An ultra-wideband feed for Chinese Spectral Radio Heliograph array

An ultra-wideband(UWB) feed, inspired by the Eleven feed, with dual circular polarization over 0.4–2GHz for Chinese Spectral Radio Heliograph (CSRH) array (Phase I) is presented in the paper. The design parameters and consideration for practical application are described. The measured voltage standing wave ratio (VSWR) and radiation patterns of the feed are given, and the measured total efficiency of the 4.5m parabolic antenna is better than 40% over 0.4–2GHz. Another UWB feed over 2–15GHz for 2m antenna (CSRH Phase II) is also expatiated.