LOOP RESONATOR APPARATUS AND METHODS FOR ENHANCED FIELD CONTROL

• US 20110156972A1
• Filed: 12/29/2009
• Published: 06/30/2011
• Est. Priority Date: 12/29/2009
• Status: Active Grant

• Current Assignee: Cantor Fitzgerald Securities (Cantor Fitzgerald, L.P.)
• Original Assignee: Cantor Fitzgerald Securities (Cantor Fitzgerald, L.P.)
• Inventors: Korva, Heikki, Annamaa, Petteri
• Granted Patent: US 8,847,833 B2
• Time in Patent Office: Days
• US Class Current: 343/745
• CPC Class Codes: H01Q 1/273 Adaptation for carrying or wearing by persons or animals
• CPC Class Codes: H01Q 1/48 Earthing means; Earth screens; Counterpoises
• CPC Class Codes: H01Q 7/00 Loop antennas with a substantially uniform current distribution around the loop and having a directional radiation pattern in a plane perpendicular to the plane of the loop
• CPC Class Codes: H01Q 9/04 Resonant antennas

Abstract

A radiating antenna element intended for portable radio devices and methods for designing manufacturing the same. In one embodiment, a loop resonator structure for enhanced field (e.g., electric field) is provided, the resonator having an inductive and a capacitive element forming a resonance in a first frequency band. The loop resonator structure is disposed substantially on the ground plane, thereby altering electrical energy distribution. The location of the resonant element is selected to reduce electric field strength proximate to one or more sensitive components, such as a mobile device earpiece, thereby improve hearing aid compliance. Capacitive tuning of the resonator, and the use of multiple resonator structures on the same device, are further described.

Claims

1. An antenna assembly for use in a mobile wireless device, said antenna assembly comprising:

a dielectric element having a longitudinal direction and a transverse direction and first and second substantially planar sides;

a conductive coating deposited on the first substantially planar side forming a ground plane;

a radiating element disposed on the second substantially planar side;

an audio component disposed at least partly on the first planar side; and

a resonant element having a longitudinal dimension and a transverse dimension and formed at least partially on said ground plane proximate to one longitudinal side of said dielectric element, said resonant element further comprising a first portion and a second portion;

wherein said conductive coating is removed from beneath said first and second portions thus forming an opening on said one longitudinal side; and

wherein a resonance is formed substantially between the first portion and the second portion.

2. The antenna assembly of claim 1, further comprising a capacitive element electrically coupled to said ground plane between a first side and a second side of said opening.

3. The antenna assembly of claim 1, wherein said resonant element comprises a resonance having a center frequency of approximately 1880 MHz.

4. The antenna assembly of claim 1, wherein said resonant element comprises a resonance having a center frequency below 900 MHz.

5. The antenna assembly of claim 1, wherein said audio component comprises a speaker.

6. A method of tuning an antenna for use in a mobile device, the mobile device further comprising an audio component, said method comprising:

disposing at least one resonator element onto a ground plane of said antenna, said element comprising at least a capacitance and an inductance;

selecting said capacitance to create a electric resonance at a first frequency; and

adjusting location of said resonator element on said ground plane to optimize an electric field distribution across said ground plane;

wherein said optimization of said electric field distribution comprises reducing an electric field strength at a location proximate to said audio component.

7. The method of claim 6, wherein said audio component comprises a speaker, and said tuning comprises tuning so that said antenna is compliant with at least one hearing aid compatibility standard or requirement.

8. The method of claim 7, wherein said at least one hearing aid compatibility standard or requirement comprises the Hearing Aid Compatibility Act of 1988 (HAC Act) as amended 2003.

9. The method of claim 6, wherein said electric resonance is formed between said capacitance and said inductance.

10. A method of altering electric field distribution across a ground plane of a mobile device antenna, said method comprising:

disposing a resonator element onto antenna ground plane, said resonator element comprising at least a capacitance and inductance;

selecting said capacitance to form a resonance at a first frequency; and

adjusting a location of said resonator element on said ground plane to optimize and electric field distribution across said ground plane.

11. The method of claim 10, wherein said mobile device further comprises an electrically sensitive component disposed proximate said ground plane, and said act of adjusting a location comprises adjusting said location so that an electric field strength is minimized substantially coincident with a location of said electrically sensitive component.

12. The method of claim 11, wherein said electrically sensitive component comprises an audio speaker, and said act of adjusting a location enables said mobile device to be compliant with a hearing aid audio-related requirement.

13. A method of enabling hearing aid compliance for use in a mobile radio device comprising a ground plane, an antenna and an audio component, said method comprising:

providing at least one resonator element for use on a ground plane of said antenna, said at least one resonator element comprising at least a capacitance and an inductance, said capacitance configured to form a resonance at a first frequency; and

disposing said at least one resonator element on said ground plane at a location selected to reduce electric field strength proximate to said audio component location, thereby reducing interference of said antenna with said audio component and effecting said hearing aid compliance.

14. An antenna for use in a mobile radio device, the antenna comprising:

a ground plane; and

at least one resonator element disposed on said ground plane of said antenna, said at least one resonator element comprising at least a capacitance and an inductance and configured to form a resonance at a first frequency;

wherein said at least one resonator element is disposed on said ground plane at a selected first location so as to reduce electric field strength at a second location.

15. The antenna of claim 14, wherein said mobile radio device comprises an interference-sensitive component, and said second location is proximate to a location of said interference-sensitive component, said reduced electrical field strength thereby reducing interference of said antenna with said interference-sensitive component.

16. The antenna of claim 14, wherein said interference-sensitive component comprises an audio component.

17. The antenna of claim 14, wherein said interference-sensitive component comprises an electric coil component.

18. The antenna of claim 14, wherein said at least one resonator element comprises a loop-type shape having at least one gap formed therein.

19. The antenna of claim 18, wherein said at least one gap comprises a single gap formed proximate a longitudinal edge of a substrate onto which said ground plane is formed.

20. A method of operating an antenna within a mobile device, the method comprising:

receiving an antenna input signal from an electronic component of said mobile device; and

creating a resonance within a resonator element of said antenna based at least in part on said input signal and a capacitance of said resonator element, said capacitance at least in part causing an electric field generated by way of said resonance to be mitigated in a desired location on said antenna while still emitting a desired radio frequency signal from said antenna.