Method and apparatus for antenna selection

• US 10,651,918 B2
• Filed: 05/14/2018
• Issued: 05/12/2020
• Est. Priority Date: 12/16/2014
• Status: Active Grant

• Current Assignee: NXP USA, Inc. (NXP Semiconductors NV)
• Original Assignee: NXP USA, Inc. (NXP Semiconductors NV)
• Inventors: Greene, Matthew Russell
• Primary Examiner(s): Liao, Hsinchun
• Application Number:
  US15/978,650
• Publication Number:
  US 20180262257A1
• Time in Patent Office: 729 Days
• CPC Class Codes: H01Q 21/0006 Particular feeding systems
• CPC Class Codes: H03H 7/40 Automatic matching of load impedance to source impedance
• CPC Class Codes: H04B 1/0458 Arrangements for matching and coupling between power amplifier and antenna or between amplifying stages matching circuits in general H03H
• CPC Class Codes: H04B 1/18 Input circuits, e.g. for coupling to an antenna or a transmission line coupling networks between antennas or lines and receivers independent of the nature of the receiver H03H
• CPC Class Codes: H04B 7/0404 the mobile station comprising multiple antennas, e.g. to provide uplink diversity
• CPC Class Codes: H04B 7/0608 Antenna selection according to transmission parameters
• CPC Class Codes: H04B 7/0802 using antenna selection H04B7/0868 takes precedence; antenna beam directivity switching H01Q3/24
• CPC Class Codes: H04W 24/10 Scheduling measurement reports ; Arrangements for measurement reports

Abstract

A system that incorporates teachings of the subject disclosure may include, for example, a system including an RF switch connected with an antenna system that includes a first antenna and a second antenna. The system can include, where the RF switch has a first position in which the first antenna operates as the primary antenna and the second antenna operates as the diversity antenna, and wherein the RF switch has a second position in which the second antenna operates as the primary antenna and the first antenna operates as the diversity antenna. The system can include a controller coupled with the matching network and with the RF switch, where the controller receives first measurements associated with the antenna system, and where the controller adjusts the RF switch to select between the first and second positions according to the first measurements.

Claims

1. A mobile device, comprising:

an RF switch that, when connected with an antenna system having a first antenna and a second antenna, has a first position in which the first antenna is operating as a primary antenna and the second antenna is operating as a diversity antenna, and wherein the RF switch has a second position in which the second antenna is operating as the primary antenna and the first antenna is operating as the diversity antenna;

a matching network coupled with a transceiver and the antenna system, wherein the matching network comprises a tunable reactive element; and

a controller that when coupled with the matching network and with the RF switch, receives first measurements associated with the antenna system,

wherein the controller adjusts the tunable reactive element according to the first measurements to provide impedance tuning corresponding to a grid location of a two-dimensional tuning grid, the grid location comprising a predetermined antenna efficiency,

wherein the controller adjusts the RF switch to select between the first and second positions according to the first measurements and the predetermined antenna efficiency.

2. The mobile device of claim 1, wherein the first measurements comprise reflection measurements.

3. The mobile device of claim 2, wherein the first measurements are limited to one of the first or second antennas.

4. The mobile device of claim 1, wherein the controller determines the predetermined antenna efficiency according to a stored antenna efficiency value.

5. The mobile device of claim 4, wherein the stored antenna efficiency value comprises an antenna radiation efficiency value.

6. The mobile device of claim 1, wherein the RF switch is in the first position, wherein the first measurements are limited to the first antenna, wherein the controller adjusts the RF switch to select the second position according to the first measurements and the predetermined antenna efficiency.

7. The mobile device of claim 6, wherein the controller receives second measurements that are limited to the second antenna, wherein the controller adjusts the tunable reactive element according to the second measurements to provide the impedance tuning.

8. The mobile device of claim 7, wherein the second measurements comprise reflection measurements, and wherein the controller adjusts the RF switch to select the first position according to the second measurements.

9. The mobile device of claim 1, wherein the predetermined antenna efficiency is determined according to a reflection loss.

10. The mobile device of claim 1, wherein the impedance tuning is for the first and second antennas, wherein the tunable reactive element comprises a first tunable reactive element and a second tunable reactive element, wherein the first tunable reactive element performs the impedance tuning for the first antenna, and wherein the second tunable reactive element performs the impedance tuning for the second antenna.

11. A method comprising:

obtaining, by a controller, first measurements for a first antenna of a communication device when an RF switch of the communication device is in a first position;

switching, by the controller, the RF switch to a second position;

obtaining, by the controller, second measurements for a second antenna when the RF switch is in the second position;

determining predetermined antenna efficiency values for the first antenna and the second antenna according to a two-dimensional tuning grid storing a plurality of predetermined antenna efficiency values;

analyzing, by the controller, the first measurements and the second measurements based on the predetermined antenna efficiency values to determine a particular one of the first and second antennas for transmission; and

switching, by the controller, the RF switch to the first position responsive to a determination that the first antenna is the particular one of the first and second antennas for transmission.

12. The method of claim 11, wherein the predetermined antenna efficiency values comprise antenna radiation efficiency values.

13. The method of claim 12, further comprising:

adjusting, by the controller, a tunable reactive element of a matching network according to one of the first measurements, the second measurements, or both to perform impedance tuning to obtain an impedance tuning result of the first antenna, the second antenna, or both.

14. The method of claim 13, wherein the adjusting of the RF switch to select the second position is further based on comparison of the impedance tuning result of the first antenna, the second antenna, or both to a free space impedance tuning result of the first antenna, the second antenna, or both.

15. The method of claim 13, wherein the RF switch has a first position in which the first antenna is operating as a primary antenna and the second antenna is operating as a diversity antenna, and wherein the RF switch has a second position in which the second antenna is operating as the primary antenna and the first antenna is operating as the diversity antenna.

16. A device, comprising:

an RF switch connected with an antenna system having a first antenna and a second antenna, wherein the RF switch has a first position in which the first antenna is operating as a primary antenna and the second antenna is operating as a diversity antenna, and wherein the RF switch has a second position in which the second antenna is the primary antenna and the first antenna is the diversity antenna; and

a controller coupled with the RF switch, wherein the controller receives first measurements associated with the antenna system, wherein the controller determines predetermined antenna efficiency values for the first antenna and the second antenna according to a two-dimensional tuning grid storing a plurality of predetermined antenna efficiency values, and

wherein the controller adjusts the RF switch to select between the first and second positions according to the first measurements and the predetermined antenna efficiency values.

17. The device of claim 16, further comprising a matching network coupled with a transceiver and the antenna system, wherein the matching network comprises a tunable reactive element.

18. The device of claim 17, wherein the tunable reactive element comprises a first tunable reactive element coupled with the first antenna and a second tunable reactive element coupled with the second antenna, and wherein tuning values for the first and second tunable reactive elements are selected according to improving impedance tuning of a receive-only function of one of the first or second antennas and compromising impedance tuning between transmit and receive functions of another of the first or second antennas.

19. The device of claim 18, wherein the controller adjusts the tunable reactive element according to the first measurements to provide impedance tuning.

20. The device of claim 16, wherein the controller receives sensed parameters associated with the device, wherein the controller adjusts the RF switch to select between the first and second positions according further to the first measurements and the sensed parameters, and wherein the sensed parameters include at least one of proximity data, first capacitive data associated with the antenna system, or second capacitive data associated with a touch screen.