A dual-band feed system

With the dual-reflector antenna configuration widely used for both earthbound and spacecraft antennas, the feed design is a crucial part of the overall system. While feed horns have been developed to cover continuous bandwidth ratios of at least 2:1, widely separated bands are more difficult to design effectively within a single feed. To achieve the necessary bandwidth for, say, C/Ku-band simultaneous operation, the dielectrically loaded corrugated, dual-frequency horn as described by M.S. Narasimhan and M.S. Sheshadri (see IEEE Trans. Antennas. Propag., vol.Ap-27, 858-60, 1979), is a strong candidate. The authors outline their approach in analysing this type of feed horn used in conjunction with a coaxial diplexer to excite the two bands in the horn.<>