Method and apparatus for adaptive impedance matching

• US 8,564,381 B2
• Filed: 08/25/2011
• Issued: 10/22/2013
• Est. Priority Date: 11/08/2006
• Status: Active Grant

• Current Assignee: NXP USA, Inc. (NXP Semiconductors NV)
• Original Assignee: Blackberry Limited
• Inventors: McKinzie, William E.
• Primary Examiner(s): Takaoka, Dean O
• Application Number:
  US13/217,748
• Publication Number:
  US 20110304408A1
• Time in Patent Office: 789 Days
• Field of Search: 333/17.3, 333/32, 324/600, 455/125
• US Class Current: 333/17.3
• CPC Class Codes: H01Q 1/50 Structural association of antennas with earthing switches, lead-in devices or lightning protectors
• CPC Class Codes: H03H 11/30 Automatic matching of source impedance to load impedance
• CPC Class Codes: H03H 7/38 Impedance-matching networks
• CPC Class Codes: H03H 7/40 Automatic matching of load impedance to source impedance
• CPC Class Codes: H04B 1/44 Transmit/receive switching
• CPC Class Codes: H04L 25/0278 Arrangements for impedance matching
• CPC Class Codes: H04W 52/18 TPC being performed according to specific parameters

Abstract

A system that incorporates teachings of the present disclosure may include, for example, an adaptive impedance matching network having an RF matching network coupled to at least one RF input port and at least one RF output port and comprising one or more controllable variable reactive elements. The RF matching network can be adapted to reduce a level of reflected power transferred from said at least one input port by varying signals applied to said controllable variable reactive elements. The one or more controllable variable reactive elements can be coupled to a circuit adapted to map one or more control signals that are output from a controller to a signal range that is compatible with said one or more controllable variable reactive elements. Additional embodiments are disclosed.

Claims

1. An apparatus, comprising:

a first matching circuit coupled to a multi-band antenna, wherein the first matching circuit comprises first variable reactances, wherein the first matching circuit is coupled with the multi-band antenna by way of a first input port, and wherein the first matching circuit is associated with a first band;

a second matching circuit coupled to the multi-band antenna, wherein the second matching circuit comprises second variable reactances, wherein the second matching circuit is coupled with the multi-band antenna by way of a second input port, and wherein the second matching circuit is associated with a second band;

an RF voltage detector coupled to the multi-band antenna, wherein the RF voltage detector is configured to produce a detected voltage;

a controller coupled to the first and second variable reactances, wherein the controller supplies one or more first bias signals to the first variable reactances to increase the power from the first input port detected by the RF voltage detector and one or more second bias signals to the second variable reactances to increase the power from the second input port detected by the RF voltage detector, wherein the first and second matching circuits are coupled to the multi-band antenna by a diplexer, wherein the first and second matching circuits, the controller and the RF voltage detector are fabricated in a multichip module; and

a high-Q inductor external to the multichip module.

2. The apparatus of claim 1, wherein the first variable reactances and the second variable reactances include voltage tunable capacitors.

3. The apparatus of claim 1, wherein the first variable reactances and the second variable reactances include semiconductor varactors.

4. The apparatus of claim 1, wherein the first variable reactances and the second variable reactances include MEMS varactors.

5. The apparatus of claim 1, wherein the first variable reactances and the second variable reactances include MEMS switched capacitors.

6. The apparatus of claim 1, wherein the RF voltage detector comprises a logarithmic amplifier.

7. The apparatus of claim 1, wherein the controller is a microprocessor, and wherein the one or more first and second bias signals are digital signals.

8. A mobile device, comprising:

a multi-band antenna;

a plurality of transmitters coupled with the multi-band antenna;

a diplexer;

a first matching circuit coupled to the multi-band antenna, wherein the first matching circuit comprised first variable reactances, wherein the first matching circuit is coupled with the multi-band antenna by way of a first input port, and wherein the first matching circuit is associated with a first band;

a second matching circuit coupled to the multi-band, antenna, wherein the second matching circuit comprises second variable reactances, wherein the second matching circuit is coupled with the mufti-band antenna by way of a second input port, wherein the second matching circuit is associated with a second band, wherein the first and second matching circuits are coupled to the multi-band antenna by the diplexer;

an RF voltage detector coupled to the multi-band antenna, wherein the RF voltage detector is configured to produce a detected voltage;

a controller coupled to the first and second variable reactances, wherein the controller supplies one or more first bias signals to the first variable reactances to increase the power from the first input port detected by the RF voltage detector and one or more second bias signals to the second variable reactances to increase the power from the second input port detected by the RF voltage detector, wherein the first and second matching circuits, the controller and the RF voltage detector are fabricated in a multichip module; and

a high-Q inductor external to the multichip module.

9. The mobile device of claim 8, wherein the first variable reactances and the second variable reactances include voltage tunable capacitors.

10. The mobile device of claim 8, wherein the first variable reactances and the second variable reactances include semiconductor varactors.

11. The mobile device of claim 8, wherein the first variable reactances and the second variable reactances include MEMS varactors.

12. The mobile device of claim 8, wherein the first variable reactances and the second variable reactances include MEMS switched capacitors.

13. The mobile device of claim 8, wherein the RF voltage detector comprises a logarithmic amplifier.

14. The mobile device of claim 8, wherein the controller supplies the one or more first and second bias signals without utilizing a directional coupler.