S/Ka- Band Shared Aperture Antenna System for Data Relay Satellites and Ground Station Applications

Antenna systems operating in widely separated dual/triple bands are becoming common requirements owing to various complex mission requirements. In this work, a Dual CP, Dual Band shared aperture feed system is developed that feeds a reflector system in Axially Displaced Configuration. S-Band CP horn operates in coaxial TE11 mode where as Ka-Band CP Horn operates in conventional circular waveguide TE11 mode. Concentric phase centres, appropriate illumination taper, dual CP operation, tracking mode using higher order TM01 are some of the salient features of this work. The designed Antenna System exhibits a gain of > 31.1 dBi and 31.8 dBi in S-Band Tx, Rx with Axial Ratio < 2 dB. At Ka-Band, the Antenna system exhibits a gain of >52.1 dBi and 53.4 dBi in Tx, Rx Bands with Axial Ratio < 2 dB. Tracking pattern null depth of > 40 dB is seen in secondary pattern.