Evaluation of Dielectric Properties of Colored Resin Plastic Button to Design a Small MIMO Antenna

Abstract

This communication proposes a two-port multiple-input-multiple-output (MIMO) antenna fabricated on a small size colored resin plastic button where full dielectric properties of the button substrate are evaluated before designing the MIMO antenna. The antenna uses partial ground plane and two coaxial feeds for the excitation of two semicircular shaped patch elements. A very simple copper ring around the four slots of the button is used to obtain very high port isolation. The antenna covers the frequency range from 7.96 to 8.76 GHz and fulfills the International Telecommunication Union (ITU) band (8-8.5 GHz) for fixed wireless communication application. It provides very high port isolation (>21 dB) and diversity gain (DG > 9.8 dB) over the whole band. The investigated envelope correlation coefficient (ECC) (<; 0.18) and channel capacity loss (CCL) (<; 0.24 b/s/Hz) are potentially very low. The mean effective gain (MEG) (±0.3 dB) over the entire application band is found in a well-accepted range. The prototype could be mounted on a textile material of on-body cloths for different wearable monitoring purposes. The simulated and measured outcomes are matched with a satisfactory level to mark the proposed two-element two-port button antenna as a suitable MIMO candidate for the specified application band.