Comparison of prime focus and dual reflector antennas for wideband radio telescopes

This paper compares the RF performance of a dual-shaped Gregorian reflector system to a classic prime focus symmetric reflector system intended for use in a wideband radio telescope. A number of wideband feeds are considered, including octave band corrugated horns, quad-ridged flared horns, log-periodic dipole antenna feeds, and quasi self-complementary structures. The efficiency, noise temperature and effective area over system temperature (Ae/Tsys) are evaluated. In all cases, the dual-shaped Gregorian system performs significantly better than the prime focus symmetric system.