Design and development of a dual-frequency (Ku/Ka), dual-polarization, wide-angle scanning airborne rain radar antenna system

A compact, dual-frequency (Ku/Ka-band), dual-polarization, wide-angle scanning antenna system has been developed as part of an airborne instrument for measuring rainfall. This system is an upgrade version of a prior single frequency airborne rain radar instrument, and was designed to generate spatially coincident horizontally and vertically polarized beams at both frequencies with 3-dB beamwidths that match within 25 percent, and have low-sidelobe levels over a wide scan angle at each polarization-and-frequency combination. The calculated results, as well as the measured electrical performance over wide-angle scanning, are presented.