# US 2019/0245273 A1 · Fabry-perot cavity antenna system having a frequency selective surface > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2019/0245273 A1 - Document ID: US20190245273A1 - Status: Published application - Kind: A1 - Application number: 16/269,957 - Filed: 2019-02-07 - Published: 2019-08-08 - Earliest claimed: 2018-02-07 - Assignees: Regents of the University of Minnesota - Applicants: Regents of the University of Minnesota - Inventors: Rhonda R. Franklin; Robert Sainati; Chanjoon Lee; Aditya Dave - Web page: https://patentgrep.com/patent/US20190245273A1 ## CPC - H01Q 3/44: varying the electric or magnetic characteristics of reflecting, refracting, or diffracting devices associated with the radiating element - H01Q 15/0033: {used for beam splitting or combining, e.g. acting as a quasi-optical multiplexer (H01Q19/191 and H01Q19/195 take precedence)} - H01Q 3/245: {in the focal plane of a focussing device} - H01Q 13/10: Resonant slot antennas - H01Q 13/18: the slot being backed by, or formed in boundary wall of, a resonant cavity (longitudinally slotted cylinder H01Q13/12 ){; Open cavity antennas} - H01Q 19/108: {Combination of a dipole with a plane reflecting surface (H01Q19/106 takes precedence; strip line H01Q9/065)} - H01Q 21/065: {Patch antenna array} - H01Q: ANTENNAS, i.e. RADIO AERIALS (radiators or antennas for microwave heating H05B6/72) ## Abstract An antenna system may include a source antenna, a frequency selective surface (FSS), and a second antenna or a fluidic channel associated with a housing. In both examples, the FSS has a first side and a second side opposite from the first side. The first side includes horizontally oriented unit cells positioned as multiple columns of unit cells. The first side of the FSS faces the source antenna and is separated from the source antenna by a defined distance. The housing is positioned on the second side of the FSS. In the latter example, the fluidic channel of the housing includes one of air or deionized water. The fluidic channel is positioned on a portion of the second side of the FSS that is opposite to a subset of the horizontally oriented unit cells on the first side of the FSS. ## Claims ### Claim 1 An antenna system, comprising: a source antenna: a frequency selective surface (FSS) having a first side and a second side opposite from the first side, wherein the first side of the FSS includes a plurality of horizontally oriented unit cells, wherein the horizontally oriented unit cells are positioned as multiple columns of unit cells on the first side of the FSS, wherein the first side of the FSS faces the source antenna, and wherein the first side of the FSS is separated from the source antenna by a defined distance; and a housing that includes a fluidic channel, wherein the housing is positioned on the second side of the FSS, wherein the fluidic channel includes one of air or deionized water, and wherein the fluidic channel is positioned on a portion of the second side of the FSS that is opposite to a subset of the horizontally oriented unit cells on the first side of the FSS. ### Claim 2 (depends on 1) The antenna system of claim 1, wherein the antenna system is Fabry-Perot Cavity (FPC) antenna system, and wherein the antenna system further comprises: a cavity-backed reflector that is separated from the source antenna by a defined cavity; and at least one metallic sidewall that is coupled to one or more of the cavity-backed reflector, the source antenna, or the FSS. ### Claim 3 (depends on 1) The antenna system of claim 1, wherein the source antenna comprises a slot dipole antenna, and wherein the antenna system further comprises: a coplanar waveguide (CPW) feedline that is configured to feed the slot dipole antenna. ### Claim 4 (depends on 1) The antenna system of claim 1, wherein the fluidic channel in the housing contains air, and wherein the horizontally oriented unit cells positioned as multiple columns of unit cells on the first side of the FSS, in conjunction with and the fluidic channel in the housing positioned on the second side of the FSS, are configured to perform beam focusing of radiation that is emitted by the source antenna. ### Claim 5 (depends on 1) The antenna system of claim 1, wherein the fluidic channel in the housing contains deionized water, and wherein the horizontally oriented unit cells positioned as multiple columns of unit cells on the first side of the FSS, in conjunction with and the fluidic channel in the housing positioned on the second side of the FSS, are configured to perform beam splitting of radiation that is emitted by the source antenna. ### Claim 6 (depends on 1) The antenna system of claim 1, wherein the subset of the horizontally oriented unit cells on the first side of the FSS are positioned substantially along a center portion of the first side of the FSS, and wherein the fluidic channel is positioned on the portion of the second side of the FSS that is substantially opposite the center portion of the first side of the FSS. ### Claim 7 (depends on 1) The antenna system of claim 1, wherein the subset of the horizontally oriented unit cells on the first side of the FSS includes at least one of the multiple columns of unit cells on the first side of the FSS, and wherein the fluidic channel is positioned on the portion of the second side of the FSS that is substantially opposite to the at least one of the multiple columns of unit cells on the first side of the FSS. ### Claim 8 (depends on 7) The antenna system of claim 7, wherein the multiple columns of unit cells on the first side of the FSS include nine columns of unit cells, wherein each of the nine columns of unit cells includes twenty-seven individual horizontally oriented unit cells, wherein the subset of the horizontally oriented unit cells on the first side of the FSS includes a particular column of the nine columns of unit cells, and wherein the fluidic channel is positioned on the portion of the second side of the FSS that is substantially opposite to the particular column of unit cells on the first side of the FSS. ### Claim 9 (depends on 8) The antenna system of claim 8, wherein the particular column of unit cells comprises a middle column within the nine columns of unit cells. ### Claim 10 (depends on 1) The antenna system of claim 1, wherein each of the horizontally oriented unit cells includes a rectangular-shaped aperture that is positioned substantially in a center of the respective horizontally oriented unit cell. ### Claim 11 (depends on 1) The antenna system of claim 1, wherein the fluidic channel in the housing has a width of 8 millimeters. ### Claim 12 (depends on 1) The antenna system of claim 1, wherein the fluidic channel in the housing has a width of 10 millimeters. ### Claim 13 (depends on 1) The antenna system of claim 1, wherein the housing is made of polydimethylsiloxane (PDMS). ### Claim 14 (depends on 1) The antenna system of claim 1, further comprising a pump that is configured to fill the fluidic channel of the housing with the one of air or deionized water. ### Claim 15 A method comprising: configuring an antenna system to operate in a first mode, wherein the first mode comprises one of a beam-splitting mode or a beam-focusing mode, and wherein the antenna system comprises: a source antenna: a frequency selective surface (FSS) having a first side and a second side opposite from the first side, wherein the first side of the FSS includes a plurality of horizontally oriented unit cells, wherein the horizontally oriented unit cells are positioned as multiple columns of unit cells on the first side of the FSS, wherein the first side of the FSS faces the source antenna, and wherein the first side of the FSS is separated from the source antenna by a defined distance; and a housing that includes a fluidic channel, wherein the housing is positioned on the second side of the FSS, wherein the fluidic channel includes one of air or deionized water, and wherein the fluidic channel is positioned on a portion of the second side of the FSS that is opposite to a subset of the horizontally oriented unit cells on the first side of the FSS; and subsequent to the antenna system operating in the first mode for a duration of time, reconfiguring the antenna system to operate in a second mode, wherein the second mode comprises one of the beam-splitting mode or the beam-focusing mode, wherein the second mode is different from the first mode, and wherein configuring the antenna system to operate in the first mode and reconfiguring the antenna system to operate in the second mode each comprise filling the fluidic channel of the housing with one of air or deionized water. ### Claim 16 (depends on 15) The method of claim 15, wherein configuring the antenna system to operate in the first mode comprises filling the fluidic channel of the housing with deionized water, wherein the first mode comprises the beam-splitting mode, and wherein, while in the beam-splitting mode, the horizontally oriented unit cells positioned as multiple columns of unit cells on the first side of the FSS, in conjunction with and the fluidic channel in the housing positioned on the second side of the FSS, are configured to perform beam-splitting of radiation that is emitted by the source antenna. ### Claim 17 (depends on 15) The method of claim 15, wherein reconfiguring the antenna system to operate in the second mode comprises filling the fluidic channel of the housing with air, wherein the second mode comprises the beam-focusing mode, and wherein, while in the beam-focusing mode, the horizontally oriented unit cells positioned as multiple columns of unit cells on the first side of the FSS, in conjunction with and the fluidic channel in the housing positioned on the second side of the FSS, are configured to perform beam focusing of radiation that is emitted by the source antenna. ### Claim 18 (depends on 15) The method of claim 15, wherein the antenna system is Fabry-Perot Cavity (FPC) antenna system, and wherein the antenna system further comprises a cavity-backed reflector that is separated from the source antenna by a defined cavity, and at least one metallic sidewall that is coupled to one or more of the cavity-backed reflector, the source antenna, or the FSS. ### Claim 19 (depends on 15) The method of claim 15, wherein the source antenna comprises a slot dipole antenna, and wherein the antenna system further comprises a coplanar waveguide (CPW) feedline that is configured to feed the slot dipole antenna. ### Claim 20 (depends on 15) The method of claim 15, wherein the subset of the horizontally oriented unit cells on the first side of the FSS are positioned substantially along a center portion of the first side of the FSS, and wherein the fluidic channel is positioned on the portion of the second side of the FSS that is opposite the center portion of the first side of the FSS. ### Claim 21 An antenna system, comprising: a transmit antenna that is configured to emit radiation: a frequency selective surface (FSS) having a first side and a second side opposite from the first side, wherein the first side of the FSS faces the transmit antenna and includes a plurality of horizontally oriented unit cells, wherein the first side of the FSS is separated from the transmit antenna by a first defined distance, wherein at least a portion of the radiation emitted by the transmit antenna passes through the plurality of horizontally oriented unit cells, and wherein the plurality of horizontally oriented unit cells includes one or more groups of cells that each includes multiple columns of one or more horizontally oriented unit cells; a receive antenna that is configured to receive at least the portion of the radiation that passes through the plurality of horizontally oriented unit cells of the FSS, wherein the receive antenna faces the second side of the FSS and is separated from the second side of the FSS by a second defined distance, and wherein the FSS is positioned between the transmit antenna and the receive antenna; and an enclosure that is configured to at least partially enclose the transmit antenna, the FSS, and the receive antenna. ### Claim 22 (depends on 21) The antenna system of claim 21, wherein the enclosure comprises a plurality of metal-coated sidewalls. ### Claim 23 (depends on 21) The antenna system of claim 21, wherein the one or more groups of cells includes a plurality of groups of horizontally oriented unit cells that are configured to perform beam splitting of the radiation that is emitted by the transmit antenna. ### Claim 24 (depends on 23) The antenna system of claim 23, wherein the plurality of groups of horizontally oriented unit cells comprises four groups of horizontally oriented unit cells, wherein each of the four groups includes three columns of horizontally oriented unit cells, and wherein each of the three columns includes nine horizontally oriented unit cells. ### Claim 25 (depends on 23) The antenna system of claim 23, wherein the receive antenna comprises a first receive antenna that is configured to receive at least a first portion of the radiation that passes through a first group of the plurality of groups of horizontally oriented unit cells, and wherein the antenna system further includes a second receive antenna that faces the second side of the FSS and that is configured to receive at least a second portion of the radiation that passes through a second group of the plurality of horizontally oriented unit cells. ### Claim 26 (depends on 23) The antenna system of claim 23, wherein each group of the plurality of groups of horizontally oriented unit cells is separated from another group of the plurality of groups of horizontally oriented unit cells by a respective plurality of vertically oriented unit cells. ### Claim 27 (depends on 21) The antenna system of claim 21, wherein each of the one or more groups of cells is surrounded by a plurality of vertically oriented unit cells. ### Claim 28 (depends on 21) The antenna system of claim 21, wherein the transmit antenna comprises a first patch antenna and a first substrate, the first patch antenna being positioned between the first substrate and the FSS, and wherein the receive antenna comprises a second patch antenna and a second substrate, the second patch antenna being positioned between the second substrate and the FSS. ### Claim 29 (depends on 21) The antenna system of claim 21, wherein the transmit antenna comprises a slot antenna, a microstrip feed, and a cavity-backed reflector, wherein the microstrip feed is positioned between the cavity-backed reflector and the slot antenna, wherein the receive antenna comprises a patch antenna, a substrate, and a ground plane, and wherein the substrate is positioned between the ground plane and the patch antenna. ### Claim 30 (depends on 21) The antenna system of claim 21, wherein the transmit antenna is included on at least a first integrated circuit, wherein the receive antenna is included on at least a second integrated circuit, and wherein the antenna system enables chip-to-chip communication between at least the first integrated circuit and the second integrated circuit in a multi-chip system. ### Claim 31 (depends on 21) The antenna system of claim 21, wherein each of the plurality of horizontally oriented unit cells includes a rectangular-shaped aperture that is positioned substantially in a center of the respective horizontally oriented unit cell. ### Claim 32 A method of providing wireless communication in an antenna system, the method comprising: emitting, by a transmit antenna of the antenna system, radiation that at least partially passes through a frequency selective surface (FSS) having a first side and a second side opposite from the first side, wherein the first side of the FSS faces the transmit antenna and includes a plurality of horizontally oriented unit cells, wherein the first side of the FSS is separated from the transmit antenna by a first defined distance, wherein at least a portion of the radiation emitted by the transmit antenna passes through the plurality of horizontally oriented unit cells, and wherein the horizontally oriented unit cells include one or more groups of cells that each includes multiple columns of one or more horizontally oriented unit cells; and receiving, by a receive antenna of the antenna system, at least the portion of the radiation that passes through the plurality of horizontally oriented unit cells of the FSS, wherein the receive antenna faces the second side of the FSS and is separated from the second side of the FSS by a second defined distance, and wherein the FSS is positioned between the transmit antenna and the receive antenna. ### Claim 33 (depends on 32) The method of claim 32, wherein the one or more groups of cells includes a plurality of groups of horizontally oriented unit cells, wherein at least the portion of the radiation received by the receive antenna of the antenna system includes at least first and second portions of the radiation, and wherein the method further comprises: splitting, by the plurality of groups of horizontally oriented unit cells, the radiation emitted by the transmit antenna into at least the first and second portions of the radiation. ### Claim 34 (depends on 33) The method of claim 33, wherein the receive antenna of the antenna system comprises a first receive antenna, wherein the FCP antenna system comprises a second receive antenna that faces the second side of the FSS, wherein the plurality of groups of horizontally oriented unit cells includes a first group and a second group, and wherein the method further comprises: receiving, by the first receive antenna of the antenna system, at least the first portion of the radiation that passes through the first group of the plurality of groups of horizontally oriented unit cells; and receiving, by the second receive antenna of the antenna system, at least the second portion of the radiation that passes through the second group of the plurality of horizontally oriented unit cells. ### Claim 35 (depends on 32) The method of claim 32, wherein the transmit antenna of the antenna system is included on at least a first integrated circuit, wherein the receive antenna of the antenna system is included on at least a second integrated circuit, and wherein receiving, by the receive antenna, at least the portion of the radiation that is emitted by the transmit antenna and that passes through the plurality of horizontally oriented unit cells of the FSS enables chip-to-chip communication between at least the first integrated circuit and the second integrated circuit.