Mutual Coupling Reduction in Wideband Electromagnetic Medical Imaging Antenna Array Using Compact Electromagnetic Band Gap

Abstract

A compact, low profile, and wideband electromagnetic band gap (EBG) unit cell for mutual coupling reduction between antennas of electromagnetic medical imaging is proposed. The EBG unit cell is designed on a 3-mm thick polymer RTV6166 substrate and consists of a square patch (14×14 mm2) with four symmetrically L-slot. The EBG unit cell is characterized using suspended transmission line method. It achieves fractional stopband bandwidth of 101.3%, which covers the low microwave frequency band from 1.18 GHz to 2.7 GHz. This usually requires large size, and high profile if conventional EBG structures are used. To further assess the proposed EBG cell and its effect on suppressing the coupling between antenna arrays, two CPW circular monopole antennas are designed and investigated with the presence of EBG unit cells. The simulation results show that the EBG unit cells are able to reduce the coupling in an array system that encloses an average human head model by 7 dB over the operational frequency range.