# US 10,122,066 B2 · Horn antenna > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 10,122,066 B2 - Document ID: US10122066B2 - Status: Granted - Kind: B2 - Application number: 15/300,748 - Filed: 2015-03-25 - Published: 2017-01-19 - Granted: 2018-11-06 - Earliest claimed: 2014-03-31 - Assignees: Tokyo Keiki Co., Ltd. - Applicants: Tokyo Keiki Inc. - Inventors: Satoshi Ito; Masaki Shimizu; Daisuke Kobayashi - Web page: https://patentgrep.com/patent/US10122066B2 ## CPC - H01Q 1/225: {used in level-measurement devices, e.g. for level gauge measurement} - G01F 23/284: Electromagnetic waves - G01S 7/03: Details of HF subsystems specially adapted therefor, e.g. common to transmitter and receiver - G01S 13/88: Radar or analogous systems specially adapted for specific applications (electromagnetic prospecting or detecting of objects, e.g. near-field detection, G01V3/00) - H01Q 13/02: Waveguide horns - H01Q 19/08: for modifying the radiation pattern of a radiating horn in which it is located {(corrugated horns H01Q13/0208; producing a circular polarisation H01Q13/0241)} - H01Q: ANTENNAS, i.e. RADIO AERIALS (radiators or antennas for microwave heating H05B6/72) - G01F: MEASURING VOLUME, VOLUME FLOW, MASS FLOW OR LIQUID LEVEL; METERING BY VOLUME - G01S: RADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES ## Abstract A horn antenna includes a metallic horn having a rear end adapted for connection with a waveguide. The horn antenna further includes a dielectric horn connected with the metallic horn and extending forward from a front end of the metallic horn. The dielectric horn includes: i) a metallic horn filler section adapted for filling an internal space of the metallic horn; ii) a waveguide filler section formed to extend rearward from a rear end of the metallic horn filler section and adapted for filling an internal space of a section of a predetermined length of the waveguide; and iii) a flared end section having a frustum shaped internal space, which is formed to flare out toward the front end of the dielectric horn. The metallic horn and the flared end section of the dielectric horn have respective cross sections whose outer contours are the same as each other. ## Claims ### Claim 1 A horn antenna, comprising: a metallic horn including a front end and a rear end, the rear end being adapted for connection with a waveguide having a cross section of a constant shape; and a dielectric horn including a front end and a rear end, the dielectric horn being connected with the metallic horn and extending forward from the front end of the metallic horn, wherein the metallic horn includes: an opening at the rear end thereof, which has a cross section corresponding to the cross section of the waveguide; and a conical frustum shaped internal space flaring out from the opening toward the front end of the metallic horn, wherein the dielectric horn comprises: a metallic horn filler section including a front end and a rear end, the metallic horn filler section being adapted for filling the conical frustum shaped internal space of the metallic horn; a waveguide filler section including a rear end, the waveguide filler section being formed to extend rearward from the rear end of the metallic horn filler section and adapted for filling an internal space of a section of a predetermined length of the waveguide; a first impedance matching section formed at the rear end of the waveguide filler section and adapted for establishing impedance matching between the waveguide and the dielectric horn; a second impedance matching section formed at the front end of the metallic horn filler section and at a center of a cross section of the metallic horn filler section, and adapted for establishing impedance matching between the dielectric horn and air; and a flared end section including a frustum shaped internal space, which is formed to flare out from in a front of the second impedance matching section toward the front end of the dielectric horn and opens at the front end of the dielectric horn, wherein the metallic horn and the flared end section of the dielectric horn have respective cross sections whose outer contours are the same as each other and correspond to the outer contour of the cross section of the waveguide, and wherein the outer contour of the cross section perpendicular to a longitudinal direction of a tip of the metallic horn and the outer contour of the cross section perpendicular to the longitudinal direction of the flared end section of the dielectric horn have same shapes and equal sizes thereof. ### Claim 2 (depends on 1) The horn antenna according to claim 1, wherein the waveguide is integrally connected with the rear end of the metallic horn. ### Claim 3 (depends on 1) The horn antenna according to claim 1, wherein the waveguide includes a circular waveguide, the metallic horn has the cross section having the outer contour which is circular in shape, and the dielectric horn has a cross section having an outer contour which is circular in shape. ### Claim 4 (depends on 1) The horn antenna according to claim 1, wherein the waveguide has a cross section having an outer contour which is smaller than the outer contour of the cross section of the metallic horn. ### Claim 5 (depends on 1) The horn antenna according to claim 1, wherein the waveguide and the metallic horn have respective outer circumferential surfaces covered by at least one fluoropolymer resin tube. ### Claim 6 (depends on 5) The horn antenna according to claim 5, wherein the at least one fluoropolymer resin tube comprises a first tube comprising a perfluoroalkoxy polymer and covering the outer circumferential surface of the metallic horn and a second tube comprising a perfluoroalkoxy polymer and covering the outer circumferential surface of the waveguide, the first and second tube being separate from each other. ### Claim 7 (depends on 1) The horn antenna according to claim 1, wherein the front end of the dielectric horn includes an annular frontal edge, and the dielectric horn include a plurality of protrusions formed along the annular frontal edge and extending forward from the annular frontal edge. ### Claim 8 (depends on 7) The horn antenna according to claim 7, wherein the protrusions are triangular in shape so that the annular frontal edge of the front end of the dielectric horn includes serrations. ### Claim 9 (depends on 1) The horn antenna according to claim 1, wherein the tip of the metallic horn is located at the front end of the metallic horn. ### Claim 10 (depends on 1) The horn antenna according to claim 1, wherein the second impedance matching section is located directly at the front end of the metallic horn filler section. ### Claim 11 (depends on 1) The horn antenna according to claim 1, wherein the second impedance matching section is located directly at the center of the cross section of the metallic horn filler section. ### Claim 12 (depends on 1) The horn antenna according to claim 1, wherein the second impedance matching section is located at the outer contour of the cross section perpendicular to the longitudinal direction of the tip of the metallic horn. ### Claim 13 (depends on 1) The horn antenna according to claim 1, further comprising: a hollow rod section including a cylindrical axial hole which extends from the front end of the second impedance matching section to the flared end section. ### Claim 14 (depends on 13) The horn antenna according to claim 13, wherein the second impedance matching section is located at a rear end of the hollow rod section and includes: a first tapering surface arranged to be in a direct contact with the hollow rod section. ### Claim 15 (depends on 14) The horn antenna according to claim 14, wherein the second impedance further includes: a second tapering surface including a step portion located relative to the first tapering surface.