# US 9,520,636 B2 · Linear resonator of a high-frequency antenna for a nuclear magnetic resonance imaging apparatus > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 9,520,636 B2 - Document ID: US9520636B2 - Status: Granted - Kind: B2 - Application number: 13/577,557 - Filed: 2011-02-07 - Published: 2013-01-17 - Granted: 2016-12-13 - Earliest claimed: 2010-02-09 - Assignees: Commissariat A L'energie Atomique Et Aux Energies Alternatives - Applicants: Guillaume Ferrand; Michel Luong; Alain France - Inventors: Guillaume Ferrand; Michel Luong; Alain France - Web page: https://patentgrep.com/patent/US9520636B2 ## CPC - H01P 5/10: for coupling balanced lines or devices with unbalanced lines or devices - G01R 33/34076: {Birdcage coils} - G01R 33/3415: comprising arrays of sub-coils {, i.e. phased-array coils with flexible receiver channels} - G01R 33/3456: {Stripline resonators} - G01R 33/365: {Decoupling of multiple RF coils wherein the multiple RF coils have the same function in MR, e.g. decoupling of a receive coil from another receive coil in a receive coil array, decoupling of a transmission coil from another transmission coil in a transmission coil array} - G01R 33/3685: {Means for reducing sheath currents, e.g. RF traps, baluns} - G01R 33/3628: {Tuning/matching of the transmit/receive coil} - G01R 33/422: of the radio frequency field - H01P: WAVEGUIDES; RESONATORS, LINES, OR OTHER DEVICES OF THE WAVEGUIDE TYPE (operating at optical frequencies G02B) - G01R: MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES (indicating correct tuning of resonant circuits H03J3/12) ## Abstract A linear resonator of a high-frequency antenna suitable for emitting a radiofrequency energisation signal and for receiving a radiofrequency relaxation signal, the linear resonator includes a radiating element to emit af radiofrequency energisation signal and receive a radiofrequency relaxation signal. The resonator also includes: a balun circuit including a power-supply line and two coupling lines; a substrate made of a dielectric material, supporting the radiating element which contains the balun circuit; two contact points connecting the balun circuit to the radiating element, the contact points being formed by one of the ends of the coupling lines extending out of the substrate, the distance separating the two contact points being selected so as to ensure the impedance matching of the resonator; and a chip floorplan separating the coupling lines from the radiating element. ## Claims ### Claim 1 A linear resonator of a high-frequency antenna capable of emitting a radiofrequency excitation signal and receiving a radiofrequency relaxation signal, said linear resonator comprising: a radiating element configured to emit a radiofrequency excitation signal and receive a radiofrequency relaxation signal, a balun circuit comprising a power supply line and two coupling lines; a substrate made of a dielectric material supporting said radiating element and in which said balun circuit is embedded; two contact points connecting said balun circuit to said radiating element, said contact points being formed by one of the ends of said coupling lines extending out of said substrate, a distance separating the two contact points being selected so as to ensure an impedance matching of said resonator; a ground plane separating said coupling lines of said radiating element. ### Claim 2 (depends on 1) The linear resonator according to claim 1, comprising an adjuster configured to adjust a resonance matching and a resonance frequency of the resonator. ### Claim 3 (depends on 2) The linear resonator according to claim 2, wherein said adjuster is connected to said balun circuit and is arranged at a distance from said radiating element such that an adjustment operation by an operator will not affect a matching or a tuning of said radiating element. ### Claim 4 (depends on 2) The linear resonator according to claim 2, wherein said adjuster is formed by a π circuit that includes two variable capacitors and an inductor. ### Claim 5 (depends on 1) The linear resonator according to claim 1, comprising a plurality of ground planes that cover each face of said substrate, said plurality of ground plane comprising a primary, upper ground plane that covers the upper part of said substrate. ### Claim 6 (depends on 5) The linear resonator according to claim 5, wherein said radiating element is brazed or welded onto two ceramic capacitors, which are brazed or welded onto said upper ground plane. ### Claim 7 (depends on 6) The linear resonator according to claim 6, wherein said ceramic capacitors are capacitors that feature a quality factor greater than 1000. ### Claim 8 (depends on 6) The linear resonator according to claim 6, wherein said ceramic capacitors are made from alumina having a purity equal to at least 96% by weight. ### Claim 9 (depends on 6) The linear resonator according to claim 6, wherein the values of said capacitors are selected such that they determine the resonance frequency of said resonator. ### Claim 10 (depends on 6) The linear resonator according to claim 6, wherein said radiating element is formed by a conducting element with a cross section in the shape of an open U. ### Claim 11 (depends on 6) The linear resonator according to claim 6, wherein said radiating element is formed by a conducting element with a rectangular cross section. ### Claim 12 (depends on 5) The linear resonator according to claim 5, wherein said radiating element is formed by a track printed on a layer of dielectric substrate affixed permanently to said upper ground plane. ### Claim 13 (depends on 12) The linear resonator according to claim 12, wherein said radiating element comprises twists at the ends thereof. ### Claim 14 (depends on 13) The linear resonator according to claim 13, wherein the twists are shaped such that they determine the resonance frequency of said resonator. ### Claim 15 (depends on 1) A high-frequency antenna for a nuclear magnetic resonance apparatus comprising an insulating body and a plurality of linear resonators according to claim 1, wherein said resonators are mounted detachably in housings of said insulating body of said antenna. ### Claim 16 (depends on 15) The antenna according to claim 15, comprising a detachable crown configured to hold said resonators in position in their respective housings. ### Claim 17 (depends on 15) The antenna according to claim 15, wherein said internal walls of said housings, with the exception of the one facing the radiating element, are metallised so as to insulate each resonator. ### Claim 18 (depends on 15) The antenna according to claim 15, wherein said housings are dimensioned so as to create a pocket of air around each radiating element of each resonator in position inside said insulating body. ### Claim 19 (depends on 15) The antenna according to claim 15, comprising a shield on a outer wall of said insulating body. ### Claim 20 A linear resonator of a high-frequency antenna, said linear resonator comprising: a radiating element configured to emit a radiofrequency excitation signal and receive a radiofrequency relaxation signal, a balun circuit comprising a power supply line and two coupling lines; a substrate made of a dielectric material supporting said radiating element and in which said balun circuit is arranged; two contact points connecting said balun circuit to said radiating element, said two contact points being formed by an end of said coupling lines extending out of said substrate, a distance separating the two contact points being selected so as to permit an impedance matching of said resonator; and a ground plane separating said coupling lines of said radiating element.