Electromechanical filter

• US 20070075806A1
• Filed: 11/19/2004
• Published: 04/05/2007
• Est. Priority Date: 11/19/2003
• Status: Active Grant

• Current Assignee: Matsushita Electric Industrial Company Limited (Panasonic Holdings Corporation)
• Original Assignee: Matsushita Electric Industrial Company Limited (Panasonic Holdings Corporation)
• Inventors: Naito, Yasuyuki, Nakanishi, Yoshito
• Granted Patent: US 7,397,326 B2
• Time in Patent Office: Days
• US Class Current: 333/186
• CPC Class Codes: H03H 2009/02496 Horizontal, i.e. parallel to the substrate plane
• CPC Class Codes: H03H 2009/02511 Vertical, i.e. perpendicular to the substrate plane
• CPC Class Codes: H03H 2009/02519 Torsional
• CPC Class Codes: H03H 9/02393 Post-fabrication trimming of parameters, e.g. resonance frequency, Q factor

Abstract

A small-size electromechanical filter that can be highly integrated and can be tuned is provided.

An electromechanical filter includes a conductor acting as a signal line (movable electrode) 101, a magnetic field generating portion 102 for generating a magnetic field passing through the conductor, and a drive electrode 103 for changing the magnetic field passing through the signal line by displacing relative positions of the conductor and the magnetic field generating portion, whereby a tuning of a ferromagnetic resonance frequency, which is difficult to realize in the prior art, can be realized by changing the magnetic field passing through the signal line.

Claims

1. An electromechanical filter comprising:

a conductor acting as a signal line;

a magnetic field generating portion which generates a magnetic field passing through the conductor; and

a drive electrode which changes the magnetic field passing through the signal line by displacing relative positions of the conductor and the magnetic field generating portion.

2. The electromechanical filter according to claim 1,

wherein the conductor is an electrode that is arranged to oppose to the drive electrode and is displaced by an electrostatic force generated between the drive electrode and the conductor.

3. The electromechanical filter according to claim 1,

wherein the magnetic field generating portion includes a magnetic material that is formed to be displaced.

4. The electromechanical filter according to claim 3,

wherein the magnetic material that is displaced by an electrostatic force of the drive electrode.

5. The electromechanical filter according to claim 1,

wherein the drive electrode is movable.

6. The electromechanical filter according to claim 2, further comprising:

a drive electrode formed on a substrate surface and constructed to vary a potential;

a conductor pattern arranged on the drive electrode to oppose thereto at a predetermined interval to constitute the signal line; and

a magnetic field generating portion comprising a magnetic material film pattern that is magnetized to have a magnetic filed component that intersects orthogonally with the signal line,

wherein the signal line is displaced by changing a potential of the drive electrode, and a ferromagnetic resonance frequency is changed by changing the magnetic field generated by the magnetic material film pattern on the signal line.

7. The electromechanical filter according to claim 2, further comprising:

a magnetic field generating portion formed of a magnetic material film pattern formed on a substrate surface;

a conductor pattern arranged movably on the magnetic material film pattern to oppose thereto at a predetermined interval to constitute the signal line; and

a drive electrode arranged in close vicinity to the signal line,

wherein the magnetic material film pattern is magnetized to have a magnetic field component that intersects orthogonally with the signal line, and

wherein the signal line is displaced by changing a potential of the drive electrode, and a ferromagnetic resonance frequency is changed by changing the magnetic field generated by the magnetic material film pattern on the signal line.

8. The electromechanical filter according to claim 6,

wherein the magnetic material film pattern is formed on an insulating film that covers a semiconductor substrate surface, and

wherein the signal line constitutes a fixed beam that is arranged to oppose to the magnetic material film pattern.

9. The electromechanical filter according to claim 6,

wherein the signal line is arranged in parallel with the drive electrode, and

wherein the magnetic material film pattern generates a magnetic field in a direction that intersects orthogonally with the signal passing through the conductor pattern.

10. The electromechanical filter according to any one of claims 6,

wherein the drive electrode includes first and second conductor film patterns arranged to put the signal line therebetween.

11. The electromechanical filter according to claim 4, further comprising:

a magnetic field generating portion formed of a magnetic material film pattern that is formed on a substrate surface movably in a space;

a conductor pattern fixed/arranged onto the substrate to oppose to the magnetic material film pattern at a predetermined interval and to constitute the signal line; and

a drive electrode arranged in close vicinity to the magnetic field generating portion to displace the magnetic field generating portion,

wherein the magnetic material film pattern is magnetized to have a magnetic field component that intersects orthogonally with the signal line,

wherein the signal line is displaced by changing a potential of the drive electrode, and

wherein a ferromagnetic resonance frequency is changed by changing the magnetic field generated by the magnetic material film pattern on the signal line.

12. The electromechanical filter according to claim 11,

wherein the magnetic material film pattern constitutes a beam member that is formed via a spacer formed on a semiconductor substrate surface.

13. The electromechanical filter according to claim 12,

wherein the signal line is a conductor pattern that is formed on a semiconductor substrate surface via an insulating film.

14. The electromechanical filter according to claim 13,

wherein the signal line is formed over the magnetic material film pattern to oppose thereto at a predetermined interval.

15. The electromechanical filter according to claim 1, further comprising:

first and second drive electrodes formed on a substrate surface and constructed to vary a potential;

a conductor pattern arranged to oppose to the first drive electrode at a predetermined interval and to constitute the signal line; and

a magnetic field generating portion comprising a magnetic material film pattern that is magnetized to have a magnetic field component that intersects orthogonally with the signal line,

wherein the signal line is displaced by changing a potential of the first drive electrode,

wherein the magnetic material film pattern is displaced by changing a potential of the second drive electrode, and

wherein a ferromagnetic resonance frequency is changed by changing the magnetic field generated by the magnetic material film pattern on the signal line.

16. The electromechanical filter according to claim 1, further comprising:

a first conductor acting as the signal line;

a magnetic field generating portion which generates the magnetic field passing through the first conductor;

a drive electrode which varies the magnetic field passing through the signal line by displacing relative positions of the first conductor and the magnetic field generating portion; and

a second conductor acting as a signal line that transmits an induced electromotive force induced by a resonance between a magnetic field generated by a high-frequency current passing through the first conductor and the magnetic field generated by the magnetic field generating portion.

17. The electromechanical filter according to claim 16,

wherein the first conductor and the second conductor are arranged to intersect orthogonally with each other.

18. The electromechanical filter according to claim 16,

wherein the first conductor and the second conductor are arranged in parallel at a predetermined interval.

19. The electromechanical filter according to claim 1,

wherein a plurality of the electromechanical filters are aligned and connected to realize a tunable band-pass filter function.

20. The electromechanical filter according to claim 1,

wherein a plurality of the electromechanical filters are aligned and connected to realize a tunable band-stop filter function.

21. The electromechanical filter according to claim 5, further comprising:

a magnetic field generating portion formed of a magnetic material film pattern that is formed on a substrate surface movably in a space;

a conductor pattern fixed/arranged onto the substrate to oppose to the magnetic material film pattern at a predetermined interval and to constitute the signal line; and

a drive electrode arranged in close vicinity to the magnetic field generating portion to displace the magnetic field generating portion,

wherein the magnetic material film pattern is magnetized to have a magnetic field component that intersects orthogonally with the signal line,

wherein the signal line is displaced by changing a potential of the drive electrode, and

wherein a ferromagnetic resonance frequency is changed by changing the magnetic field generated by the magnetic material film pattern on the signal line.

22. The electromechanical filter according to claim 21,

wherein the magnetic material film pattern constitutes a beam member that is formed via a spacer formed on a semiconductor substrate surface.

23. The electromechanical filter according to claim 22,

wherein the signal line is a conductor pattern that is formed on a semiconductor substrate surface via an insulating film.

24. The electromechanical filter according to claim 23,

wherein the signal line is formed over the magnetic material film pattern to oppose thereto at a predetermined interval.

25. The electromechanical filter according to claim 7,

wherein the magnetic material film pattern is formed on an insulating film that covers a semiconductor substrate surface, and

wherein the signal line constitutes a fixed beam that is arranged to oppose to the magnetic material film pattern.

26. The electromechanical filter according to claim 7,

wherein the signal line is arranged in parallel with the drive electrode, and

wherein the magnetic material film pattern generates a magnetic field in a direction that intersects orthogonally with the signal passing through the conductor pattern.

27. The electromechanical filter according to claim 7,

wherein the drive electrode includes first and second conductor film patterns arranged to put the signal line therebetween.