Dual-reflector system with a spherical main reflector and shaped subreflector for compact range

For many years, the compact range has successfully been used to evaluate antenna electromagnetic radiation and target scattering. Single offset paraboloidal reflectors, dual parabolic-cylindrical reflectors, and dual shaped reflectors exist for the compact-range reflector systems. A dual-reflector compact-range system with a spherical main reflector and a shaped subreflector is described with this design, an arbitrary position of the feed is permissible for the anechoic-chamber size and existing chamber-fitting considerations. A spherical surface is adopted to reduce manufacturing cost. A Gregorian-type dual-reflector system with a 1.83 m-diameter truncated spherical main reflector has been evaluated and manufactured. The test results, for frequencies from 8 to 39.5 GHz, showed that the performance of the quiet zone is within ±0.4 dB amplitude ripple and ±5° phase ripple over a 70% area of the main reflector projected in the quiet-zone direction