Adaptive tuning of an impedance matching circuit in a wireless device

Patent metadata

Field	Value
Publication number	US-9054756-B2
Application number	US-201113236423-A
Country	US
Kind code	B2
Filing date	Sep 19, 2011
Priority date	Sep 19, 2011
Publication date	Jun 9, 2015
Grant date	Jun 9, 2015

Abstract

Techniques for adaptively tuning an impedance matching circuit are disclosed. In an aspect, the impedance matching circuit is pre-characterized. The performance of the impedance matching circuit is determined for multiple settings of the impedance matching circuit, stored in memory, and used to tune the impedance matching circuit. In another aspect, the impedance matching circuit is tuned based on measurements for one or more parameters such as delivered power, return loss, power amplifier current, antenna/load impedance, etc. In an exemplary design, an apparatus includes a memory and a control unit. The memory stores information for multiple settings of an impedance matching circuit. The control unit selects one of the multiple settings of the impedance matching circuit based on the information for the multiple settings and measurements for the impedance matching circuit. The impedance matching circuit performs impedance matching for a load circuit (e.g., an antenna) based on the selected setting.

First claim

What is claimed is:

1. An apparatus comprising:
a sensor configured to obtain measurements for an impedance matching circuit; and
a control unit configured to select one of the plurality of settings of the impedance matching circuit based on information for the plurality of settings and the measurements for the impedance matching circuit, the impedance matching circuit including at least one reactive element that is reconfigurably connectable as either a series element or a shunt element.

2. The apparatus of claim 1 , wherein performance of the impedance matching circuit is pre-characterized for each of the plurality of settings, and wherein the apparatus is configured to store information indicative of the performance of the impedance matching circuit for the plurality of settings.

3. The apparatus of claim 1 , wherein the plurality of settings of the impedance matching circuit are associated with different frequencies at which peak performance is obtained, and wherein the plurality of settings of the impedance matching circuit are ordered based on the frequencies at which the peak performance is obtained.

4. The apparatus of claim 1 , further comprising a memory configured to store, for each of the plurality of settings, information indicative of a frequency or a range of frequencies for which the setting is applicable, at least one switch setting for at least one switch within the impedance matching circuit, at least one control setting for at least one variable reactive element within the impedance matching circuit, or a combination thereof.

5. The apparatus of claim 1 , wherein the measurements relate to at least one of delivered power, return loss, and load impedance.

6. The apparatus of claim 1 , wherein the control unit is configured to select an initial setting for the impedance matching circuit based on an operating frequency of a wireless device, and to select a next higher setting or a next lower setting in the plurality of settings based on the measurements for the impedance matching circuit.

7. The apparatus of claim 1 , wherein the control unit is configured to periodically receive the measurements for the impedance matching circuit and to periodically determine whether to maintain a current setting or select a new setting for the impedance matching circuit based on the measurements.

8. The apparatus of claim 1 , wherein the control unit is configured to select one of the plurality of settings of the impedance matching circuit based further on contextual information for a wireless device.

9. An apparatus comprising:
means for obtaining measurements for an impedance matching circuit; and
means for selecting one of a plurality of settings of the impedance matching circuit based on information for the plurality of settings and the measurements for the impedance matching circuit, the impedance matching circuit including at least one reactive element that is reconfigurably connectable as either a series element or a shunt element.

10. The apparatus of claim 9 , wherein the measurements relate to at least one of delivered power, return loss, and load impedance.

11. The apparatus of claim 9 , the means for selecting comprising:
means for selecting an initial setting for the impedance matching circuit based on an operating frequency of a wireless device, and
means for selecting a next higher setting or a next lower setting in the plurality of settings based on the measurements for the impedance matching circuit.

12. The apparatus of claim 9 , the means for obtaining measurements comprising means for periodically obtaining the measurements for the impedance matching circuit, and the means for selecting comprising means for periodically determining whether to maintain a current setting or select a new setting for the impedance matching circuit based on the measurements.

13. The apparatus of claim 9 , further comprising:
means for storing the information for the plurality of settings of the impedance matching circuit.

14. The apparatus of claim 13 , the means for storing comprising:
means for storing information indicative of performance of the impedance matching circuit for the plurality of settings, the performance of the impedance matching circuit being pre-characterized for each of the plurality of settings.

Assignees

• See Puay Hoe
• Zhang Xiangdong
• Qualcomm Inc

Inventors

• See Puay Hoe
• Zhang Xiangdong

Classifications

• H03H7/40

  Automatic matching of load impedance to source impedance · CPC title

• H04B1/0458 Primary

  Arrangements for matching and coupling between power amplifier and antenna or between amplifying stages (matching circuits in general H03H) · CPC title

• H04B1/18

  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 title