High aperture efficiency wide corrugations bull’s-eye antenna working at 60 GHz

Abstract

A full metallic Bull’s-Eye (BE) antenna operating at 60 GHz is numerically and experimentally analyzed. The antenna presents wide grooves, rather than narrow ones, which support higher order resonances that lead to a large gain enhancement with just a pair of corrugations, achieving an overall miniaturization and increase of its aperture efficiency. In addition, an annular soft surface of 5 grooves is placed on the edge of the antenna, giving rise to a slight increase of the gain, reduced side lobe level as well as reduced end-fire and backward radiation, when compared with an antenna without soft surface and another antenna with narrow corrugations. A narrow beam antenna with a gain of 19 dBi and nearly 16 dB side lobe level and 10.8 deg beamwidth is numerically obtained at the operating frequency. Measurements and numerical results show overall good agreement, with an experimental gain of 20.2 dBi, 13.2 dB side lobe level, 10.4 deg beamwidth and 32% of aperture efficiency.