170 results about "Selective surface" patented technology

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 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 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.

The application belongs to the technical field of electromagnetic materials, and provides a design method and system of a conical surface tunable frequency selective surface with stable performance. According to the performance evolution law of the FSS under the conical surface conformal transformation, the FSS period shape and arrangement mode are determined. Whether the geometric parameter value of the optimized conical surface tunable frequency selective surface structure meets the set target IL value is judged. If the geometric parameter value of the optimized conical surface tunable frequency selective surface structure does not meet the set target IL value, the geometric parameter value of the conical surface tunable frequency selective surface structure is redesigned according to the insertion loss improvement strategy. The proposed curved surface TFSS design process has low IL, high conformality and wide angle domain stability.

The application discloses a multi-mode absorbing frequency selective surface with adjustable wave absorbing capacity, which comprises a metal pattern layer, a first dielectric substrate, a metal back plate, a second dielectric substrate and a metal feed line layer arranged in sequence from top to bottom, wherein the metal pattern layer comprises a plurality of metal unit structures arranged in an array, each metal unit structure comprises a polygonal metal sheet located at the center of the unit, metal bands extending from the periphery of the polygonal metal sheet, and metal arms extending from the four corners of the unit, the metal arms comprise two independent metal structures, the polygonal metal sheet and the metal bands are connected to each other through a first varactor diode, the two independent metal structures are connected to each other through a second varactor diode, and the metal arms in adjacent metal unit structures jointly form a new rotating cross structure. The independent feed line network is built through the metal through hole, so that the structure is divided into two independently regulated parts, and the whole has single and double adjustable wave absorbing modes.

The utility model relates to the technical field of antenna stealth, specifically relates to a frequency selection unit and frequency selection surface for low frequency range, the frequency selection unit is spliced by first metal layer, second metal layer, third metal layer and fourth metal layer, the first metal layer is formed by MXM square metal patch, wherein 3<=M<=7 and M is odd, second metal layer is spliced by four sub metal layer units and second metal layer is central symmetry structure, the sub metal layer unit is the structure after first metal layer equal proportion reduction to one fourth, third metal layer and first metal layer structure are same and both are in diagonal position, fourth metal layer and second metal layer structure are same and both are in diagonal position, the frequency selection unit structure simple in the utility model can realize the absorption of internal fixed frequency point electromagnetic wave, and the electromagnetic wave of other frequency is completely transparent, can satisfy the frequency selection of antenna, and does not influence the use of antenna itself.

The application provides a low-frequency antenna, an antenna array and an electronic device. The low-frequency antenna comprises a dielectric substrate and a plurality of radiation units arranged on the dielectric substrate. Each radiation unit comprises a ring-shaped radiation element and a frequency selective surface arranged in the ring-shaped radiation element, and the frequency selective surface and the ring-shaped radiation element are insulated from each other. Each ring-shaped radiation element is provided with a gap. The low-frequency antenna provided by the application has a relatively wide wave transmission characteristic, and can realize relatively independent regulation and control.

This invention discloses a single-polarization broadband signal anti-reflection power-generating glass, an etching method, and an installation method, relating to the fields of communication and photovoltaic power generation technology. The power-generating glass includes an ultra-clear glass substrate and a plurality of single-segment thin-film solar cells connected in series within a layer of the ultra-clear glass substrate. Each single-segment thin-film solar cell includes a positive electrode, a power-generating thin film layer, and a back electrode. The positive electrode, power-generating thin film layer, and back electrode are sequentially stacked and bonded along the thickness direction of the ultra-clear glass substrate, and each is etched with periodically arranged rectangular patterns. The long side of each rectangular pattern is horizontal, forming a frequency-selective surface for the penetration of vertically polarized electromagnetic signals. This invention, by etching rectangular patterns on the power-generating glass, achieves efficient transmission of signals in the target frequency band while ensuring power generation functionality, solving the problem of traditional power-generating glass blocking communication signals and improving the quality of broadband signal transmission.

The disclosed technology relates to an antenna module comprising: at least one array of antenna elements (101); at least one layer comprising a frequency selective surface (102; 107) configured to control the transmission and reflection of electromagnetic waves; and a reflector (104), the reflector comprising an opening. In accordance with the disclosed techniques, one of the at least one layer comprising a frequency selective surface (FSS) is mounted on / to the opening in the reflector (104), and an antenna element (106) mounted on the at least one FSS layer (107) is capacitively coupled to a conductive reflector material surrounding the opening in the reflector (104).

A method for making an uncoated fine mesh design on a coated surface. The aim of this design is to completely or partially reflect or transmit specific frequencies of the electromagnetic spectrum. Such design is referred to as a frequency selective surface (FSS). More particularly, the invention relates to masking a portion of the surface of the substrate prior to deposition of the coating and later removing the mask by water washing in the process, leaving the designed fine mesh FSS pattern.

This invention relates to the field of optical imaging technology, specifically providing an optical radar co-aperture off-axis imaging system, comprising: an off-axis mirror assembly, a frequency-splitting device, a radar transceiver system, and an optical imaging system. The frequency-splitting device is disposed in the rear optical path of the secondary mirror and is used to reflect light waves and transmit microwaves. The frequency-splitting device includes a frequency-selective surface, which comprises an FSS pattern layer and a bias line layer. The FSS pattern layer includes periodically arranged FSS units. Nonlinear capacitors are electrically connected to the FSS units. The bias line layer applies a voltage to the nonlinear capacitors according to the received microwave band. By changing the voltage applied to the nonlinear capacitors, the resonant frequency of the FSS units is tuned, thereby changing the microwave passband frequency of the frequency-splitting device. This invention not only achieves a reflective wave-transmitting microwave design but also solves the problem that transmitting only a single band of microwaves in microwave-transmitting and light-reflecting methods is difficult to adapt to different task requirements.

The invention relates to a dual-band wave-transparent frequency selective surface structure with stable polarization and angle, the frequency selective surface structure is formed by periodically arranging 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; an external regular hexagon metal ring, a middle regular hexagon metal ring and an internal regular hexagon metal sheet are sequentially nested in the single-layer metal layer at intervals from outside to inside, first grooves are etched in all edges of the middle regular hexagon metal ring at intervals, the number of the first grooves is a first number, and the depth of the first grooves is within a first depth range. Second grooves with the second number being the second number and the depths within the second depth range are etched in all the edges of the internal regular hexagon metal sheet at intervals, and all the grooves corresponding to all the edges are symmetrically distributed relative to the center lines of the edges where the grooves are located. According to the invention, good polarization and angle stability and a small structure size are realized.

The invention discloses a cascade frequency selective surface with a steep transition band and a wide passband. The cascade frequency selective surface sequentially comprises a frequency selective surface with a steep sideband, a honeycomb core layer and a frequency selective surface with a wide passband from top to bottom along a Z-axis direction, the frequency selective surface with the steep sideband is used for providing a frequency response characteristic of rapid roll-off at the edge of a passband to form a steep transition band; the frequency selective surface with the wide passband is used for providing a broadband wave-transparent characteristic and a broadband stop-band suppression characteristic; the honeycomb core layer is used for cascading a frequency selective surface with a steep sideband and a frequency selective surface with a wide passband; and electromagnetic coupling between the upper and lower layers of frequency selection surfaces is reduced, so that the frequency selection surface with a steep sideband and the frequency selection surface with a wide passband maintain relatively independent resonance characteristics. According to the invention, the square annular patch with central symmetry is used, and the four branches are added, so that the symmetry enables the angle to be stable, and the processing complexity is simplified.

This invention discloses a bandpass frequency-selective surface structure based on strongly coupled pairs, composed of multiple basic structural units. Each basic structural unit has a vertically symmetrical structure along its thickness direction. Both the upper and lower symmetrical portions include a first metal layer and a first dielectric layer in symmetrical positions. The first metal layer contains a first resonator pair, a second resonator pair, and a third resonator pair, each using metal patches as resonators. A second metal layer and a second dielectric layer, separated along the thickness direction of the basic structural unit and in asymmetrical positions, are disposed between the upper and lower symmetrical portions. The upper and lower symmetrical portions are connected by metal conductive posts. This invention operates stably at a center frequency of 5 GHz, introduces four transmission zeros, achieves a fourth-order frequency response within 8.4% of the relative bandwidth, has an insertion loss of less than 0.49 dB, and 40° angular stability, exhibiting superior performance.

The invention discloses a high-selectivity broadband optical transparent energy selective surface and a control method. The high-selectivity broadband optical transparent energy selective surface comprises a single-layer optical transparent substrate and a parallel circuit structure, the LC series resonance branch is used for forming a fixed stop band in a conventional working state and can form a double-stop-band coupling structure with the field nonlinear device series branch after impedance change under strong electromagnetic attack so as to expand the protection bandwidth, and stable and efficient shielding in the whole target protection frequency band is achieved; and the field-induced nonlinear device series branch is used for performing main shielding and passband adaptive adjustment under strong electromagnetic attack through state switching of the field-induced nonlinear device, that is, the field-induced nonlinear device series branch can change the impedance characteristic under strong electromagnetic field excitation. The LC series branch and the field nonlinear device series branch are integrated on the single-layer light transparent base material, broadband protection performance and low insertion loss which are equivalent to those of a multi-layer or cascade structure are obtained, and meanwhile an extremely small section and a compact structure are achieved.

This invention belongs to the field of electromagnetic protection technology and provides a low-profile energy selective surface with ultra-wideband protection to solve electromagnetic protection problems. This invention improves the equivalent circuit design of a cascaded energy selective surface and a frequency selective surface, resulting in a low-profile energy selective surface with ultra-wideband protection. Under low power density incidence, the energy selective surface generates a passband in the S-band, ensuring normal signal reception and transmission for the protected antenna. Under high power density incidence, the energy selective surface can totally reflect electromagnetic waves across the entire frequency band. Furthermore, this invention employs a rotationally symmetric structure, exhibiting polarization insensitivity. Compared with existing technologies, the energy selective surface proposed in this invention has a simpler structure, a lower profile, higher shielding effectiveness, and provides wider bandwidth protection, achieving ultra-wideband protection.

This application relates to a dual-band frequency selective surface structure, in which an aerogel layer serves as the intermediate dielectric layer, and two single-level frequency selective surface units are arranged on opposite sides. Each single-level frequency selective surface unit is formed by two ceramic layers sandwiching a periodic metal structure, thus forming a coupled structure of a dual-layer frequency selective surface. This coupled structure can improve the selectivity of the frequency response to electromagnetic waves, thereby effectively shielding electromagnetic waves outside the operating frequency band. The combination of ceramic and aerogel layers can ensure the transmission stability of electromagnetic waves during incident, maintaining a stable electromagnetic transmission response even when electromagnetic waves are incident at large angles. At the same time, it can achieve low-loss transmission of electromagnetic waves within the operating frequency band, effectively balancing the angular stability and high frequency selectivity of dual-band electromagnetic wave transmission. This solves the technical problems of existing multi-frequency selective surfaces having poor angular stability, poor out-of-band suppression, and the inability to simultaneously achieve both angular stability and high selectivity.

This invention discloses a dual-band common-aperture conformal transflective array antenna with a high frequency division ratio, belonging to the field of emergency communication. It comprises, from top to bottom, a common-aperture, coplanar integrated dielectric substrate, three shared frequency selective surfaces, and a reflection-transmission coordinated control layer. Each of the three shared frequency selective surfaces includes a central cascaded frequency selective surface and surrounding extended frequency selective surfaces. The reflection-transmission coordinated control layer includes a double-opening ring located at the bottom of the central cascaded frequency selective surface, with its diameter limited by the period of the central cascaded frequency selective surface, and surrounding extended frequency selective control surfaces. Using this dual-band common-aperture conformal transflective array antenna with a high frequency division ratio, independent amplitude and phase control of the two frequency bands at 35GHz and 140GHz, with a 4:1 frequency division ratio, is achieved without mutual interference.

This invention discloses a broadband non-contact terahertz near-field trace substance detection device and method. The device includes a vector network analyzer, a terahertz signal transmitter, an extended hemispherical lens, a trace substance detection chip, and a terahertz signal receiver. The terahertz signal transmitter includes a first terahertz S-parameter detection module, a first lens, a second terahertz S-parameter detection module, a second lens, a first frequency selective surface, and a first reflector. The terahertz signal receiver includes a third terahertz S-parameter detection module, a third lens, a fourth terahertz S-parameter detection module, a fourth lens, a second frequency selective surface, and a second reflector. The device and method disclosed in this invention use quasi-optical technology to achieve non-contact connection between the trace substance detection chip and the terahertz S-parameter detection module. Simultaneously, quasi-optical band splicing technology enables detection over a broadband range, which can improve the detection speed of the sample and achieve broadband non-destructive non-contact detection of the sample.

The invention provides a broadband wave-transparent base station antenna, relates to the technical field of microwave and millimeter wave communication, and solves the technical problem that most common-caliber base station antenna design schemes in the prior art are relatively narrow in wave-transparent bandwidth. According to the technical scheme, the antenna comprises a low-frequency radiation unit, a high-frequency radiation unit and a rectangular reflection ground; the four high-frequency radiation units are arranged at the four corner ends of the low-frequency radiation unit respectively. Compared with a traditional frequency selective surface structure, more capacitance and inductance components are introduced, and the broadband wave-transparent performance is achieved.

The application discloses a full-band super-high power density electromagnetic pulse protection energy selection surface and a communication device. The energy selection surface comprises a first dielectric substrate and a second dielectric substrate which are sequentially stacked. The first dielectric substrate and the second dielectric substrate are separated by an air gap layer. The top of the first dielectric substrate is provided with a first metal unit, and the bottom of the second dielectric substrate is provided with a second metal unit. The first metal unit and the second metal unit are both center-symmetric structures. The application realizes adjustable functions, can switch between transmission and shielding states, breaks the limitation of the single function of the frequency selection surface and the limitation of the narrow bandwidth of other energy selection surfaces.

The invention discloses a planar embedded feed design method for a reconfigurable frequency selective surface. A feed network has no metalized via holes, and adopts a planar feed mode; the unit structure is a band-pass frequency selective surface structure which is formed by a plurality of metal patches, gaps and metal patches and is etched on a dielectric substrate, and PIN diodes are loaded at gap joints. The conduction and cut-off of the PIN diode are realized by applying bias voltage, so that the switching between a wave transmission state and a cut-off state is realized; a planar embedded feed network is introduced, a patch is slotted to add a bonding pad, all middle metal patches are connected together through a method of bridging an inductor on the bonding pad, the inductor is located right above a metal thin wire and is not in electric contact with a peripheral metal square ring, direct-current connection of all internal metal patches is achieved, and unified feed is facilitated. According to the planar embedded feed design method, the structure is simple, the thickness is small, the structure is light, and great engineering application value is achieved.

The invention provides a polarized wave independent control active frequency selection surface loaded with PIN diodes, which comprises a dielectric substrate, periodically arranged strip-shaped metal patches are arranged on the upper surface and the lower surface of the dielectric substrate, and the metal patches on the upper surface and the lower surface of the dielectric substrate are perpendicular to each other in different planes; a notch is formed in the middle of the metal patch, and a PIN diode is bridged at the notch; according to the invention, through a double-layer different-plane vertical strip-shaped metal patch structure and loading the PIN diodes at the middle notches of the patches, dynamic switching of stop bands of an X wave band and a Ku wave band on the same device is realized through independent control of the on-off states of the two PIN diodes, independent filtering control of horizontal and vertical polarized waves can be realized, and the performance of the device is improved. And the adaptability, the flexibility and the integration degree of the frequency selective surface in a complex electromagnetic environment are remarkably improved.

The application belongs to the field of electromagnetic field and microwave technology, and discloses a circularly polarized filtering transmission array antenna adopting linear polarization feed, which comprises a feed antenna for radiating linearly polarized electromagnetic waves; a transmission array adopting an antenna-filter-antenna technology frequency selective surface (AFAFSS) unit; and a periodic unit of the antenna-filter-antenna frequency selective surface (AFAFSS) sequentially comprises a rectangular filtering patch antenna as a linear polarization receiving antenna, two cascaded substrate integrated waveguide (SIW) resonant cavities as filters and a wideband circularly polarized antenna as a circular polarization transmitting antenna from a bottom end to a top end in a hierarchical metal structure. The antenna integrates the functions of filters, linear polarization-circular polarization wave conversion and high-gain radiators, and through rotating the transmitting antennas of hundreds of AFAFSS units, appropriate phase compensation can be realized to form a high-gain CP radiation beam, and meanwhile, the AFAFSS has the functions of filtering and linear polarization-circular polarization wave conversion.

This invention discloses an integrated ultra-wideband absorbing material. From top to bottom, the material comprises a first lossy dielectric substrate, multiple lightweight interlayers, five resistive frequency selective surfaces, a metal backplate, and a composite material frame penetrating between the layers. Through slots are formed between the square rings and concentric geometric patterns of each resistive frequency selective surface. The composite material frame is embedded in these slots and continuously arranged along the thickness direction, creating a non-uniform dielectric structure within the material composed of high-dielectric and low-dielectric regions. This structure jointly regulates the resonance conditions and equivalent impedance gradient of the multiple resistive frequency selective surfaces, shifting the low-frequency absorption initiation frequency towards lower frequencies without increasing the thickness, and maintaining stable absorption performance at large oblique incidence angles. Simultaneously, the composite material frame improves the overall structural mechanical stability. This invention achieves thinness, wide bandwidth, and wide-angle absorption characteristics, making it suitable for electromagnetic stealth and electromagnetic compatibility applications.

The invention relates to a design, processing and manufacturing method of a novel silicon-based terahertz frequency selection surface, and belongs to the technical field of electromagnetic fields and microwaves. The specific processing and manufacturing steps are as follows: manufacturing a silicon wafer; manufacturing a base; manufacturing a pressing ring; manufacturing a gasket; the gasket, the silicon wafer and the pressing ring are installed on the base, and manufacturing of the silicon-based terahertz frequency selection surface is completed; the silicon wafer is formed by stacking an upper silicon-based bonding structure, a middle silicon-based bonding structure and a lower silicon-based bonding structure; the thicknesses of the layers are the same; wherein the upper surface and the lower surface of the silicon wafer are respectively etched with periodic array patterns and then are subjected to gold plating treatment; the gap between the vertical side wall of the base and the silicon wafer is adjusted through the gasket; a chamfer is arranged on the side wall of the inner ring of the pressing ring; a supporting rib plate is arranged on the side wall of the base; the structure has the advantages of being high in structural strength, compact, good in universality, high in installation precision and the like, and can resist mechanical conditions in the rocket launching stage while meeting the requirement for filtering electrical performance.

The application provides a base station antenna and a base station. The base station antenna comprises a first antenna array, a frequency selective surface, a second antenna array and an antenna conductive component; the frequency selective surface is located between a first radiator of a radiation unit of the first antenna array and the second antenna array, and is used for reflecting a radiation signal of the first antenna array and transmitting a radiation signal of the second antenna array; the antenna conductive component is located on the same side of an array plane of the second antenna array as the first antenna array; the antenna conductive component comprises a conductive base body, a first structural unit and a second structural unit; the first structural unit and the second structural unit both surround the conductive base body, and are arranged in a spaced and adjacent mode and form a capacitor. The base station comprises a guyed mast and the base station antenna, and the base station antenna is fixed to the guyed mast. The application can improve the electromagnetic shadow problem caused by the shielding of the metal component.

Antennas include a first radiating element that is configured to operate in a first operating frequency band, and a second radiating element that is configured to operate in a second operating frequency band that encompasses higher frequencies than the first operating frequency band. The first radiating element includes a first dipole radiator having first and second dipole arms and a second dipole radiator having third and fourth dipole arms. The first dipole arm includes a first metal region that substantially surrounds a first non-metal interior region, and the first non-metal interior region is configured so that currents induced on a first portion of the first metal region by RF energy emitted by the second radiating element substantially cancel currents induced on a second portion of the first metal region by the RF energy emitted by the second radiating element.