X-Band Choke Ring Horn Telecom Antenna for Interference Mitigation on NASA’s SWOT Mission

A low-gain antenna (LGA) is designed for high cross-polarization discrimination (XPD) and low backward radiation within the 8.025–8.4-GHz frequency band to mitigate cross-polarization and multipath interference given the spacecraft layout constraints. The X-band choke ring horn was optimized, fabricated, and measured. The antenna gain remains higher than 2.5 dBi for angles between 0° and 60° off-boresight. The XPD is higher than 15 dB from 0° to 40° and higher than 20 dB from 40° to 60° off-boresight. The calculated and measured data are in excellent agreement.