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:
Oct. 26, 1999
Filed:
May. 22, 1997
John R Sanford, Palo Alto, CA (US);
William Comisky, Oakland, CA (US);
Endgate Corporation, Sunnyvale, CA (US);
Abstract
An improved reflector antenna with far improved return loss than prior art subreflector antennas is disclosed herein. The invention uses a circular waveguide antenna feed employing a non-planar, subreflector having a radial cavity which reflects the energy from the waveguide onto a rotationally symmetrical main reflector. The dimensions of the feed tube, the subflector, and the connection between them are chosen to make the total reflection back into the feed tube very close to zero. The dimensions of the antenna feed are also chosen such that its radiation pattern has an amplitude null along the antenna feed axis. This further improves return loss by minimizing the amount of energy from the main reflector that gets directed back into the feed tube. An alternate embodiment features a feed radiation pattern with an asymmetric amplitude taper for improvement of the sidelobe envelope in a preferred plane.