STEPPED-REFLECTOR ANTENNA FOR SATELLITE COMMUNICATION PAYLOADS

摘要

A stepped reflector for being illuminated by at least one multiple-band feed is provided. The reflector includes a central region and a first annular region with an annular width of w. The first annular region is axially stepped a height h above the central region, where h is approximately equal to m × [Φ± (φ⁡ (Θ= 0 ) -φ⁡ (Θ=Θ0 ) ) ] ×π180 ×λ2 ⁢ π× 1 2 , where m is a positive odd integer,Φis a desired amount of phase shift of an outer region of a phase front for reflecting off of the reflector,φis a feed phase contribution for an angleΘ, andΘ0 is an angle formed between an axis of the at least one feed and a line connecting a phase center of the at least one feed and an inner edge of the at least one annular region. The central region and the annular region of the reflector may be parabolically curved or may alternately be shaped. The reflector may be fed by one or more multiple-band horn antennas.