A newly developed method of design for a shaped reflector antenna is described. A conventional quadratic reflector configuration is assumed; the reflectors are then modified to yield the desired aperture shape and field distribution by introducing shaping functions. This method is useful for designing antennas with an arbitrary shaped beam, such as an elliptical-beam antenna, and has been verified through a 4.7 m × 2.3 m (equivalent to 3.3 m diameter) dual-band (30–20 GHz) earth-station antenna for the Japanese domestic satellite system CS. The measured aperture efficiency is more than 76%, and the ratio of the major and minor axes of the elliptical beam is 2:1.