SPATIAL FILTER FOR NEAR FIELD MODIFICATION IN A WIRELESS COMMUNICATION DEVICE

• US 20100283691A1
• Filed: 05/07/2010
• Published: 11/11/2010
• Est. Priority Date: 05/07/2009
• Status: Active Grant

• Current Assignee: Kyocera AVX Components Corporation (Kyocera Corporation)
• Original Assignee: Ethertronics, Inc. (Kyocera Corporation)
• Inventors: Dong, Ting Ting, Shamblin, Jeffrey, Desclos, Laurent, Rowson, Sebastian, Su, Xiaomeng
• Granted Patent: US 8,421,685 B2
• Time in Patent Office: Days
• US Class Current: 343/702
• CPC Class Codes: H01Q 1/245 with means for shaping the antenna pattern, e.g. in order to protect user against rf exposure
• CPC Class Codes: H01Q 15/0053 Selective devices used as spatial filter or angular sidelobe filter

Abstract

A spatial filter is developed for specific absorption rate (SAR) reduction in a wireless device. A conductive element is designed to modify the near field distribution of an antenna operating in a wireless device. This reduces SAR while minimizing degradation of antenna efficiency at one or several frequency bands that the antenna is designed to operate over. Lumped reactance can be designed into the conductive element to generate low pass, band pass, and/or high pass frequency characteristics. Distributed reactance can be designed into the conductive element to replace or to work in conjunction with the lumped reactance. Active components can be designed into the conductive element to provide dynamic tuning of the frequency response of the conductive element.

Claims

1. A wireless communication device, comprising:

an antenna element positioned in proximity to a conductive element;

said conductive element adapted to couple to said antenna element for spreading an electromagnetic field about a large volume;

wherein said conductive element further includes one of;

a lumped reactance component, or a distributed reactance region.

2. The wireless device of claim 1, further comprising an active component.

3. The wireless device of claim 2, wherein said active component is one of:

a capacitor, varicap diode, or switch.

4. The wireless device of claim 1, wherein said conductive element is adapted to provide a filter component to modify the frequency response of the conductive element.

5. The wireless device of claim 1, said conductive element further comprising a first portion and a second portion.

6. The wireless device of claim 5, wherein said first portion is connected to said second portion by at least one of:

an inductor, capacitor, resistor, diode, transistor, RF switch, tunable capacitor, and mechanical switch.

7. The wireless device of claim 6, said first portion further comprising a distributed reactance region, wherein said distributed reactance region includes at least one of:

an inductance, or capacitance section.

8. The wireless device of claim 1, comprising two or more conductive elements positioned in proximity to said antenna element.

9. The wireless device of claim 8, wherein a first of said two or more conductive elements is connected to a second of said two or more conductive element.

10. The wireless device of claim 8, wherein a first of said two or more conductive elements is connected to a ground plane.

11. The wireless device of claim 8, wherein a first of said two or more conductive elements is connected to a shield can.

12. The wireless device of claim 8, wherein a first of said two or more conductive elements is connected to a circuit board.

13. The wireless device of claim 8, wherein a first of said two or more conductive elements is connected to one of:

a second conductive element, a ground, a circuit board, or a shield can by an active component.

14. The wireless device of claim 8, wherein a first of said two or more conductive elements is connected to one of:

a second conductive element, a ground, a circuit board, or a shield can by a lumped reactance component.

15. A wireless communications device, comprising:

an antenna element positioned above a circuit board;

said circuit board further comprising a plurality of electronic components;

a conductive element positioned above said circuit board and attached electronic components in proximity with said antenna element;

said conductive element adapted to couple to said antenna element for distributing an electromagnetic field along a large volume;

wherein said conductive element includes at least one of;

a lumped reactance component, or a distributed reactance region.

16. The wireless device of claim 15, said conductive element further comprising a first portion connected to a second portion;

wherein at least one of said first and second portions include a distributed reactance region.

17. The wireless device of claim 16, wherein said distributed reactance region includes a capacitive section and an inductive section.

18. A wireless communications device, comprising:

a circuit board including a plurality of electronic components;

an antenna element; and

a conductive element;

said circuit board further comprising an etched portion, wherein one or more conductive elements are connected across said etched portion.

19. The wireless device of claim 18, further comprising a lumped reactance component, said lumped reactance component connected to said conductive element for altering the field characteristics of the wireless device.

20. The wireless device of claim 19, further comprising an active component for dynamic tuning of the antenna near field characteristics.