Microstrip monopole antenna with a novel UC-EBG for 2.4 GHz WBAN applications

Abstract

A microstrip monopole antenna backed with a novel uniplanar compact electromagnetic bandgap (UC-EBG) structure for 2.4 GHz wireless body area network applications is proposed here. The proposed antenna has a size reduction of 50% when the number of EBG array is optimised from 3 × 4 to 2× 3, while the radiation performance is almost invariable at the same time. The operating frequency band under different conditions has the capability of covering the 2.4-2.4835 GHz industrial, scientific, and medical band. Due to the addition of 2×3 UC-EBG on the back, the radiation patterns become unidirectional, and the measured average gain increases from 2.1 to 5.6 dB. Meanwhile, the cross-polarisation of the monopole antenna can be suppressed prominently by the EBG array. The simulated specific absorption rate values are 0.0536 W/kg under 1 g standard and 0.0296 W/kg under 10 g standard, which are far below the limitation of USA and Europe. These results can manifest the reliable wearable performance of the proposed antenna.