Abstract: An antenna system adapted to be mounted on an exterior surface of a mobile platform and having a reduced overall height to reduce aerodynamic drag caused by the antenna system. The antenna system includes a movable platform disposed concentrically within an annular stationary platform. The movable platform includes a slip ring assembly formed on its lower surface which is in physical contact with a brush assembly supported from a lower surface of the stationary platform. By locating the slip ring assembly and the brush assembly adjacent the lower surface of the movable platform, the overall height of the antenna is reduced. Reliability is also improved since contaminants are less likely to accumulate on the slip ring assembly due to its presence on the lower surface of the movable platform.

Abstract: A dual polarized, transmit/receive Cassegrain antenna system having an improved gain/temperature (G/T) ratio and improved effective isotropic radiated power (EIRP). The antenna has a main reflector, a subreflector, a waveguide feedhorn and a waveguide diplexer—ortho-mode transducer (OMT) attached to the waveguide feedhorn at the vertex in the back of the main reflector. Vertical and horizontal components of the transmit and receive signals are separated into four independent channels. The four channels are coupled from the waveguide diplexer-OMT in four directions to allow placement of the vertical and horizontal solid state power amplifiers (SSPA) and the vertical and horizontal low noise amplifiers (LNA) directly on the back of the antenna. Location of the SSPAs and LNAs in this manner provides minimum transmission loss and volume.

Abstract: An antenna system adapted to be mounted on an exterior surface of a mobile platform and having a reduced overall height to reduce aerodynamic drag caused by the antenna system. The antenna system includes a movable platform disposed concentrically within an annular stationary platform. The movable platform includes a slip ring assembly formed on its lower surface which is in physical contact with a brush assembly supported from a lower surface of the stationary platform. By locating the slip ring assembly and the brush assembly adjacent the lower surface of the movable platform, the overall height of the antenna is reduced. Reliability is also improved since contaminants are less likely to accumulate on the slip ring assembly due to its presence on the lower surface of the movable platform.