TUNABLE ANTENNA SYSTEM

• US 20080088517A1
• Filed: 10/15/2007
• Published: 04/17/2008
• Est. Priority Date: 10/17/2006
• Status: Active Grant

• Current Assignee: Maxlinear Incorporated
• Original Assignee: Quantenna Communications, Inc. (ON Semiconductor Corporation)
• Inventors: Ansari, Saied, Rezvani, Behrooz
• Granted Patent: US 8,063,839 B2
• Time in Patent Office: Days
• US Class Current: 343/745
• CPC Class Codes: H01Q 1/38 formed by a conductive layer on an insulating support patch antennas H01Q9/0407; microstrip dipole antennas H01Q9/065; microstrip slot antennas H01Q13/106; transmission line microstrip antennas H01Q13/206; manufacturing reflecting surfaces using insulating material for supporting the reflecting surface H01Q15/142
• CPC Class Codes: H01Q 23/00 Antennas with active circuits or circuit elements integrated within them or attached to them
• CPC Class Codes: H01Q 9/145 by varying the electrical length
• CPC Class Codes: H01Q 9/27 Spiral antennas
• CPC Class Codes: H01Q 9/42 with folded element, the folded parts being spaced apart a small fraction of the operating wavelength

Abstract

A technique for tuning an antenna may include one or more of the following: working against a ground plane, utilizing the third dimension by alternating layers on a substrate, integrating an inductive short stub in the substrate to improve port matching, and making a tuning port available for capacitive loading and resonance modification.

Claims

1. A tunable antenna system comprising:

an antenna structure;

a dynamic capacitive loading device coupled to the antenna structure, wherein the dynamic capacitive loading device has a variable capacitive load that depends upon voltage provided on a voltage input of the dynamic capacitive loading device;

wherein, in operation, voltage provided by the voltage source is adjusted in accordance with a performance metric to tune the antenna.

2. The system of claim 1 wherein the antenna structure is embodied in an IC package.

3. The system of claim 1 wherein the antenna structure is selected from the group consisting of a patch antenna and a monopole antenna.

4. The system of claim 1 wherein the antenna structure includes a folded spiral structure.

5. They system of claim 1 wherein the antenna structure includes a three dimensional antenna structure with a first portion of the antenna structure on a first substrate layer and a second portion of the antenna structure on a second substrate layer.

6. The system of claim 1 further comprising:

an antenna feed coupled to the antenna structure;

an inductive stub coupled between the antenna feed and at least a portion of the antenna structure, wherein when an input impedance associated with the antenna structure is capacitive at a desired resonant frequency, the inductive stub matches the input to a desired resistive value.

7. The system of claim 1 further comprising a voltage source for providing variable voltage on the voltage input of the dynamic capacitive loading device.

8. They system of claim 1 wherein the dynamic capacitive loading device includes a varactor.

9. The system of claim 1 further comprising:

a substrate on which the antenna structure is formed;

an internal trace coupled to a first portion of the antenna structure on a first layer of the substrate, wherein a second portion of the antenna structure is on a second layer of the substrate.

10. The system of claim 1 further comprising a tuning voltage calculator for providing a tuning voltage to the dynamic capacitive loading device.

11. The system of claim 1, further comprising a radio receiver capable of extracting performance metric data from signals received from the antenna structure, wherein the performance metric data is used to determine a tuning voltage for the dynamic capacitive loading device that is estimated to improve performance according to a performance metric associated with the performance metric data.

12. The system of claim 1, further comprising a performance quantification engine to derive a performance control signal from historic data and performance metric data derived from signals received from the antenna structure, wherein a tuning voltage is provided to the dynamic capacitive loading device in accordance with the performance control signal.

13. A method comprising:

designing an antenna without loading;

providing an initial capacitive load;

repeating until an acceptable optimization threshold is reached;

adjusting capacitive loading;

optimizing response with capacitive loading.

14. The method of claim 13, further comprising:

determining available dynamic capacitive device tuning range;

introducing an initial capacitive load in accordance with the available tuning range.

15. A method comprising:

setting a tuning voltage to an initial value, wherein tuning voltage impacts antenna performance;

quantifying performance metric data associated with one or more signals, wherein performance metric data is associated with the antenna performance and the one or more signals;

estimating, using the performance metric data, a tuning voltage that would improve the antenna performance;

varying tuning voltage in accordance with the estimated tuning voltage to improve the antenna performance.

16. The method of claim 15, further comprising repeating the quantifying, estimating, and varying.

17. The method of claim 15, wherein the quantifying, estimating, and varying are associated with a baseline tuning, further comprising fine tuning.

18. The method of claim 15, wherein the quantifying, estimating, and varying are associated with a first stage tuning, further comprising:

quantifying second performance metric data associated with one or more different performance metrics;

estimating, using the second performance metric data, a second tuning voltage that would improve the antenna performance;

varying tuning voltage in accordance with the estimated second tuning voltage to improve the antenna performance.

19. A system comprising:

a radio receiver;

a performance quantification engine coupled to the radio receiver;

a tuning voltage calculator coupled to the performance quantification engine;

wherein, in operation;

the radio receiver receives a signal from an antenna;

the radio receiver sends performance metric data from the signal to the performance quantification engine;

the performance quantification engine provides a performance control signal derived from the performance metric data to the tuning voltage calculator;

the tuning voltage calculator estimates a tuning voltage that, when provided to a dynamic capacitive loading device coupled to the antenna, would improve performance of the antenna.

20. The system of claim 19, further comprising:

the antenna, coupled to the radio receiver;

the dynamic capacitive loading device electrically coupled to the tuning voltage calculator.