Mcdonnell Douglas Corporation

Edward L Pelton

John R Glabe

A broadband flared slot notch antenna combined with an overhead metal plate resulting in an improved front-to-back ratio and a reduced response to crossed polarized radiation. The antenna is provided by a metal layer deposited on a dielectric substrate which is etched to form a pair of symmetrical slot sections having facing edges which increasingly curve away from each other to a maximum spacing point which is the antenna aperture. A linking slot interconnects the slot sections at a feed point spaced from the aperture. High frequency electrical voltage applied at the feed point achieves launch of an electromagnetic wave from the aperture. The overhead metal plate is parallel and closely spaced above and shorted to the antenna thereby reducing radiation emissions that are not in the direction of that launched from the aperture. The metal plate is shorted to the antenna along a line orthogonal and adjacent to the linking slot to prevent radiation from being launched in a direction opposite that described above. The forward edge of the metal plate is terminated with a tapered resistive card to prevent radiation scatter off the edge. The back portion of the space enclosed by the plane of the antenna and the metal plate may be filled with electromagnetic radiation absorbing material to further reduce such radiation. In addition, the sides of the metal plate, may be partially or completely closed with metal walls that are shorted to the metal plate for reducing radiation emissions that are orthogonal to that launched from the aperture.

Broad band parallel plate antenna

An antenna (10) is provided by a metal layer (12) deposited on a dielectric substrate (16) which is etched to form a pair of symmetrical slot sections (20,22) having facing edges which increasingly curve away from each other to a maximum spacing point which is the antenna aperture (26). A linking slot (32) interconnects the slot sections (20,22) at a feed point (30) spaced from the aperture (26). High frequency electrical voltage applied at the feed point (30) achieves launch of an electromagnetic wave from the aperture (26). An alternative feed network uses a 180.degree. hybrid (60) providing simultaneous horizontal and vertical polarization operation.

Growing community of inventors

San Diego, CA, United States of America

Edward L Pelton