# US 12,771,023 B2 · Communication device comprising a retroreflective structure > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 12,771,023 B2 - Document ID: US12771023B2 - Status: Granted - Kind: B2 - Application number: 18/820,756 - Filed: 2024-08-30 - Published: 2025-02-20 - Granted: 2026-10-20 - Earliest claimed: 2020-04-01 - Assignees: Huawei Technologies Co., Ltd. - Applicants: Huawei Technologies Co., Ltd. - Inventors: Vladimir Lenets; Ana Diaz Rubio; Francisco Cuesta Soto; Sergei Tretyakov; Xuchen Wang; Alexander Khripkov; Janne Ilvonen; Antti Karilainen - Web page: https://patentgrep.com/patent/US12771023B2 ## CPC - H01Q 3/2647: {Retrodirective arrays} - H01Q 1/422: {comprising two or more layers of dielectric material (H01Q1/425 takes precedence)} - H01Q: ANTENNAS, i.e. RADIO AERIALS (radiators or antennas for microwave heating H05B6/72) ## Abstract The disclosure relates to suppressing surface waves in a communication device for a wireless communication system. The communication device includes a dielectric layer extending along a plane between a chassis and a glass layer, an antenna element configured to emit a radio wave, and a retroreflective structure extending inside the dielectric layer and being located adjacent to the antenna element, and where the retroreflective structure is configured to reflect the radio wave in an angle non-parallel to the plane. The retroreflective structure hence prevents parasitic channeling of the antenna energy into surface waves in and behind the glass layer and directs the radiation into the desired direction. ## Claims ### Claim 1 A communication device for a wireless communication system, the communication device comprising: a chassis; a glass layer; a dielectric layer extending along a plane between the chassis and the glass layer; an antenna element configured to emit a radio wave; and a retroreflective structure extending inside the dielectric layer and being located adjacent to the antenna element, wherein the retroreflective structure is configured to reflect the radio wave in an angle non-parallel to the plane and provides a beamforming surface for the antenna element, wherein the retroreflective structure is a conductive film, and wherein the conductive film comprises capacitive elements and inductive elements forming a capacitive and inductive pattern. ### Claim 2 (depends on 1) The communication device according to claim 1, wherein the retroreflective structure has an inhomogeneous impedance along an extension inside the dielectric layer. ### Claim 3 (depends on 2) The communication device according to claim 2, wherein the extension of the retroreflective structure inside the dielectric layer is less than half of the wavelength of the radio wave. ### Claim 4 (depends on 1) The communication device according to claim 1, wherein the retroreflective structure is conductively or capacitively coupled to the antenna element. ### Claim 5 (depends on 4) The communication device according to claim 4, wherein a first end of the retroreflective structure is conductively or capacitively coupled to the antenna element. ### Claim 6 (depends on 1) The communication device according to claim 1, wherein the retroreflective structure is located within a range from the antenna element being less than half of the wavelength of the radio wave. ### Claim 7 (depends on 1) The communication device according to claim 1, wherein the antenna element is arranged perpendicular to or parallel to the plane of the dielectric layer. ### Claim 8 (depends on 1) The communication device according to claim 1, wherein a size of each capacitive element and each inductive element is less than quarter of the wavelength of the radio wave. ### Claim 9 (depends on 1) The communication device according to claim 1, wherein the capacitive and inductive pattern is a non-repeating pattern. ### Claim 10 (depends on 1) The communication device according to claim 1, wherein the capacitive and inductive pattern forms a grid pattern. ### Claim 11 (depends on 1) The communication device according to claim 1, wherein the radio wave is a transverse magnetic polarized radio wave. ### Claim 12 A method for producing a communication device for a wireless communication system, the method comprising: obtaining a chassis and a glass layer; obtaining a dielectric layer extending in a plane, the dielectric layer comprising a retroreflective structure extending inside the dielectric layer, and wherein the retroreflective structure is configured to reflect a radio wave in an angle being non-parallel to the plane; arranging the dielectric layer between the chassis and the glass layer; arranging an antenna element adjacent to the retroreflective structure; and conductively or capacitively coupling the antenna element to the retroreflective structure providing a beamforming surface for the antenna element, wherein the retroreflective structure is a conductive film, and wherein the conductive film comprises capacitive elements and inductive elements forming a capacitive and inductive pattern. ### Claim 13 (depends on 12) The method of claim 12, wherein the retroreflective structure has an inhomogeneous impedance along an extension inside the dielectric layer. ### Claim 14 (depends on 13) The method of claim 13, wherein the extension of the retroreflective structure inside the dielectric layer is less than half of the wavelength of the radio wave. ### Claim 15 (depends on 12) The method of claim 12, wherein the retroreflective structure is conductively or capacitively coupled to the antenna element. ### Claim 16 (depends on 15) The method of claim 15, wherein a first end of the retroreflective structure is conductively or capacitively coupled to the antenna element. ### Claim 17 (depends on 12) The method of claim 12, wherein the retroreflective structure is located within a range from the antenna element being less than half of the wavelength of the radio wave. ### Claim 18 (depends on 12) The method of claim 12, wherein the antenna element is arranged perpendicular to or parallel to the plane of the dielectric layer. ### Claim 19 (depends on 12) The method of claim 12, wherein a size of each capacitive element and each inductive element is less than quarter of the wavelength of the radio wave. ### Claim 20 (depends on 12) The method of claim 12, wherein the capacitive and inductive pattern is a non-repeating pattern.