# US 12,763,469 B2 · Antenna device > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 12,763,469 B2 - Document ID: US12763469B2 - Status: Granted - Kind: B2 - Application number: 18/318,263 - Filed: 2023-05-16 - Published: 2023-09-14 - Granted: 2026-10-13 - Earliest claimed: 2020-11-20 - Assignees: Murata Manufacturing Co., Ltd. - Applicants: Murata Manufacturing Co., Ltd. - Inventors: Yoshihiro Sako - Web page: https://patentgrep.com/patent/US12763469B2 ## CPC - H01Q 7/08: Ferrite rod or like elongated core - H01Q: ANTENNAS, i.e. RADIO AERIALS (radiators or antennas for microwave heating H05B6/72) ## Abstract An antenna device is provided that includes an antenna circuit and a resistance circuit. The antenna circuit has a first inductor. The resistance circuit has a second inductor and is electrically connected to the antenna circuit. The first inductor has a first winding and a core arranged inside the first winding. The second inductor has a second winding that comprises an air-core coil. ## Claims ### Claim 1 An antenna device comprising: an antenna circuit having a first inductor that includes a first winding and a core inside the first winding; and a resistance circuit having a second inductor and that is electrically connected to the antenna circuit, wherein the second inductor has a second winding that forms an air-core coil, and wherein the second winding includes a first winding portion and a second winding portion that are aligned in an axial direction of the air-core coil, wherein the antenna circuit has a capacitor electrically connected to the first inductor, and wherein the first inductor is located on a side opposite to the second inductor with respect to the capacitor. ### Claim 2 (depends on 1) The antenna device according to claim 1, wherein the second winding has a resistivity that is greater than a resistivity of the first winding. ### Claim 3 (depends on 1) The antenna device according to claim 1, wherein the second winding has a number of turns that is less than a number of turns of the first winding. ### Claim 4 (depends on 1) The antenna device according to claim 1, wherein the second inductor has an inductance that is smaller than an inductance of the first inductor. ### Claim 5 (depends on 1) The antenna device according to claim 1, further comprising: first and second connection terminals electrically connected to an antenna drive circuit, wherein the antenna circuit and the resistance circuit are electrically connected between the first and second connection terminals. ### Claim 6 (depends on 1) The antenna device according to claim 1, wherein the air-core coil comprises the second winding wound with a space therebetween. ### Claim 7 An antenna device comprising: an antenna circuit having a first inductor that includes a first winding and a core inside the first winding; and a resistance circuit having a second inductor and that is electrically connected to the antenna circuit and a third inductor electrically connected to the second inductor, wherein the second inductor has a second winding that forms an air-core coil, wherein the second winding includes a first winding portion and a second winding portion that are aligned in an axial direction of the air-core coil, wherein the third inductor has a third winding that forms an air-core coil, and wherein an axial direction of the third winding intersects an axial direction of the first winding. ### Claim 8 (depends on 7) The antenna device according to claim 7, wherein the third winding has a cross-sectional area that is smaller than a cross-sectional area of the second winding. ### Claim 9 (depends on 7) The antenna device according to claim 7, wherein the third winding has a resistivity that is greater than a resistivity of the first winding. ### Claim 10 (depends on 7) The antenna device according to claim 7, wherein the antenna circuit has a capacitor electrically connected to the first inductor. ### Claim 11 (depends on 10) The antenna device according to claim 10, wherein the first inductor is located on a side opposite to the second inductor with respect to the capacitor. ### Claim 12 An antenna device comprising: an antenna circuit having a first inductor with a first winding and a first core inside the first winding; and a resistance circuit having a second inductor that is electrically connected to the antenna circuit and has a second winding and a second core inside the second winding, wherein the second winding has a set of a first winding portion and a set of a second winding portion, wherein a winding direction of the first winding portion is opposite to a winding direction of the second winding portion, wherein the first winding portion and the second winding portion are aligned in an axial direction of the second core, and wherein the antenna circuit has a capacitor electrically connected to the first inductor, and the first inductor is located on a side opposite to the second inductor with respect to the capacitor. ### Claim 13 (depends on 12) The antenna device according to claim 12, wherein the second winding portion is wound around the second core over the first winding portion. ### Claim 14 (depends on 12) The antenna device according to claim 12, wherein the second inductor has a thermally conductive material that fills a space between the second core and the second winding. ### Claim 15 (depends on 12) The antenna device according to claim 12, wherein the second inductor has a thermal conductive sheet between the second core and the second winding. ### Claim 16 (depends on 12) The antenna device according to claim 12, wherein the first core and the second core are configured continuously and integrally. ### Claim 17 (depends on 12) The antenna device according to claim 12, wherein the second winding has a resistivity that is greater than a resistivity of the first winding. ### Claim 18 (depends on 12) The antenna device according to claim 12, wherein the second winding has a number of turns that is less than a number of turns of the first winding.