Adaptively tunable antennas incorporating an external probe to monitor radiated power

• US 20070285326A1
• Filed: 01/16/2007
• Published: 12/13/2007
• Est. Priority Date: 01/14/2006
• Status: Active Grant

• Current Assignee: NXP USA, Inc. (NXP Semiconductors NV)
• Original Assignee: Blackberry Limited
• Inventors: McKinzie, William
• Granted Patent: US 8,125,399 B2
• Time in Patent Office: Days
• US Class Current: 343/746
• 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. An apparatus, comprising:

an adaptively-tuned antenna including a variable reactance network, connected to said antenna;

an RF field probe located near the antenna;

an RF detector to sense voltage from said field probe;

a controller that monitors said RF voltage and supplies control signals to a driver circuit; and

wherein said driver circuit converts said control signals to bias signals for said variable reactance network.

2. The apparatus of claim 1, wherein said variable reactance network comprises a shunt capacitance.

3. The apparatus of claim 1, wherein said variable reactance network comprises a series capacitance.

4. The apparatus of claim 1, wherein a multiplicity of variable reactance networks are connected to the antenna.

5. A method, comprising:

improving the efficiency of a transmitting antenna system by using a variable reactance network;

sensing the RF voltage present on a near field probe; and

controlling the bias signal presented to said variable reactance network to maximize the RF voltage present on said near field probe.

6. The method of claim 5, wherein said antenna comprises a patch antenna, a monopole antenna, or a slot antenna.

7. The method of claim 5, further comprising maximizing the RF voltage using an algorithm implemented on a digital processor.

8. The method claim 7, wherein the digital processor is a baseband processor in a mobile phone.

9. An apparatus adapted to make an antenna tunable, comprising:

a variable reactance network connected to said antenna; and

a closed loop control system that senses the RF voltage at a near field probe and adjusts the reactance of said network to maximize the RF voltage.

10. An apparatus, comprising:

an adaptively-tuned receive antenna including a variable reactance network connected to said antenna;

an RF test probe located near said antenna from which is radiated a test signal;

an RF detector to sense voltage from a point on the antenna; and

a controller that monitors said RF voltage and supplies control signals to a driver circuit, wherein said driver circuit converts control signals to bias signals for said variable reactance network.

11. The apparatus of claim 10, wherein a variable reactance network comprises a shunt capacitance.

12. The apparatus of claim 10, wherein a variable reactance network comprises a series capacitance.

13. The apparatus of claim 10, wherein a multiplicity of variable reactance networks are connected to the antenna.

14. A method to improve the efficiency of a receiving antenna system, comprising

transmitting a narrowband RF signal at a desired test frequency;

using a variable reactance network connect to said antenna;

sensing the RF voltage present on the antenna;

controlling the bias signal presented to the variable reactance network; and

maximizing the RF voltage present on said antenna.

15. The method of claim 14, wherein the antenna comprises a patch antenna, a monopole antenna, or a slot antenna.

16. The method of claim 15, further comprising using an algorithm implemented on a digital processor to maximize the RF voltage.

17. The method system of claim 16, wherein said digital processor is a baseband processor in a mobile phone.

19. The machine-accessible medium of claim 17, further comprising said instructions causing said machine to perform operations further comprising controlling an algorithm implemented on a digital processor to maximize the RF voltage is.

20. The machine-accessible medium of claim 19, further comprising said instructions causing said machine to perform operations further comprising using the digital processor in a baseband processor in a mobile phone.

18. A machine-accessible medium that provides instructions, which when accessed, cause a machine to perform operations comprising:

improving the efficiency of a receiving antenna system by controlling the transmission of a narrowband RF signal at a desired test frequency, using a variable reactance network connected to said antenna, sensing the RF voltage present on the antenna, controlling the bias signal presented to said variable reactance network and maximizing the RF voltage present on said antenna.