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:
May. 01, 2001
Filed:
Mar. 22, 2000
Yuu Yamaguchi, Tokyo, JP;
NEC Corporation, Tokyo, JP;
Abstract
A dielectric refractor, a refractive index of which varies in accordance with a frequency, is situated between a primary horn serving as a electric wave source and a concave sub-reflector. A desired transmitting wave in the desired transmitting frequency band is refracted by the dielectric refractor so as to illuminate the sub-reflector. An undesired transmitting wave outside the desired transmitting frequency band is refracted by the dielectric refractor so as to pass along a path for the undesired wave, and reaches a electric wave-absorber to be absorbed thereby. Accordingly, the undesired transmitting wave does not reach the sub-reflector, and is prevented from being radiated to the outside of the antenna apparatus via the sub-reflector and the main reflector.