Granted Patent B2

US 8,350,695 · App. 12/803,338 · Granted Jan 8, 2013

Abstract

Claims (37)

1. A body coupled antenna system comprising:

an antenna element for connection to an RF circuit;

a coupling plate for conductively coupling to an adjacent body for broadening a tuning frequency and reducing a loading sensitivity;

a first capacitance interconnected between said coupling plate and said antenna element; and

a second capacitance interconnected between the coupling plate and the RF circuit;

said first and second capacitances being set to restore a predetermined matching impedance level While maintaining the broadened tuning frequency.

2. The body coupled antenna system of claim 1 in ich said antenna element includes a helical conductor.

3. The body coupled antenna system of claim 1 in which said coupling plate is capacitively coupled to the adjacent body.

4. The body coupled antenna system of claim 1 in which said first and second capacitances are adjustable.

5. The body coupled antenna system of claim 1 in which said body is a human body.

6. The body coupled antenna system of claim 5 in which said antenna system is worn on the body wrist.

7. The body coupled antenna system of claim 1 in which said antenna system is contained in a housing adapted to be mounted on the body.

8. The body coupled antenna system of claim 1 in which said coupling plate is separated by a gap from said body.

9. The body coupled antenna system of claim 1 in which said RF circuit includes a transmitter circuit.

10. The body coupled antenna system of claim 1 in which said RF circuit includes a transmitter and receiver circuits.

11. The body coupled antenna system of claim 7 in which said RF circuit is contained in said housing.

12. The body coupled antenna system of claim 7 in which said housing includes a power supply for the RF circuit.

13. The body coupled antenna system of claim 1 in which said RF circuit includes a receiver circuit.

14. A personal locator unit comprising:

a body coupled antenna system;

an RF circuit;

a housing for said body coupled antenna system and said RF circuit;

said body coupled antenna system including an antenna element for connection to the RF circuit;

a coupling plate for conductively coupling to an adjacent body for broadening a tuning frequency and reducing a loading sensitivity;

a first capacitance interconnected between said coupling plate and said antenna element;

and a second capacitance interconnected between the coupling plate and the RF circuit;

said first and second capacitances being set to restore a predetermined matching impedance level while maintaining the broadened tuning frequency.

15. The personal locator unit of claim 14 in which said RF circuit includes a transmitter circuit.

16. The personal locator unit of claim 14 in which said RF circuit includes a transmitter circuit and receiver circuit.

17. The personal locator unit of claim 16 in which said RF circuit includes a decode circuit responsive to said receiver circuit, for identifying a personal identification code associated with the instant personal locator unit and a switch circuit for enabling said transmitter circuit.

18. The personal locator unit of claim 14 in which said transmitter circuit transmits at least said personal identifier code associated with the instant personal locator unit.

19. The personal locator unit of claim 14 in which said RF circuit includes a power supply.

20. The personal locator unit of claim 14 in which said housing includes a device for carrying said housing on the body.

21. The personal locator unit of claim 20 in which said device includes a strap.

22. The personal locator unit of claim 14 in which said coupling plate is capacitively coupled to the adjacent body.

23. The personal locator unit of claim 14 in which said coupling plate is separated by a gap from said body.

24. The personal locator unit of claim 14 in which said RF circuit includes a receiver circuit.

Assignments (18)