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:
Apr. 09, 1991
Filed:
Mar. 28, 1990
Mon N Wong, Torrance, CA (US);
Robert J Patin, Hawthorne, CA (US);
Brennan J Trese, Los Angeles, CA (US);
Krishnan K Raghavan, Redondo Beach, CA (US);
Hughes Aircraft Company, Los Angeles, CA (US);
Abstract
A patch antenna is formed of one or more flat disc-shaped radiators disposed parallel to and spaced apart from a common ground-plane element. At each radiator, there is a feed assembly of two feeds positioned to one side of a center of the radiator in space quadrature and excited in phase quadrature for generating circularly polarized radiation from the radiator. Each of the feeds, in a preferred embodiment of the invention, is formed as a post extending through an aperture in the ground-plane element partway to the radiator for capacitive coupling with the radiator. At each radiator, a reactance element on the form of a capacitive block extends from the ground-plane element partway to the radiator at a location diametrically opposite the feed assembly. Capacitive reactance of the reactance element is approximately one order of magnitude less than the sum of the capacitive reactance of the two feeds at each radiator to reduce mutual coupling between the feeds of each radiator to counteract any elliptical polarization to produce accurately a circular polarization.