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:
Jun. 27, 1989
Filed:
Nov. 16, 1987
Abstract
A new type of passive trihedral corner reflector is described which rotates the polarization of a reflected microwave beam by 90.degree. and thereby permits a reflected radar beam to be more easily distinguished by the interrogating radar system from the random reflections from nearby objects, i.e., clutter. Rotation of the incident beam is provided by locating a passive polarizing or 'twist' grid of closely spaced thin parallel wires spaced above one conducting surface by air or by a dielectric to give an electric spacing from the surface of about 0.25 .lambda.. The spacing of the wires is less than 0.25 .lambda. so that the wires constitute a reflecting surface for signals polarized parallel to the wires. The reflector can have triangular or square sides which are mutually orthogonal. In a preferred embodiment the reflector is tipped forward by 35.degree. from a reference horizontal plane and tilted clockwise in a vertical reference plane by 15.degree. to optimize reflections. The reflector has particular application to navigation systems, especially to maritime navigation systems.