APPARATUS AND METHOD FOR OPERATION OF AN ANTENNA SYSTEM ENABLING CONTROL OF RADIATION CHARACTERISTICS

• US 20120050109A1
• Filed: 08/27/2010
• Published: 03/01/2012
• Est. Priority Date: 08/27/2010
• Status: Active Grant

• Current Assignee: NETGEAR, Inc.
• Original Assignee: Sierra Wireless Incorporated
• Inventors: Nysen, Paul A., Van Cleave, Todd
• Granted Patent: US 8,842,044 B2
• Time in Patent Office: Days
• US Class Current: 343/700.MS
• CPC Class Codes: H01Q 1/243 with built-in antennas
• CPC Class Codes: H01Q 21/28 Combinations of substantially independent non-interacting antenna units or systems multiple beam H01Q25/00
• CPC Class Codes: H01Q 25/00 Antennas or antenna systems providing at least two radiating patterns arrangements for changing or varying the orientation or the shape of the directional pattern H01Q3/00
• CPC Class Codes: H01Q 3/247 by switching different parts of a primary active element
• CPC Class Codes: H04B 1/3838 Arrangements for reducing RF exposure to the user, e.g. by changing the shape of the transceiver while in use

Abstract

An antenna system for a wireless device and a method for operating same are provided for controlling radiation characteristics of the antenna system. The antenna system includes first and second sets of feed points disposed so that first and second radiation pattern are generated by the antenna system when drive currents are provided at the first and second set of feed points, respectively. The second radiation pattern is different from the first radiation pattern. The first and second drive currents are supplied such that a predetermined overall radiation pattern is generated. The predetermined overall radiation pattern is at least in part a combination of the first radiation pattern and the second radiation pattern. The system and method may be directed toward SAR mitigation.

Claims

1. An antenna system for a wireless device, the antenna system having:

a. a first set of one or more feed points, the first set of one or more feed points disposed so that a first radiation pattern is being generated when a first set of drive currents is provided to the antenna system at the first set of one or more feed points; and

b. a second set of one or more feed points, the second set of one or more feed points disposed so that a second radiation pattern is being generated when a second set of drive currents is provided to the antenna system at the second set of one or more feed points,

wherein the second radiation pattern is at least in part different from the first radiation pattern, and wherein controlling supply of the first set of one or more drive currents and the second set of one or more drive currents results in an overall radiation pattern being generated, the overall radiation pattern being at least in part a combination of the first radiation pattern and the second radiation pattern.

2. The antenna system according to claim 1, the antenna system comprising an antenna having at least a first feed point and a second feed point, wherein the first set of drive currents comprises a first drive current applied to the antenna at the first feed point and the second set of drive currents comprises a second drive current applied to the antenna at the second feed point.

3. The antenna system according to claim 1, wherein the first radiation pattern corresponds to a first set of one or more hotspots and the second radiation pattern corresponds to a second set of one or more hotspots located differently from the first set of one or more hotspots.

4. The antenna system according to claim 3, wherein the first set of one or more hotspots is non-overlapping with the second set of one or more hotspots.

5. The antenna system according to claim 1, wherein the first set of one or more drive currents is applied during a first set of time intervals, and the second set of one or more drive currents is applied during a second set of time intervals, the first set of time intervals at least partially different from the second set of time intervals.

6. The antenna system according to claim 5, wherein the first set of time intervals is non-overlapping with the second set of time intervals.

7. The antenna system according to claim 1, wherein the first set of one or more feed points is partially different from the second set of one or more feed points.

8. The antenna system according to claim 1, wherein the first set of one or more feed points is disjoint from the second set of one or more feed points.

9. The antenna system according to claim 1, wherein the overall radiation pattern is a combination of N different radiation patterns and irradiation due to the overall radiation pattern corresponds “

to an average of irradiations due to the N different radiation patterns, and wherein irradiation of tissue in at least one location due to one set of the N different radiation patterns is higher than irradiation of tissue in the at least one location due to another set of the N different radiation patterns.

10. The antenna system according to claim 9, wherein irradiation of tissue in the at least one location is primarily due to one radiation pattern of the N different radiation patterns, said one radiation pattern contributing to a fraction of the overall radiation pattern, thereby resulting in a reduction of irradiation of tissue in the at least one location by substantially said fraction compared with irradiation of tissue in the at least one location when the overall radiation pattern comprises substantially only said one radiation pattern.

11. A wireless device including an antenna system having:

a. a first set of one or more feed points, the first set of one or more feed points disposed so that a first radiation pattern is generated by the antenna system when a first set of drive currents is provided to the antenna system at the first set of one or more feed points; and

b. a second set of one or more feed points, the second set of one or more feed points disposed so that a second radiation pattern is generated by the antenna system when a second set of drive currents is provided to the antenna system at the second set of one or more feed points;

wherein the second radiation pattern is at least in part different from the first radiation pattern, and wherein controlling supply of the first set of one or more drive currents and the second set of one or more drive currents results in an overall radiation pattern being generated, the overall radiation pattern being at least in part a combination of the first radiation pattern and the second radiation pattern.

12. The wireless device according to claim 11, wherein the first radiation pattern corresponds to a first set of one or more hotspots and the second radiation pattern corresponds to a second set of one or more hotspots located differently from the first set of one or more hotspots, and wherein irradiation due to the overall radiation pattern is an average of irradiations due to at least the first radiation pattern and the second radiation pattern, thereby spreading irradiation over at least the first set of one or more hotspots and the second set of one or more hotspots.

13. The wireless device according to claim 11, further comprising a drive current system operatively coupled to the antenna system, the drive current system configured to provide the first set of drive currents during at least a first time interval, the drive current system configured to provide the second set of drive currents during at least a second time interval at least partially different from the first time interval.

14. The wireless device according to claim 13, wherein the drive current system is configured to switch a master set of drive currents to selectively supply the first set of one or more feed points and the second set of one or more feed points, thereby selectively providing the first set of drive currents and the second set of drive currents.

15. The wireless device according to claim 13, wherein the drive current system is configured to produce at least a first drive current and a second drive current differing in one or more of:

magnitude and phase.

16. The wireless device according to claim 13, further comprising one or more sensors operatively coupled to the drive current system, the one or more sensors configured for determining one or more of:

proximity of the wireless device to a user, position of the wireless device, and orientation of the wireless device, wherein the drive current system is configured for adjusting the overall radiation pattern based on signals provided by the one or more sensors.

17. A method for providing drive current to an antenna system for a wireless device, the antenna system having a first set of feed points disposed so that a first radiation pattern is generated corresponding to a first set of drive currents provided to the antenna system at the first set of feed points;

and a second set of feed points disposed so that a second radiation pattern is generated corresponding to a second set of drive currents provided to the antenna system at the second set of feed points;

wherein the second radiation pattern is at least in part different from the first radiation pattern;

the method comprising;

a. providing the first set of drive currents for a first predetermined time;

b. providing the second set of drive currents for a second predetermined time;

c. repeating steps a) and b) until occurrence of a predetermined event,

whereby an overall radiation pattern is being generated, the overall radiation pattern being at least in part a combination of the first radiation pattern and the second radiation pattern.

18. The method according to claim 17, wherein the first predetermined time is non-overlapping with the second predetermined time.

19. The method according to claim 17, wherein the first predetermined time partially overlaps with the second predetermined time.

20. The method according to claim 17, wherein the first radiation pattern corresponds to a first set of one or more hotspots and the second radiation pattern corresponds to a second set of one or more hotspots located at least partially differently from the first set of one or more hotspots.

21. The method according to claim 17, wherein the first set of one or more feed points is at least partially different from the second set of one or more feed points.

22. The method according to claim 17, further comprising providing N different sets of drive currents during N corresponding time intervals, thereby generating N different radiation patterns, the overall radiation pattern being a combination of the N different radiation patterns and irradiation due to the overall radiation pattern being an average of irradiations due to the N different radiation patterns, thereby spreading irradiation over the N different radiation patterns.

23. The method according to claim 17, the method further comprising switching a master set of drive currents to supply the first set of feed points for the first predetermined time and switching the master set of drive currents to supply the second set of feed points for the second predetermined time, thereby selectively providing the first set of drive currents and the second set of drive currents.

24. The method according to claim 17, the method further comprising:

d. detecting one or more position attributes selected from the group consisting of;

proximity of the wireless device to a user, position of the wireless device, and orientation of the wireless device; and

e. adjusting the overall radiation pattern based on the one or more position attributes; and

f. providing the first set of drive currents for a first predetermined time.