ADAPTIVELY TUNABLE ANTENNAS INCORPORATING AN EXTERNAL PROBE TO MONITOR RADIATED POWER

• US 20120157026A1
• Filed: 02/24/2012
• Published: 06/21/2012
• Est. Priority Date: 01/14/2006
• Status: Active Grant

• Current Assignee: NXP USA, Inc. (NXP Semiconductors NV)
• Original Assignee: Paratek Microwave Incorporated (Blackberry Limited)
• Inventors: McKinzie, William E., Mendolia, Greg, Manssen, Keith
• Granted Patent: US 8,405,563 B2
• Time in Patent Office: Days
• US Class Current: 455/193.1
• CPC Class Codes: H01Q 23/00 Antennas with active circuits or circuit elements integrated within them or attached to them
• CPC Class Codes: H01Q 5/321 within a radiating element or between connected radiating elements
• CPC Class Codes: H01Q 9/0407 Substantially flat resonant element parallel to ground plane, e.g. patch antenna dipole H01Q9/285; monopole H01Q9/40
• CPC Class Codes: H01Q 9/0421 with a shorting wall or a shorting pin at one end of the element H01Q9/0414 takes precedence
• CPC Class Codes: H01Q 9/145 by varying the electrical length

Abstract

An embodiment of the present invention an apparatus, comprising an apparatus, comprising an adaptively-tuned antenna including a variable reactance network connected to the antenna, an RF field probe located near the antenna, an RF detector to sense voltage from the field probe, a controller that monitors the RF voltage and supplies control signals to a driver circuit and wherein the driver circuit converts the control signals to bias signals for the variable reactance network.

Claims

1. A method comprising:

obtaining an RF voltage present on an RF field probe that is located in proximity to an antenna of a communication device, wherein the RF voltage is generated based on radiated power of the antenna, and wherein the RF voltage is sensed by an RF detector of the communication device;

utilizing a processor for generating control signals based on the obtained RF voltage; and

providing the control signals to a driver circuit for conversion into bias voltages that are used by a variable reactance network of the communication device for tuning the antenna via applying the bias voltages to at least one variable capacitor of the variable reactance network to adjust a capacitance of the at least one variable capacitor.

2. The method of claim 1, wherein the processor is a digital processor, and wherein the providing of the control signals and the conversion into the bias voltages is an iterative process.

3. The method of claim 1, wherein the RF probe is positioned within one Wheeler radian sphere of a center of the antenna.

4. The method of claim 1, wherein the variable reactance network comprises at least one of a semiconductor varactor, a micro-electro-mechanical systems (MEMS) varactor, a MEMS switched reactive element, a semiconductor switched reactive element or a ferroelectric capacitor.

5. The method of claim 1, wherein the antenna comprises a patch antenna, a monopole antenna or a slot antenna.

6. The method of claim 1, wherein the capacitance of the at least one variable capacitor is adjusted differently for transmit and receive modes of the communication device.

7. The method of claim 1, wherein the adjusting of the capacitance of the at least one variable capacitor causes the RF voltage to increase.

8. The method of claim 1, wherein the antenna comprises a planar inverted F antenna.

9. A method comprising:

receiving a control signal at a variable reactance network of a communication device, wherein the control signal is received from a control system of the communication device and is based on an RF voltage present on an RF field probe that is located in proximity to an antenna of the communication device, wherein the RF voltage is generated based on radiated power of the antenna, and wherein the RF voltage is sensed by an RF detector of the communication device; and

tuning the antenna utilizing the variable reactance network by adjusting a reactance of at least one variable reactive element of the variable reactance network based on the control signal.

10. The method of claim 9, wherein the adjusting of the reactance is an iterative process, and wherein the control signal comprises a bias voltage received from a driver circuit of the control system.

11. The method of claim 9, wherein the RF probe is positioned within one Wheeler radian sphere of a center of the antenna.

12. The method of claim 9, wherein the at least one variable reactive element comprises at least one of a semiconductor varactor, a micro-electro-mechanical systems (MEMS) varactor, a MEMS switched reactive element, a semiconductor switched reactive element or a ferroelectric capacitor.

13. The method of claim 9, wherein the antenna comprises a planar inverted F antenna, a patch antenna, a monopole antenna or a slot antenna.

14. The method of claim 9, wherein the at least one reactive element comprises a voltage tunable ferroelectric variable capacitor, and wherein a capacitance of the voltage tunable ferroelectric variable capacitor is adjusted differently for transmit and receive modes of the communication device.

15. The method of claim 9, wherein the adjusting of the reactance of the at least one variable reactive element causes the RF voltage to increase.

16. A method comprising:

receiving a signal at a variable reactance network of a communication device, wherein the signal is based on an RF voltage present on an RF field probe that is located in proximity to an antenna of the communication device, wherein the RF voltage is generated based on radiated power of the antenna; and

tuning the antenna utilizing the variable reactance network by adjusting a reactance of at least one variable reactive element of the variable reactance network based on the signal.

17. The method of claim 16, wherein the at least one variable reactive element comprises a voltage tunable ferroelectric variable capacitor.

18. The method of claim 16, wherein the reactance of the at least one variable reactive element is adjusted differently for transmit and receive modes of the communication device.

19. The method of claim 16, wherein the at least one variable reactive element comprises at least one of a semiconductor varactor, a micro-electro-mechanical systems (MEMS) varactor, a MEMS switched reactive element, a semiconductor switched reactive element or a ferroelectric capacitor.

20. The method of claim 16, wherein the antenna comprises a planar inverted F antenna, a patch antenna, a monopole antenna or a slot antenna.