Apparatus and method for antenna matching

• US 9,491,007 B2
• Filed: 05/19/2014
• Issued: 11/08/2016
• Est. Priority Date: 04/28/2014
• Status: Active Grant

• Current Assignee: Google Technology Holdings LLC (Alphabet Inc.)
• Original Assignee: Google Technology Holdings LLC (Alphabet Inc.)
• Inventors: Black, Gregory R., Asrani, Vijay L., Kim, Young Hun
• Primary Examiner(s): WEST, LEWIS G
• Application Number:
  US14/280,775
• Publication Number:
  US 20150312058A1
• Time in Patent Office: 904 Days
• US Class Current: 1/1
• CPC Class Codes: H01Q 1/242 specially adapted for hand-held use
• CPC Class Codes: H01Q 1/50 Structural association of antennas with earthing switches, lead-in devices or lightning protectors
• CPC Class Codes: H01Q 1/52 Means for reducing coupling between antennas; Means for reducing coupling between an antenna and another structure absorbing means H01Q17/00
• CPC Class Codes: H01Q 21/28 Combinations of substantially independent non-interacting antenna units or systems multiple beam H01Q25/00
• CPC Class Codes: H03H 7/40 Automatic matching of load impedance to source impedance
• CPC Class Codes: H04B 1/0458 Arrangements for matching and coupling between power amplifier and antenna or between amplifying stages matching circuits in general H03H
• CPC Class Codes: H04B 1/18 Input circuits, e.g. for coupling to an antenna or a transmission line coupling networks between antennas or lines and receivers independent of the nature of the receiver H03H
• CPC Class Codes: H04B 3/03 Hybrid circuits for transceivers H04B1/52, H04B1/58
• CPC Class Codes: H04L 25/0278 Arrangements for impedance matching
• CPC Class Codes: H04M 1/0274 for an electrical connector module
• CPC Class Codes: H04M 2250/12 including a sensor for measuring a physical value, e.g. temperature or motion telephones including GPS signal receivers H04M2250/10

Abstract

A method and apparatus are for performing antenna matching and include determining a cable connection state of a cable connector, generating a cable detection signal that indicates the cable connection state, and modifying impedance transform of a tunable matching circuit in response to the cable detection signal. The cable detection signal indicates one of a presence and an absence of a cable connector. The tunable matching circuit couples a transceiver and an antenna. The tunable matching circuit couples the selected impedance transform between the transceiver and the antenna. The apparatus is a radio communication device that includes a transceiver, a processing system, an antenna, a tunable matching circuit, an input/output section, a cable connector, and a sensor.

Claims

1. An apparatus, comprising:

a transceiver having a transceiver impedance;

an antenna having an antenna impedance and a cable connector element through which a cable connection is formable, the cable connector element having a location that degrades an effectiveness of an impedance transform for matching the antenna impedance with the transceiver impedance when the cable connection is formed by a cable connected to the cable connector element;

a tunable matching circuit for coupling the impedance transform between the transceiver and the antenna;

a sensor that determines a cable connection state of the cable connector element and generates a cable detection signal that indicates the cable connection state; and

a control circuit coupled to the cable detection signal and a tuning input of the tunable matching circuit, the control circuit configured to;

modify, via the tuning input and in response to an indication of the cable connection state indicating that the cable is connected to the cable connector element, the impedance transform used by the tunable matching circuit to match the antenna impedance with the transceiver impedance; and

cause, via the modifying, a first system efficiency while the tunable matching circuit is modified for the presence of the cable and the cable is connected, the first system efficiency providing a substantial increase above a second system efficiency that exists while the effectiveness of the impedance transform is degraded when a cable is connected to the cable connector.

2. The apparatus according to claim 1, wherein the antenna comprises an antenna element and wherein a periphery of the cable connector element is at least partially within the antenna element.

3. The apparatus according to claim 1, wherein the tunable matching circuit has a frequency range and the substantial increase is an improvement of at least 5 dB for at least one frequency in the frequency range.

4. The apparatus according to claim 3, wherein the frequency range includes a frequency range within frequency limits 0.60 GHz and 0.80 GHz.

5. The apparatus according to claim 1, wherein the sensor uses one of a contact switch and a magnetic switch.

6. The apparatus according to claim 1, wherein the apparatus is a handheld cellular communication device.

7. The apparatus according to claim 1, wherein the modification of the impedance transform used by the tunable matching circuit is achieved by switching passive electronic components that are coupled between the transceiver and the antenna.

8. An apparatus, comprising:

a transceiver having a transceiver impedance;

an antenna having an antenna impedance and a cable connector element through which a cable connection is formable, the cable connector element having a location on the apparatus that affects the antenna impedance when the cable connection is formed by a cable connected to the cable connector element;

a tunable matching circuit;

a sensor that determines a cable connection state of the cable connector element, the cable connection state being one of present and absent, and generates a cable detection signal that indicates the cable connection state; and

a processing system coupled to the cable detection signal and a tuning input of the tunable matching circuit, the processing system configured to;

tune, via the tuning input, the tunable matching circuit in response to the cable connection state indicating that the cable is connected to the cable connector element, the tuning causing the tunable matching circuit to select a first impedance transform and couple the selected first impedance transform between the transceiver and the antenna; and

generate, while the cable is connected, a first system efficiency, the first system efficiency providing a substantial increase above a second system efficiency, the second system efficiency existing while the cable is connected and while no cable detection signal is coupled to the processing system;

or

tune the tunable matching circuit in response to the cable connection state being the state of absent, the tuning causing the tunable matching circuit to select a second impedance transform that causes the transceiver impedance to match the antenna impedance while the cable is not connected.

9. The apparatus according to claim 8, wherein the antenna comprises an antenna element and wherein a periphery of the cable connector element is at least partially within the antenna element.

10. The apparatus according to claim 8, wherein the tunable matching circuit has a frequency range and the substantial increase is an improvement of at least 5 dB for at least one frequency in the frequency range.

11. The apparatus according to claim 10, wherein the frequency range includes a frequency range within frequency limits 0.60 GHz and 0.80 GHz.

12. The apparatus according to claim 8, wherein the sensor uses one of a contact switch and a magnetic switch.

13. The apparatus according to claim 8, wherein the apparatus is a handheld cellular communication device.

14. The apparatus according to claim 8, wherein tuning the tunable matching circuit in response to the cable connection state is achieved by switching passive electrical components coupled between the transceiver and the antenna.

15. A method, comprising:

determining a cable connection state of a cable connector element of an antenna through which a cable connection is formable, the cable connector element degrading an effectiveness of an impedance transform of a tunable matching circuit when the cable connection is formed by a cable connected to the cable connector element;

generating a cable detection signal that indicates the cable connection state; and

modifying the impedance transform of the tunable matching circuit in response to the cable detection signal indicating a presence of the cable, the tunable matching circuit coupling the modified impedance transform between a transceiver and the antenna, the modifying causing a first system efficiency while the tunable matching circuit is modified for the presence of the cable and the cable is connected, the first system efficiency providing a substantial increase above a second system efficiency that exists while the effectiveness of the impedance transform is degraded when the cable is connected to the cable connector.

16. The method according to claim 15, wherein the antenna comprises an antenna element and wherein a periphery of the cable connector element is disposed at least partially within the antenna element.

17. The method according to claim 15, wherein the tunable matching circuit has a frequency range and the substantial increase is an improvement of at least 5 dB for at least one frequency in the frequency range.

18. The method according to claim 17, wherein the frequency range includes a frequency range within frequency limits 0.60 GHz and 0.80 GHz.

19. The method according to claim 15, wherein the cable connection state is determined by one of a contact switch and a magnetic switch.

20. The method according to claim 15, wherein the modifying of the impedance transform of the tunable matching circuit is achieved by switching passive electrical components coupled between the transceiver and the antenna.