An ultra wideband “ OM ” shaped DRA with a defected ground structure and dual polarization properties for 4G / 5G wireless communications

Abstract

This research article reports a new Dielectric Resonator Antenna (DRA) with its Dielectric resonator (DR) modified to an “OM” shape for UWB (3.1-11.1 GHz), to support high data rate multimedia applications for 4G/5G communications. The proposed DRA reports a peak gain of 7.68 dB and a dual polarization behavior for a frequency band from 6 to 11.1 GHz. It has overall antenna dimensions of 50 × 40 × 4.87 mm3 and is fabricated on a commercially available Rogers RT 5880 substrate (with εr = 2.2), which is fed using a microstrip feedline with a P-type transformer that offers an input impedance of 50 Ω to the DR. A conformal strip between the feedline and the OM shaped DR improves the impedance matching at the UWB frequency response of the DRA. This UWB frequency response is mainly because of its optimized “OM” shaped DR structure that excites a TE111 mode at 4.9 GHz and two higher order modes TE211 and TE221 at resonant frequencies of 7.2 and 8.35 GHz, respectively. Additionally the proposed OM shaped DR also generates orthogonal modes of TE211x and TE211y at 6.5 and 7.2 GHz and TE221x and TE221y at 8.35 and 10 GHz, respectively. The proposed DRA therefore exhibits an elliptically polarized behavior with axial ratio bandwidth of 5.1 GHz (≤10 dB) from 6 to 11.1 GHz. A measured impedance bandwidth of 5.25 GHz from 3.8 to 9.05 GHz and 1.5 GHz from 10 to 11.5 GHz and a peak-measured gain of 7.68 dB at 10.5 GHz (with an average gain of 4.6 dB) has been reported for the proposed DRA. An UWB performance, with good gain properties and an elliptically polarized behavior allows the proposed “OM” shaped DRA to be suitable for short range 4G/5G UWB wireless communications for future multimedia rich WPAN (wireless personal area networks), WLAN, Wi-MAX, INSAT applications, satellite applications, and X band RADAR (for defense communication) applications.