Abstract: 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.

Abstract: 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.

Abstract: A surface used as a space filter in electromagnetic space. The filter surface is formed as a periodic array of recurrent filter components clustered in groups of three each incorporating pairs of elements extending outwardly at an internal angle of 120.degree.. A reactive load present as a U-shaped loop is coupled with the terminal portions of each element and extends outwardly therebetween.

Abstract: An antenna system in which a conical shaped metallic radome has a surface composed of a periodic array of radiating slot elements. Each slot element has three arms connected to each other and extending radially outward with the angular distance between adjacent arms equal to 120.degree.. The slot elements are aligned in order to have each of the arms in an element parallel to an arm in an adjacent element forming a uniform periodic array.