A Compact Four-Port Ultra-Wideband MIMO Antenna Employing Slot-Based Penta-Band Suppression and Centralized EBG Decoupling Network

Abstract

This study presents a small four-elements ultra-wideband (UWB) antenna system with inbuilt multi-band suppression and enhanced isolation that has a multi-input multi-output (MIMO) antenna configuration. To achieve the performance of wideband, the antenna is built based on circular monopole radiators printed on an adjusted ground plane. In order to reduce the electromagnetic interaction between the closely spaced elements, a periodic electromagnetic bandgap (EBG) structure with periodic 3×3 pattern is inserted in the center of the substrate to essentially limit the amount of surface-wave coupling. Each radiating patch has five resonant inverted U-shaped slots that form controlled rejection bands in the UWB spectrum that reject interferon of the existing wireless systems between 3.36 GHz and 5.50 GHz. Expertise experimentally shows an operating bandwidth of 3.0 to 14.0 GHz.  Experimental performance indicates that the operation bandwidth is 3.0 to 14.0 GHz (|S11| ≤ −10 dB), with an inter port isolation of more than -22.5 dB, a gain of 6.2 dB, and a radiative efficiency of approximately 79%. The design is suitable in development of small high-speed UWB-MIMO communication equipment where there is a need to have a reliable interference mitigation and low mutual coupling.