366 results about "Dielectric plate" patented technology

The invention provides a novel low-cost miniaturized TRSiP packaging structure, which relates to the field of wireless communication equipment and comprises an upper ceramic dielectric plate, a lower ceramic dielectric plate, a radio frequency circuit and a metal enclosure frame, a first metal bonding pad is arranged on the upper surface of the upper-layer ceramic dielectric plate, and a second metal bonding pad is arranged on the upper surface of the lower-layer ceramic dielectric plate; the radio frequency circuit comprises a radio frequency generation assembly and a metal column. The radio frequency generation assembly is arranged on the lower ceramic dielectric plate, the radio frequency generation assembly is connected with the second metal bonding pad, the lower end of the metal column is connected with the second metal bonding pad, and the upper end of the metal column is connected with the first metal bonding pad; and the metal enclosure frame is arranged between the upper-layer ceramic dielectric plate and the lower-layer ceramic dielectric plate and surrounds the radio frequency circuit. The structure has the advantages of being low in cost, small in size, high in integration, good in air tightness and high in structural strength, and the reliability is greatly improved.

The invention provides a low-cost dual-polarization electric scanning base station antenna applied to 5G communication, and provides an effective method for the design of a low-cost electric control scanning base station antenna. According to the invention, an antenna array surface is formed based on 2-bit dual-polarized microstrip antenna units, the antenna array surface and a feed network are in plug-in connection, and the feed phase of each antenna unit is controlled through an external wave control circuit board, so that phased wave beam scanning is realized. The base station antenna has the beneficial effects that compared with a traditional fixed beam base station antenna, the coverage range of the base station antenna can be effectively expanded; according to the invention, the microstrip antenna units are separated from each other and are not printed on a whole dielectric plate, so that the array scale can be flexibly controlled according to actual requirements; the antenna unit integrates two functions of radiation and phase shift, so that an external phase shifter is omitted, and the processing, assembling and maintenance costs are greatly reduced.

The invention relates to the technical field of high-voltage commutation, and discloses a control method and system for a composite LC filter of a high-voltage converter station, and a storage medium. According to the method, on the basis of staggered solid / liquid-filled dielectric plates and series hollow inductors in a sealed oil tank, by obtaining a capacitance / inductance adjusting instruction, the filling and pumping volume and speed of insulating liquid and magnetic liquid are controlled according to the absolute value of an adjusting value, and continuous and accurate adjustment of the filtering frequency and reactive power is achieved. The method comprises multiple optimization: monitoring high fluctuation of liquid, synchronously filling, pumping and radiating, balancing efficiency and energy consumption according to an adjusting frequency adaptive circulation speed, and performing reverse linkage cooperative adjustment on a dielectric medium pump and a magnetic liquid pump; and magnetic liquid leakage and insulation abnormity are treated in stages, so that operation is guaranteed. The method solves a traditional adjustment dead zone, does not need a power electronic device, is low in cost, is small in loss, is adaptive to outdoors, and improves the electric energy quality and equipment safety of a converter station.

The present application relates to the technical field of communications, and discloses a base station antenna unit, a base station antenna array, and a base station. The base station antenna unit comprises a dielectric plate, a metal ground plate, a first dielectric resonator, a second dielectric resonator, a dielectric coupling path, and a feeding structure; the metal ground plate and the feeding structure are arranged on two sides of the dielectric plate, respectively, and a cross-shaped slot is formed on the metal ground plate; the first dielectric resonator and the second dielectric resonator are of a symmetrical structure, and the first dielectric resonator and the second dielectric resonator are arranged on the dielectric plate; the dielectric coupling path is arranged on the dielectric plate, located between the first dielectric resonator and the second dielectric resonator, coupled to the first dielectric resonator and the second dielectric resonator, and located above the cross-shaped slot; and the feeding structure has two feeding ports, feeding input by means of different feeding ports excites the cross-shaped slot to generate an orthogonal electric field, and electromagnetic waves of the orthogonal electric field reach the first dielectric resonator and the second dielectric resonator by means of the dielectric coupling path.

The invention discloses a Ka-band broadband filtering antenna, which comprises a probe, a ground paving layer, and a first horizontal dielectric plate, a first radiation patch, a second horizontal dielectric plate and a second radiation patch which are arranged on the ground paving layer, and is characterized in that the first radiation patch is provided with a c-shaped groove, the c-shaped groove is internally provided with a circular groove, and the circular groove is internally provided with a pair of branches; one ends of the two branches are combined to form a combined end connected to the first radiation patch, and the other ends of the two branches are parallel and have a gap to form a parallel opening end; and the center of the second radiation patch is close to the combined end of the two branches on the first radiation patch and far away from the parallel opening ends of the two branches on the first radiation patch. According to the invention, through collaborative design of slotting and branch knot loading, a filtering structure is innovatively constructed. The core innovation lies in the collaborative design of the two filtering structures and the spread spectrum structure, and the filtering frequency domain and the passband width are remarkably improved. The method can be widely applied to the fields of base stations, national defense and military industry and the like.

The invention, which relates to the technical field of modern communication, discloses a metasurface-based high-gain low-profile dual-circularly polarized antenna comprising a first dielectric plate, a second dielectric plate arranged below the first dielectric plate, and a metasurface structure arranged above the first dielectric plate. Three rows and three columns of periodically arranged metasurface structures are arranged above the first dielectric plate, a multi-level cooperative working mechanism is constructed by combining 45-degree symmetrical composite gaps etched in a layer indirect floor and a microstrip feeder line which is orthogonally arranged on the lower layer, and the metasurface array realizes high-gain radiation by regulating and controlling the phase of electromagnetic waves. The composite slot structure efficiently converts microstrip line energy into an orthogonal degenerate mode through non-contact coupling, circular polarization purity is guaranteed, the axial ratio bandwidth is expanded to 24.2%, an orthogonal microstrip feeder line forms a 90-degree phase difference through accurately controlled size, high isolation and stable standing-wave ratio of double ports are guaranteed, and the antenna has a wide application prospect. And finally, dual-circular-polarization independent radiation is realized in a 5mm low-profile structure.

A modular structure supports elevated rail segments for delivering electrical power to a moving work machine, such as a hauler at a mining site. Opposite ends of a roadside barrier contain complementary tubular couplers arranged vertically. A lower end of a dielectric post positioned in one of the tubular couplers has opposing dielectric plates at an upper end. A top edge of each plate has a creepage concavity between a pair of rail recesses. Another dielectric post of similar configuration is positioned in the other of the tubular couplers. Holes within the couplers and the posts ensure alignment of respective rail recesses in which conductive rails are placed. Dielectric inserts frictionally lock the rails into the rail recesses.

The invention discloses a broadband / high gain / high isolation / low cross polarization dual polarized antenna for millimeter wave communication. The antenna is formed by combining and fastening three layers of dielectric plates through screws, and double surfaces of each layer of dielectric plate are coated with copper. From top to bottom, the first dielectric plate is provided with a square substrate integrated cavity (SIC) enclosed by metal through holes, a first metal layer is etched along the range of the SIC to form an open aperture for antenna radiation, and meanwhile, a windmill type metal patch is loaded at the central position of the aperture surface to maintain an internal electric field of the SIC to be in a TM mode in a working frequency band; the symmetrical structure provides a dual-polarization radiation condition. And meanwhile, the SIW feed transmission lines are orthogonally arranged, so that the requirement of high isolation between the two input ports can be met.

Disclosed are a susceptor for enabling uniform plasma treatment over the entire surface of a wafer, and a manufacturing method therefor. Provided is the susceptor comprising: a dielectric plate having an upper surface on which a wafer is loaded, and a lower surface facing same; and an inner RF electrode and an outer RF electrode that are buried in the dielectric plate, wherein, with respect to the lower surface, the height of a first plane in which the inner RF electrode is buried is less than the height of a second plane in which the outer RF electrode is buried.

A modular structure supports elevated rail segments for delivering electrical power to a moving work machine, such as a hauler at a mining site. Opposite ends of a roadside barrier contain complementary tubular couplers arranged vertically. A lower end of a dielectric post positioned in one of the tubular couplers has opposing dielectric plates at an upper end. A top edge of each plate has a creepage concavity between a pair of rail recesses. Another dielectric post of similar configuration is positioned in the other of the tubular couplers. Holes within the couplers and the posts ensure alignment of respective rail recesses in which conductive rails are placed. Dielectric inserts frictionally lock the rails into the rail recesses.

The invention provides a filtering circularly polarized antenna with a wide axial ratio bandwidth. The filtering circularly polarized antenna comprises a first dielectric plate, a second dielectric plate, a third dielectric plate and a fourth dielectric plate which are sequentially arranged in parallel from bottom to top, a metal reflecting plate is printed on the lower surface of the first dielectric plate; a feed network is printed on the lower surface of the second dielectric plate, a slotted metal ground is printed on the upper surface of the second dielectric plate, a feed port is formed in one side edge of the second dielectric plate, and the feed port is electrically connected with the feed network and the slotted metal ground; a second square patch and an octagonal parasitic microstrip line frame are printed on the upper surface of the third dielectric plate, and the octagonal parasitic microstrip line frame surrounds the outer side of the second square patch; and a first square patch is printed on the lower surface of the fourth dielectric plate. Through an interlayer coupling collaborative design, 2.3-5.0 GHz broadband circular polarization radiation and high gain characteristics are realized, and the antenna also has high out-of-band rejection capability and can effectively filter out-of-band clutter interference.

The circularly polarized metasurface antenna comprises a metasurface layer, a first dielectric plate layer, a metal floor layer, a second dielectric plate layer and a feed network layer which are sequentially stacked from top to bottom, the metasurface layer comprises a plurality of mutually orthogonal metasurface subunits, each metasurface subunit comprises a plurality of metasurface structures arranged in an array period, and each metasurface structure is provided with a monopole radiation structure; the feed network layer is provided with a plurality of output feed points, and the number of the output feed points is the same as that of the metasurface structures. The output feeding points are connected with probes, and the probes sequentially penetrate through the second dielectric plate layer, the metal floor layer and the first dielectric plate layer until the probes are connected with the input feeding points of the corresponding radiation structures. According to the antenna, each layer adopts a covering laminated design, the structure is compact, the antenna has the characteristics of ultra-wideband circular polarization radiation, high gain and good cross polarization, the dual ultra-wideband characteristics of working and RCS reduction are realized, the RCS reduction bandwidth completely covers the working bandwidth, and effective invisibility in and out of the antenna band is achieved.

The invention relates to a miniaturized broadband power dividing filter applied to an X frequency band. The antenna comprises a metal layer and a dielectric substrate layer, and the metal layer is divided into two layers including an upper metal layer and a lower metal layer; the upper metal layer comprises a section of input feeder line, a first output feeder line, a second output feeder line, an isolation resistor, a first filtering branch knot and a second filtering branch knot, and each of the first filtering branch knot and the second filtering branch knot comprises two same dual composite left and right hand resonance units; the lower metal layer is of a metal grounding plate structure, and two grooves are formed in the metal grounding plate. According to the invention, the sub-wavelength characteristic is fully utilized, the miniaturization of the circuit is realized, the defect of overlarge size of a traditional cascade scheme is effectively overcome, and the circuit is suitable for a high-frequency (x-waveband) application scene. The whole structure is based on the double-sided microwave dielectric plate, has the advantages of simple processing and low cost, and is suitable for large-scale production.

The invention provides a curved surface polarization torsion reflecting surface and an antenna using the same, and belongs to the technical field of antennas. The curved surface polarization torsion reflection surface comprises a curved surface dielectric plate, and a metal bottom plate and an electromagnetic metasurface which are respectively arranged on the outer side and the inner side of the curved surface dielectric plate; the electromagnetic metasurface is formed by periodically arranging a plurality of single-layer electromagnetic metasurface units. The single-layer metasurface unit with the polarization torsion function is conformal on the curved surface, so that the technical problems that a traditional multi-layer planar polarization torsion structure is complex to process, curved surface conformal is difficult, and the performance is deteriorated after conformal are solved. The reflecting surface is preferably a paraboloid, so that the incident wave polarization torsion is realized, and the spherical wave can be converted into the plane wave to improve the antenna gain. The metasurface unit keeps good cross polarization reflection performance within the wide incidence angle range of 0-40 degrees, is suitable for curved surface conformal design, can be integrally formed through 3D printing, and is easy and convenient to machine and stable in performance.

This invention generates uniform plasma by reducing the possibility of dielectric breakdown even when a dielectric plate is divided into a plurality of parts. This plasma processing device is provided with: an antenna (3) that generates plasma inside a vacuum container (1); and a plurality of dielectric plates (22) that are disposed so as to close an opening (11) of the vacuum container (1). At least a portion of the antenna (3) that overlaps a gap (22A) formed between the end surfaces of two adjacent dielectric plates (22) has insulating properties.

The invention discloses an energy selection surface with a polarization conversion function, which is formed by periodically arranging a plurality of energy selection surface units with the same structure, each unit comprises a polarization conversion layer and an energy selection layer, and the polarization conversion layer is composed of two metal layers and three dielectric plate layers so as to realize the polarization conversion function; the energy selection layer is composed of two metal layers, two dielectric plate layers and an air layer so as to realize an energy selection function; the polarization conversion layer and the energy selection layer are separated by an air layer. According to the energy selection surface, through the combined action of the polarization conversion layer and the energy selection layer, the insertion loss of the energy selection surface can be lower than-1dB in a wave transmission mode in a working frequency band, and the polarization conversion efficiency exceeds 90%. In a protection mode, the energy selection surface shows a remarkable energy selection characteristic in an ultra-wideband range, the protection efficiency is superior to-20dB, and the energy selection surface is suitable for an aircraft antenna housing.

The application belongs to the technical field of antennas, and discloses an S / Ka-band common-aperture antenna and communication equipment, which comprises a first dielectric plate and a second dielectric plate stacked from top to bottom; the top surface, the middle and the bottom surface of the first dielectric plate are respectively provided with a rectangular patch array, a first metal through hole and a first metal layer; wherein the rectangular patch array, the first metal through hole and the first metal layer form a magneto-electric dipole antenna array; the magneto-electric dipole antenna array works in the Ka-band and is used for realizing satellite communication; the top surface, the middle and the bottom surface of the second dielectric plate are respectively provided with a second metal layer, a second metal through hole and a third metal layer; wherein the second metal layer, the second metal through hole and the third metal layer form a low-profile monopole antenna; the low-profile monopole antenna works in the S-band and is used for realizing ground equipment communication; the application has a simple structure, can realize different beams and polarization characteristics, effectively improves the space utilization rate of the antenna and has high integration.

The invention discloses a double-resonance microwave sensor, and relates to the technical field of sensors, the double-resonance microwave sensor comprises a dielectric plate, the front surface of the dielectric plate is provided with a microwave resonance layer, and complementary opening resonance units are etched on the microwave resonance layer; the complementary opening resonance unit comprises an inner ring groove and an outer ring groove which are concentrically arranged, one side of the inner ring groove is provided with a connecting bridge extending outwards, and the connecting bridge is communicated with the outer ring groove; interdigital slotting units which are symmetrical to each other are arranged on the two sides of the outer ring groove respectively; the back surface of the dielectric plate is provided with microstrip lines corresponding to the complementary opening resonance units. According to the invention, by adopting a dual-resonance structure in which the complementary opening resonance units are coupled with the microstrip lines, dual-resonance transmission response can be excited and formed, so that the detection precision and sensitivity of the sensor are improved.

The invention discloses a wide-angle-domain polarization conversion metasurface with an ultra-wideband characteristic and electronic equipment, the wide-angle-domain polarization conversion metasurface with the ultra-wideband characteristic is formed by periodically arranging a plurality of polarization conversion metasurface units, each polarization conversion metasurface unit comprises two dielectric plate layers and three metal layers, the three metal layers are arranged to be a top-layer metasurface, a middle-layer metasurface and a bottom-layer metal floor from top to bottom, the two dielectric plate layers are arranged among the three metal layers at intervals, and two metal holes are formed in the longitudinal central axis of a metal strip of the top-layer metasurface. And each metal hole penetrates through the upper-layer dielectric plate and is in short circuit with the two rectangular metal patches in the middle of the middle-layer metasurface to form a magnetic resonator. Efficient cross polarization conversion can be achieved within the ultra-wideband range of 9.79-20.62 GHz, the polarization conversion rate is always kept to be 0.9 or above within the wide angular domain of 0-42 degrees, and the ultra-wideband high-polarization-conversion-efficiency ultra-wideband antenna has the advantages of being ultra-wideband, high in polarization conversion efficiency and stable in wide angular domain performance.

An apparatus for treating a substrate includes a housing including an open top and a treatment space therein, a gas supply unit configured to supply gas to the treatment space, a support unit including a chuck configured to support the substrate in the treatment space and an upper electrode provided to surround the check when viewed from the top, a dielectric plate unit including a dielectric plate arranged to oppose the substrate supported by the support unit in the treatment space, an upper electrode unit coupled to the dielectric plate unit and including an upper electrode arranged to oppose the lower electrode, and an aligning unit configured to align a horizontal arrangement of the dielectric plate unit, in which a lid extending from the housing in the horizontal direction and coupled to the upper electrode unit is provided on the housing, and the aligning unit is coupled to the lid.

The utility model discloses an assembling and positioning device for an antenna oscillator assembly. The assembling and positioning device comprises a clamp main body, a positioning element and a clamping element, the clamp main body is provided with an oscillator plate mounting surface matched with the antenna oscillator assembly; a dielectric plate positioning groove is formed in the oscillator plate mounting surface; the positioning element comprises a group of dielectric plate positioning assemblies and a plurality of groups of oscillator plate positioning assemblies; the dielectric plate positioning assembly comprises a positioning hole and a positioning pin which are arranged at one end of the dielectric plate positioning groove; each group of oscillator plate positioning assemblies comprises two oscillator assembly positioning holes formed in one side of the oscillator plate mounting surface and two corresponding positioning pins, and each group of oscillator plate positioning assemblies are distributed along the length direction of the clamp main body; the clamping element and the dielectric plate positioning assembly are located at the two ends of the clamp body in the length direction respectively. And the clamping element comprises a clamping screw and a fixing plate which are arranged on the mounting surface of the oscillator plate. The line oscillator assembly assembling and positioning device can effectively improve assembling precision and meet production requirements.

A feeding structure comprises: a dielectric plate for vehicle window having a first surface and a second surface opposite to the first surface; a feeding unit positioned on the first surface side of the dielectric plate; and a receiving unit positioned on the second surface side of the dielectric plate, wherein the dielectric plate includes a first dielectric region between the feeding unit and the receiving unit, and a second dielectric region adjacent to the first dielectric region in a plan view, and the second dielectric region has a relative permittivity lower than that of the first dielectric region when the feeding unit and the receiving unit are electromagnetically coupled to each other.

The rocker assembly comprises a mounting seat, a rocker and a first capacitance detection assembly, the rocker is movably arranged on the mounting seat, and the first capacitance detection assembly comprises a dielectric plate, a first detection polar plate, a second detection polar plate and a compensation polar plate. The first detection polar plate, the second detection polar plate and the compensation polar plate are respectively fixed relative to the position of the mounting seat, the first detection polar plate and the second detection polar plate are arranged at intervals and form a detection capacitor, the dielectric plate is arranged between the first detection polar plate and the second detection polar plate, and the dielectric plate is linked with the rocker to be driven to move relative to the detection capacitor; the compensation polar plate and the first detection polar plate are arranged at an interval and form a compensation capacitor, the relative movement of the dielectric plate and the detection capacitor can cause the capacitance value change of the detection capacitor, and the compensation capacitor can be used for detecting the influence of environmental factors such as temperature and humidity on the capacitance value, so that the detection of the detection capacitor can be compensated. The motion detection precision of the rocker is ensured.

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

The application relates to the technical field of mobile communication, and discloses a dual-polarization dipole antenna based on odd mode and even mode fusion, which comprises a dielectric plate, a first dipole and a second dipole, the first dipole is printed on the upper surface of the dielectric plate, the second dipole is printed on the lower surface of the dielectric plate, and the first dipole is perpendicular to the second dipole. The application solves the problems that the existing dual-polarization dipole antenna cannot simultaneously meet the requirements of miniaturization and wide bandwidth.

The application discloses a double-resonance microwave sensor and relates to the technical field of sensors, which comprises a dielectric plate, the front surface of the dielectric plate is provided with a microwave resonance layer, and the microwave resonance layer is etched with a complementary open resonant unit; the complementary open resonant unit comprises concentrically arranged inner ring grooves and outer ring grooves, one side of the inner ring grooves is provided with an outwardly extending connecting bridge, the connecting bridge is in communication with the outer ring grooves; the two sides of the outer ring grooves are respectively provided with interdigitated slotted units that are symmetrical to each other; and the back surface of the dielectric plate is provided with a microstrip line corresponding to the complementary open resonant unit. The double-resonance structure of the complementary open resonant unit and the microstrip line coupling can excite a double-resonance transmission response, so that the detection precision and sensitivity of the sensor are improved.

The application discloses a low-cost air antenna and relates to the technical field of antennas, which comprises an antenna reflecting plate, an antenna dielectric plate, a metal column and a feeding component, the first surface and the second surface of the antenna dielectric plate are respectively provided with a first radiating element and a second radiating element, the second surface is the side of the antenna dielectric plate opposite to the antenna reflecting plate, the first radiating element and the second radiating element generate a first resonant frequency and a second resonant frequency respectively, the antenna dielectric plate is provided with an opening, the first end of the metal column is fixedly connected with the antenna reflecting plate, and the second end of the feeding component penetrates through the opening, so that the first radiating element and the second radiating element are coupled and fed through the opening; the two radiating units are coupled and fed, the bandwidth can be expanded, the four feeding components are coupled, the axial ratio is better, there are fewer feeding points and fewer devices compared with the four feeding components of the laminated four feeding components, the assembly difficulty is simplified, and the assembly cost, the material cost and the antenna weight are reduced.

A direction finding system including a gradient index lens having a plurality of stacked dielectric plates with through holes causing a gradual variation of a refractive index across a diameter of each of the plurality of stacked dielectric plates. A plurality of antennas located around a section of a perimeter of the gradient index lens. The variation of the refractive index in each of the plurality of stacked dielectric plates causes the gradient index lens to direct a radio frequency (RF) signal received by the gradient index lens towards a target antenna of the plurality of antennas. An RF processing system is configured to process an RF signal received by the plurality of antennas and determine a direction of arrival of the RF signal based on a location of the target antenna of the plurality of antennas that outputs the received signal strength above a threshold.

The utility model relates to the technical field of antennas, provides a circularly polarized antenna, an antenna device and a vehicle, and can solve the problem that the size of the circularly polarized antenna is too large in the prior art. The circularly polarized antenna comprises a floor, a dielectric plate, a plurality of first radiation arms, a plurality of parasitic radiation arms and a feed unit, the dielectric plate and the floor are arranged separately; the plurality of first radiation arms are arranged on the dielectric plate and form at least one crossed dipole; the multiple parasitic radiation arms are distributed at the edge of the dielectric plate in the circumferential direction of the dielectric plate, each parasitic radiation arm is coupled with the first radiation arm close to the parasitic radiation arm, each parasitic radiation arm is provided with a grounding end and an open end, the grounding end is connected to the floor, the open end is located at the edge of the dielectric plate, and the open end is connected to the ground. The cross sectional area of the parasitic radiation arm at the grounding end is smaller than that at the open end; the feed unit is used for feeding each first radiation arm. The device can be used on a vehicle.

Disclosed in the embodiments of the present application are a metasurface unit, and a metasurface array antenna and a communication device containing same. The metasurface unit includes a first-layer dielectric plate, a second-layer dielectric plate and a third-layer dielectric plate, wherein the second-layer dielectric plate includes a metal grounding layer, a liquid-crystal material layer, a metal patch having anisotropic characteristics, and a direct-current bias line, and both the direct-current bias line and the metal patch are printed on the liquid-crystal material layer; and the first-layer dielectric plate is one surface of the metasurface unit, the third-layer dielectric plate is another surface of the metasurface unit, and the second-layer dielectric plate is located between the first-layer dielectric plate and the third-layer dielectric plate.