A passive beamforming hemispherical liquid antenna using a simple metal ball

Abstract

Abstract The authors propose a novel yet simple way of passive beamforming using a liquid antenna. A hemispherical dielectric resonator antenna filled with a dielectric liquid is considered to realise the fundamental TE111 mode, and a small, weighted metal ball is dropped inside the hemispherical container. This metal ball functions as a movable director and passively steers the realised fundamental mode of the DRA always towards the ground. The proposed design finds its applications in static‐subject‐based applications such as indoor base stations, and beam‐stabilisation/pattern‐correction works in case of dynamic‐subject‐based applications. The overall profile of the antenna is 0.60λ0 × 0.60λ0 × 0.19λ0 targeting the ISM band at 2.4 GHz with decent efficiency and far‐field characteristics. The working prototype is developed and experimentally verified.

Keywords

• beam steering
• dielectric materials
• dielectric resonator antennas