A C/X/Ku-band dual polarized Cassegrain antenna system

There is an increasing demand for multiple frequency band capability in satellite Earth station antenna systems. This paper describes an 18.3 m shaped Cassegrain antenna with a single aperture, tri-band, six-port receive-only, feed system. The frequencies of operation are 3.4-4.2 GHz, 7.25-7.75 GHz, and 10.9-12.75 GHz. The C- and X-band feed ports offer dual circular polarization, and the Ku-band ports offer dual linear polarization with an internal polarization vector angle adjustment mechanism. Frequency and polarization multiplexing is performed by a novel OMJ structure.