Wireless communication over a transducer device

• US 20070082611A1
• Filed: 10/06/2006
• Published: 04/12/2007
• Est. Priority Date: 03/16/2001
• Status: Active Grant

• Current Assignee: Freelinc Holdings, LLC
• Original Assignee: Radeum, Inc.
• Inventors: Palermo, Vincent, Terranova, Domenic
• Granted Patent: US 7,574,173 B2
• Time in Patent Office: Days
• US Class Current: 455/41.100
• CPC Class Codes: H04B 5/22 Capacitive coupling
• CPC Class Codes: H04B 5/26 using coils
• CPC Class Codes: H04B 5/48 Transceivers
• CPC Class Codes: H04M 1/6041 Portable telephones adapted for handsfree use
• CPC Class Codes: H04M 1/6066 including a wireless connection
• CPC Class Codes: H04M 1/727 Identification code transfer arrangements
• CPC Class Codes: H04M 1/737 Characterised by transmission of electromagnetic waves other than radio waves, e.g. infrared waves
• CPC Class Codes: H04R 2420/07 Applications of wireless loudspeakers or wireless microphones

Abstract

One aspect of the present invention is generally directed towards a system and method of tuning a transducer for transmitting and receiving a wireless signal. In an illustrative embodiment, a single transducer is coupled to a first or second circuit for either transmitting or receiving, respectively. Generally, electrical characteristics of the first circuit are adjusted to increase a magnetic field generated by the transducer. Conversely, electrical characteristics of the second circuit are adjusted to increase a signal generated by the transducer for receiving a magnetic field. Accordingly, a single transducer device can be tuned for either transmitting or receiving a corresponding wireless signal.

Claims

1. A method for supporting inductive communication, the method comprising the steps of:

coupling a transducer to a selected first or second circuit for either transmitting or receiving;

adjusting electrical characteristics of the first circuit to increase a magnetic field generated by the transducer;

adjusting electrical characteristics of the second circuit to increase a signal generated by the transducer.

2. A method as in claim 1, wherein the characteristics of the first and second circuits are adjusted using passive circuit components.

3. A method as in claim 1 further comprising the steps of:

transmitting a magnetic field over the transducer when the transducer is coupled to the first circuit; and

receiving a magnetic field over the transducer when the transducer is coupled to the second circuit.

4. A method as in claim 1 further comprising the step of:

adjusting a capacitance of the first circuit to reduce an effective impedance of the transducer for transmitting; and

adjusting a capacitance of the second circuit to increase an effective impedance of the transducer for receiving.

5. A method as in claim 1 further comprising the step of:

time division multiplexing the transducer between the first and second circuits to support bidirectional communication with a transceiver at a remote location.

6. A method as in claim 1, wherein the electrical characteristics of the first and second circuits are adjusted to achieve an efficient coupling between either a transmitter or receiver.

7. A method as in claim 1 further comprising the step of:

adjusting a reactance of the first circuit to transmit a magnetically encoded signal at a first carrier frequency and adjusting characteristics of the second circuit to receive a magnetically encoded signal at a second carrier frequency.

8. A method as in claim 1 further comprising the step of:

disposing an inductive element in the second circuit, the inductive element having an approximate inductance as that of the transducer.

9. A method as in claim 1, wherein the second circuit includes at least a portion of the first circuit that is coupled via a switch.

10. A method as in claim 1, wherein the first circuit serially tunes the transducer for transmitting over the transducer and the second circuit parallel tunes the transducer for receiving over the transducer.

11. A method for supporting communication, the method comprising the steps of:

switching to select either transmitting or receiving over a transducer;

via a first circuit, effectively tuning the transducer to be a low impedance device for generating a magnetic field when a transmitter is switched to transmit over the transducer;

via a second circuit, effectively tuning the transducer to be a high impedance device for receiving a magnetic field when a receiver is switched to receive over the transducer.

12. A method as in claim 11 wherein the first circuit is serially tuned for transmitting over the transducer and the second circuit is parallel tuned for receiving over the transducer.

13. A method as in claim 11 further comprising the step of:

in a transmitting mode, reducing an overall reactance of the first circuit including the transducer by substantially matching an inductance of the transducer with a capacitance provided by the first circuit.

14. A method as in claim 11 further comprising the step of:

via switching, decoupling the transmitter from the first circuit and transducer, and coupling the receiver and portion of the second circuit to the first circuit and the transducer.

15. A method as in claim 11 further comprising the step of:

from the transmitter, generating an output at one of two voltages that is coupled to drive the transducer.

16. A method as in claim 11 further comprising the step of:

disposing a resistance in series with the transducer.

17. A method as in claim 11 further comprising the step of:

tuning a combined impedance of the first circuit and transducer for maximal magnetic power output of the transducer at a particular carrier frequency.

18. A method as in claim 11 further comprising the step of:

adjusting an impedance of the first and second circuit to transmit and receive over the transducer at a substantially similar carrier frequency.

19. A method as in claim 11 further comprising the step of:

varying inductive characteristics of the transducer to adjust a combined impedance of the first circuit and transducer.

20. A method as in claim 11 further comprising the step of:

adjusting a reactance of the first or second circuits by switching selected capacitors of a capacitor bank.