A slotted waveguide antenna with adjustable polarisation

A new slotted waveguide antenna has been developed which has adjustable polarization, as well as good control of azimuth patterns, a light weight, and low windage. The design of the antenna is based on three slotted waveguides in a symmetrical configuration, which generate two orthogonal polarizations in a parallel plate region. Two arrays with matched inclined/displaced slots are used for the transverse polarization, while one array with matched edge slots is used for the longitudinal polarization. A corrugated horn is used to obtain equal vertical patterns. A prototype antenna with a 0.5 deg beamwidth and a weight of about 100 kg is presently under construction.