Structure and EM‐driven design of novel compact UWB slot antenna

Abstract

In this study, a structure and design optimisation procedure of a novel compact ultra-wideband (UWB) slot antenna has been presented. In order to achieve small size of the structure and maintain acceptable electrical performance, a sufficiently large number of geometry parameters have been introduced. These include a stepped-impedance feed line and a meandered slot with all of dimensions being parameterised and subject to optimisation. All parameters are simultaneously adjusted using automated electromagnetic (EM)-simulation-driven optimisation algorithm. The design process is oriented towards explicit size reduction of the antenna structure. Penalty function approach is utilised to control the reflection response. In order to reduce the computational cost of the optimisation process, variable-fidelity EM models are utilised. The footprint of the optimised antenna is only 8.93 × 17.9 mm (160 mm2) while maintaining reflection below the –10 dB threshold in the entire UWB frequency range. The antenna has been favourably compared with the state-of-the-art compact structures in terms of the size. The obtained numerical results are supported by measurements of the fabricated antenna prototype.