A low-cost Ka-band Cassegrain polarimetric tracking antenna

A low-cost Ka-band Cassegrain tracking antenna based on a novel feed concept has been designed and built. The antenna will be used in a monopulse application and can transmit a circular or linear polarized sum pattern and receive the sum vertical, horizontal, and difference signals on receive. The feed consists of four sections: a rectangular waveguide, folded hybrid-tee; an orthogonal, slot-coupled, rectangular-to-circular waveguide junction; a circular waveguide section; and a conical horn. A prototype antenna was built and characterized in an anechoic chamber. The gains of the three ports are compared with the results of a physical optics based analysis.<
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