G/T sensitivity comparison of different topologies using ultra wide band, active, conical sinuous antenna

Future radio astronomy arrays will benefit greatly from an ultra wideband feed that provides high efficiency and exhibit low noise behavior. A comparison based on G/T_sys sensitivity is presented for three sinuous based feeds. The analysis can be easily extended to a wider range of feeds and used for a side by side comparison. Results from Table 1 show that the three cases have comparable performance at room temperature with the ground plane based version with the highest sensitivity. The T_spill contribution is considered the same for both ambient and cryogenic tem peratures, as it is not feasible to cool the absorber used for suppression of the back lobe. As a result, the ground plane version shows significantly higher sensitivity at cryogenic temperature. Based on this analysis we plan to build a cryogenic version of the ground plane based antenna in the near future.