Circularly polarized offset-fed DRA elements & their application in compact MIMO antenna

Abstract

In this work, the generation of circular polarization (CP) in two different dielectric resonator antenna (DRA) elements (one element gets energized by the offset conformal-strip and another one is by the offset microstrip-slot) is precisely explored. CP radiations from the presented DRA elements are acquired by removing a proper asymmetrical notch from the rectangular dielectric resonators (rDRs) and feeding the rDRs at an appropriate offset distance from the center. Furthermore, these two DRA elements are integrated into one antenna system, which can be used for multiple-input-multiple-output (MIMO) application. Owing to the use of two different excitation schemes, the dielectric resonators are mounted on two opposite sides of the substrate and are being radiated in two opposite directions to realize pattern diversity compact MIMO system. So, the presented MIMO design is able to diminish the intersecting spatial field components between the antenna elements, which in turn reduce the envelope correlation coefficient and improve the inter-port isolation. The proposed diversity/MIMO antenna can be utilized as a proficient contender in rich multipath environments to overcome the appearances of channel fading. Experimental outcomes convey that the proposed MIMO antenna features overlapping 3-dB axial ratio (AR) band ranging from 5.30 to 5.87 GHz and overlapping 10-dB impedance band ranging from 5.15 to 6.12 GHz with inter-port isolation of greater than 17 dB throughout the usable frequency band.