The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Sep. 17, 1996
Filed:
Jun. 22, 1994
Evert C Nygren, Los Altos, CA (US);
Peter W Lord, Mountainview, CA (US);
Vito J Jakstys, Penn Valley, CA (US);
Sina Barkeshli, Saratoga, CA (US);
Levent Ersoy, Cupertino, CA (US);
Space Systems/Loral, Inc., Palo Alto, CA (US);
Abstract
An antenna has one feed for an S-band electromagnetic signal, and a second feed constructed as an array of radiators to service two C-band signal channels. A subreflector having a microwave frequency selective surface (FSS) is placed in front of a main reflector. The C-band feed is constructed of an array of square aperture horns joined by separate transmit and receive barline beam-forming networks, and a meanderline polarizer to produce circularly polarized radiation patterns. Tapered ridges extend longitudinally along inner wall surfaces of each of the horns to provide increased bandwidth to the C-band feed. The frequency selective surface is constructed, typically, of a generally planar substrate of material transparent to electromagnetic radiation, and numerous metallic, generally annular, radiating elements, or resonators, arranged on the substrate in an array of repeating nested sets of the radiating elements. The lower frequency S-band feed is located behind and to the side of the subreflector for transmission of radiation via a folded optical path to the main reflector. The C-band feed is located in front of and to the side of the subreflector for transmission of radiation along a straight path through the FSS to the main reflector. The locating of the two feeds to the side of the subreflector permits the subreflector to be stowed by folding down upon the C-band feed, and the main reflector to be stowed by folding down upon both the S-band feed and the stowed subreflector.