142 results about "Radar cross-section" patented technology

The invention belongs to the technical field of superconducting wires, and relates to a niobium-tin composite superconducting wire and a preparation method thereof. The invention provides a Nb3Sn composite superconducting wire. The Nb3Sn composite superconducting wire sequentially comprises an Nb3Sn superconducting wire core, a barrier layer, a stable layer, a transition layer, a substrate layer and a functional layer from inside to outside, the transition layer is formed by mixing copper and a dielectric polymer, and the copper content is continuously decreased in a gradient manner from inside to outside; the substrate layer is the dielectric polymer; the functional layer is a plurality of protruding metal microstructures. According to the invention, the functional layer with the broadband electromagnetic stealth function is integrated on the basis of the Nb3Sn superconducting wire rod, so that the radar cross section is obviously reduced while the Nb3Sn superconducting wire rod bears high-density superconducting current and generates a strong magnetic field, and the technical problem that a high-field superconducting magnet system is easy to detect in an electromagnetic environment is solved.

The invention discloses an icing monitoring method and system for a corner reflector deployed based on an unmanned aerial vehicle, and relates to the technical field of environment monitoring, and the method comprises the steps: deploying a corner reflector network, collecting radar cross-section characteristics and environment parameters to generate a data packet, and carrying out the icing monitoring based on the generated data packet; calculating a signal-to-clutter ratio, obtaining a standard deviation of target positioning and phase estimation by using a Cramer-Rao lower bound method, generating a dynamic weight by using the standard deviation, obtaining a corner reflector icing thickness estimation value through data fusion, and generating an optimized signal-to-clutter ratio based on the icing thickness estimation value; and carrying out cooperative judgment by utilizing the generated optimized signal-to-clutter ratio and combining the icing thickness and the attitude deviation, triggering combined adjustment based on a judgment result, and after the combined adjustment is triggered, obtaining the SAR image again and carrying out main and auxiliary image registration and interference pair optimization. According to the invention, the sensing precision and the monitoring robustness of the unmanned aerial vehicle on the state of the corner reflector in an icing environment are improved.

The invention discloses a large-scale cluster target electromagnetic scattering analysis method and system based on a parallel equivalence principle, and the method specifically comprises the steps: carrying out the geometric modeling and equivalent surface construction of each target unit in a cluster target, and generating discrete surface element information; starting a parallel computing process, and distributing a target-equivalent face by adopting a greedy algorithm; a calculation process group corresponding to each sub-domain is partitioned according to a two-dimensional Cartesian coordinate grid, a transfer operator matrix between the sub-domains is partitioned according to the same two-dimensional calculation process grid, global parallel iterative solution circulation is carried out, and the equivalent surface flow of the sub-domain is updated; and the converged equivalent surface flow of each sub-domain is used as an equivalent source, and the radar cross section RCS of the whole cluster target in the specified observation direction is synthesized through far-field radiation integration. The method has good parallel expandability and calculation efficiency, is suitable for complex and diverse cluster target scenes, reduces memory requirements and calculation time overhead, improves calculation efficiency, and is high in engineering practicability.

Procedures, methods, architectures, apparatuses, systems, devices, and computer program products are provided for object detection over a wireless network. A method performed by a wireless transmit / receive unit (WTRU) includes receiving, from a wireless network, a configuration that includes a configured target profile for a target and information indicative of an identification of the target, wherein the configured target profile comprises a radar cross section profile associated with the target; receiving at least one signal from the wireless network; generating a measured profile based on the at least one signal; determining that the at least one signal was reflected by the target based at least in part on the information indicative of the identification of the target and a comparison between the configured target profile and the measured profile; and performing sensing measurements associated with the target using the at least one signal based at least in part on the determination.

The invention provides a broadband absorption and transmission integrated frequency selective surface with a high selection characteristic, which comprises a first loss layer, a second loss layer and a frequency selection layer, and is characterized in that the first loss layer and the second loss layer realize a transmission band with the high selection characteristic and the broadband characteristic at the same time by using dual-order resonance; the second loss layer and the frequency selection layer are cascaded to realize the absorption and transmission integrated characteristic, and the first loss layer is used for improving the low-frequency and high-frequency wave absorption characteristics and expanding the wave absorption bandwidth. Under the combined action of the first loss layer, the second loss layer and the frequency selection layer, wave transmission within the frequency band of 7.72-11.89 GHz and wave absorption within the frequency band of 1.96-7.12 GHz and the frequency band of 12.95-17.33 GHz are achieved. The antenna has high selection characteristics and broadband characteristics, can effectively suppress interference of external electromagnetic waves of other frequency bands or electromagnetic waves of a frequency band close to a communication frequency band on communication, can reduce the radar cross section of a target, and facilitates target stealth.

The invention belongs to the technical field of radar stealth testing, and particularly relates to a method for obtaining background scattering by measuring the RCS of a cone and a related device. The method comprises the following steps: mounting an eccentric cone on a low-scattering bracket, and enabling the mounting center of the eccentric cone to coincide with the rotating center of a rotary table of the low-scattering bracket; transmitting radar waves to the eccentric cone, rotating the turntable by a set angle at a fixed step length, and collecting echo signals of the eccentric cone rotating by the set angle; and performing fitting based on the acquired echo signal to obtain a background signal. According to the method, an eccentric cone is used as a calibration carrier, a high-signal-to-noise-ratio circular track is formed on a complex plane when the eccentric cone rotates, an optimal circle model is fitted by adopting an RANSAC method, and abnormal value elimination and background estimation are synchronously realized.

The invention discloses a radar low-altitude target recognition method based on a multi-dimensional feature nonlinear coupling network, and relates to the technical field of radar target intelligent recognition. The method comprises the following steps: inputting a distance-Doppler (RD) image into a trained nonlinear coupling network, and obtaining a prediction probability of at least one candidate category corresponding to a target; according to a candidate category obtained through a radar cross section (RCS) value of a target, the prediction probability of the candidate category is adjusted, the target category of the target is determined to be the candidate category with the maximum prediction probability, and the nonlinear coupling network comprises a feature extraction enhancement module, a feature decoupling fusion module, a feature modeling module and a prediction module. Therefore, the identification precision, the anti-interference capability and the robustness of the radar low-altitude target can be improved.

The invention discloses a stealth coating material for aviation aircrafts. According to the invention, a three-layer composite structure design is adopted; the intelligent sensing layer is composed of graphene quantum dots and a piezoelectric nanofiber composite network, so that real-time sensing of electromagnetic wave signals is realized; the tunable metamaterial layer comprises a liquid crystal elastomer matrix and nickel-titanium alloy nanowires dispersed in the liquid crystal elastomer matrix, and electromagnetic parameters of the material are dynamically adjusted by applying an electric field or a temperature field; vanadium dioxide nanoparticles, a photonic crystal structure and carbon nanotube aerogel are integrated in the multispectral stealth layer, and radar, infrared and visible light multispectral synergistic stealth is achieved. The coating is further integrated with a microencapsulation repairing agent and an intelligent control system, and has the self-repairing and self-adaptive adjusting functions. Compared with the prior art, 0.1-40 GHz ultra-wide frequency band radar wave absorption is achieved, the radar cross section is reduced by 25-30 dB, the infrared radiation characteristic is reduced by 80% or above, the surface density is only 1.2-1.5 kg / m, the weight is reduced by 65% compared with a traditional coating, and a key material technical support is provided for a new generation of stealth aircrafts.

The invention provides a satellite-borne SAR radiometric calibration precision evaluation method and system, a medium and equipment, and belongs to the technical field of radiometric calibration, and the method comprises the steps: recognizing and analyzing an error source which affects the calibration precision; selecting a flat area as a calibration field according to the error source; arranging a plurality of standard calibration devices with known radar cross sections in an imaging band according to the satellite top crossing position and the wave position; controlling the satellite-borne SAR to irradiate the selected area at a specified wave position, acquiring and processing scene echo data, and generating an SAR image; according to the SAR image and a known radar cross section, calculating a radar cross section measurement value; and evaluating the satellite-borne SAR radiometric calibration precision according to the measured value of the scattering sectional area and the true value of the scattering sectional area. According to the method, multiple types of error sources in the radiometric calibration link are identified and analyzed, the calibration field is selected and multiple standard calibration devices are arranged based on the error sources, and the actually measured data are compared with the true value, so that the accuracy and credibility of radiometric calibration precision evaluation are improved.

The application discloses a broadband low radar scattering cross section antenna loaded with an ATFSS, which comprises three layers of dielectric plates, namely, an upper layer plate, a middle layer plate and a lower layer plate, the upper surface and the lower surface of the upper layer plate are attached with wave absorbing structures, the lower surface of the middle layer plate is attached with a band-pass FSS structure, the upper surface of the lower layer plate is attached with a patch antenna, the lower surface of the lower layer plate is a metal ground plate, coaxial line feeding is adopted, and the upper layer plate, the middle layer plate and the lower layer plate are all air cavities. The broadband low radar scattering cross section antenna adopts the wave absorbing structure with a multi-resonance structure and the band-pass FSS structure, can realize the integrated characteristics of wave absorption and wave transmission, and the wave absorbing structure and the band-pass FSS can be loaded as a coating above the microstrip patch antenna to realize the RCS reduction in a wide frequency band under the condition of ensuring the normal radiation of the antenna.

The invention discloses a tracking system and method based on millimeter wave radar end-to-end multi-target detection, and mainly solves the problems of low detection precision and poor tracking stability of pedestrians, non-motor vehicles and motor vehicles in a complex traffic scene in the prior art. The system comprises a radar signal processing unit, a radar detection and identification network and a DeepSORT tracking module. The radar detection and identification network adopts a hybrid architecture comprising an encoder and a decoder, and the encoder comprises a 3D CNN network and an expansion convolution DAM module; the decoder comprises a T-W / SW-MSA module and a full connection layer, according to the DeepSORT tracking module, a radar cross section RCS value and micro-Doppler radar physical characteristics are introduced, cascade matching and confirmation of a new trajectory state are added, so that the stability and robustness of target tracking are improved, and long-term stable tracking of a target is achieved by fusing a target detection result and combining a Hungary algorithm and a Kalman filtering technology. The method is high in detection precision and good in tracking stability, and can be used for intelligent traffic and automatic driving.

This invention discloses a method for obtaining the wide-angle single-station RCS of a medium target based on a compressed sensing algorithm. The steps are as follows: setting a wide-angle uniform incident plane wave illuminating the medium target; defining RWG basis functions and calculating the excitation vector for each incident angle; performing sparsification and compression on the excitation vectors respectively; generating the PMCHWT equations for the target surface and solving to obtain the compressed induced electromagnetic current matrix; recovering the original induced electromagnetic current matrix from each column of the compressed induced electromagnetic current matrix using the OMP algorithm; and calculating the radar cross section of the medium target based on the induced electromagnetic current vectors. This invention can obtain the RCS result at any angle with fewer PMCHWT equation solutions and combined with the OMP recovery algorithm, reducing the solution time for the wide-angle RCS of the medium target while ensuring accuracy.

Procedures, methods, architectures, apparatuses, systems, devices, and computer program products are provided for object detection over a wireless network. A method performed by a wireless transmit / receive unit (WTRU) includes receiving, from a wireless network, a configuration that includes a configured target profile for a target and information indicative of an identification of the target, wherein the configured target profile comprises a radar cross section profile associated with the target; receiving at least one signal from the wireless network; generating a measured profile based on the at least one signal; determining that the at least one signal was reflected by the target based at least in part on the information indicative of the identification of the target and a comparison between the configured target profile and the measured profile; and performing sensing measurements associated with the target using the at least one signal based at least in part on the determination.

The invention discloses a wave-absorbing metasurface low-profile wide-angle RCS (radar cross section) reduction tight coupling dipole antenna. The array is composed of a radiation layer, a middle layer, a wave-absorbing metasurface layer and a metal ground layer. The top layer of the radiation layer is a dipole antenna, and the tail ends of radiation arms of the dipole antenna are loaded with coupling patches through metal through holes; the middle layer is a dielectric substrate; the top layer of the wave-absorbing metasurface layer is a pair of symmetrical trident-shaped resistive films loaded with metal through holes, and the bottom layer of the wave-absorbing metasurface layer is a dielectric substrate; the metal ground layer is located at the lowermost layer. According to the invention, the wave-absorbing metasurface is embedded in the tight coupling dipole array antenna to replace a traditional metal ground, so that a low-profile structure is realized. According to the antenna, within the frequency band of 7-14 GHz, the wave absorbing efficiency is higher than 75% when electromagnetic waves are incident at the wide angle of 0-60 degrees, meanwhile, good radiation performance and wide-angle scanning capacity are kept, and the radar cross section is remarkably reduced. The method can be popularized to the low radar cross section design of a traditional antenna, and is suitable for radar and wireless communication systems.

This invention belongs to the field of computational electromagnetics numerical simulation and provides a simulation method for electromagnetic scattering of thin-coated targets based on Schur complement preconditions. First, for the IBC scattering target to be solved, equivalent surface current and equivalent surface magnetic current are introduced as independent unknowns. The electromagnetic scattering solution equation is established using SDIE and then discretized. Next, the impedance matrix is ​​decomposed into near-field and far-field matrices using an octree structure. For the near-field matrix, key operator sub-blocks are explicitly assembled and extracted. Then, approximate operators in block diagonal form and Schur complement operators are constructed and approximately inverted. Simultaneously, the diagonal product of intermediate blocks is pre-calculated and stored based on the approximate operators. Finally, the constructed preconditions are applied to the GMRES iterative solver. When the iteration error reaches the preset convergence criterion, the current and magnetic current distributions on the target surface are output. Further calculations of radiation characteristic parameters such as the target's radar cross section are then performed, achieving low-cost, high-efficiency, and easily parallelizable electromagnetic simulation solutions.

The invention provides a honeycomb chessboard array broadband RCS reduction metasurface device, and relates to the field of electromagnetic signal detection, the method comprises a metal grounding layer, a unit layer and a packaging layer, the unit layer is arranged on the metal grounding layer, the unit layer comprises a first type of metasurface unit and a second type of metasurface unit, and the packaging layer is arranged on the first type of metasurface unit and the second type of metasurface unit. The first type of metasurface units and the second type of metasurface units are arranged in a mixed mode according to a specific period rule, the first type of metasurface units comprise a plurality of first patch units, each first patch unit comprises a plurality of first rectangular metal patches, and the second type of metasurface units comprise a plurality of second patch units. Each second patch unit comprises a second rectangular metal patch and a third metal patch, the third metal patch surrounds the second rectangular metal patch, the shape of the third metal patch is a semi-hexagonal ring, and the packaging layer is arranged on the unit layer. Through the first type of metasurface units and the second type of metasurface units, it is ensured that efficient and stable radar cross section (RCS) reduction performance is achieved within the X-waveband range.

The present application relates to a kind of radar scattering cross section test methods based on deep learning and ISAR imaging inversion, the method includes using ISAR imaging test mode to obtain target and calibration body broadband radar scattering echo signal, calibration processing and applying filter-inverse projection imaging algorithm to carry out ISAR imaging, application completes the deep learning model of accurate extraction ISAR image scattering signal area, application FFT transform-interpolation integral ISAR imaging inversion algorithm high-precision inversion reconstruction RCS value, change ISAR imaging aperture center azimuth angle traversal acquisition target all azimuth angle RCS data.The radar scattering cross section test method based on deep learning and ISAR imaging inversion provided by the present application solves the accurate extraction ISAR image scattering area and ISAR image high-precision inversion reconstruction RCS and other test practical problems, expands RCS data acquisition method.

The utility model relates to an antenna radar cross section test turntable system, which comprises a mobile base, a protective cylinder, a turntable, a motion control assembly, a communication assembly, an upper computer and a wave-absorbing protective cover, the protective cylinder is arranged on the mobile base, the turntable is arranged on the mobile base in the protective cylinder, the turntable is electrically connected with the motion control assembly, and the communication assembly is electrically connected with the upper computer. The motion control assembly is connected and communicated with an upper computer through the communication assembly, the wave-absorbing protective cover surrounds the movable base and the rotary table, the wave-absorbing protective cover is formed by splicing a plurality of wave-absorbing plates, and wave-absorbing materials are arranged on the wave-absorbing plates. The beneficial effects of the utility model are that: can satisfy indoor and outdoor test demand simultaneously, can realize the multi-functional remote control of turntable, convenient to use, the test precision is high.

The application discloses a polarization converter using terminated filter circuit to control frequency characteristics, comprising: a dual-polarized antenna array and a filter circuit arranged on the back of the antenna array floor, the dual-polarized antenna array is used for transmitting the received electromagnetic wave signal to the filter circuit arranged on the back of the antenna array floor, and transmitting the signal output through the filter circuit to the free space; the filter circuit is used for realizing the control on the frequency characteristics of the polarization converter. By arranging different filter circuits on the back of the antenna array floor, the polarization converter with different frequency characteristics can be obtained. The application designs a reflection type polarization converter with super wideband and double frequency band. When linear x-polarized or y-polarized electromagnetic wave irradiates to the surface of the polarization converter, the reflected wave is the orthogonal polarization thereof. The application can be used for antenna design, radar cross section (RCS) reduction and wireless communication technology.

The application provides a radar scattering cross section (RCS) acquisition method based on CBFM-AIM-EDM, and the implementation steps are as follows: initializing parameters; calculating main characteristic basis functions of each sub-region based on CBFM-AIM; calculating secondary characteristic basis functions of each sub-region based on CBFM-AIM-EDM; constructing a reduction matrix and acquiring the radar scattering cross section (RCS). The main characteristic basis functions and the secondary characteristic basis functions of each sub-region are calculated by using the characteristic basis function method (CBFM), then the RWG basis functions and their divergence on each sub-region can be projected on the matrix grid respectively by using the adaptive integration method (AIM) to obtain the Topelitz matrix, so that the calculation speed is accelerated, the RCS acquisition efficiency is improved under the condition of ensuring the accuracy, and the coupling between two sub-regions of the target is equivalent to the coupling between equivalent dipoles by using the equivalent dipole moment method (EDM), so that the RCS acquisition efficiency is further improved.

This invention belongs to the field of radar signal processing and target detection technology, specifically relating to a statistical scattering method for clutter particles in radar detection. The method includes: acquiring single scattering parameters and simulation control parameters of the clutter particles; dynamically determining the simulation space length based on the single extinction coefficient and asymmetry factor; initializing a quasi-Monte Carlo low-discrepancy sequence; after initializing each photon packet, randomly generating a propagation step size and updating the cumulative propagation step size; when the photon packet does not exceed the boundary, determining whether scattering has occurred based on the single extinction coefficient and cumulative propagation step size; if scattering has occurred, updating the scattering direction based on the Henyey-Greenstein phase function and attenuating the energy weight; employing an adaptive dynamic threshold roulette wheel mechanism to dynamically adjust the survival probability based on scattering efficiency, photon position, and propagation direction, and maintaining statistical unbiasedness through energy weight compensation; after traversing all photon packets, calculating the total transmitted energy and total reflected energy, and calculating the equivalent extinction coefficient and radar cross section. This invention significantly improves simulation efficiency while ensuring statistical accuracy through physically guided importance sampling and a quasi-Monte Carlo low-discrepancy sequence, providing reliable support for radar anti-environmental clutter interference design.

The invention discloses a reinforcement learning-based multi-unmanned aerial vehicle radar cross section optimization method and system, and relates to the technical field of multi-unmanned aerial vehicle cooperative control. Selecting an unmanned aerial vehicle as a main agent, and taking a radar cross section RCS value as a reference; the other unmanned aerial vehicles are slave agents; the method comprises the following steps: acquiring state information of an unmanned aerial vehicle group in real time, inputting the state information into an action strategy network constructed on the basis of a TD3 algorithm, outputting continuous action vectors, generating a real-time RCS adjustment instruction, dynamically simulating and generating a cooperative flight path of the unmanned aerial vehicle group in a three-dimensional space on the basis of a Lie group SO (3) theory, and designing a multi-dimensional reward function. And calculating a reward value reflecting an RCS cooperation effect in real time, circularly updating a strategy network through a reinforcement learning mechanism, and training a cooperation control strategy. Through cooperative RCS adjustment of the master unmanned aerial vehicle and the slave unmanned aerial vehicles, the RCS features of the slave unmanned aerial vehicles are dynamically adjusted to the level similar to that of the master unmanned aerial vehicle, and highly similar RCS feature distribution of the multiple unmanned aerial vehicles in radar detection is achieved.

The utility model discloses a metasurface structure for reducing normal incident scattering of an antenna, and the metasurface structure employs a double-layer design, combines an absorption layer and a frequency selection surface layer, and achieves broadband absorption through a periodically two-dimensional unfolded microstrip patch unit and a three-layer resistor loading metal ring. Ansys electromagnetic field simulation software verifies that the structure effectively reduces the radar cross section of the microstrip antenna within the frequency band of 3-10 GHz, and ensures the normal work of the antenna at the same time. Through deep analysis and simulation optimization, key factors influencing the performance are determined, and the balance between the wave permeability and the wave absorbing property is realized. Besides, an adjustable resistance circuit, a reconfigurable mechanism, an intelligent algorithm and a sensor technology are integrated, the stability and the automation level of the antenna performance are further improved, and an effective solution is provided for improving the scattering reduction effect during forward incidence of radar waves.

The application discloses a multi-unmanned aerial vehicle radar cross section optimization method and system based on reinforcement learning, and relates to the technical field of multi-unmanned aerial vehicle cooperative control. An unmanned aerial vehicle is selected as a master agent, and a radar cross section (RCS) value is taken as a reference; the rest unmanned aerial vehicles are slave agents; state information of the unmanned aerial vehicle group is acquired in real time and input into an action policy network constructed based on a TD3 algorithm, a continuous action vector is output, real-time RCS adjustment instructions are generated, a cooperative flight trajectory of the unmanned aerial vehicle group in a three-dimensional space is dynamically simulated and generated based on Lie group SO (3) theory, a multi-dimensional reward function is designed, a reward value reflecting the RCS cooperative effect is calculated in real time, the policy network is cyclically updated through a reinforcement learning mechanism, and a cooperative control strategy is trained. Through cooperative RCS adjustment of the master unmanned aerial vehicle and the slave unmanned aerial vehicle, the RCS characteristic of the slave unmanned aerial vehicle is dynamically adjusted to a similar level of the master unmanned aerial vehicle, and a plurality of unmanned aerial vehicles present a highly similar RCS characteristic distribution in radar detection.

The invention relates to a traffic road sign and a road sign detection method, and the traffic road sign comprises a body which is provided with at least one first reflection region; the first reflecting film comprises a base body and a plurality of reflecting protrusions, the base body covers the first reflecting area of the body, and all the reflecting protrusions are arranged on the surface of the side, opposite to the body, of the base body; wherein the first reflective film is made of a metal material. According to the traffic sign, the first reflecting film is made of the metal material, and the plurality of reflecting bulges are convexly arranged on the surface of one side, back on to the body, of the first reflecting film, so that the radar scattering sectional area and the anti-interference performance of the traffic sign are effectively improved, and the quantitative improvement of the target identification stability is realized; the radar sensing performance is improved with low cost, and meanwhile, the traditional visible light warning function is also ensured.

The invention discloses a coated target electromagnetic scattering modeling method based on multi-core heterogeneous parallel computing, and belongs to the field of computational electromagnetism and high-performance computing. The method comprises the steps that an MPI + OpenMP + DSP three-level heterogeneous parallel framework is constructed, and optimal configuration of computing resources is achieved through one-to-one binding of an MPI process and a DSP acceleration card and one-to-one mapping of an OpenMP thread and a CPU core; dispersing a to-be-solved coating target by adopting a triangular grid, and defining an RWG primary function to expand surface current; substituting the surface current approximate expansion into an electric field integral equation based on impedance boundary conditions; carrying out impedance matrix calculation by adopting a process-based parallel filling strategy, and carrying out parallel solution on a matrix equation based on a ScaLAPACK library; and finally, calculating a far-region scattering field and a radar scattering sectional area according to the solved current coefficient. According to the method, through an innovative heterogeneous parallel architecture and a calculation task scheduling strategy, the problems of insufficient memory and low calculation efficiency during processing of an electrically large coated target in a traditional method are effectively solved, and an efficient and reliable technical means is provided for electromagnetic stealth design of a complex target.

The application discloses a reconfigurable transmissive array antenna with low radar cross section, which comprises an amplitude modulation layer, a phase modulation layer and a feed source, wherein the feed source is used for transmitting or receiving electromagnetic waves; the amplitude modulation layer is used for absorbing electromagnetic waves in free space to reduce the radar cross section of the antenna; the phase modulation layer is used for modulating the transmission phase of incident electromagnetic waves received by the feed source, and the working frequency band of the amplitude modulation layer is located on both sides of the working frequency band of the phase modulation layer. The application can have the functions of fast beam switching, beam shaping and electromagnetic stealth, etc.

The invention belongs to the field of antennas, and relates to an electromagnetic protection type low RCS metasurface antenna and a working method thereof, and the metasurface antenna comprises an upper dielectric substrate, a gap metal ground, a lower dielectric substrate and a feed microstrip line. A polarization conversion metasurface unit is etched on the upper dielectric substrate; among the four polarization conversion metasurface units of the gap structure of the gap metal ground, two polarization conversion metasurface units located on one side of the feed microstrip line are connected through a PIN diode, and two polarization conversion metasurface units located on the other side of the feed microstrip line are connected through a PIN diode. According to the invention, a low radar cross section, normal communication and high-power microwave self-protection function are integrated, and through cooperation of the polarization conversion metasurface unit and the PIN diode, self-adaptive reliable switching between a normal state stealth communication state and an instant destroy-resistant protection state is realized. The problem that an existing low-RCS metasurface antenna lacks protection capability under the HPM threat is solved.

The invention provides a method and device for testing the obstacle recognition function of a vehicle-mounted intelligent driving system, and relates to the technical field of automatic driving, and the method comprises the steps: employing a wave-transparent material to make a three-dimensional base, and the three-dimensional base comprises a plurality of surfaces; a mapping relation between the aging degree and physical attributes is established, the physical attributes of the different surfaces are determined based on the mapping relation, and the physical attributes comprise radar cross-sectional areas and contrast ratios; according to the physical attributes, radar reflecting layers with different radar scattering sectional areas and visual texture layers with different visual textures are arranged on all the surfaces of the three-dimensional base, so that obstacles with different aging degrees on the different surfaces are generated; the obstacle recognition function of the vehicle-mounted intelligent driving system is tested by using the obstacle. By adopting the method and the device for testing the obstacle recognition function of the vehicle-mounted intelligent driving system, the function test efficiency and the test scene coverage when the vehicle-mounted intelligent driving system is tested are improved.

The application provides a target radar cross section test method and a verification method thereof, and relates to the technical field of radar stealth test. The test method comprises the following steps: obtaining an RCS amplitude curve and an RCS phase curve of a carrier; obtaining the RCS amplitude curve and the RCS phase curve of a low-scattering target and the carrier; correcting the RCS amplitude and the RCS phase of the low-scattering target and the carrier; and obtaining RCS test data of the low-scattering target through a carrier vector cancellation method. The verification method is used for verifying the effectiveness of the target radar cross section test method. The target radar cross section test method solves the problems of inaccurate cancellation and large evaluation error caused by inconsistent placement postures of the low-scattering target and the carrier.