, it is generally not repeated. When understanding the technical solutions and other contents of this application, for the same or similar term concepts, technical solutions and / or application scenarios that are not described in detail later, reference can be made to the relevant detailed descriptions before.
[0085] In this application, the descriptions of each embodiment have their own emphases. For the parts not detailed or recorded in a certain embodiment, reference can be made to the relevant descriptions of other embodiments.
[0086] It should be noted that the embodiments in this specification are all described in a progressive manner. The key point of each embodiment is to illustrate the differences from other embodiments. The same or similar parts among the embodiments can be referred to each other.
[0087] As described above, it is only the specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any changes or substitutions that can be easily thought of by those skilled in the art within the technical scope disclosed by the present invention should be covered within the protection scope of the present invention. Therefore, the protection scope of the present invention should be subject to the appended claims.
Claims
1. A tuning method for a multi-band RF antenna, characterized in that, Including: Determine the reference frequency band and the interference frequency band of the radio frequency signal based on the target operating frequency band of the radio frequency signal; Determine the interference signal corresponding to the interference frequency band, and confirm the signal type of the interference signal according to the interference characteristics of the interference signal; Determine the tuning parameter of the interference frequency band relative to the reference frequency band based on the signal type of the interference signal; Determine the search space corresponding to the tuning parameter, use the search space corresponding to the tuning parameter as the reference center, determine the optimal value of the tuning parameter through domain search, and perform tuning processing on the radio frequency signal based on the optimal value of the tuning parameter.
2. The tuning method of the multi-band RF antenna according to claim 1, wherein The determining the reference frequency band and the interference frequency band of the radio frequency signal based on the target operating frequency band of the radio frequency signal specifically includes: Perform frequency sweeping on the radio frequency signal to obtain the power spectral density distribution of the radio frequency signal; Based on the power spectral density distribution, divide the radio frequency signal into continuous sub-band units according to power characteristics; Determine the power variance of each sub-band unit, record the sub-band units with power variance within the range of the target power variance as the reference frequency band, and record the sub-band units with power variance outside the range of the target power variance as the interference frequency band.
3. The tuning method of the multi-band RF antenna according to claim 1, characterized in that The signal types of the interference signal include narrowband interference, multipath fading interference, and broadband noise interference.
4. The tuning method of the multi-band RF antenna according to any one of claims 1-3, characterized in that, The confirming the signal type of the interference signal according to the interference characteristics of the interference signal specifically includes: When the frequency offset of the interference signal is less than a preset nominal frequency threshold, the period stability of the continuous sine wave of the waveform feature is greater than a preset stability threshold, there are sudden spikes in the baseline of the bit error rate, and there is a significant peak in the power spectral density at the peak power frequency point, determine that the signal type of the interference signal is narrowband interference; and / or When the number of peaks of the waveform feature of the interference signal is greater than a preset quantity threshold, the power variance is greater than a preset maximum variance threshold, the bit error rate has periodic fluctuations, and the frequency offset is random and less than a preset nominal frequency threshold, determine that the signal type of the interference signal is multipath fading interference; and / or When the 3dB bandwidth of the interference signal is greater than a preset bandwidth threshold, the waveform feature is a Gaussian distributed random signal, the frequency offset continuously increases and is greater than the maximum frequency threshold, and the power variance is less than a preset minimum variance threshold, determine that the signal type of the interference signal is broadband noise interference.
5. The tuning method of the multi-band RF antenna according to any one of claims 1-3, characterized in that, The determining the tuning parameter of the interference frequency band relative to the reference frequency band based on the signal type of the interference signal specifically includes: If the signal type of the interference signal is narrowband interference, the tuning parameters include the inductance compensation amount and the capacitance compensation amount, and the calculation formulas for the inductance compensation amount and the capacitance compensation amount are: Among them, the is the inductance compensation amount of the adjustable inductor ; the is the capacitance compensation amount; the is the characteristic impedance of the transmission line; the is the center frequency of the narrowband interference signal; the is the real part of the equivalent impedance of the RF antenna; the is the operating frequency of the reference frequency band; the is the initial value of the adjustable inductor .
6. The tuning method of the multi-band RF antenna according to any one of claims 1-3, characterized in that The determining the tuning parameter of the interference frequency band relative to the reference frequency band based on the signal type of the interference signal specifically includes: If the signal type of the interference signal is multipath fading interference, the tuning parameter includes the capacitance correction amount, and the calculation formula for the capacitance correction amount is: Among them, the is the capacitance correction amount; the is the operating frequency of the reference frequency band; the is the initial value of the inductor; the is the phase offset, ; the is the multipath time delay difference; the is the effective dielectric constant.
7. The tuning method of the multi-band RF antenna according to any one of claims 1-3, characterized in that The determining the tuning parameter of the interference frequency band relative to the reference frequency band based on the signal type of the interference signal specifically includes: If the signal type of the interference signal is wideband noise interference, the tuning parameter includes the adjustment amount of the microstrip line length, and the calculation formula of the adjustment amount of the microstrip line length is: Among them, the is the adjustment amount of the microstrip line length; the is the speed of light constant, ; the is the multipath time delay difference; the is the phase offset, ; the is the multipath time delay difference; the is the effective dielectric constant; the is the operating frequency of the reference frequency band.
8. The tuning method of the multi-band RF antenna according to claim 1, characterized in that Taking the search space corresponding to the tuning parameter as the reference center, determining the optimal value of the tuning parameter through neighborhood search specifically includes: Based on a preset search step size, taking the search space corresponding to the tuning parameter as the reference center, determining the neighborhood space of the search space; the tuning parameter of the neighborhood space is determined according to the tuning parameter of the reference center and the search step size; Determining the fitness of each neighborhood space based on the reflection coefficient, bit error rate, and inter-subcarrier interference power of each neighborhood space, and selecting the neighborhood space with the minimum fitness as the new reference center; If the fitness of the neighborhood space corresponding to the reference center reaches the fitness threshold, determining the tuning parameter corresponding to the reference center as the optimal value.
9. The tuning method of the multi-band RF antenna according to claim 8, wherein The search space is defined according to the parameters of the tuning element; Before taking the search space corresponding to the tuning parameter as the reference center and determining the neighborhood space of the search space, it further includes: If the signal type of the interference signal is wideband noise interference, introducing a random frequency offset, and defining the search space based on the frequency offset and the parameters of the tuning element.
10. A wireless antenna system, characterized in that, It includes a processor and a memory; wherein, the memory stores a computer program, and the computer program is used to be loaded and executed by the processor for the tuning method of the multi-band radio frequency antenna as described in any one of claims 1-9.
Citation Information
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Unmanned aerial vehicle interference source identifying, positioning and avoiding method
CN121934018A