A wideband quadruple-ridged horn antenna for the multifeed S-band receiver of the Sardinia radio telescope

A feed horn for the multifeed S-band receiver of the Sardinia Radio Telescope (SRT) has been designed. The antenna consists of a truncated circular waveguide with four ridges of variable height inside. The horn antenna has been designed and tested using Ansys HFSS and, then, the multifeed system has been coupled with the SRT using GRASP by TICRA. The return loss of the feed horn is larger than 20dB over a 60% bandwidth (between 2.3 and 4.3GHz), and the edge taper and the cross-polarization level of the multifeed system meet the specifications of the SRT S-band receiver.