Ultra broadband antenna having asymmetrical shorting straps

• US 6,621,457 B1
• Filed: 12/13/2001
• Issued: 09/16/2003
• Est. Priority Date: 10/30/2000
• Status: Expired due to Fees

• Current Assignee: United States Department Of Health And Human Services
• Original Assignee: the united states of america as represented by the secretary of the navy
• Inventors: Adams, Richard C., Abramo, Robert S.
• Primary Examiner(s): Wimer, Michael C.
• Application Number:
  US10/016,202
• Time in Patent Office: 642 Days
• Field of Search: 343/718, 343/741-743, 343/769, 455/575
• US Class Current: 343/718
• CPC Class Codes: A41D 1/002 adapted to accommodate electronic equipment patients' garments for medical monitoring A41D13/1281; luminous ornaments A41D27/085
• CPC Class Codes: H01Q 1/12 Supports; Mounting means
• CPC Class Codes: H01Q 1/276 for mounting on helmets
• CPC Class Codes: H01Q 13/10 Resonant slot antennas
• CPC Class Codes: H01Q 9/28 Conical, cylindrical, cage, strip, gauze, or like elements having an extended radiating surface; Elements comprising two conical surfaces having collinear axes and adjacent apices and fed by two-conductor transmission lines waveguide horns or mouths H01Q13/00; slot antennas H01Q13/00

Abstract

An antenna includes a liner shaped to fit over a helmet; a first RF element attached to the liner; a second RF element attached to the liner so that the first and second RF elements are separated by a gap; an RF feed electrically connected to the first RF element for providing RF energy to the first RF element; a ground feed electrically connected to the second RF element; a first shorting strap that is electrically connected to the first and second elements opposite from the RF feed; and a second shorting strap electrically connected to the first and second RF elements between the first shorting strap and the RF feed. The shorting straps are used to generally match the impedance of the antenna to an electrical device such as a transmitter, receiver, or transceiver. A matching circuit may be connected in series between the first RF element and the RF feed to further refine matching the antenna impedance to the electrical device. In another embodiment of the invention, the RF elements may be mounted directly to the helmet, in applications where the helmet is made of a dielectric material.

Claims

1. An antenna, comprising:

a liner shaped to fit over a helmet;

a first RF element attached to said liner;

a second RF element attached to said liner so that said first and second RF elements are separated by a gap;

an RF feed electrically connected to said first RF element for providing RF energy to said first RF element;

a ground feed electrically connected to said second RF element;

a first shorting strap that is electrically connected to said first and second RF elements opposite from said RF feed; and

a second shorting strap electrically connected to said first and second RF elements between said first shorting strap and said RF feed.

2. The antenna of claim 1 wherein said first and second RF elements are made of a flexible electrically conductive material.

3. The antenna of claim 2 wherein said flexible electrically conductive material is woven into a mesh structure.

4. The antenna of claim 3 further including a helmet made of a dielectric material for supporting said liner.

5. The antenna of claim 4 wherein said first and second RF elements each have an annulus shape when said liner is fitted over said helmet.

6. The antenna of claim 5 wherein said antenna operates with a voltage standing wave ratio of 3:

1 over a frequency range of 440 through 2310 MHz.

7. The antenna of claim 1 further including a matching circuit connected in series between said first RF element and said RF feed.

8. An antenna, comprising:

a helmet made of a dielectric material;

a first RF element attached to said dielectric material;

a second RF element attached to said dielectric material so that said first and second RF elements are separated by a gap;

an RF feed electrically connected to said first RF element for providing RF energy to said first RF element;

a ground feed electrically connected to said second RF element;

a first shorting strap that is electrically connected to said first and second RF elements opposite from said RF feed; and

a second shorting strap electrically connected to said first and second RF elements between said first shorting strap and said RF feed.

9. The antenna of claim 8 wherein said first and second RF elements are made of a flexible electrically conductive material.

10. The antenna of claim 9 wherein said flexible conductive material is woven into a mesh structure.

11. The antenna of claim 10 wherein said antenna operates with a voltage standing wave ratio of 3:

1 over a frequency range of 440 through 2310 MHz.

12. The antenna of claim 8 further including a matching circuit connected in series between said first RF element and said RF feed.

13. The antenna of claim 8 wherein said first and second RF elements each have an annulus shape.