Wideband Circularly Polarized Rectangular Dielectric Resonator Antenna Using Inverted U-shaped Ground Plane for Sub 6GHz and Upper Mid-bands 5G Applications

In this paper, a wideband circularly polarized (CP) rectangular dielectric resonator antenna (RDRA) supported by an inverted U-shaped ground plane has been proposed for Sub 6 GHz and upper mid-bands 5G applications. The proposed RDRA comprises of printed inverted U-shaped ground plane on the bottom side and feeding strip on the top side where the rectangular dielectric resonator was placed. The proposed antenna configuration is able to excite orthogonal degenerate mode, i.e.,
$TE_{11\delta}$
, which is responsible for getting a CP fields. The proposed CP RDRA operates for sub 6 GHz and upper mid-bands 5G having wide -10 dB impedance bandwidth
$(S_{11})$
of approximately 28.77% (2.95 GHz-3.94 GHz) and wide 3 dB axial ratio bandwidth of approximately 28.41% (3.20 GHz-4.26 GHz) in broadside direction, respectively. Hence, it shows the wideband CP overlapping bandwidth of 20.72% in
$\theta=0^{\circ}$
and
$\phi=0^{\circ}$
. The presented CP RDRA exhibits simulated maximum total gain of 4.40 dBic and radiation efficiency of 95.47% respectively in
$\theta=0^{\circ}$
and
$\phi=0^{\circ}$
. The proposed radiator is a bidirectional having LHCP field in +
$Z$
-direction whereas RHCP field in -Z-direction for the same resonance frequency, which is verified by the CP radiation patterns. Therefore, the proposed CP RDRA is useful for Sub 6 GHz and upper mid-bands 5G applications.