Method and apparatus for detecting or transmitting magnetic field using detachable magnetic resonator

• US 8,188,744 B2
• Filed: 08/07/2009
• Issued: 05/29/2012
• Est. Priority Date: 08/08/2008
• Status: Expired due to Fees

• Current Assignee: Electronics and Telecommunications Research Institute
• Original Assignee: Electronics and Telecommunications Research Institute
• Inventors: Lee, Wangjoo, Ju, Jeong Ho, Kim, Dong Ho, Choi, Jae Ick
• Primary Examiner(s): SHRIVASTAV, BRIJ B
• Application Number:
  US12/538,084
• Publication Number:
  US 20100033178A1
• Time in Patent Office: 1,026 Days
• Field of Search: 324300-322, 600407-445
• US Class Current: 324/319
• CPC Class Codes: G01R 33/34007 Manufacture of RF coils, e.g. using printed circuit board technology; additional hardware for providing mechanical support to the RF coil assembly or to part thereof, e.g. a support for moving the coil assembly relative to the remainder of the MR system
• CPC Class Codes: G01R 33/341 comprising surface coils
• CPC Class Codes: G01R 33/3642 Mutual coupling or decoupling of multiple coils, e.g. decoupling of a receive coil from a transmission coil, or intentional coupling of RF coils, e.g. for RF magnetic field amplification

Abstract

An apparatus for detecting a magnetic field includes a coil type magnetic resonator having a resonant frequency with respect to a magnetic field varying at a particular frequency and a loop antenna inductively coupled to the coil type magnetic resonator.

Claims

1. An apparatus for detecting a magnetic field, the apparatus comprising:

a coil type magnetic resonator having a resonant frequency with respect to a magnetic field varying at a particular frequency, and amplifying a strength of a magnetic field applied to the coil type magnetic resonator, the coil type magnetic resonator being formed of a coil wound at least one turn without discontinuity or a pattern of a ring shape extending from one end to the other end without discontinuity; and

a loop antenna inductively coupled to the coil type magnetic resonator, the loop antenna detecting the magnetic field amplified by the coil type magnetic resonator based on a voltage in the loop antenna induced by a change in a current in the coil type magnetic resonator.

2. The apparatus of claim 1, wherein the loop antenna has a wideband characteristic.

3. The apparatus of claim 1, wherein the coil type magnetic resonator and the loop antenna are arranged on a same plane or on different planes parallel to each other.

4. The apparatus of claim 1, further comprising:

a case formed of a non-magnetic material for accommodating the coil type magnetic resonator; and

a case formed of a non-magnetic material for accommodating the loop antenna.

5. The apparatus of claim 4, wherein the case for accommodating the coil type magnetic resonator is mechanically coupled to or is detachable from the case for accommodating the loop antenna.

6. The apparatus of claim 1, wherein the coil type magnetic resonator is formed of a non-magnetic material.

7. The apparatus of claim 6, wherein the coil type magnetic resonator is formed of a coil obtained by winding a non-magnetic metal wire at least one turn.

8. The apparatus of claim 7, wherein the resonant frequency of the coil type magnetic resonator is adjustable by changing a shape of the coil.

9. The apparatus of claim 6, wherein the coil type magnetic resonator is formed of a non-magnetic metal pattern of a ring shape on a printed circuit board.

10. The apparatus of claim 1, wherein the coil type magnetic resonator comprises a replaceable capacitor or a variable capacitor for adjusting the resonance frequency.

30. The apparatus of claim 1, wherein the coil type magnetic resonator and the loop antenna are arranged on a same plane or on different planes parallel to each other, and a center of the coil type magnetic resonator and a center of the loop antenna are aligned.

31. The apparatus of claim 1, wherein the loop antenna is a single metal wire having two ends, the loop antenna being wound at least one turn extending from one end to the other end without discontinuity.

11. An apparatus for detecting a magnetic field, the apparatus comprising:

a plurality of coil type magnetic resonators having different resonant frequencies, and amplifying a strength of a magnetic field applied to the coil type magnetic resonator, each coil type magnetic resonator being formed of a coil wound at least one turn without discontinuity or a pattern of a ring shape extending from one end to the other end without discontinuity; and

a loop antenna inductively coupled to the coil type magnetic resonators, the loop antenna detecting the magnetic field amplified by the coil type magnetic resonator based on a voltage in the loop antenna induced by a change in a current in the coil type magnetic resonator.

12. The apparatus of claim 11, wherein the loop antenna has a wideband characteristic.

13. The apparatus of claim 11, wherein the coil type magnetic resonators and the loop antenna are arranged on a same plane or on different planes parallel to each other.

14. The apparatus of claim 11, further comprising:

a case formed of a non-magnetic material for accommodating the coil type magnetic resonators; and

a case formed of a non-magnetic material for accommodating the loop antenna.

15. The apparatus of claim 14, wherein the case for accommodating the coil type magnetic resonators is mechanically coupled to or is detachable from the case for accommodating the loop antenna.

16. The apparatus of claim 11, wherein each of the coil type magnetic resonator is formed of a non-magnetic material.

17. The apparatus of claim 16, wherein each of the coil type magnetic resonators is formed of a coil obtained by winding a non-magnetic metal wire at least one turn.

18. The apparatus of claim 17, wherein the resonant frequency of each of the coil type magnetic resonators is adjustable by changing a shape of the coil.

19. The apparatus of claim 16, wherein each of the coil type magnetic resonators is formed of a non-magnetic metal pattern of a ring shape on a printed circuit board.

20. The apparatus of claim 11, wherein each of the coil type magnetic resonators comprises a replaceable capacitor or a variable capacitor for adjusting the resonance frequency.

21. A method of detecting a magnetic field, the method comprising:

generating resonance in a coil type magnetic resonator according to a magnetic field that is linked to the coil type magnetic resonator and varies at a resonant frequency of the coil type magnetic resonator, wherein the coil type magnetic resonator amplifies a strength of the magnetic field linked to the coil type magnetic resonator and is formed of a coil wound at least one turn without discontinuity or a pattern of a ring shape extending from one end to the other end without discontinuity; and

detecting the magnetic field amplified by the coil type magnetic resonator using a loop antenna inductively coupled to the coil type magnetic resonator, based on a voltage in the loop antenna induced by a change in a current in the coil type magnetic resonator.

22. The method of claim 21, wherein the loop antenna has a wideband characteristic.

23. The method of claim 21, wherein the coil type magnetic resonator and the loop antenna are arranged on a same plane or on different planes parallel to each other.

24. The method of claim 21, wherein the coil type magnetic resonator is formed of a non-magnetic material.

25. The method of claim 24, wherein the coil type magnetic resonator is formed of a coil obtained by winding a non-magnetic metal wire at least one turn.

26. The method of claim 24, wherein the coil type magnetic resonator is formed of a non-magnetic metal pattern of a ring shape on a printed circuit board.

27. The method of claim 21, wherein the coil type magnetic resonator comprises a replaceable capacitor or a variable capacitor, and the method further comprises adjusting the resonant frequency by replacing the replaceable capacitor or adjusting capacitance of the variable capacitor.

28. A method of transmitting a magnetic field, the method comprising:

generating a time-varying magnetic field by applying a current that varies at a resonant frequency of a coil type magnetic resonator to a loop antenna, wherein the coil type magnetic resonator is formed of a coil wound at least one turn without discontinuity or a pattern of a ring shape extending from one end to the other end without discontinuity; and

generating resonance in the coil type magnetic resonator inductively coupled to the loop antenna by the time-varying magnetic field.

29. The method of claim 28, wherein the loop antenna has a wideband characteristic.