Wrist mounted wireless instrument and antenna apparatus

• US 6,366,250 B1
• Filed: 12/09/1999
• Issued: 04/02/2002
• Est. Priority Date: 12/09/1999
• Status: Expired due to Term

• Current Assignee: CSR Technology Incorporated (Qualcomm, Inc.)
• Original Assignee: SIRF Technology Incorporated (Qualcomm, Inc.)
• Inventors: McConnell, Richard Joseph
• Primary Examiner(s): Wong, Don
• Assistant Examiner(s): TRAN, CHUC
• Application Number:
  US09/457,773
• Time in Patent Office: 845 Days
• Field of Search: 343/718, 343/730, 343/866, 368/10, 368/282, 368/13, 368/281, 368/278, 224/165, 224/174, 455/274, 455/351, 455/718
• US Class Current: 343/718
• CPC Class Codes: H01Q 1/273 Adaptation for carrying or wearing by persons or animals
• CPC Class Codes: H04B 1/385 Transceivers carried on the body, e.g. in helmets

Abstract

A wrist mounted wireless instrument is provided with a wrist strap containing an antenna therein. An electrically conductive shield is disposed in the wrist strap between the antenna and the wrist to shield the antenna from the effects of the body of the user.

Claims

1. An antenna device for a wireless instrument in a wrist mounted case, comprising:

a strap attached to the case to secure the case to the wrist;

an antenna element connected to the instrument and disposed within the strap; and

an electrically conductive ground shield electrically connected within the instrument case and disposed within the strap between the antenna element and the wrist.

2. The device of claim 1, wherein the antenna element comprises an electrically conductive strip extending along at least a length of the wrist strap.

3. The device of claim 2, wherein the ground shield extends along a longer length of the strap than the antenna element.

4. The device of claim 2, wherein the strap is formed of a dielectric material.

5. The device of claim 4, wherein a portion of the dielectric material is disposed between the ground shield and the wrist to insulate the ground shield from the wrist.

6. The device of claim 5, wherein a portion of the dielectric material is disposed between the ground shield and the antenna element to insulate the antenna element from the ground shield.

7. The device of claim 3, further comprising:

a conductive plate disposed within the case and connected to the ground shield; and

wherein

the ground shield extends along the entire length of the strap to form a closed loop with the case conductive plate.

8. The device of claim 1, wherein the strap is comprised of two elongated portions attached to the case and each comprising an antenna element and a ground shield element.

9. The device of claim 8, further comprising:

a clasp device attached to one of the strap portions to releasably secure to the other strap portion.

10. The device of claim 9, wherein each antenna element comprises an electrically conductive strip extending along at least a portion of the respective wrist strap portion.

11. The device of claim 10, wherein each ground shield element extends along a longer portion of the respective strap portion than the respective antenna element.

12. The device of claim 11, wherein the strap portions are formed of a dielectric material.

13. The device of claim 12, wherein a portion of the dielectric material in each strap portion is disposed between the respective ground shield element and the wrist to insulate each shield from the wrist.

14. The device of claim 13, wherein a portion of the dielectric material is disposed between each ground shield element and the respective antenna element to insulate each antenna element from the respective ground shield element.

15. The device of claim 14, further comprising:

a conductive plate disposed within the case and connected to the ground shield elements; and

wherein

each ground shield element extends along the entire length of the respective strap portion; and

the clasp is formed with an electrically conductive element to electrically connect the two ground shield elements to form a closed loop with the case conductive plate when the strap portions are secured together by the clasp.

16. The device of claim 7, wherein the antenna element is connected to the ground shield at a point located at approximately the electrical center of the ground shield.

17. The device of claim 16, wherein the antenna element is connected to the clasp conductive element.

18. The device of claim 14, wherein:

each ground shield element extends along the entire length of the respective strap portion; and

the clasp is configured to secure the two strap portions in at least partially overlying relationship to capacitively couple the ground shield elements.

19. A wireless instrument device, comprising:

a case configured for attachment to a user'"'"'s wrist;

a strap to secure the case to the wrist;

circuitry disposed within the case to process electrical signals;

an antenna disposed within the strap and connected to the circuitry to transfer signals thereto; and

an electrically conductive ground shield electrically connected within the instrument case and disposed within the strap between the antenna and the wrist and configured to shield the antenna from the inductive and capacitive effects of the user'"'"'s body.

20. The device of claim 19, further comprising:

a conductive plate disposed within the case and connected to the ground shield to form a closed loop therewith.

21. The device of claim 20, wherein the strap is comprised of two elongated portions attached to the case and each comprising an antenna element and a ground shield element.

22. The device of claim 21, further comprising:

a clasp device attached to the end of a strap portion to releasably secure to the other strap portion and connect the shield elements to one another.

23. The device of claim 21, wherein the antenna elements form a dipole antenna.

24. The device of claim 19, wherein the antenna is a monopole antenna.