Highly selective multiple-notched UWB-MIMO antenna with low correlation using an innovative parasitic decoupling structure

Abstract

In ultra-wideband (UWB) communications, highly selective notch bands are required to avoid interference with other licensed bands. This study presents a highly selective triple-notch UWB-MIMO antenna, which consists of a four-radiating patch antenna and an isolator. The single-element antenna consists of a radiating patch, substrate, ground plane, electromagnetic bandgap (EBG) structures, and split ring resonators (SRR). To achieve the designated UWB bandwidth, the lower edges of the antenna patch are cut by a quarter-circle radius. The three sharp notches are achieved by utilizing four EBGs and two SRRs at the back of the antenna. The notch bandwidth can also be controlled by changing the parameters such as the width and length of the EBG structure and SRR. The single antenna is then translated into 4-port MIMO systems. The high correlation between elements is reduced by inserting a unique parasitic decoupling structure. The decoupling structure is designed in a way that reduces the mutual coupling in all passbands. The proposed antenna offers a (|S11| < –10 dB) of 3.1 – 11.8 GHz impedance bandwidth. The proposed MIMO antenna having an overall size of 54 × 54 × 1.52 mm3 is fabricated to verify the simulation results. The MIMO antenna shows exceptional diversity properties, including better isolation between unit elements of MIMO antenna (>20 dB), a diversity gain (DG) very close to 10 dB (>9.99 dB), an envelope correlation coefficient which is less than 0.001, and suitable mean effective gain is also in the defined range. The suggested parasitic element UWB – MIMO antenna thus supports its suitability for use in UWB communication networks.