398 results about "Selective surface" patented technology

The present invention relates to the field of electronic devices of wireless communication systems. Disclosed is an ultra-wideband and high-protection-efficiency filtering energy selective surface, comprising one or more layers of reflecting surfaces; each reflecting surface is mainly composed of a plurality of metal sheets which are located on the same plane, have the same shape and are arranged in central symmetry; a gap for electrical isolation is formed between every two adjacent metal sheets; each gap is provided with a PIN diode; the anodes and cathodes of all the PIN diodes are arranged in a clockwise or counterclockwise direction; and all the gaps form an interconnected gap structure on the plane where the reflecting surface is located. The ultra-wideband and high-protection-efficiency filtering energy selective surface can be achieved by a first-order filtering energy selective surface unit or a second-order filtering energy selective surface unit. The filtering energy selective surface of the present invention has a small surface thickness and a simple structure, can achieve fast roll-off filtering for low-power signals, achieve an ultra-wide suppression stopband, and achieve ultra-wideband and high-efficiency protection for high-power electromagnetic waves.

The invention relates to the field of electromagnetic functional composite materials, and particularly discloses a multi-layer composite structure flexible frequency selective surface material and a preparation method thereof. The ultra-high molecular weight polymer fiber-reinforced polymer-based composite material thin-film mechanical enhanced band-pass frequency selection array sequentially comprises an acrylic acid polyvinylidene fluoride organic polymer coating environment-resistant layer, a metal oxide organic film isolation layer, an ultra-high molecular weight polymer fiber-reinforced polymer-based composite material thin-film mechanical enhanced layer, a band-pass frequency selection layer and a packaging protection layer from top to bottom, and the band-pass frequency selection layer is a hexagonal / circular ring nested band-pass frequency selection pattern array. The packaging protection layer is formed by printing a conductive coating composed of conductive filler / polymer resin matrix, and the packaging protection layer is an ink coating. The flexible frequency selective surface material has the characteristics of light weight, high strength, salt fog / rain / ultraviolet and other severe environments, frequency selective wave transmission and multiple functions, has good gas barrier property, is beneficial to maintaining the shape of an inflatable hangar made of a skin and ensuring normal operation of radar equipment, and has good practical engineering application value.

The present invention relates to the field of high-rate mobile wireless communications. Disclosed are a multi-frequency multi-polarized wide-beam scanning base station system, and an optimization design method. The method comprises: on the basis of an aperture field expansion theory and a mode coupling theory, designing a conical horn feed source antenna capable of radiating a Gaussian fundamental mode beam, and providing a stable beam width and a stable phase center; designing a beam separation device based on a periodic structure, wherein the beam separation device includes band-pass frequency selective surfaces and a linear polarization grid; and combining front-end quasi-optical links of multiple frequency channels and multiple polarized channels, so as to increase the bandwidth and communication rate of a base station antenna. In the present invention, a genetic optimization algorithm is combined with reflector shaping, thereby effectively reducing the conflict between a shielding effect of a dual-reflector antenna and a scanning angle, and realizing the multiplication of a beam scanning angle.

A microwave filter arrangement (100) for quantum computing applications, the filter arrangement (100) comprising a first port (113) and a second port (114). The microwave filter arrangement (100) comprises a main waveguiding structure (110) arranged between the first (113) and second (114) port, where the main waveguiding structure (110) comprises an inner conductor (111) having a circular cross-section that is surrounded by a hollow outer conductor (112) having a rectangular cross-section with two opposed long sides and two opposed short sides. The waveguiding structure (110) comprises a plurality of hollow waveguides (115) extending away from one or both of the long sides of the outer conductor, the hollow waveguides (115) comprising a dielectric material (122) and being terminated by an electromagnetically absorptive material (124).

A frequency selection surface manufacturing method based on femtosecond laser induced graphene belongs to the technical field of frequency selection surface manufacturing and comprises the following steps: (1) graphene patterning: forming a graphene periodic micro-nano structure on the surface of a flexible substrate through induction by femtosecond laser; (2) a frequency selection unit structure design step: a nested resonance structure is obtained by layering and stacking graphene resonance units with different geometrical shapes, and selective transmission or reflection of multi-band electromagnetic waves is realized; the graphene resonance unit is the graphene periodic micro-nano structure; and (3) a large-area manufacturing step: processing a frequency selection surface with the area larger than 10cm < 2 > by adopting femtosecond laser dynamic scanning and energy regulation and control technologies. According to the invention, the local structure modification of the graphene is induced by femtosecond laser, and the metasurface design is combined, so that the large-area and multi-band frequency selection characteristic is realized.

The invention discloses a band-pass type active frequency selective surface based on double-element composite loading. The band-pass type active frequency selective surface comprises at least one resonance unit which is periodically arranged, the resonance unit sequentially comprises a top metal frequency selection surface layer, a first dielectric structure layer, a middle metal feed layer, a second dielectric structure layer and a bottom metal frequency selection surface layer from top to bottom; the top metal layer and the bottom metal layer are composed of square ring aperture grooves subjected to deformation processing, and the middle feed layer is of a cross zigzag metal structure, plays a role in coupling an electromagnetic field and serves as a bias network of the AFSS. And the metal through holes penetrate through the resonance units in the vertical direction, so that the middle layer feeder line can respectively provide reverse bias voltage for independently regulating and controlling the resonance frequency for the PINs and the variable capacitance diodes on the top layer and the bottom layer. According to the invention, the functions of band switching and wide-range frequency tuning can be met, so that the problem of insertion loss increase caused by limited design frequency regulation and control range and element loading of the AFSS in the prior art can be solved.

A broadband low-transmittance and high-absorption wave absorption and transmission integrated frequency selection surface comprises three wave absorption layers and two wave transmission layers which are sequentially stacked from top to bottom, and the three wave absorption layers are sequentially divided into an upper wave absorption layer, a middle wave absorption layer and a lower wave absorption layer from top to bottom; the two wave-transparent layers are sequentially divided into an upper wave-transparent layer and a lower wave-transparent layer from top to bottom; the multi-layer composite structure design is adopted, collaborative optimization of the wave absorbing performance and the wave transmitting performance is achieved by combining the two wave transmitting layers on the lower portion and the three wave absorbing layers on the upper portion, through organic combination of the upper layer structure and the lower layer structure, dual performance improvement of broadband wave absorbing and broadband wave transmitting is achieved, and a transition zone between a wave absorbing zone and a wave transmitting zone is greatly reduced.

The invention discloses an ultra-wideband RCS (radar cross section) reduction metasurface with mixed wave absorption and diffuse scattering and a wave-transparent window, and belongs to the technical field of electromagnetic metamaterials. The metasurface adopts a four-layer cascade structure and comprises a first layer of polarization conversion structure, a second layer of 2.5 D lossy structure, a third layer of Jerusalem cross-shaped lossy structure and a fourth layer of frequency selective surface structure. By loading a lumped resistor at a specific position and adopting a metal through hole interconnection technology, dual functions of radar cross section reduction in a 1-20GHz ultra-wideband and low insertion loss wave transmission in a 8-12GHz frequency band are realized. The structure of each layer adopts a highly symmetrical design and has the characteristic of polarization insensitivity, and meanwhile, by optimizing interlayer air gaps and dielectric material selection, the structure compactness is realized on the premise of ensuring the performance. The method has important application value in the aspect of integration of stealth equipment and a communication system.

The invention provides a frequency selective surface inverse design method, device and equipment. The method comprises the steps of obtaining a target square wave; the target square wave is used for representing the expected transmission performance of the frequency selective surface; inputting the target square wave into a pre-trained multi-layer perceptron model to obtain a target design parameter corresponding to the frequency selection surface; the pre-trained multilayer perceptron model is obtained by training based on a preset sample data set; the preset sample data set is an equivalent circuit model established based on a transmission line theory, and is calculated by adopting an equivalent inductive reactance and capacitive reactance empirical formula. According to the method, the equivalent circuit model based on the transmission line theory is used for replacing full-wave simulation, the complex electromagnetic field solving process is avoided, the sample data preparation time is remarkably shortened, due to the fact that the pre-trained multi-layer perceptron model is introduced, the target square waves are directly mapped to the corresponding design parameters, rapid and efficient reverse design is achieved, and the method is suitable for large-scale popularization and application. And the efficiency and the precision of the frequency selective surface design are obviously improved.

The invention provides a frequency selective surface unit and a frequency selective surface antenna housing, and relates to the technical field of communication. The frequency selection surface unit is composed of a first metal layer, a first dielectric layer, a second metal layer, a second dielectric layer, another second metal layer, a third dielectric layer and another first metal layer which are sequentially stacked from top to bottom. Wherein the two first metal layers form an improved square gap ring, and the two second metal layers form an improved Jerusalem cross gap. Moreover, the two first metal layers and the two second metal layers are respectively of a rotational symmetry structure, and the rotation centers of the two first metal layers coincide with the rotation centers of the two second metal layers. And the M * N periodically arranged frequency selective surface units form the frequency selective surface antenna housing. The frequency selective surface antenna housing provided by the invention has the advantages of high frequency selectivity, large-angle incidence stability and miniaturization while realizing a dual-frequency dual-polarization function.

A multi-band antenna includes a first column of radiating elements that are configured to operate in a first operating frequency band mounted on a reflecting plate; a second column of radiating elements that are configured to operate in a second operating frequency band mounted on the reflecting plate; a first fence and a second fence located on both sides of the reflecting plate that extend forward from the reflecting plate, where the first and second columns of radiating elements are arranged in between the first and second fences, the first fence and the second fence respectively comprise a frequency selective surface with a passband and a stopband, the passband covers at least the first operating frequency band, and the stopband covers at least the second operating frequency band.

The invention relates to an electromagnetic protection component preparation method based on an energy selective surface technology. The method comprises the steps that S1, a protection component design model is split into protection component design models, protection components are prepared in a fragmented mode according to the protection component design models, and a positioning identifier is machined on each protection component; s2, a conformal tool with the same appearance as the protected component is machined, and positioning points are machined on the surface of the conformal tool; s3, the conformal tool is fixedly connected with a rotating shaft of the five-axis rotating table; s4, the protection components are transferred to a conformal tool to be spliced and temporarily fixed, and positioning points on the surface of the conformal tool and positioning marks on the protection components are used for position alignment; and S5, the conformal tool is driven to rotate through the five-axis rotating table, the parts, needing to be connected, of the protection components are moved to the position below a laser ball spraying soft soldering device, electronic circuits on the protection components are welded in a laser ball spraying mode, and the electromagnetic protection component is obtained.

The embodiment of the invention provides a design method of a wave-absorbing / wave-transmitting electrically-controlled switchable antenna housing, the structure of the antenna housing comprises an absorbing layer frequency selective surface, a dielectric layer and a wave-transmitting layer frequency selective surface from top to bottom, the absorbing layer frequency selective surface can carry out in-band loss and in-band transmission, the wave-transmitting layer can carry out in-band transmission and out-of-band reflection, and the dielectric layer can carry out in-band transmission and out-of-band reflection. The overall structure interacts to form a radar radome structure integrating absorption and transmission; a microwave network is adopted to carry out impedance analysis on the absorption and transmission radome, parameters are set to represent the characteristics of the microwave network, and meanwhile, a transmission matrix of the microwave network is analyzed through a matrix. The designed antenna housing not only has good out-of-band wave-absorbing stealth performance, but also can switch an in-band wave-transmitting state to a wave-absorbing state through electric control to realize limit stealth.

A frequency selective unit, a frequency selective surface, and an antenna base station. The frequency selective unit comprises a metal reflector plate and at least two conductive material pattern layers, wherein through holes are provided in the metal reflector plate, the at least two conductive material pattern layers run through the through holes, and there is a gap between the conductive material pattern layers and the metal reflector plate; and at least one conductive material pattern layer comprises a first transmission mode, and at least the other conductive material pattern layer comprises a second transmission mode, and in a transition band, electromagnetic waves in the two transmission modes have opposite phases and cancel each other, such that the electromagnetic waves cannot be transmitted through the frequency selective unit; moreover, an electromagnetic wave transmission zero can be generated in the transition band, and a sharp roll-off is formed at an out-of-band edge of a second band, thereby realizing high-frequency selectivity. The conductive material pattern layers are not parallel to the metal reflector plate, the transmission direction of the electromagnetic waves is parallel to the surfaces of the conductive material pattern layers, and it is not necessary to provide a metallized via hole between the at least two conductive material pattern layers to perform electrical connection, thereby simplifying the manufacturing process and processing difficulty of the frequency selective unit.

The invention discloses a multi-layer resistive film frequency selective surface composite wave-absorbing device with high bearing and wave-absorbing integrated functional characteristics. The composite wave absorbing device sequentially comprises a mechanical bearing layer composed of a wave-transparent dielectric plate subjected to impedance modification and a dielectric isolation layer from top to bottom. The wave-absorbing functional layer is formed by arranging three layers of resistive film frequency selective surfaces, three layers of dielectric isolation layers and six layers of wave-transparent dielectric plates at intervals; and the total reflection bottom plate is formed by a carbon fiber plate or a metal plate. According to the invention, a layer of resistive film frequency selective surface is embedded in the wave-transparent dielectric plate, so that the wave-absorbing bandwidth can be effectively expanded while the high-bearing mechanical property is ensured; a layer of wave-transparent dielectric plate is laid on the upper portion and the lower portion of the frequency selective surface of each resistive film in the wave-absorbing functional layer so as to further reinforce the mechanical bearing characteristic of the composite wave-absorbing device.

The present invention discloses a modeling method for a non-rotational airborne radar radome, comprising: performing surface configuration and solid modeling on the non-rotational surface airborne radar radome to obtain a reconstructed digital model of the non-rotational airborne radar radome; and generating a frequency selective surface of the non-rotational airborne radar radome based on the digital model of the non-rotational airborne radar radome. The present invention realizes the precise creation of the digital model of the non-rotational airborne radar radome, so that the finally designed radome product can achieve the initially designed electrical performance index in the actual application environment.

The invention provides a miniaturized multilayer ultra-wideband millimeter wave frequency selective surface, and relates to the technical field of frequency selective surfaces, the miniaturized multilayer ultra-wideband millimeter wave frequency selective surface comprises a first metal patch layer, a first dielectric layer, a second metal patch layer, a second dielectric layer, a third metal patch layer and a third dielectric layer which are stacked in sequence, the first metal patch layer comprises a plurality of concave parts, each concave part is arranged on each side of the first metal patch layer, the second metal patch layer comprises a first sub-patch and a second sub-patch, the centers of the first sub-patch and the second sub-patch coincide, and the third metal patch layer comprises a plurality of third sub-patches which are annularly arranged at equal intervals. According to the invention, the angle stability of the frequency selective surface is improved.

The integrated optical structure includes a frequency-selective reflecting structure disposed between a decorative cover layer and an underlying metal layer. The underlying metal layer is configured to reflect and / or absorb radio frequency electromagnetic waves transmitted by the decorative cover layer and the frequency-selective reflecting structures. Each of the frequency-selective reflecting structures includes a frequency-selective surface layer having metal elements arranged on a multilayer stack and repeated across the frequency-selective surface layer to form an array. The integrated optical structure reflects collimated incident RF electromagnetic waves having a wavelength in the range of 1.0 mm to 10 cm and incident at an incident angle at a reflection angle different from the incident angle as collimated reflected waves. For normally incident light having a first visible wavelength, the frequency-selective reflecting structure has an optical transmittance greater than 50%.

The utility model provides a waveguide antenna structure with a frequency selective surface structure and a waveguide radar, and the structure comprises a waveguide antenna which is provided with a waveguide slot array and a frequency selective surface structure; the waveguide slot array is arranged on the waveguide antenna in a penetrating manner, and the frequency selective surface structures are distributed on the peripheral side of the waveguide antenna; the frequency selective surface structure comprises surface structure units, and the frequency selective surface structure is formed by arranging a plurality of surface structure units. According to the utility model, the frequency selective surface structure absorbs reflection between the top surface of the antenna and the antenna housing and reduces distortion of a directional diagram; surface waves can be reduced, space coupling between the antennas is reduced, and the isolation between the antennas is improved; the beam directivity can be adjusted, and beam performance specific directivity can be shaped.

The invention provides a reverse design method for a multi-layer frequency selective surface filter based on machine learning, which combines topology modeling and parameter modeling and comprises the following steps of: constructing a multi-layer frequency selective surface microwave filter structure, namely constructing a filter structure comprising a metal resonance patch and key physical parameters; a training data set construction step: constructing a training data set including an input and output data set; and a machine learning model training and reverse design step: training the data set by using a Res-MLP network, inputting a target electromagnetic response on the trained model, fitting a filter structure through the Res-MLP network, and realizing reverse design. According to the method, hybrid modeling is realized by combining topology modeling and parameter modeling, the FSS filter with a specific layer number and structure is deduced according to requirements, the filter design with higher design freedom and application frequency band is realized, and the FSS filter design outside the training frequency band can be realized based on the frequency band offset of the FSS under the low-dispersion or non-dispersion material.

The invention discloses a metamaterial frequency selective surface and a preparation method thereof, and belongs to the technical field of electromagnetic wave frequency selective surfaces. The method comprises the following steps: designing a periodic array pattern with wave absorbing property, and carrying out selective laser cladding on a dielectric material paved with a metal powder layer according to the periodic array pattern. The metamaterial frequency selective surface is directly and efficiently prepared on the surface of the dielectric material, no extra coating or deposition step needs to be introduced in the process, and compared with photoetching, silk-screen printing, ink-jet printing and the like, the preparation process is simplified, the production cost is effectively reduced, and the stability and durability of the obtained structure are remarkably improved.

The invention provides a frequency selective surface antenna housing for a base station antenna. Comprising a first dielectric layer, a common metal layer and a second dielectric layer; the common metal layer is arranged between the first dielectric layer and the second dielectric layer; a first patch resonance unit is attached to the upper surface of the first dielectric layer, and a second patch resonance unit is attached to the lower surface of the second dielectric layer; each of the first patch resonance unit and the second patch resonance unit is composed of four groups of patch resonators, and the four groups of patch resonators are also provided with resonance grooves with the same size, thereby achieving the accurate regulation and control of the specific modes of the patch resonators, and improving the stability of the filtering performance.

The invention discloses an ultrathin single-layer dual-passband frequency selective surface structure, and belongs to the field of electromagnetic fields and microwaves. The frequency selective surface structure is formed by periodically arranging the same unit structures, and each unit structure comprises a single-layer dielectric substrate and a single-layer metal layer loaded on the upper surface of the dielectric substrate; the single-layer metal layer is formed by sequentially nesting three concentric annular patches, and the three concentric annular patches are respectively a metal mesh tightly attached to the boundary of the unit, four square metal rings bent outwards and arranged in the metal mesh, and four circular metal rings bent outwards and arranged in the square metal rings from outside to inside. The ultra-thin single-layer dual-passband frequency selective surface structure can form two passbands with high relative bandwidths when electromagnetic waves are incident, has excellent angle stability under TE and TM polarization, and can be used for improving the performance of the antenna by changing the size parameters of the square metal ring and the circular metal ring. The two transmission zero points can be regulated and controlled, so that the position of the passband is adjusted.

The invention provides a wave-transparent band frequency-adjustable frequency selection surface, which comprises a loss layer, a frequency selection layer and a bias network, the loss layer and the frequency selection layer are periodically arranged, the loss layer comprises a first resonant structure and a second resonant structure, and the frequency selection layer comprises a third resonant structure. The upper bias network and the lower bias network are respectively connected with direct-current voltages with different polarities, so that the variable capacitance diodes in the first resonant structure and the third resonant structure work under different voltages to generate different capacitance values, the resonant frequency point of the loss layer and the resonant frequency point of the frequency selection layer in the structures generate frequency shift at the same time, and finally continuous adjustability in the wave-transparent frequency band of 5.51 GHz to 6.31 GHz is achieved. Under the action of the second resonant structure and other lumped resistors of the loss layer, wave absorption within the frequency band range of 4.31 GHz to 5.15 GHz and the frequency band range of 6.31 GHz to 13.81 GHz is achieved. The device has the characteristics of continuous frequency modulation and out-of-band wave absorption, can effectively suppress interference of outside electromagnetic waves in other frequency bands or electromagnetic waves in a frequency band close to a communication frequency band on communication, can reduce the radar cross section of a target, and is beneficial to target stealth.

The invention belongs to the field of electromagnetic wave absorbing materials, and particularly relates to a thin broadband composite wave absorber based on a frequency selective surface. According to the invention, the wave-transparent layer is added in the middle of the multi-layer magnetic material, the mindset of simply stacking the same type of materials in the traditional multi-layer wave-absorbing structure is broken, and the wave-transparent layer is introduced to change the original characteristic that the impedance gradually changes in sequence; meanwhile, a magnetic wave-absorbing material, a frequency selection surface and a medium matching layer are subjected to composite design, the frequency selection surface generates an electromagnetic coupling effect at high frequency, phase and impedance conversion of electromagnetic waves in a multi-layer structure is controlled, and efficient impedance matching and electromagnetic wave energy dissipation in a broadband are achieved through electromagnetic absorption and interference cancellation; and an excellent wave absorbing effect is achieved. The total thickness of the composite wave absorber ranges from 0.064 lambda to 0.1 lambda, the-10 dB absorption bandwidth ranges from 3.3 GHz to 18 GHz, and the relative bandwidth reaches 138%; and meanwhile, the wave absorber has a wide angular domain characteristic under oblique incidence, and a novel thin broadband composite wave absorber scheme is provided.

The invention discloses a frequency selective surface performance prediction method and related equipment. The method comprises the following steps: constructing a pre-training data set; constructing a variational auto-encoder model, and extracting potential common features of a performance curve by using a variational auto-encoder as a generative model; training a variational auto-encoder model by using the pre-training data set; preprocessing the data of the target frequency selective surface scene, extracting resonance characteristics of the performance curve, and obtaining a characteristic data set; constructing a resonance sensing variable-length proxy model; and sampling the characteristic data set to train a resonance sensing variable-length proxy model, and using the trained model to predict the performance of the frequency selective surface. According to the method, physical priori knowledge is embedded in the agent model training process to improve the curve representation capability, a resonance point sensing curve generation mechanism is introduced, the physical consistency modeling and high-quality reconstruction of the performance curve are realized from the resonance point characteristics of the curve, and the expression capability of the model to the complex resonance characteristics is remarkably improved.

The invention relates to the technical field of terahertz wave application, in particular to a terahertz low-pass filter based on a frequency selective surface, which comprises a first dielectric layer, a second dielectric layer, a third dielectric layer, a first metal layer and a second metal layer. The first dielectric layer, the second dielectric layer and the third dielectric layer are stacked in sequence; the first metal layer is arranged on the surfaces of the first dielectric layer and the third dielectric layer, and the first metal layer is formed by arranging four metal sheets in a square shape; the second metal layer is arranged between the first dielectric layer and the second dielectric layer and between the second dielectric layer and the third dielectric layer, and the second metal layer is of an annular structure with a through hole. According to the terahertz wave filter, the filtering effect on terahertz waves can be achieved, the working frequency band can cover a microwave band and a terahertz band, the cut-off frequency of the terahertz wave filter can be regulated and controlled, and the cut-off frequency range of the terahertz wave filter is 0.01-1 THz; the device is simple in structure and low in preparation difficulty; the band-pass filter has high transmissivity in a passband, and has a good stop-band suppression characteristic at a high frequency.

The invention belongs to the technical field of microwave antennas, and particularly provides a tight coupling phased array with a tail end unit loaded with asymmetric dipoles. The main structure of the antenna comprises a radiation structure (I) which is composed of frequency selection surfaces which are arranged above folded dipoles and are periodically arranged, dipoles which are symmetrically arranged in a central unit and dipoles which are asymmetrically arranged in an edge unit; and the feed structure II is composed of a gradient microstrip feeder line, a metal floor and a coaxial line. According to the invention, a frequency selective surface is loaded above a folded dipole, a traditional tight coupling phased array is replaced, a heavy dielectric layer is loaded above the dipole, and a 1 * 8 one-dimensional linear array is designed. Besides, by prolonging the length of the folded dipole on the tail end array element, compared with a traditional structure, extra capacitance is introduced under the condition that the height of the array section is not changed, and the problem that the array is difficult to match at low frequency is effectively relieved.

The invention relates to a high-temperature-resistant Si3N4-based wave-absorbing material based on FSS and a preparation method thereof. The high-temperature-resistant Si3N4-based wave-absorbing material based on the FSS comprises a frequency selective surface layer, a porous silicon nitride dielectric layer and a metal substrate which are sequentially stacked from top to bottom, the frequency selective surface layer is composed of M * N FSS units which are periodically arranged in a two-dimensional plane and are in a Jerusalem cross pattern, M is larger than or equal to 8, and N is larger than or equal to 8. The high-temperature-resistant Si3N4-based wave-absorbing material based on the FSS provided by the invention can realize effective absorption of C-Ku wave band electromagnetic waves, has the characteristics of thin thickness, low reflectivity, high strength, high temperature resistance, light weight and wide frequency band, and can realize the purpose that the high-temperature-resistant Si3N4-based wave-absorbing material can be used for absorbing high-temperature-resistant Si3N4-based wave-absorbing material in a complex and severe physical environment with relatively small physical burden. And efficient, reliable and lasting absorption of broadband electromagnetic waves is realized.

The invention is suitable for the technical field of electromagnetic wave regulation and control, and provides a dual-polarization angle selection surface for suppressing antenna side lobes, which comprises a plurality of periodically arranged dual-polarization angle selection surface units, the dual-polarization angle selection surface unit comprises a first metal layer, a first dielectric substrate, PMI foam, a second dielectric substrate and a second metal layer which are sequentially stacked from top to bottom; the centers of the first metal layer, the first dielectric substrate, the PMI foam, the second dielectric substrate and the second metal layer coincide; the first metal layer and the second metal layer are of the same structure and each comprise a hexagonal gap and a gap shaped like a Chinese character'mi '. According to the invention, the in-band radiation performance can be ensured, and the antenna sidelobe can be significantly reduced.