487 results about "Reflection coefficient" patented technology

The invention provides a composite board detection method and system, and relates to the technical field of board detection, and the method comprises the steps: carrying out the ultrasonic scanning of a composite board, dividing the composite board into a plurality of acoustic characteristic layers, building a sound wave propagation model based on a recursive transfer matrix method, and calculating the reflection coefficient and transmission coefficient of each layer interface. A deep learning algorithm is combined with physical constraints to dynamically correct acoustic parameters, the corrected parameters are substituted into a model reconstruction signal, and defects are accurately positioned. And performing grid division on the defect position to analyze stress field distribution, and determining a stress concentration position. And fine scanning is carried out on a stress concentration area by adjusting probe parameters, and high-resolution data is obtained to update defect distribution information. And finally, outputting detection data including defect positions, stress concentration distribution and hazard levels, and realizing accurate detection and evaluation of the defects of the composite board.

The invention discloses a cable defect detection method and system based on double-path coupling frequency domain reflection, and the method comprises the steps: enabling a signal generator to generate two groups of correlated sine frequency sweeping signals, namely a test signal S1 and a reference signal S2; s1 is injected into the head end of the cable, and a reflected signal R1 is collected; respectively extracting the spectrum characteristics of the amplitudes and the phase differences of the R1, the S1 and the S2 by adopting a double-path signal comparison device, carrying out comprehensive judgment, and determining the reflection spectrum characteristic of the R1; the reflection coefficient spectrum is optimized through a window function, and signal features are obtained; converting the optimized frequency spectrum into a time domain reflection waveform, and extracting reflection peak time information; and calculating defect positions by combining electromagnetic wave propagation velocity. According to the cable defect detection method and system based on double-path coupling frequency domain reflection, high-precision detection of a long-distance cable is realized; and two paths of coupling signals are introduced for comparison, so that the accuracy of phase measurement is improved, and an efficient nondestructive detection scheme is provided for power grid operation and maintenance and the like.

The invention belongs to the field of ultrasonic oil film thickness measurement, and discloses a minimum oil film thickness calibration method considering different friction pair shape structures, which utilizes an ultrasonic oil film thickness calibration platform capable of designing a corresponding calibration test piece according to different structure shapes of a measured friction pair, and aims at the shape structure characteristics of different friction pairs. The minimum oil film thicknesses of friction pairs with different shapes and structures are accurately controlled, ultrasonic reflection signals under the different minimum oil film thicknesses are collected and subjected to frequency domain analysis processing, and on the basis, polynomial fitting is conducted on the minimum oil film thicknesses and reflection coefficients in combination with a film thickness calculation model; and the ultrasonic minimum oil film thickness calibration under a special friction pair structure is realized.

The invention discloses a method and system for measuring the ultrasonic proportionality coefficient of the thickness of a lubricating film of a sliding bearing, and the method comprises the steps: firstly, obtaining the comprehensive response coefficient of sound waves in a transition combination layer of a substrate and a lining through calculating the proportionality coefficient of a reflection echo signal of a bearing bush in an air medium and a reflection echo signal of a substrate-lining interface; characterizing the propagation rule of sound waves in a base body and lining combination layer; secondly, a proportionality coefficient is constructed based on a lubricating film reflection echo signal and a matrix-lining interface reflection echo signal, a lubricating film reflection coefficient is calculated in combination with a comprehensive response coefficient of sound waves in a matrix-lining transition combination layer, and finally the thickness of the lubricating film is solved through a resonance model method or a composite model method. According to the invention, the influence of the change of the binding force between the sensor and the substrate and the unstable voltage of ultrasonic pulse emission equipment on the reference signal can be avoided, the robustness is high, and the long-term reliable monitoring of the thickness of the lubricating film of the sliding bearing is facilitated.

The invention provides a blade lightning protection channel online test method and system based on a pulse current method, and belongs to the technical field of blade lightning protection detection.The method comprises the steps that a pulse waveform is generated through a pulse current generator to simulate lightning impulse, and the lightning impulse is injected into the surface of a lightning arrester of a blade lightning protection system; measuring channel currents at different positions of the surface of the lightning arrester in the length direction by using a distributed sensor; a high-voltage differential probe is used for collecting and measuring the waveform of an incident wave and the waveform of a reflected wave of an injection point; detecting blade surface potential distribution by using a capacitive coupling sensor; comparing the waveform of the incident wave, the waveform of the reflected wave and the theoretical waveform, determining a time domain reflection coefficient and a frequency domain impedance spectrum, and determining a fault type; after the fault type is determined, the fault point is positioned based on the channel current and the blade surface potential distribution, the lightning impulse is simulated through the pulse waveform, the lightning protection channel is further tested, shutdown is not needed, the testing efficiency of the blade lightning protection channel is effectively improved, and the power generation efficiency is ensured.

Disclosed are systems, apparatuses, processes, and computer-readable media for wireless communications. For example, an example of a process includes transmitting, to a reconfigurable intelligent surface (RIS), a plurality of reference signal beams in a plurality of directions. The process may further include receiving, from the RIS, a plurality of reflection reference signal beams in the plurality of directions based on a plurality of backtracking reflection coefficients. The process may include measuring a signal strength of each reflection reference signal beam in each direction of the plurality of directions for each backtracking reflection coefficient of the plurality of backtracking reflection coefficients. The process may further include determining, basing on measuring the signal strength, a selected beam direction from the plurality of directions and a selected backtracking reflection coefficient of the plurality of backtracking reflection coefficients.

The invention provides a crustal stress prediction method and device, electronic equipment and a storage medium, and relates to the technical field of seismic survey. The method comprises the following steps: obtaining observation seismic data of seismic wavelets in a strong VTI medium, and constructing a to-be-inverted parameter matrix based on a PP wave reflection coefficient corresponding to the strong VTI medium; constructing a posterior probability function obeyed by an inversion parameter matrix corresponding to the to-be-inverted parameter matrix based on a Bayesian inversion theory and observation seismic data, and determining a target functional based on a prior probability function and a likelihood function corresponding to the posterior probability function; determining medium density and each stiffness matrix coefficient based on an inversion parameter matrix solving result of the target functional, and determining a flexibility matrix of the strong VTI medium based on each stiffness matrix coefficient; and predicting the ground stress distribution of the target profile in the strong VTI medium based on the medium density and the positive strain matrix and the flexibility matrix corresponding to the strong VTI. Therefore, the crustal stress prediction accuracy under the strong VTI medium is improved.

The invention provides a photovoltaic power generation optimization method for a fishing-light complementary site and a related device. The method comprises the following steps: acquiring a photovoltaic panel sunlight angle, a water surface wind speed, a water surface wave height, a water depth, a photovoltaic panel core parameter, a reflector parameter and double-measuring-point actually-measured light intensity data; determining the initial receiving radiation quantity of the photovoltaic panel according to the sunlight angle of the photovoltaic panel, the core parameters of the photovoltaic panel, the parameters of the reflector and the actually measured light intensity data of the double measuring points; according to the water surface wind speed, the water surface wave height, the water depth, the double-measuring-point actually-measured light intensity data and the reflector parameters, the water surface correction reflection coefficient is determined; correcting the initial received radiation quantity of the photovoltaic panel by adopting the water surface correction reflection coefficient to obtain the actual received radiation quantity of the photovoltaic panel; and according to the actually received radiation quantity of the photovoltaic panel, the inclination angle of the photovoltaic panel is adjusted, and then the photovoltaic power generation process of the fishing-light complementary site is optimized. Excessive concentration of local radiation quantity caused by secondary reflection of sunlight through a water surface-reflector can be avoided, and generation of hot spots on the photovoltaic panel is inhibited.

A method includes defining a design domain for a meta-element configured to be attached to an edge of thin wall structure with an arbitrary boundary condition, and executing a topological optimization process on the design domain and providing a topology optimized shape for the meta-element. The topological optimization process includes an objective function that minimizes a reflection coefficient of flexural waves in the audible frequency range propagating towards and impinging the meta-element.

The invention relates to a spherical wave oscillation-slow nuclear high-order decoupling method and device for physical property inversion, and belongs to the field of geophysical detection and acoustic detection. The method comprises the following steps: obtaining and inputting observation data, and initializing seabed elastic parameters; determining an integral interval according to the observation data, decomposing the integral interval into a plurality of sub-intervals, and setting a decoupling order; calculating an oscillation nuclear local integral matrix of each order corresponding to the observation data incident angle; calculating the angle deviation guiding quantity of each order of the slowly-varying kernel; calculating a reflection coefficient vector of each order of spherical wave; calculating a spherical wave reflection coefficient of high-order decoupling; and solving a subsequent inversion problem by using the obtained high-order decoupled spherical wave reflection coefficient. According to the method, the calculation efficiency of the seabed spherical wave reflection coefficient in the inversion process is effectively improved; the decoupling order is improved, the calculation precision is improved, or the number of the subintervals can be reduced by improving the decoupling order under the condition that the calculation precision is certain.

The invention discloses a polyether-ether-ketone-based composite material with low reflection and high electromagnetic shielding effectiveness and a preparation method of the polyether-ether-ketone-based composite material, and belongs to the technical field of electromagnetic shielding materials. The problems that an existing electromagnetic shielding material is high in reflection coefficient, insufficient in shielding effectiveness, poor in high temperature resistance and corrosion resistance and difficult to adapt to severe environment service are solved. The composite material is composed of a porous conductive substrate and an asymmetric conductive layer. Wherein the porous conductive substrate is formed by blending a soluble ketimine type polyether-ether-ketone solution and a conductive filler suspension and then carrying out non-solvent induced phase separation and acidification reduction reaction, the electric conductivity is 2.8 * 10 <-4 >-0.1839 S / cm, and the porosity is 80%-90%; the asymmetric conductive layer is plated on the surface of one side of the porous conductive substrate, and the asymmetric conductive layer is made of nickel-phosphorus alloy. The composite material significantly reduces the electromagnetic wave reflection coefficient through an absorption-reflection-reabsorption mechanism, has high electromagnetic shielding effectiveness and excellent high temperature resistance and corrosion resistance, and is suitable for serving in a severe environment.

The invention provides a sea surface oil spill GNSS reflection signal simulation system and method, and the method comprises the steps: building an oil spill sea surface dielectric constant module, determining the effective dielectric constant of an oil spill sea surface, and obtaining a Fresnel reflection coefficient; establishing an oil spill sea surface rough spectrum module, obtaining a model of a sea wave spectrum of the oil spill sea surface according to a traditional model of the sea wave spectrum and the influence of oil spill on the sea wave spectrum, and obtaining a surface spectral density function and a surface root-mean-square height; establishing a microwave scattering module of the oil spill sea surface, and determining a microwave scattering coefficient according to the Fresnel reflection coefficient, the surface spectral density function and the surface root-mean-square height; a DDM simulation module is established, and a DDM waveform is obtained through simulation according to the GNSS signal parameters and the microwave scattering coefficients; and the DDM waveform is obtained through simulation of each module. According to the simulation system and method, a unified mathematical model is established to describe the relation between the oil film and the GNSS reflection signal, and accurate simulation of the influence of the oil film on the GNSS reflection signal is achieved.

The invention relates to a seabed elastic parameter inversion method, system and device under an earthquake spherical reflection wave oscillation-gradual change nuclear decoupling framework, and belongs to the field of geophysical detection and acoustic detection. The method comprises the following steps: (1) inputting observation data and initializing seabed elastic parameters; (2) determining an integral interval and decomposing the integral interval into a plurality of sub-intervals; (3) calculating an oscillation nuclear local integral matrix corresponding to the incident angle of the observation data; (4) calculating a slowly-varying kernel local mean vector; (5) calculating a spherical wave reflection coefficient of oscillation-gradual change kernel decoupling; and (6) constructing a target function by using the decoupled spherical wave reflection coefficient, and solving the target function. In the objective function solving process, only the steps (4) and (5) need to be repeatedly executed after the seabed elastic parameters are updated, the oscillation nuclear local integral matrix in the step (3) does not need to be repeatedly calculated, redundant calculation about oscillation nuclear integration is avoided, and the calculation efficiency is improved.

The invention discloses a design method of a double-layer metasurface wave absorber, the double-layer metasurface wave absorber comprises a pixelated unit located on the upper layer and a regular topological pattern structure located on the lower layer, and the method comprises the following steps: dispersing a resistive film-air structure of the pattern layer of the pixelated unit into a pixelated structure image, and representing the pixelated structure image by using a 0-1 matrix; generating a plurality of groups of 0-1 matrixes, constructing a pixelated unit, and obtaining a reflection coefficient curve; combining the target reflection coefficient curve and multiple groups of random noise into combined vectors, inputting the combined vectors into a generator, generating multiple target pixelated structure images, and obtaining multiple target pixelated units; determining design parameters of a resonance pattern layer, inputting the target reflection coefficient curve into a DNN neural network, outputting target design parameters, and obtaining a target regular topological pattern structure; and combining the target pixelated unit with the target regular topological pattern structure to obtain the target double-layer metasurface wave absorber. According to the method, rapid design of the double-layer metasurface wave absorber can be completed.

The invention relates to the technical field of cable line operation and maintenance, in particular to a cable fault accurate positioning method and system based on electromagnetic time reversal correction. And in combination with a reflection coefficient correction and local energy extraction method in a time inversion process, the problems that the fault traveling wave signal is attenuated and distorted under strong noise and high transition resistance, and the EMTR positioning effect is influenced by fault resistance are solved. Constructing a multi-scale evaluation system fusing time domain, frequency domain and wavelet domain features, and screening an optimal modal component; and constructing an actual fault resistor in a reverse phase of the EMTR to correct a reflection coefficient, and providing a criterion for positioning by using local energy at a first traveling wave to realize accurate positioning of a cable fault. According to the method, the ranging error can be effectively reduced under the conditions of high transition resistance, low signal-to-noise ratio and unknown fault resistance, and the robustness and engineering applicability of cable fault diagnosis are improved.

The invention discloses a cable hidden damage fault positioning method and device and a computer program product, and the method comprises the steps: S1, obtaining the structural parameters of a detected cable, building a one-dimensional distribution parameter transmission line model according to the structural parameters, and dividing the whole cable into a plurality of normal sub-segments and defect sub-segments; s2, calculating a reflection coefficient spectrum of a cable head end reflection coefficient along with frequency change according to distribution parameter change caused by moisture intrusion; s3, performing spectrum analysis on the reflection coefficient spectrum by adopting windowing Fourier transform, inhibiting spectrum leakage and extracting a periodic component of the spectrum leakage; and S4, determining a defect position according to the extracted periodic component frequency in combination with the propagation speed of the electromagnetic wave in the cable. According to the method, the positioning precision of the hidden damage fault of the cable can be improved, the test frequency requirement is reduced, and the diagnosis robustness in different load environments is enhanced.

The invention discloses a double-probe film thickness and defect collaborative decoupling method. The method comprises the steps that microwave reflection signals of a thermal barrier coating are synchronously collected through a coaxial resonance probe and a CSRR resonance ring probe; the microwave reflection signal comprises reflection coefficient amplitude, reflection coefficient phase and resonant frequency; constructing a frequency deviation model based on the microwave reflection signal; training the dual-channel deep learning network based on the frequency deviation model to obtain a trained dual-channel deep learning network; and obtaining film thickness information and a defect positioning result based on the trained dual-channel deep learning network. According to the method, collaborative decoupling of the film thickness and the defect signal is achieved through a physical-data fusion method, effective decoupling and independent recognition of the coating film thickness change and the defect response signal are achieved, and the resolution ratio, the accuracy rate and the practicability of a detection system are improved.

The invention discloses a three-dimensional ground penetrating radar detection method, system and equipment for road roadbed diseases and a medium, and relates to the technical field of road engineering detection. Controlling a high-frequency antenna and a low-frequency antenna to emit electromagnetic waves to a road roadbed based on the movement of the detection vehicle so as to receive reflected high-frequency data and low-frequency data; processing the high-frequency data and the low-frequency data based on the positioning attitude data to obtain processed high-frequency data and processed low-frequency data; processing and fusing the processed high-frequency data and the processed low-frequency data to obtain a full-band reflection coefficient sequence; calculating the full-band reflection coefficient sequence to obtain broadband geological radar data; inputting broadband geological radar data into the convolutional neural network model to obtain a disease type and a disease semantic segmentation map; and generating a three-dimensional visual model of the roadbed disease based on the disease semantic segmentation map, and outputting maintenance suggestion data matched with the disease type. By implementing the technical scheme, the accuracy of deep hidden disease recognition is improved.

The present application relates to the flexible DC power grid single-ended line protection method based on time domain voltage traveling wave, according to the difference of voltage traveling wave reflection coefficient under the positive and negative direction short circuit fault or lightning disturbance, the direction criterion is constituted, and the protection misoperation under the reverse direction fault or lightning is avoided, second, the function model that the first traveling wave of protection fault voltage satisfies under the short circuit fault in the area and the positive direction non-area short circuit fault is analyzed by using voltage traveling wave transfer function, according to the different matching degree between the first traveling wave of fault and the reference function model, the complete line single-ended protection method is formed by combining the starting criterion and the pole selection criterion.The present application builds the flexible DC power grid model on the PSCAD platform to verify the protection performance, and a large number of simulation results show that the proposed protection has high reliability and can tolerate 500Ω transition resistance.

The invention provides a projection lamp shadow effect intelligent adjustment method based on artificial intelligence, and the method comprises the steps: obtaining the material type and reflection coefficient of the wall surface of each region of an exhibition space through a pre-established wall surface material database, carrying out the classification processing according to the reflection characteristics of different materials, and obtaining a material reflection distribution diagram; acquiring light intensity distribution in the space based on stray light distribution characteristics, performing gridding decomposition on the light intensity distribution, and obtaining light intensity and light field distribution uniformity of each grid area through numerical integration; according to the adjusted projection angle and light source position, generating a control parameter for the projection equipment, adjusting the output intensity and direction of the projection light source, and obtaining the light distribution intensity after the control parameter of the projection equipment is adjusted; and if the contrast ratio and the color deviation value of the detail area do not meet the preset standard, optimizing the light source control parameters through an ambient light compensation mechanism in combination with the accumulated intensity data of the space corner to obtain a light compensation result.

Examples are directed toward a system and method relating to extracting a complex permittivity of a material. For example, a system includes a Vector Network Analyzer (VNA) that performs a first reflection measurement for a front interface of the material, and obtains first time-domain data by applying an inverse fast Fourier transform (IFFT) to the first reflection measurement. The VNA performs a second reflection measurement for a back interface of a material, and obtains second time-domain data by applying the IFFT to the second reflection measurement. The system performs a set of two measurements, including the measurements set forth above at the interfaces with the material, and similar measurements at the locations of the interfaces but without the material (e.g., empty measurements). A processor determines a real part of a refractive index of the material based on velocity, and determines an imaginary part of the refractive index of the material based on energy loss.

The invention discloses a grounding grid corrosion and soil defect diagnosis method based on impact square wave modulation, and relates to the technical field of electric power system intelligent operation and maintenance and equipment state monitoring. A broadband impact square wave modulated by a Gaussian window is generated and injected into a grounding down lead, and electromagnetic response of an underground conductor and soil is stimulated; the method comprises the following steps: acquiring an electric field signal by using an earth surface distributed sensor array, and extracting reflection time delay and frequency domain characteristics in combination with short-time Fourier transform STFT; reconstructing a time domain dielectric constant through reflection coefficient inversion and inverse Fourier transform, and decoupling metal corrosion and soil environment abnormity; based on a multi-parameter fusion criterion, accurate positioning and classification of defects such as fracture, corrosion, water accumulation and cavities are realized, and a resistivity-dielectric property dual-channel thermodynamic diagram is generated. According to the method, excavation is not needed, live detection can be achieved, the advantages of high resolution, non-destructiveness and visualization are achieved, and the accuracy and the intelligent level of grounding grid state diagnosis are remarkably improved.

The invention provides a microwave detection method and device for PE pipe hot-melting weld defects, and the method comprises the following steps: 1) taking a hot-melting weld of a PE pipe and a base material near the weld as detection objects, and carrying out axial and circumferential microwave scanning to obtain a reflection coefficient of each position point; 2) carrying out two-dimensional space Fourier transform on the reflection coefficient of each position point; 3) carrying out phase correction on the converted data in the depth direction; 4) carrying out two-dimensional space inverse Fourier transform on the corrected data to obtain a reflection coefficient of the target; 5, image reconstruction is carried out on the reflection coefficient of the target, and information of the defects in the PE pipe hot-melt welding seam is obtained.According to the scheme, the method has the advantages that the defects can be detected, the defect positions can be determined, and conclusion obtaining does not excessively depend on personnel skills.

The invention relates to the technical field of noise filtering, in particular to an electronic circuit with a transmission line type noise filter, and the electronic circuit comprises a frequency determination device which is used for determining the working frequency and voltage of the electronic circuit; the device determining device is used for selecting a microstrip line as a transmission line and optimizing the filter by using a composite right / left hand transmission line and an open-circuit T-shaped structure; the impedance matching device is used for matching the impedance of the filter with the impedance of the transmission line; the matching measuring device is used for measuring the impedance matching effect by using a reflection coefficient and a VSWR (Voltage Standing Wave Ratio); and the software simulation device is used for simulating and optimizing the matched filter and transmission line by using simulation software. According to the invention, the impedance of the filter is matched with the impedance of the transmission line, so that the impedance change of the signal in the transmission process is reduced, the reflection of the signal is reduced, and the transmission quality and efficiency of the signal are improved.

The invention discloses a method for acquiring the thickness of a lubricating oil film by utilizing an ultrasonic multi-part wave reflection coefficient, which comprises the following steps of: acquiring a reference signal corresponding to a detection position of an ultrasonic probe, and fitting by utilizing a Gaussian echo model to obtain a plurality of echoes and echo parameters of the reference signal; an ultrasonic multi-reflection signal of the hinge structure lock shaft is collected on line, the reference signal is subtracted from the multi-reflection signal, and an oil film layer part signal to be solved is obtained; and finally obtaining a lubricating oil film thickness value by combining the obtained amplitude coefficient and the time shift coefficient. According to the method, all time domain information of the measured echo signals in the four-layer hinged structure is integrated, and compared with a traditional three-layer structure reflection coefficient solving algorithm, indexes such as precision, stability and range of lubricating oil film thickness calculation and solving are obviously improved; in addition, as the thickness of the oil film is obviously changed after the lock shaft is abraded, the method is beneficial to monitoring the abrasion of the lock shaft of the injection molding machine.

A high-frequency power supply system according to the present disclosure includes a first power supply, a second power supply, and a first matcher. The first power supply performs frequency modulation control in a second power supply ON period and performs frequency offset control to output a forward wave voltage VF3 having a fundamental frequency F3 obtained by adding an offset frequency to a fundamental frequency F1 in a second power supply OFF period. An optimum value of an initial phase α of a modulation signal is searched for, and an offset frequency Fos at which a difference between a reflection coefficient ρ11 or load-side impedance Z11 corresponding to a center of a locus and a reflection coefficient ρ12 or load-side impedance Z12 is minimum is searched for, and the fundamental frequency F3 in the second power supply OFF period is set.

The invention relates to a river channel sand body random model generation method and device based on hidden Markov model data filling, a medium and equipment. The method comprises the steps that logging data of a target area are collected and arranged; dividing logging data according to a logging gas-bearing interpretation conclusion, and carrying out analytical statistics on the velocity and density of longitudinal and transverse waves in the logging data; initializing an initial state probability, a state transition matrix, and a mean value and a covariance of Gaussian distribution in the hidden Markov model; inputting a three-dimensional observation vector composed of the velocity and density of the longitudinal and transverse waves into the initialized hidden Markov model for iterative training; performing down-sampling on the lithology data, then constructing a state transition probability matrix, and further constructing a lithology sequence conforming to a geological law through simulation; according to the lithologic sequence, calling a hidden Markov model to generate longitudinal wave velocity, transverse wave velocity and density corresponding to the lithologic sequence; and calculating a reflection coefficient of the synthetic stratum, setting a Ricker wavelet dominant frequency, and obtaining synthetic seismic response data through convolution.

The invention discloses a mechanical non-resonant one-bit phase electromagnetic reflection metasurface unit, and belongs to the field of artificial electromagnetic materials. The unit comprises a non-resonant electromagnetic structure and a mechanical driving device. The non-resonant electromagnetic structure comprises a dielectric layer, an air layer and an adjustable metal backboard from top to bottom; the mechanical driving device adopts a bidirectional self-holding electromagnet, a screw rod of the bidirectional self-holding electromagnet is connected with the metal back plate, the back plate is driven to be switched between two preset positions through forward / reverse pulse current, the thickness of an air layer is accurately adjusted, and therefore one-bit dynamic switching of a reflection phase between 0 degree and 180 degrees is achieved through propagation phase accumulation. In the 5G millimeter wave frequency band of 20 GHz to 29.5 GHz, the reflection coefficients of the two states are both larger than 0.99, the phase difference is stabilized within 180 degrees + / -20 degrees, and good robustness is achieved for mechanical displacement deviation. The unit has the advantages of zero static energy consumption, low insertion loss, wide bandwidth, simple structure and simple control, and is suitable for a low-power-consumption intelligent reflecting surface and a dynamic beam forming system.

A standing wave radar includes: a transmitter to set a frequency of a transmission signal to frequencies, and output the transmission signal taking the respective frequencies in a time-division manner; a receiver to receive a reflected signal taking the frequencies in a time-division manner, the reflected signal being the transmission signal reflected by an object; and a processor to obtain reflection coefficients of the frequencies by obtaining each reflection coefficient of the transmission signal and the reflected signal taking a same frequency, for the transmission signal and the reflected signal taking the frequencies, and to execute a first inverse Fourier transform process of calculating a first distance spectrum for the object by an inverse Fourier transform on the reflection coefficients, and a first distance measurement process of determining presence of the object and calculating a distance to the object, based on the first distance spectrum.