Abstract: A coplanar slot antenna includes a generally planar continuous conductive disc supported by a dielectric substrate, wherein radiating features are defined by removing conductive material to form dielectric-filled slot openings. A central radial feed slot terminates inward of the disc periphery and intersects a transverse slot to form a T-shaped slot junction with opposing arms. The slot geometry transitions into opposing arcuate slots that are concentric with the disc and arranged in mirrored relationship, and into linear tip slots oriented substantially parallel to the feed slot and extending to the disc periphery. A coplanar feed structure applies radio-frequency excitation across the feed slot with ground and signal conduction pathways disposed in the same plane as the disc.

Abstract: A rotatable waveguide polarizer feed assembly for satellite and microwave antenna systems includes a stationary waveguide structure, a rotatable waveguide body, and an internal polarization-transforming structure positioned in an axial waveguide passage of the rotatable waveguide body. Internal transfer passages in the rotatable waveguide body selectively communicate with stationary waveguide channels. Rotation of the rotatable waveguide body changes the angular orientation of the polarization-transforming structure and selectively reverses polarization state, including reversal between opposite circular polarizations. The assembly may effect polarization reversal on a microsecond timescale, enabling satellite terminals to traverse spot beam boundaries of opposite circular polarization handedness without dropping the active communications link or requiring a modem reset.

Abstract: A multibeam hemispherical X-band array inserts nulls at horizontal and near horizontal angles to suppress interfering signals, without degrading authentic signals arriving at other angles. The multibeam hemispherical array includes three annular (360) rows of antenna elements, each row having 64 elements. Elements of the first row, which have the smallest elevation angle, have pairs of circular patches coupled with a phase delay line. Each pair of circular patches is spaced apart from and aligned with two pairs of similarly shaped (circular) and sized parasitic directors. The spacing between driven patches of adjacent elements in a row is about equal to one half of the wavelength of the radiated wave. The array fits within a conventional 24-inch diameter marine radome.

Abstract: A low profile patch antenna surface mounted to a metal base produces superior gain in horizontal directions. A dielectric spacer and matching circuit are sandwiched between a thin circular patch radiator and an opposite ground plate, with the matching circuit between the spacer and ground plate and electrically coupled to the ground plate and radiator. The matching circuit increases antenna efficiency and bandwidth by attaining the best possible energy transfer between a transceiver and the antenna, taking into account impedance mismatch, component losses, and losses in the antenna structure.

Abstract: A low profile antenna assembly for an aircraft radome includes a reflector, a feed with a stacked array of septum polarizers, a mount, and a bracket. The feed, which includes bandpass and low pass filters, and broadwall branchline couplers, and the stacked array of septum polarizers, together determine polarization of the waves, attenuating unwanted signals and illuminating the entire reflector. The reflector comprises a portion of a parabolic reflector.

Abstract: A low profile antenna assembly for an aircraft radome includes a reflector, a feed with a stacked array of septum polarizers, a mount, and a bracket. The feed, which includes bandpass and low pass filters, and broadwall branchline couplers, and the stacked array of septum polarizers, together determine polarization of the waves, attenuating unwanted signals and illuminating the entire reflector. The reflector comprises a portion of a parabolic reflector.