# US 2021/0344119 A1 · Antenna structure > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2021/0344119 A1 - Document ID: US20210344119A1 - Status: Published application - Kind: A1 - Application number: 17/374,954 - Filed: 2021-07-13 - Published: 2021-11-04 - Earliest claimed: 2020-03-03 - Assignees: Compal Electronics, Inc. - Inventors: Chun-Cheng Chan; Shih-Chia Liu; Yen-Hao Yu; Li-Chun Lee; Jui-Hung Lai; Chih-Heng Lin - Web page: https://patentgrep.com/patent/US20210344119A1 ## CPC - H01Q 1/521: {reducing the coupling between adjacent antennas} - H01Q 21/06: Arrays of individually energised antenna units similarly polarised and spaced apart - H01Q 1/48: Earthing means; Earth screens; Counterpoises - H01Q 21/28: Combinations of substantially independent non-interacting antenna units or systems {(multiple beam H01Q25/00)} - H01Q 9/42: with folded element, the folded parts being spaced apart a small fraction of the operating wavelength - H01Q: ANTENNAS, i.e. RADIO AERIALS (radiators or antennas for microwave heating H05B6/72) ## Abstract The disclosure provides an antenna structure including a ground plane, a first coupling antenna and a reference antenna. The first coupling antenna includes a first excitation source connected to the ground plane. The first excitation source is configured to excite a first resonant mode, and the first coupling antenna forms a first zero current area on the ground plane in response to the first resonant mode. The reference antenna includes a second excitation source connected to the ground plane. The second excitation source is configured to excite a second resonant mode, and the reference antenna forms a second zero current area on the ground plane in response to the second resonant mode. The first excitation source is located in the second zero current area, and the second excitation source is located in the first zero current area. ## Claims ### Claim 1 An antenna structure comprising: a ground plane; a first coupling antenna comprising a first excitation source connected to the ground plane, wherein the first excitation source is configured to excite a first resonant mode, and the first coupling antenna forms a first zero current area on the ground plane in response to the first resonant mode; and a reference antenna comprising a second excitation source connected to the ground plane, wherein the second excitation source is configured to excite a second resonant mode, and the reference antenna forms a second zero current area on the ground plane in response to the second resonant mode, wherein the first excitation source is located in the second zero current area, and the second excitation source is located in the first zero current area. ### Claim 2 (depends on 1) The antenna structure according to claim 1, wherein the first coupling antenna further comprises: a first radiator connected to the ground plane; and a first feeding portion connected to the ground plane through the first excitation source, wherein the first feeding portion is coupled to the first radiator to excite the first resonant mode, and a first current is formed on the first radiator, wherein the first current flows into the ground plane to form a first ground current. ### Claim 3 (depends on 2) The antenna structure according to claim 2, wherein the reference antenna further comprises: a second radiator, wherein the second radiator and the ground plane generate a first coupling current in response to the first current, a part of the first coupling current of the ground plane offsets a part of the first ground current, and the first zero current area on the ground plane is formed. ### Claim 4 (depends on 3) The antenna structure according to claim 3, wherein the first radiator has at least a first strong current zone and a first weak current zone in response to the first current, and the second radiator has at least a second strong current zone and a second weak current zone in response to the first coupling current, wherein a vertical projection of the first weak current zone on the ground plane at least partially overlaps a vertical projection of the second weak current zone on the ground plane. ### Claim 5 (depends on 4) The antenna structure according to claim 4, wherein a vertical projection of the first strong current zone on the ground plane at least partially overlaps a vertical projection of the second strong current zone on the ground plane. ### Claim 6 (depends on 4) The antenna structure according to claim 4, wherein a first distance exists between the first radiator and the second radiator, a second distance exists between the first excitation source and the second excitation source, and the first distance is not greater than the second distance. ### Claim 7 (depends on 1) The antenna structure according to claim 1, wherein the reference antenna further comprises: a second radiator exciting the second resonant mode through the second excitation source to form a second current flowing on the second radiator, wherein the ground plane forms a second ground current in response to the second current. ### Claim 8 (depends on 7) The antenna structure according to claim 7, wherein the first coupling antenna further comprises: a first feeding portion connected to the ground plane through the first excitation source; a first radiator connected to the ground plane, wherein the first radiator forms a second coupling current flowing on the first radiator and the ground plane in response to the second current, a part of the second coupling current flowing on the ground plane offsets a part of the second ground current, and the second zero current area on the ground plane is formed. ### Claim 9 (depends on 8) The antenna structure according to claim 8, wherein the reference antenna is a second coupling antenna, and the reference antenna further comprises: a second feeding portion connected to the second excitation source and connected to the ground plane through the second excitation source, wherein the second feeding portion is coupled to the second radiator to excite the second resonant mode, and the second current is formed on the second radiator. ### Claim 10 (depends on 9) The antenna structure according to claim 9, wherein the first radiator is a ¼-wavelength resonance structure, the second radiator is a double-end opening ½-wavelength resonance structure, and a fundamental resonance frequency of the second radiator is same as a fundamental resonance frequency of the first radiator. ### Claim 11 (depends on 9) The antenna structure according to claim 9, wherein the first radiator is a ¼-wavelength resonance structure, the second radiator is a double-end shorting ½-wavelength resonance structure, and a fundamental resonance frequency of the second radiator is same as a fundamental resonance frequency of the first radiator. ### Claim 12 (depends on 9) The antenna structure according to claim 9, wherein the first radiator is a ¼-wavelength resonance structure, the second radiator is a ¼-wavelength resonance structure, and a harmonic resonance frequency of the second radiator is same as a fundamental resonance frequency of the first radiator. ### Claim 13 (depends on 8) The antenna structure according to claim 8, wherein the first radiator has at least a third strong current zone and a third weak current zone in response to the second coupling current, and the second radiator has at least a fourth strong current zone and a fourth weak current zone in response to the second current, wherein a vertical projection of the third weak current zone on the ground plane at least partially overlaps a vertical projection of the fourth weak current zone on the ground plane. ### Claim 14 (depends on 13) The antenna structure according to claim 13, wherein a vertical projection of the third strong current zone on the ground plane at least partially overlaps a vertical projection of the fourth strong current zone on the ground plane. ### Claim 15 (depends on 7) The antenna structure according to claim 7, wherein one terminal of the second radiator is connected to the ground plane through the second excitation source, and an other terminal of the second radiator is an open terminal. ### Claim 16 (depends on 1) The antenna structure according to claim 1, wherein the antenna structure is disposed in a communication device, the first coupling antenna is a transmitting antenna of the communication device, and the reference antenna is an induction metal portion of a proximity sensor of the communication device.