Bandwidth control of cylindrical ring dielectric resonator antennas using metallic cap and sleeve loading

Abstract

This study investigates the effect of loading a monopole‐fed cylindrical ring dielectric resonator antenna using a metallic cap and metallic sleeve on its top and outer surface, respectively. The proposed design exhibits a considerable shift of its upper cut‐off frequency (from 13.8 to 20.5 GHz for top loading and 8.2 to 15.9 GHz for outer‐surface loading) with varying inner radii (height) of the metallic cap (sleeve), thereby providing the bandwidth (BW) controllability. Fabricated prototypes were measured and compared with simulations and good agreement was obtained. The measured return loss exhibits the desired BW control without affecting the peak gain and radiation pattern of the antenna, which is also confirmed by the measured radiation patterns. The proposed concept can be used to reconfigure the BW of the antenna according to the user's requirements and improve signal‐to‐noise ratio by rejecting unwanted frequency bands without employing any additional filter section.

Alternative Surface Integral Equation-Based Characteristic Mode Formulations for Composite Metallic-Dielectric Objects

“…The top and the cross-sectional view of the DRA are displayed in Fig. 1a in [27]. The parameters of the antenna configurations refer to Section II and Table 1 in [27].…”

“…1a in [27]. The parameters of the antenna configurations refer to Section II and Table 1 in [27]. The inner radius R i = 2 mm is selected, i.e., cap 4 in [27].…”

Tri-band and quad-band dual L-slot coupled circularly polarized dielectric resonator antennas

“…Four different aperture configurations presented in Figure 2a-d are studied for the surface current distribution and S 11…”

“…A CDRA embedded with the ring DRA excited by slot‐coupling to get over 50% of impedance bandwidth . The effect of loading metallic cap and sleeve on top and outer surface of CDRA respectively is addressed for bandwidth controllability . Asymmetric CDRAs are slot coupled to get enhanced gain over a wideband .…”

“…10 The effect of loading metallic cap and sleeve on top and outer surface of CDRA respectively is addressed for bandwidth controllability. 11 Asymmetric CDRAs are slot coupled to get enhanced gain over a wideband. 12 A physically realizable feed for improved version of CDRA for dual-band, dual-mode with broadside radiation and wide bandwidth is proposed.…”