Electric field coupler, communication apparatus, communication system, and fabrication method for electric field coupler

• US 8,198,960 B2
• Filed: 07/20/2009
• Issued: 06/12/2012
• Est. Priority Date: 07/28/2008
• Status: Expired due to Fees

• Current Assignee: Sony Corporation (Sony Group Corp.)
• Original Assignee: Sony Corporation (Sony Group Corp.)
• Inventors: Washiro, Takanori
• Primary Examiner(s): Takaoka, Dean O
• Application Number:
  US12/505,730
• Publication Number:
  US 20100019871A1
• Time in Patent Office: 1,058 Days
• Field of Search: 333/236, 333/238, 333/204, 333/219
• US Class Current: 333/204
• CPC Class Codes: H01Q 1/362 for broadside radiating helical antennas
• CPC Class Codes: H01Q 11/08 Helical antennas
• CPC Class Codes: H01Q 9/42 with folded element, the folded parts being spaced apart a small fraction of the operating wavelength
• CPC Class Codes: Y10T 29/4902 Electromagnet, transformer or inductor

Abstract

An electric field coupler includes a strip-like coil formed by bending a strip-like conductor which snakes along a plane perpendicular to a coupling direction in which electric field coupling occurs, such that coil axes are perpendicular to the coupling direction, the strip-like coil having an electrical length of one-half wavelength of a predetermined frequency of a radio-frequency signal and having a form in which the coil axes surround a central portion along the plane. The strip-like coil produces coupling by a longitudinal wave electric field which vibrates in the coupling direction at the central portion.

Claims

1. An electric field coupler comprising:

a strip-like coil formed by bending a strip-like conductor which snakes along a plane perpendicular to a coupling direction in which electric field coupling occurs, such that coil axes are perpendicular to the coupling direction, the strip-like coil having an electrical length of one-half wavelength of a predetermined frequency of a radio-frequency signal and having a form in which the coil axes surround a central portion along the plane,

a resonance portion that resonates with a radio-frequency signal having the predetermined frequency which is supplied from a feed end and that is connected to one end of the strip-like coil at a location corresponding to an antinode of a standing wave of a voltage by the resonance; and

a ground provided on one side of the strip-like coil that is opposite to the coupling direction,

wherein an other end of the strip-like coil is grounded, the strip-like coil produces coupling by a longitudinal wave electric field which vibrates in the coupling direction at the central portion, and a winding direction of the strip-like coil is reversed at the middle of the strip-like coil.

2. The electric field coupler according to claim 1, wherein a suction point where a strip width is extended is formed at a part of the strip-like coil so that a mounter can suck the suction point upon fabrication.

3. The electric field coupler according to claim 2, wherein the suction point is formed at a center of gravity of the strip-like coil in the plane perpendicular to the coupling direction.

4. The electric field coupler according to claim 1, wherein the strip-like coil has, on a side of the coil, an overhanging portion that overhangs in a direction perpendicular to the coupling direction.

5. A communication apparatus comprising:

a strip-like coil formed by bending a strip-like conductor which snakes along a plane perpendicular to a coupling direction in which electric field coupling occurs, such that coil axes are perpendicular to the coupling direction, the strip-like coil having an effective length of one-half wavelength of a predetermined frequency of a radio-frequency signal and having a form in which the coil axes surround a central portion along the plane,

a resonance portion that resonates with a radio-frequency signal having the predetermined frequency which is supplied from a feed end and that is connected to one end of the strip-like coil at a location corresponding to an antinode of a standing wave of a voltage by the resonance; and

a ground provided on one side of the strip-like coil that is opposite to the coupling direction,

wherein an other end of the strip-like coil is grounded, the strip-like coil performs contactless communication by producing coupling by a longitudinal wave electric field which vibrates in the coupling direction at the central portion, and a winding direction of the strip-like coil is reversed at the middle of the strip-like coil.

6. A communication system comprising:

two communication apparatuses that perform contactless communication by producing electric field coupling,

wherein

at least one of the two communication apparatuses has a strip-like coil formed by bending a strip-like conductor which snakes along a plane perpendicular to a coupling direction in which the electric field coupling occurs, such that coil axes are perpendicular to the coupling direction, the strip-like coil having an electrical length of one-half wavelength of a predetermined frequency of a radio-frequency signal and having a form in which the coil axes surround a central portion along the plane, a resonance portion that resonates with a radio-frequency signal having the predetermined frequency which is supplied from a feed end and that is connected to one end of the strip-like coil at a location corresponding to an antinode of a standing wave of a voltage by the resonance; and

a ground provided on one side of the strip-like coil that is opposite to the coupling direction, wherein an other end of the strip-like coil is grounded, and

the strip-like coil performs contactless communication by producing coupling by a longitudinal wave electric field which vibrates in the coupling direction at the central portion and a winding direction of the strip-like coil is reversed at the middle of the strip-like coil.