Abstract: Methods and apparatus for a radiator assembly having a feed circuit with an air interface to a quadridge feed structure to excite an antenna, such as a stacked patch antenna. Embodiments of the assembly can provide enhanced bandwidth, scan angle performance, and coincident phase centers for dual-linear polarizations.

Abstract: A waveguide feed structure having a coaxial transmission line. A conductive, planar septum is disposed in, and along a diameter of, the transmission line. A feed port is electrically coupled to the transmission line. The septum has a rear portion disposed proximate the feed port, such rear portion of the septum extending between the inner conductor and the outer conductor. The feed port and the rear portion of the septum are arranged to establish an electric field in the transmission line between the inner conductor and the outer conductor with a component substantially TE11 mode along a direction perpendicular to the planar septum. A forward portion of the septum is asymmetrically disposed with respect to said diameter in order to provide a gap between the inner conductor and the outer conductor, such gap establishing an electric field component within the transmission line having a TE11 component along said diameter of the transmission line parallel to the plane of the septum.

Abstract: A waveguide feed structure having a coaxial transmission line. A conductive, planar septum is disposed in, and along a diameter of, the transmission line. A feed port is electrically coupled to the transmission line. The septum has a rear portion disposed proximate the feed port, such rear portion of the septum extending between the inner conductor and the outer conductor. The feed port and the rear portion of the septum are arranged to establish an electric field in the transmission line between the inner conductor and the outer conductor with a component substantially TE11 mode along a direction perpendicular to the planar septum. A forward portion of the septum is asymmetrically disposed with respect to said diameter in order to provide a gap between the inner conductor and the outer conductor, such gap establishing an electric field component within the transmission line having a TE11 component along said diameter of the transmission line parallel to the plane of the septum.

Abstract: An integrated directional patch antenna uses multiple patch radiating elements to control the direction of a beam of radio frequency energy (RF) over a large scan volume. The antenna includes a ground plane element and a first dielectric planar member placed on a major surface of the ground plane element. A plurality of first patch radiator elements is arranged on a surface of the first dielectric member remote from the ground plane element. A second dielectric planar member is placed on first patch radiator elements, and a plurality of second patch radiator elements arranged on a surface of the second dielectric member remote from the first patch radiator elements.