Patent ID: 7737903

Claim:
A reflector for being illuminated by at least one feed, the reflector comprising: a central region; and at least one annular region surrounding the central region, axially stepped a height h above or below the central region, wherein the height h is selected to create a 180° phase reversal between radiation reflected from the central region and radiation reflected from the at least one annular region at one of a receive or transmit frequency band, wherein h is approximately equal to m × [ Φ ± ( ϕ ⁡ ( Θ = 0 ) - ϕ ⁡ ( Θ = Θ 0 ) ) ] × π 180 × λ 2 ⁢ π × 1 2 , where m is a positive odd integer, Φ is a desired amount of phase shift of an outer region of a phase front for reflecting off of the reflector, φ is a feed phase contribution for an angle Θ, and Θ 0 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.