Single End-Fire Antenna for Dual-Beam and Broad Beamwidth Operation at 60 GHz by Artificially Modifying the Permittivity of the Antenna Substrate

A technique is proposed to generate a dual-beam and broad beamwidth radiation in the E-plane of a printed bow-tie antenna operating over 57-64 GHz. This is achieved by artificially modifying the dielectric constant of the antenna substrate using arrays of metamaterial inclusions realized using stub-loaded H-shaped unit cells to provide a high index of refraction. The H-shaped inclusions are tilted with respect to the axis of the antenna and embedded in the direction of the end-fire radiation. The resulting dual-beam radiation in the E-plane has maxima at +60° and 120° with respect to the end-fire direction (90°), with a maximum peak gain of 9 dBi at 60 GHz.