CONTROL OF TRANSMIT POWER AND ADJUSTMENT OF ANTENNA TUNING NETWORK OF A WIRELESS DEVICE

• US 20130331042A1
• Filed: 11/02/2012
• Published: 12/12/2013
• Est. Priority Date: 06/08/2012
• Status: Active Grant

• Current Assignee: Qualcomm, Inc.
• Original Assignee: Qualcomm, Inc.
• Inventors: See, Puay Hoe, Zhang, Xiangdong
• Granted Patent: US 9,392,558 B2
• Time in Patent Office: Days
• US Class Current: 455/77
• CPC Class Codes: H04B 17/12 of transmit antennas, e.g. of the amplitude or phase
• CPC Class Codes: H04W 52/367 Power values between minimum and maximum limits, e.g. dynamic range

Abstract

Techniques for controlling transmit power and adjusting an antenna tuning network of a wireless device are disclosed. In an exemplary design, an apparatus (e.g., a wireless device or a circuit module) includes a directional coupler and at least one detector. The directional coupler receives an input radio frequency (RF) signal at a first port, provides an output RF signal at a second port, and provides a coupled RF signal at a third port. The detector(s) receive at least one RF signal on at least one port of the directional coupler, measure the at least one RF signal, and provide measurements that are used to control the transmit power of the wireless device and adjust an antenna tuning network. For example, the measurements may be used to determine incident power, reflected power, delivered power, etc., which may be used to control the transmit power and/or adjust the antenna tuning network.

Claims

1. An apparatus comprising:

a directional coupler configured to receive an input radio frequency (RF) signal at a first port, provide an output RF signal at a second port, and provide a coupled RF signal at a third port; and

at least one detector coupled to the directional coupler and configured to receive at least one RF signal on at least one port of the directional coupler, measure the at least one RF signal, and provide measurements used to control a transmit power of a wireless device and adjust an antenna tuning network on the wireless device.

2. The apparatus of claim 1, further comprising:

at least one control module configured to;

receive the measurements from the at least one detector; and

generate controls based on the measurements to control the transmit power of the wireless device and adjust the antenna tuning network.

3. The apparatus of claim 2, the at least one control module is further configured to:

determine a current transmit power of the wireless device based on the measurements;

determine whether the current transmit power exceeds a maximum transmit power allowed for the wireless device; and

limit the transmit power of the wireless device to be within the maximum transmit power.

4. The apparatus of claim 2, the at least one control module is further configured to:

determine incident power and reflected power based on the measurements;

determine delivered power based on the incident power and the reflected power; and

control the transmit power of the wireless device based on the delivered power.

5. The apparatus of claim 2, the at least one control module is further configured to:

determine a current state of the antenna tuning network;

select a new state of the antenna tuning network based on the measurements; and

set the antenna tuning network to the new state.

6. The apparatus of claim 2, the at least one control module is further configured to:

determine delivered power, or reflected power, or both based on the measurements; and

adjust the antenna tuning network to increase the delivered power, or reduce the reflected power, or both.

7. The apparatus of claim 2, further comprising:

at least one analog-to-digital converter (ADC) configured to digitize the measurements from the at least one detector and provide measurement values; and

a control/interface unit configured to send the measurement values to the at least one control module.

8. The apparatus of claim 1, the directional coupler is further configured to provide a reflected RF signal at a fourth port, and the at least one RF signal comprising at least one of the input RF signal, the output RF signal, the coupled RF signal, and the reflected RF signal.

9. The apparatus of claim 1, the at least one detector comprising:

at least one power detector configured to provide measurements for power level of the at least one RF signal.

10. The apparatus of claim 1, the at least one detector comprising at least one of a power detector, a voltage detector, a current detector, or a phase detector.

11. The apparatus of claim 2, the at least one control module is further configured to determine at least one parameter based on the measurements, the at least one parameter including at least one of incident power, reflected power, delivered power, voltage standing wave ratio (VSWR), impedance of a load, or phase of the load.

12. The apparatus of claim 2, the at least one control module is further configured to adjust the antenna tuning network based on transmit timing, or receive timing, or both of the wireless device.

13. The apparatus of claim 2, the at least one control module is further configured to adjust the antenna tuning network at or before transmit boundaries, or receive boundaries, or both of the wireless device.

14. The apparatus of claim 2, the at least one control module residing within an integrated circuit, and the directional coupler and the at least one detector residing within a front-end module external to the integrated circuit.

15. A method comprising:

coupling a first portion of an input radio frequency (RF) signal at a first port of a directional coupler as an output RF signal at a second port of the directional coupler;

coupling a second portion of the input RF signal as a coupled RF signal at a third port of the directional coupler;

obtaining measurements for at least one RF signal on at least one port of the directional coupler;

controlling a transmit power of a wireless device based on the measurements; and

adjusting an antenna tuning network on the wireless device based on the measurements.

16. The method of claim 15, the controlling the transmit power comprising:

determining a current transmit power of the wireless device based on the measurements;

determining whether the current transmit power exceeds a maximum transmit power allowed for the wireless device; and

limiting the transmit power of the wireless device to be within the maximum transmit power.

17. The method of claim 15, the adjusting the antenna tuning network comprising:

determining a current state of the antenna tuning network;

selecting a new state of the antenna tuning network based on the measurements; and

setting the antenna tuning network to the new state.

18. An apparatus comprising:

means for coupling a first portion of an input radio frequency (RF) signal as an output RF signal and coupling a second portion of the input RF signal as a coupled RF signal;

means for obtaining measurements for at least one RF signal on at least one port of the means for coupling;

means for controlling a transmit power of a wireless device based on the measurements; and

means for adjusting an antenna tuning network on the wireless device based on the measurements.

19. The apparatus of claim 18, the means for controlling the transmit power comprising:

means for determining a current transmit power of the wireless device based on the measurements;

means for determining whether the current transmit power exceeds a maximum transmit power allowed for the wireless device; and

means for limiting the transmit power of the wireless device to be within the maximum transmit power.

20. The apparatus of claim 18, the means for adjusting the antenna tuning network comprising:

means for determining a current state of the antenna tuning network;

means for selecting a new state of the antenna tuning network based on the measurements; and

means for setting the antenna tuning network to the new state.