Method and apparatus for adaptive impedance matching

• US 8,558,633 B2
• Filed: 03/21/2012
• Issued: 10/15/2013
• 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. III
• Primary Examiner(s): Takaoka, Dean O
• Application Number:
  US13/425,626
• Publication Number:
  US 20120223786A1
• Time in Patent Office: 573 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 apparatus having an RF matching network including one or more variable reactive elements, where the RF matching network has a first port coupled to a transceiver and second port coupled to an antenna. The RF matching network can modify signal power transferred between the first port and the second port according to one or more bias signals applied to the one or more variable reactive elements to vary a variable impedance of the RF matching network. The one or more variable reactive elements are coupled to a circuit that maps one or more control signals to the one or more bias signals, and wherein the one or more control signals are generated by a controller according to a mode of operation of a communication device. Additional embodiments are disclosed.

Claims

1. An apparatus, comprising:

an RF matching network comprising one or more variable reactive elements, wherein the RF matching network has an RF input port coupled to a transmitter producing an RF signal supplied to the RF input port, and wherein the RF matching network comprises an RF output port coupled to an antenna; and

an RF voltage detector that receives a signal from the RF output port of the RF matching network, wherein the RF voltage detector detects an RF voltage magnitude representative of the signal produced by the RF output port of the RF matching network,

wherein said RF matching network modifies signal power transferred the RF input port to the RF output port according to one or more bias signals applied to the one or more variable reactive elements to vary a variable impedance of the RF matching network,

wherein the one or more variable reactive elements are coupled to a circuit that maps one or more control signals to the one or more bias signals, and wherein the one or more control signals are generated by a controller according to a mode of operation of a communication device and the RF voltage magnitude.

2. The apparatus of claim 1, wherein the mode of operation comprises information that describes one of a mode of transmitting RF signals by the communication device, or a mode of receiving RF signals by the communication device.

3. The apparatus of claim 1, wherein the mode of operation comprises information describing each of one or more frequencies of signals transferred between the RF input port and the RF output port.

4. The apparatus of claim 1, wherein the one or more variable reactive elements comprise at least one of:

one or more reactive elements configurable with one or more semiconductor devices, wherein the one or more semiconductor devices are controlled by the one or more bias signals generated by the circuit;

or

one or more reactive elements controlled with one or more micro-electro-mechanical systems (MEMS) devices, wherein the one or more MEMS devices are controlled by the one or more bias signals;

or

one or more reactive elements each having a reactance controllable by at least one of the

one or more bias signals;

or combinations thereof.

5. The apparatus of claim 1, wherein the one or more bias signals generated by the circuit enable or disable one or more switches that control a variable reactance of the RF matching network.

6. The apparatus of claim 5, wherein the one or more switches correspond to one or more semiconductor switches.

7. The apparatus of claim 5, wherein the one or more switches correspond to one or more mechanical switches.

8. The apparatus of claim 7, wherein the one or more mechanical switches correspond to one or more micro-electro-mechanical systems (MEMS) switches.

9. The apparatus of claim 5, wherein the one or more bias signals comprise one or more digital signals.

10. The apparatus of claim 1, wherein the RF matching network is adapted to reduce signal reflections at one of the RF input port, or the RF output port, or both.

11. The apparatus of claim 1, wherein the one or more bias signals comprise at least one of one or more analog signals, or one or more digital signals, or both.

12. A matching network, comprising:

a variable reactive element coupled to an RF input port and an RF output port, wherein the RF input port is coupled to a transmitter producing an RF signal supplied to the RF input port and the RF output port is coupled to an antenna of a device; and

an RF voltage detector coupled to the RF output port for detecting an RF voltage magnitude associated with a signal produced by the RF output port of the RF matching network,

wherein the variable reactive element is adapted to change power transferred between the RF input port and the RF output port responsive to a control signal generated by a controller that is mapped by a circuit to adjust a reactance of the variable reactive element according to a mode of operation of the device and the RF voltage magnitude.

13. The matching network of claim 12, wherein the device is a communication device, and wherein the controller determines the mode of operation from a mode of transmitting RF signals from the communication device.

14. The matching network of claim 12, wherein the device is a communication device, and wherein the controller determines the mode of operation from a mode of receiving RF signals at the communication device.

15. The matching network of claim 12, wherein the device is a communication device, and wherein the controller determines the mode of operation according to a frequency of a signal transferred between the RF input port and RF output port.

16. The matching network of claim 12, wherein the controller is adapted to adjust the reactance of the variable reactive element according to an external signal supplied to the controller.

17. The matching network of claim 12, wherein the variable reactive element comprise at least one of a variable inductor, or a variable capacitor, or combinations thereof.

18. A non-transitory machine-readable storage medium, comprising computer instructions, wherein responsive to a processor executing the computer instructions, the processor performs operations comprising:

determining a mode of operation of a device;

receiving RF voltage magnitude data an RF detector, wherein a transmitter produces an RF signal supplied to an RF input port of a matching network, wherein the matching network comprises an RF output port coupled to an antenna, and wherein the RF detector detects the RF voltage magnitude data at the RF output port of the matching network;

generating according to the mode of operation and the RF voltage magnitude data a control signal that is mapped by a circuit to a bias signal; and

outputting the bias signal to the matching network to modify a reactance therein that causes a change in power transferred from the RF input port to the RF output port of the matching network.

19. The non-transitory machine-readable storage medium of claim 18, wherein responsive to executing the computer instructions the processor performs operations comprising determining the mode of operation according to at least one of RF signals transmitted by the device, or RF signals received by the device, or both.

20. The non-transitory machine-readable storage medium of claim 18, wherein the matching network comprises at least one of:

one or more reactive elements configurable with one or more semiconductor devices, wherein the one or more semiconductor devices are controlled by the one or more bias signals generated by the circuit;

or

one or more reactive elements controlled with one or more micro-electro-mechanical systems (MEMS) devices, wherein the one or more MEMS devices are controlled by the one or more bias signals;

or

one or more reactive elements each having a reactance controllable by at least one of the one or more bias signals;

or

combinations thereof.