Low profile antenna for measuring the shielding effectiveness of hemp protected enclosures

• US 7,750,868 B1
• Filed: 06/09/2008
• Issued: 07/06/2010
• Est. Priority Date: 06/09/2008
• Status: Active Grant

• Current Assignee: Scientific Applications and Research Associates Incorporated
• Original Assignee: Scientific Applications and Research Associates Incorporated
• Inventors: Dunn, Scott, McCrea, Charles, Yowell, Jeff, Eldridge, Scott, Fromme, Dave
• Primary Examiner(s): Nguyen; Hoang V
• Application Number:
  US12/135,455
• Time in Patent Office: 757 Days
• Field of Search: 343/895, 343/872
• US Class Current: 343/895
• CPC Class Codes: H01Q 19/10 using reflecting surfaces
• CPC Class Codes: H01Q 9/27 Spiral antennas

Abstract

A low profile broadband antenna capable of measuring shielding effectiveness (SE) of a shielded boundary above or below ground for permanent installation behind walls, under floors, above ceilings and other areas with limited transverse (as opposed to lateral) available space is provided. A spiral antenna having a wide operating bandwidth is positioned within the interior of an environmentally sealed enclosure. The enclosure likewise has a low profile suited for installation in such locations.

Claims

1. An antenna installation assembly for the evaluation of shielding effectiveness of a boundary, comprising:

an enclosure defining a center region and an outer periphery;

a conductive spiral antenna defining a center origin point positioned within the interior of the enclosure, the center origin point being generally aligned with the center region of the enclosure;

a coaxial cable in electrical communication with the spiral antenna and attached to a center origin point thereof, the coaxial cable extending toward the outer periphery of the enclosure; and

a cable interface in electrical communication with the coaxial cable and mounted to the enclosure, a shielding effectiveness test device being attachable to the assembly via the cable interface;

wherein a depth dimension of the enclosure is substantially less than lateral dimensions of the enclosure.

2. The antenna installation assembly of claim 1, wherein the spiral antenna is defined by counter rotating dual spirals extending from the center origin point.

3. The antenna installation assembly of claim 1, wherein the spiral antenna has a sufficient gain with necessary measurement range above the noise for the evaluation of shielding effectiveness for signals ranging in frequency from 10 kHz to 1 GHz.

4. The antenna installation assembly of claim 1, wherein the enclosure is environmentally sealed.

5. The antenna installation assembly of claim 1, wherein the enclosure is further defined by a top member mated to a bottom member.

6. The antenna installation assembly of claim 5, wherein the bottom member defines one or more concentric support ribs and intersecting cross members for reinforcement of the enclosure.

7. The antenna installation assembly of claim 5, further comprising:

an antenna support member receivable within the bottom member, the antenna support member defining an upper surface with a spiral groove conforming to the shape of the spiral antenna.

8. The antenna installation assembly of claim 7, wherein the antenna support member and the bottom member are integrally formed and are of a unitary construction.

9. The antenna installation assembly of claim 7, wherein the antenna support member further defines a channel extending from the outer periphery to the center region, the coaxial cable being routed through the channel.

10. The antenna installation assembly of claim 1, wherein the enclosure is thermoformed plastic.

11. The antenna installation assembly of claim 1, wherein the conductive spiral antenna is comprised of sections of copper plated circuit boards, each of the sections being brazed together at the mating edges thereof.

12. The antenna installation assembly of claim 1, wherein the cable interface is mounted to the enclosure in a recessed relation to the outer periphery.