Beam shaping of RF feed energy for reflector-based antennas

A reflector-based antenna, comprising:

• a primary reflector having a focal point;
• an antenna feed spaced from the primary reflector and located approximately at the focal point for illuminating the primary reflector with or receiving from the primary reflector radio frequency (RF) energy of a first predefined RF wavelength;
• a sensor for receiving or transmitting energy of a second predefined wavelength different from the predefined RF wavelength from the primary reflector;
• a secondary reflector having a forward surface facing the primary reflector and the sensor and a rear surface facing the antenna feed, said secondary reflector comprising a selective coating on the forward surface that allows transmission energy at the first predefined RF wavelength there through and reflects energy of the second predefined wavelength, said antenna feed, said secondary reflector and said sensor creating a central blockage of the primary reflector along a boresight axis, said forward and rear surfaces having different curvatures such that the dielectric material has non-uniform thickness, said dielectric material being thinner near the boresight axis to steer energy from the feed that is transmitted through the dielectric material away from the central blockage towards unblocked regions of the primary reflector.

A reflector-based antenna, comprising:

• a primary reflector having a focal point;
• an antenna feed spaced from the primary reflector and located at approximately the focal point for illuminating the primary reflector with or receiving from the primary reflector radio frequency (RF) energy, said feed forming a blockage of the primary reflector;
• and
• an RF beam-shaping element located between the primary reflector and the antenna feed, said RF beam shaping element comprising a conical cutout formed in a rear surface of a dielectric material facing the antenna feed that directs RF energy from the feed that is transmitted through the dielectric material away from the blockage towards unblocked regions of the primary reflector.