Millimeter-Wave Miniaturized Planar Dual-Reflector Antenna via Transformation Optics

A novel millimeter-wave wideband multibeam planar dual-reflector antenna with a three-layered parallel plate waveguide (PPW) configuration is proposed in this paper. To miniaturize the dual-reflector beam-former, a transformation optic (TO) approach is used to flatten the main-reflector contour, which achieves a reduction of 50% on the longitudinal size. The periodic dielectric hole units compose the transformation material filled in the PPW beam-former. Moreover, multiple waveguide feeds following a two-feed-per-beam scheme and a metallic flare acting as the radiator are combined with the dual-reflector beam-former to fulfill the Ka-band multibeam radiation. A wide bandwidth of 32%, stable multibeam radiation with a scanning range of ±42° and a gain of up to 15.3 dBi are realized, which is attractive for future millimeter-wave applications.