MULTILAYER OFFSET FRESNEL ZONE-PLATE REFLECTOR

An offset phase-correcting Fresnel zone plate (FZP) reflector antenna based on the multilayer configuration is presented. The reflector cons ists of a conducting ground and four layers of conducting patterns sep arated by four dielectric substrates. An experimental prototype design ed at 10.39 GHz was fabricated and tested. With a 0.32 m by 0.34 m ell iptical reflector aperture and a pyramidal feedhorn, the antenna achie ved -20-dB sidelobe level and 61% maximum efficiency. Compared with a phase reversal FZP of the same size, a 3.3-dB gain improvement and sig nificant sidelobe reduction were obtained.