SYSTEM AND METHODS FOR ADAPTIVE ANTENNA OPTIMIZATION

• US 20130005278A1
• Filed: 06/04/2012
• Published: 01/03/2013
• Est. Priority Date: 06/30/2011
• Status: Active Grant

• Current Assignee: Google Technology Holdings LLC (Alphabet Inc.)
• Original Assignee: Motorola Mobility, Inc. (Lenovo Group Ltd.)
• Inventors: Black, Gregory R., Nagode, Thomas D., Schwent, Dale G.
• Granted Patent: US 9,564,676 B2
• Time in Patent Office: Days
• US Class Current: 455/77
• CPC Class Codes: H01Q 1/241 used in mobile communications, e.g. GSM H01Q1/247, H01Q1/248 take precedence
• CPC Class Codes: H01Q 5/335 at the feed, e.g. for impedance matching

Abstract

A method (600) and devices for enhancing the performance of one or more antennas (440) is provided. A control circuit (104) assesses performance of an antenna (101) in a plurality of bands, such as a receive band and a transmit band. The control circuit (104) can then adjust an adjustable impedance matching circuit (103) coupled to the antenna (101) to improve the efficiency of the antenna (101) in the selected band and can adjust a resonance of the antenna (101) to further improve an efficiency of the antenna (101) in the selected band. Operating parameters for the antenna (101) can be selected from one or more multi-dimensional lookup tables (120) where the parameters are indexed both to a first operating band (702) and a second operating band (703).

Claims

1. A method of optimizing performance of an antenna system in a wireless communication device operating in multiple bands, the antenna system comprising at least one radiating element, the method comprising:

accessing a multi-dimensional lookup table having entries indexed to at least two bands;

selecting parameters corresponding to an initial resonant frequency from the multi-dimensional lookup table; and

altering a resonance of the at least one radiating element in accordance with the parameters from the multi-dimensional lookup table.

2. The method of claim 1, wherein the parameters comprise a tuning capacitor value for a tuning capacitor operable with the at least one radiating element and a bypass capacitor value for a bypass capacitor operable with the at least one radiating element.

3. The method of claim 1, wherein the multi-dimensional lookup table further comprises matching circuit information indexed to the at least two bands, further comprising:

selecting matching circuit parameters corresponding to the at least two bands; and

adjusting an impedance matching circuit coupled to the at least one radiating element in accordance with the matching circuit parameters.

4. The method of claim 1, further comprising:

assessing performance of the antenna system in a first band having a first channel frequency;

assessing performance of the antenna system in a second band having a second channel frequency, wherein the first channel frequency and the second channel frequency are different;

selecting one of the first band or the second band as a selected band for which the antenna system will be optimized; and

one or more of;

adjusting an impedance matching circuit coupled to the antenna system to improve efficiency of the antenna system;

or

altering a resonance of the antenna system to improve the efficiency of the antenna system.

5. The method of claim 4, wherein the first band comprises one of a transmit band or a receive band, further wherein the second band comprises another of the transmit band or the receive band.

6. The method of claim 4, further comprising accessing another multi-dimensional lookup table comprising resonant frequency range parameters indexed to at least the first band and the second band, wherein the altering comprises altering the resonance of the at least one radiating element in accordance with the resonant frequency range parameters.

7. The method of claim 6, further comprising prohibiting the altering of the resonance of the at least one radiating element beyond limits of the resonant frequency range parameters.

8. The method of claim 6, wherein the resonant frequency range parameters comprise tuning capacitor ranges of a tuning capacitor value for a tuning capacitor operable with the at least one radiating element and bypass capacitor ranges of a bypass capacitor value for the bypass capacitor operable with the at least one radiating element.

9. The method of claim 4, further comprising monitoring an unselected band during the adjusting the impedance matching circuit and the altering the resonance of the at least one radiating element to ensure a signal characteristic in the unselected band meets a predetermined criterion.

10. The method of claim 4, wherein:

the antenna system comprises a plurality of antennas;

the adjusting the impedance matching circuit coupled to the at least one radiating element to improve the efficiency of the antenna system in the selected band comprises adjusting a plurality of matching circuits, each one of the plurality of matching circuits being coupled to one of the plurality of antennas; and

the altering the resonance of the at least one radiating element to further improve the efficiency of the antenna system in the selected band comprises altering a plurality of resonances, each one of the plurality of resonances being associated with the one of the plurality of antennas.

11. An antenna tuning circuit in a wireless communication device operating simultaneously in at least a first channel in a first band and a second channel in a second band, comprising:

an antenna;

an adjustable impedance matching circuit coupled to the antenna;

a tuning circuit operable to alter a resonance of the antenna; and

a control circuit that;

accesses a multi-dimensional lookup table having resonance parameters indexed to at least the first band and the second band;

selects parameters corresponding to an initial resonant frequency from the multi-dimensional lookup table; and

alters the resonance of the antenna in accordance with the parameters from the multi-dimensional lookup table.

12. The antenna tuning circuit of claim 11, wherein the control circuit is operable to further:

select one of the first band or the second band of the wireless communication device as a selected band; and

one or more of;

cause the adjustable impedance matching circuit to change an impedance state to improve efficiency of the antenna in the selected band;

or

cause the tuning circuit to alter the resonance of the antenna to further improve the efficiency of the antenna in the selected band.

13. The antenna tuning circuit of claim 12, further comprising another multi-dimensional lookup table comprising resonance ranges indexed to the first band and the second band, wherein the control circuit is operable to:

access the another multi-dimensional lookup table for predetermined resonance ranges corresponding to the first band and the second band; and

altering the resonance of the antenna in accordance with the predetermined resonance ranges to improve the efficiency of the antenna.

14. An antenna tuning circuit, comprising:

an antenna; and

a control circuit that is operable with the antenna and configured to;

accesses a multi-dimensional lookup table having resonance parameters indexed to at least a first band and a second band;

selects parameters corresponding to an operating frequency from the multi-dimensional lookup table; and

alters a resonance of the antenna in accordance with the parameters from the multi-dimensional lookup table;

wherein the parameters from the multi-dimensional lookup table comprises a range of values corresponding to the operating frequency.

15. The antenna tuning circuit of claim 14, wherein the parameters from the multi-dimensional lookup table comprise one or more capacitor values that correspond to an initial operating frequency.

16. The antenna tuning circuit of claim 14, wherein the parameters from the multi-dimensional lookup table comprise one or more capacitor value ranges that correspond to the operating frequency.

17. The antenna tuning circuit of claim 14, wherein the parameters from the multi-dimensional lookup table comprise one or more mode switch combinations corresponding to one or more resonant frequency states or impedance matching states associated with the antenna.

18. The antenna tuning circuit of claim 14, wherein the parameters from the multi-dimensional lookup table comprise one or more desired return loss measurements or ranges associated with the antenna.

19. The antenna tuning circuit of claim 14, wherein the parameters from the multi-dimensional lookup table comprise one or more operating modes for the control circuit.

20. The antenna tuning circuit of claim 14, wherein the parameters from the multi-dimensional lookup table are indexed both to a first operating band and a second operating band.