Narrow-beam azimuthally omni-directional millimetre-wave antenna using freeformed cylindrical woodpile cavity

Abstract

A freeformed cylindrical electromagnetic bandgap (EBG) structure and its application for millimetre-wave antennas are presented. The cylindrical EBG structure is fabricated using the extrusion freeforming technique in which the design is downloaded directly to a building platform. The fabricated cylindrical woodpile exhibits bandgap characteristics around 95 GHz and is used for realising a resonant cavity antenna. The fabricated antenna achieves a narrow beam with 6.5° measured half-power beam-width in the elevation plane without using an array configuration. The overall antenna gain is approximately 5 dBi at 94.2 GHz, suitable for future short-range gigabit wireless communications.