METHOD AND APPARATUS FOR TUNING ANTENNAS IN A COMMUNICATION DEVICE

• US 20120112852A1
• Filed: 11/08/2010
• Published: 05/10/2012
• Est. Priority Date: 11/08/2010
• Status: Active Grant

• Current Assignee: NXP USA, Inc. (NXP Semiconductors NV)
• Original Assignee: Paratek Microwave Incorporated (Blackberry Limited)
• Inventors: Manssen, Keith R., Greene, Matthew R., Rabe, Duane
• Granted Patent: US 9,379,454 B2
• Time in Patent Office: Days
• US Class Current: 333/105
• CPC Class Codes: H01Q 1/243 with built-in antennas
• CPC Class Codes: H01Q 1/50 Structural association of antennas with earthing switches, lead-in devices or lightning protectors
• CPC Class Codes: H01Q 21/06 Arrays of individually energised antenna units similarly polarised and spaced apart
• CPC Class Codes: H01Q 21/28 Combinations of substantially independent non-interacting antenna units or systems multiple beam H01Q25/00
• CPC Class Codes: H01Q 5/50 Feeding or matching arrangements for broad-band or multi-band operation
• 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 17/12 of transmit antennas, e.g. of the amplitude or phase

Abstract

A system that incorporates teachings of the present disclosure may include, for example, a process for obtaining a first operational metric for a transmitter of a communication device, determining a range of impedances based on the first operational metric where the range of impedances is associated with an acceptable level of performance for the communication device, obtaining a second operational metric for the transmitter, determining a target impedance within the range of impedances based on the second operational metric, and tuning a first impedance matching network based on the target impedance, where the first impedance matching network is coupled with a first antenna of the communication device, and where the tuning is based on adjusting a first variable component of the first impedance matching network. Additional embodiments are disclosed.

Claims

1. A method comprising:

obtaining a first operational metric for a transmitter of a communication device;

determining a range of impedances based on the first operational metric, wherein the range of impedances is associated with an acceptable level of performance for the communication device;

obtaining a second operational metric for the transmitter;

determining a target impedance within the range of impedances based on the second operational metric; and

tuning a first impedance matching network based on the target impedance, wherein the first impedance matching network is coupled with a first antenna of the communication device, and wherein the tuning is based on adjusting a first variable component of the first impedance matching network.

2. The method of claim 1, further comprising:

determining a predetermined relationship based on the target impedance, a transmit frequency and a receive frequency; and

tuning a second impedance matching network based on the predetermined relationship, wherein the second impedance matching network is coupled with a second antenna of the communication device, and wherein the tuning is based on adjusting a second variable component of the second impedance matching network.

3. The method of claim 1, wherein the obtaining of the first operational metric is performed using a directional coupler connected between the transmitter and the first antenna.

4. The method of claim 3, wherein the obtaining of the second operational metric is performed using a detector connected in proximity to a second antenna of the communication device without using a detector connected to an input of the first antenna.

5. The method of claim 4, wherein the detector connected in proximity to the second antenna comprises a directional coupler.

6. The method of claim 1, wherein the second operational metric is transmitter output power that is measured at a second antenna, wherein the second antenna is a diversity reception antenna.

7. A method of tuning a communication device, the method comprising:

obtaining an RF voltage at an output of a tunable matching network of the communication device, the RF voltage being obtained at a transmission frequency of the communication device by a detector, the tunable matching network having one or more variable capacitors with variable capacitance values;

determining derivative information associated with the RF voltage based on derivatives of the RF voltage and the variable capacitance values; and

tuning the tunable matching network using the derivative information.

9. The non-transitory computer-readable storage medium of claim 7, wherein the first antenna is a transmit and receive antenna, wherein the second antenna is a diversity reception antenna, and wherein at least one of the one or more operational metrics is associated with the second antenna without measuring any parameters at the input of the first antenna.

10. The non-transitory computer-readable storage medium of claim 7, wherein the at least one of the one or more operational metrics is measured at the second antenna using a directional coupler.

11. The non-transitory computer-readable storage medium of claim 7, wherein the current figure of merit is based on a return loss.

12. The non-transitory computer-readable storage medium of claim 7, wherein the first antenna is a transmit and receive antenna, wherein the second antenna is a diversity reception antenna, and wherein at least one of the one or more operational metrics is obtained by a directional coupler connected between the transmitter and the tunable matching network without measuring any parameters at the inputs of the first and second antennas.

13. The non-transitory computer-readable storage medium of claim 7, comprising computer instructions to switch the transmitter between the first and second antennas based on measurements taken during a receive mode of the communication device.

14. The non-transitory computer-readable storage medium of claim 7, comprising computer instructions to:

determine a predetermined relationship based on a transmit frequency and a receipt frequency; and

adjust a setting of another variable component of another tunable matching network based on the predetermined relationship, wherein the other tunable matching network is connected with the other of the first antenna or the second antenna of the communication device.

15. The non-transitory computer-readable storage medium of claim 7, wherein the one or more operational metrics comprises at least one of output power of the transmitter, return loss, received power, current drain or transmitter linearity.

16. The non-transitory computer-readable storage medium of claim 7, wherein the one or more operational metrics are obtained using first and second directional couplers, wherein the first directional coupler is connected between the transmitter and the first antenna, and wherein the second directional coupler is connected at the second antenna.

8. A non-transitory computer-readable storage medium, comprising computer instructions to:

obtain one or more operational metrics for a transceiver of a communication device;

calculate a current figure of merit as a function of the one or more operational metrics;

compare the current figure of merit to a target figure of merit; and

adjust a setting of a variable component of a tunable matching network to a value expected to change the current figure of merit relative to the target figure of merit, wherein the tunable matching network is connected with one of a first antenna or a second antenna of the communication device.

17. A matching network for a communication device, the matching network comprising:

a first variable component connectable along a first path between a first antenna and a front end module of the communication device;

a second variable component connectable along a second path between a second antenna and the front end module of the communication device; and

a switching element for selectively switching a detector between the first and second paths to obtain operational metrics, wherein the first and second antennas are independently tuned by adjusting the first and second variable components based on the operational metrics.

18. The matching network of claim 17, wherein the first and second antennas are tuned independently without detecting measurements at inputs of the first and second antennas.

19. The matching network of claim 17, wherein selective switching between the first and second antennas for a transmit mode is based on the operational metrics obtained during a receive mode.

20. The matching network of claim 17, wherein the switching element is a double-pole double-throw RF switch.