522 results about "Selective surface" patented technology

The invention discloses a dual-polarization angle selective surface structure with a wide passband angle and out-of-band steep drop, which is formed by mutually connecting a plurality of periodic units, each periodic unit is provided with at least two metal structure layers from top to bottom, and an air dielectric layer unit is arranged between the adjacent metal structure layers; wherein the metal structure layer comprises a dielectric substrate, an upper surface metal layer and a lower surface metal layer are arranged on the upper surface and the lower surface of the dielectric substrate respectively, and the upper surface metal layer and the lower surface metal layer are connected through a metal via hole formed in the dielectric substrate; the upper surface metal layer and the lower surface metal layer have the same structure, and each periodic unit internally comprises Jerusalem-type metal sheets which are circumferentially distributed around the center of the dielectric substrate; the Jerusalem type metal sheet support arms are mutually connected; the middle through hole of the cross-shaped metal main arm of the Jerusalem metal sheet is the end part of the metal via hole, and the metal via hole is connected with the middle part of the cross-shaped metal main arm at the corresponding position of the upper and lower surfaces of the dielectric substrate.

An antenna, a formation method of the antenna, and an antenna group are provided in the present disclosure. The antenna includes a first substrate, a second substrate, a third substrate and a feed source. A first frequency selective surface is on a side of the first substrate; a reflective layer is on a side of the second substrate; a first electrode layer is on a side of the third substrate; and the third substrate is on a side of the second substrate away from the first substrate, and liquid crystal molecules are between the second substrate and the third substrate; or the third substrate is on a side of the first substrate away from the second substrate, and liquid crystal molecules are between the third substrate and the first substrate. The feed source is on the side of the second substrate or on the side of the third substrate.

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 invention belongs to the technical field of microwaves. The invention provides a broadband frequency selective surface radome with a wide-angle harmonic suppression function. According to the embodiment of the invention, the regular hexagonal periodic arrangement mode is selected, so that the structures of the FSS units under wide-angle incidence can be ensured to have good in-band wave-transparent characteristics and harmonic band suppression characteristics. By adopting the structure of the double-layer FSS unit, the wide wave-transparent bandwidth can be realized. A transmission zero point can be introduced by loading a circular hole on the aperture type FSS unit, and the position of the transmission zero point and the bandwidth of a stop band can be adjusted by adjusting the size of the circular hole, thereby achieving a good inhibition effect in a harmonic frequency band. By designing the FSS unit form, the wave-transparent bandwidth of the frequency selective surface structure is improved, and two transmission zeros are introduced at the harmonic position, so that good isolation is achieved in the harmonic band of the wave-transparent bandwidth. By optimizing the thickness and the stacking arrangement of the core layer, the filter has good passband transmission characteristics and harmonic band suppression characteristics under a large incident angle.

An antenna system includes a radiating element layer including a plurality of radiating elements, a reflective frequency selective surface (FSS) layer having a resonance transmission frequency range, and an absorptive FSS layer between the reflective FSS layer and the radiating element layer and having a resonance absorption frequency range. The resonance transmission frequency range is greater than the resonance absorption frequency range.

An antenna system includes a first antenna and a second antenna. The first antenna includes a first radiating element, a first frequency selective surface, and a first feed network. The first radiating element is disposed on a side of the first frequency selective surface, and the second antenna is disposed on a side that is of the first frequency selective surface and that is away from the first radiating element. The first frequency selective surface includes a plurality of first strip-shaped structures and a plurality of second strip-shaped structures. The first strip-shaped structures and the second strip-shaped structures are made of metal. The plurality of first strip-shaped structures intersect with the plurality of second strip-shaped structures to form a plurality of grids. The first feed network includes a first structure, and the first structure is disposed on the first strip-shaped structure.

The invention provides a partitioned strengthening and toughening treatment method for an additive remanufacturing hot forging die, which comprises the following steps of: firstly, deeply cleaning a cavity of a failed forging die to remove impurities, residues and the like in the cavity, and creating a good basic condition for subsequent remanufacturing treatment; secondly, the repairing area of the forging die is subjected to remanufacturing treatment, so that the basic toughness requirement of the additive remanufacturing hot forging die is met, and cracking is prevented; afterwards, selective surface nitriding or carburizing strengthening treatment is conducted on the strengthening area of the additive remanufacturing hot forging die, so that the strength and hardness of the strengthening area are improved, the abrasion resistance is guaranteed, the strength and toughness partition of the surface of a cavity of the additive remanufacturing hot forging die is achieved, and then the comprehensive performance of the strengthened hot forging die is comprehensively improved; and finally, the service life of the reinforced hot forging die is prolonged.

The invention discloses a zigzag structure-based low-pass high-absorption energy selection surface, which comprises a plurality of periodically distributed units, each unit sequentially comprises a frequency selection layer, a dielectric layer and an energy selection layer from top to bottom, the frequency selection layer comprises a first dielectric substrate and a plurality of metal zigzag structures and resistors on the upper surface and the lower surface of the first dielectric substrate, and the metal zigzag structures and the resistors are arranged on the upper surface and the lower surface of the first dielectric substrate. The selectable layer comprises a second dielectric substrate, and a plurality of metal block structures and diodes on the upper surface of the second dielectric substrate; and the frequency selection layer and the selectable layer are separated by the dielectric layer. The energy selection surface and the frequency selection surface are matched in impedance through the dielectric layer, so that when low-power electromagnetic waves are incident, a low-frequency passband with low insertion loss is realized, and a relatively wide absorption frequency band is formed outside the passband; and when high-power electromagnetic waves are incident, a reflection frequency band with relatively high shielding effectiveness is realized in a working frequency band, and a relatively wide absorption frequency band is formed outside the band. The device is simple and clear in overall design structure principle and has a wide application prospect.

The invention discloses a frequency selective surface unit, an array, a structure and an antenna. The frequency selective surface unit comprises a dielectric plate; the first metal patch comprises a plurality of first extension parts connected with the central part of the dielectric plate, and the plurality of first extension parts extend towards the periphery from the central part of the dielectric plate; the second metal patch comprises a plurality of second extension parts, each second extension part is connected to the tail end of one first extension part, the plurality of second extension parts extend along the edge of the dielectric plate, and the second extension parts are arranged at intervals; wherein the first metal patch and the second metal patch form an LC equivalent resonance circuit. According to the frequency selective surface unit, the array, the structure and the antenna provided by the invention, the frequency response range can be expanded, multi-band electromagnetic waves can be effectively processed, and the performance of the frequency selective surface unit in the aspects of working band, bandwidth coverage, angle stability and the like can be improved.

The invention relates to the technical field of wireless communication and antenna design, and discloses a circularly polarized antenna based on a multi-mode frequency selective surface, an integration method and a terminal. A wave absorbing layer, a first diffuse reflection layer and a second diffuse reflection layer are sequentially integrated on the circularly polarized antenna body from top to bottom. Wherein the circularly polarized antenna body has a working frequency band, the wave absorbing layer has a wave absorbing frequency band, the first diffuse reflection layer has a first diffuse reflection frequency band, and the second diffuse reflection layer has a second diffuse reflection frequency band; the working frequency band, the wave absorbing frequency band, the first diffuse reflection frequency band and the second diffuse reflection frequency band are efficiently integrated, the requirements for high-flexibility radiation and strong electromagnetic stealth are met, and the design of the multi-mode radiation stealth integrated array antenna is achieved. According to the invention, the out-of-band radar cross section (RCS) can be efficiently suppressed while the radiation efficiency in the working band of the antenna is not influenced, and the fusion target of high-performance radiation and ultra-wideband RCS suppression stealth is fundamentally completed.

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.

The invention provides a broadband stealth material based on an active regulation and control metasurface and a preparation method. A cross structure resistive frequency selection surface, a first dielectric layer, a second dielectric layer, a square ring structure resistive frequency selection surface, a third dielectric layer, a fourth dielectric layer, a multi-fractal structure active frequency selection surface, a fifth dielectric layer, a multi-fractal structure active frequency selection surface, a sixth dielectric layer and a metal backboard are sequentially arranged from top to bottom. The problem that low-frequency wave absorption of a passive absorber and high-frequency wave absorption of an active absorber are difficult to realize at the same time is solved. Resistance type frequency selective surfaces of a cross structure and a square ring structure are adopted for cascade connection, a wide absorption frequency band is generated at high frequency, and a centrosymmetric pattern is adopted, so that polarization stability is achieved. A double-layer multi-fractal structure frequency selective surface is adopted, and a variable capacitance diode and a chip resistor are loaded, so that active tuning of an absorption frequency band can be realized at low frequency. The working range covers the P-K wave band, and the application potential is achieved in the aspects of electromagnetic regulation and control, radar stealth and the like.

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 relates to an annular ultra-wide frequency selective surface unit based on a liquid crystal material and an antenna. The annular ultra-wide frequency selective surface unit sequentially comprises a first dielectric layer, a first metal tuning patch layer, a liquid crystal substrate, a second metal tuning patch layer and a second dielectric layer from top to bottom, on the X frequency band, the first metal tuning patch layer is inductive, the second metal tuning patch layer is capacitive, the sizes of patches in the first metal tuning patch layer and the second metal tuning patch layer are changed, so that the interaction of equivalent inductance and equivalent capacitance between the patches is tuned, the band elimination function is achieved, the liquid crystal substrate is equivalent to a variable capacitor, and the band elimination function is achieved. The dielectric constant is changed through the electric adjustable characteristic, so that the coupling capacitance of the liquid crystal substrate is changed, and the dynamic adjustment of the resonant frequency is realized. The broadband airborne stealth radar antenna effectively solves the problems that a traditional airborne radar antenna is small in bandwidth and tuning range, and meets the development requirements of a miniaturized and integrated broadband airborne stealth radar antenna.

The invention relates to the technical field of electromagnetic fields and microwaves, in particular to a high-order dual-band band-pass frequency selective surface, which comprises an upper metal layer, a dielectric substrate and a lower metal layer, and is characterized in that the dielectric substrate is arranged between the upper metal layer and the lower metal layer; a large rectangular ring gap and four small rectangular ring gaps are etched on the upper metal layer and the lower metal layer respectively, the four small rectangular ring gaps are located on the four edges of the large rectangular ring gap, and four small rectangular metal patches, a large rectangular metal patch and irregular peripheral metal patches are adopted after etching. According to the invention, the overall performance of the frequency selective surface can be enhanced, so that the frequency selective surface shows more excellent selectivity and stability in multi-band application.

The invention discloses a polarization conversion wave-absorbing ultra-wideband stealth metasurface structure which comprises a polarization conversion layer, a first filling layer, a frequency selection surface layer, a second filling layer and a wave-absorbing layer which are sequentially arranged from top to bottom. The polarization conversion layer comprises a polarization conversion patch, the polarization conversion patch comprises a plurality of 2 * 2 subarrays, and the angle arrangement difference between adjacent 2 * 2 units is 90 degrees. The frequency selective surface layer comprises a first patch, a second patch and a third patch which are sequentially arranged from top to bottom. The wave absorbing layer comprises a resistive film patch, and the impedance of the wave absorbing layer is matched with that of the second filling layer.

The hexagonal dual-polarization high-selectivity frequency selective surface comprises a middle filtering layer and two magnetoelectric dipole antennas, and the section of the hexagonal dual-polarization high-selectivity frequency selective surface is hexagonal; the two magnetoelectric dipole antennas have the same structure and are symmetrically arranged relative to the middle filtering layer, the middle filtering layer is a middle metal layer with a central slot, the appearance of the middle metal layer is a regular hexagon, the central slot is hollowed out by a hexagon located in the center, and the middle metal layer is a rectangular metal layer. The six edge grooves extend outwards from the six edges of the hexagonal hollowed-out part respectively, and each edge groove faces one end point of the regular hexagon appearance of the middle metal layer. The middle filtering layer serves as a band-pass filter, electromagnetic waves penetrate through the middle filtering layer during resonance, suppression of low-frequency and high-frequency stop bands is achieved, and meanwhile the middle filtering layer serves as a common ground plane of the two magnetoelectric dipole antennas. According to the invention, the problems of high insertion loss in a wave-transparent window, insufficient out-of-band suppression, over-wide transition zone, poor angle stability and the like of the existing frequency selective surface can be solved.

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 discloses a high-angle stable frequency selective surface with an adjustable dual-frequency wave-transparent window. The frequency selective surface comprises a metal resonant structure, a dielectric substrate and a bottom-layer metal feed structure, the top metal resonant structure comprises a crossed dipole with an arc-shaped branch knot, an arc-shaped metal ring with a bent branch knot, and a square patch with an inner concave fillet at the periphery; the first variable capacitance diode is welded between the arc-shaped branch knot and the bent branch knot, and the second variable capacitance diode is welded between the patch and the arc-shaped metal ring; the bottom layer metal feed structure comprises a cross metal feed line and a T-shaped metal feed line, and lumped resistors are loaded between the feed lines to form a complete direct current power supply network; the upper surface and the lower surface of the dielectric substrate are communicated through metal via holes in the vertical direction, so that the bottom feeder line can provide reverse bias voltage for independently regulating and controlling the passband resonant frequency for the two sets of variable capacitance diodes on the top layer. According to the invention, the number of adopted active devices is small, and the antenna has the advantages of double-frequency independence, continuous adjustability and high-angle stability.

The invention discloses a three-dimensional water-based frequency selective absorber with convertible electromagnetic performance. The three-dimensional water-based frequency selective absorber comprises a plurality of symmetrical three-dimensional gradient structure dielectric square waveguide frequency selective surface unit structures and periodic water-based metamaterial absorber units, the three-dimensional gradient structure dielectric square waveguide frequency selective surface unit structure has broadband transmission performance with high frequency selectivity. The periodic water-based metamaterial absorber unit is packaged around the frequency selective surface unit structure and has ultra-wideband absorption performance; three transmission poles and two transmission zero points are generated by cascading three metal square rings up and down in the three-dimensional gradient structure dielectric square waveguide frequency selective surface unit structure, so that a high-frequency-selectivity broadband band-pass three-dimensional frequency selective surface is realized; by controlling the on-off of water in the periodic water-based metamaterial absorber unit, the conversion of transmission band external absorption and reflection electromagnetic characteristics is realized. According to the invention, the transmission bandwidth is expanded, the absorption frequency band is wide, the absorption rate is high, and dual polarization can be realized.

The invention belongs to the technical field of frequency selective surface radomes, and particularly relates to a frequency selective surface-based low-frequency wave-transparent and high-frequency reflection device and a satellite radome, which sequentially comprise a first low-pass layer, a first dielectric isolation layer, a first band-stop layer, a second dielectric isolation layer and a second low-pass layer from top to bottom, the first low-pass layer and the second low-pass layer are the same in structure, and each of the first low-pass layer and the second low-pass layer comprises first metal patch patterns which are periodically arranged; each first metal patch pattern is composed of four square ring patterns and a cross-shaped pattern, and the four ends of the cross-shaped pattern are connected with the four square ring patterns respectively; and the first band stop layer comprises second metal patch patterns which are periodically arranged. The novel low-pass layer / band-stop layer pattern multilayer structure is constructed, the effects of ultra-wideband low-frequency wave transmission and high-frequency reflection are achieved under the condition that the thickness is sacrificed, the problem that in-band ultra-wideband wave transmission and out-of-band ultra-wideband reflection are difficult to give consideration to in-band ultra-wideband wave transmission and out-of-band ultra-wideband reflection at the same time in existing frequency selection is effectively solved, and then normal work of a satellite antenna housing is guaranteed.

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.

The invention discloses a self-adaptive electromagnetic radiation suppression method for equipment in a high-intensity radiation field. The method comprises the following specific steps: establishing an electronic equipment model under external plane wave irradiation; plane wave intensity is set, and field intensity distribution of an inner cavity of the electronic equipment model is obtained; determining shielding electromagnetic effect weak points according to the field intensity distribution of the inner cavity of the electronic equipment model; establishing an energy selection surface structure comprising a plurality of slot resonance patches arranged in an array; the energy selective surface structure is arranged on the surface where the shielding electromagnetic effect weak point is located, and an energy selective surface protection structure model is established; and comparing the field intensity at the shielding electromagnetic effect weak point in the energy selective surface protection structure model with a protection requirement, and judging whether the energy selective surface structure meets the protection requirement or not.

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.