Multiband ring focus antenna employing shaped-geometry main reflector and diverse-geometry shaped subreflector-feeds

A method of configuring an antenna for operation at a selected one of a plurality of different frequency bands comprising the steps of:

• (a) providing a main reflector having a shaped, non-regular conical surface of revolution about a boresight axis of said antenna;
• (b) locating a sub-reflector, having a shaped, non-regular conical surface of revolution about said boresight axis, in spaced apart relationship with said main reflector along said boresight axis, said shaped, non-regular conical surface of said sub-reflector having a ring-shaped focus characteristic about said boresight axis, said sub-reflector being selected from a plurality of respectively different sub-reflectors having shaped, non-regular conical surfaces of revolution about said boresight axis and configured for operation at spectrally different frequency bands;
• and
• (c) locating a feed element adjacent to a vertex of said subreflector on said boresight axis, said feed element being selected from a plurality of different feed elements respectively configured for operation at said spectrally different frequency bands, said selected feed element being configured for operation at the band of operation of said selected sub-reflector.

An antenna adapted to be operational at a selected one of a plurality of different frequency bands comprising:

• a main reflector having a shaped, non-regular conical surface of revolution about a boresight axis of said antenna;
• a sub-reflector, having a shaped, non-regular conical surface of revolution about said boresight axis, located in spaced apart relationship with said main reflector along said boresight axis, said shaped, non-regular conical surface of said sub-reflector having a ring-shaped focus characteristic about said boresight axis, said sub-reflector being selected from a plurality of respectively different sub-reflectors having shaped, non-regular conical surfaces of revolution about said boresight axis and configured for operation at spectrally different frequency bands;
• and
• a feed element located adjacent to a vertex of said sub-reflector on said boresight axis, said feed element being selected from a plurality of different feed elements respectively configured for operation at said spectrally different frequency bands, said selected feed element being configured for operation at the band of operation of said selected sub-reflector.