Small Size Radially Embedded Probe-Fed Dielectric Resonator Antenna for Ultra-Wideband Applications

Radially embedded probe-fed circular disc dielectric resonator antenna (DRA) for ultrawideband applications is investigated. Initially, a single-layer probe fed DRA is developed. The probe length is adjusted to optimize S11 performance. For a probe length of 10 mm, a measured −10 dB bandwidth of 47.8% (4.75–7.74 GHz) is obtained. The design is modified with two concentric rings of different dielectric materials with a hollow center. The modified configuration improves the matching from an S11 value of −18 dB at 5.23 GHz to −24.2 dB at 4.56 GHz. However, the measured −10 dB bandwidth reduces to some extent to 38.4% (4.2–6.2 GHz). In another modified design, an air gap is introduced between two inner discs of Alumina supported by a solid outer ring of Teflon. The radially embedded feeding probe, therefore, protrudes into the circular air pocket sandwiched between the two Alumina discs. An improved measured bandwidth of 55.9% (6.66–11.83 GHz) is obtained. Measured S11 of −24.1 dB is similar to that obtained for the concentric ring design but at a higher frequency of 9 GHz. All three antenna designs feature a reduced size with a volume of approximately 1963.5 mm3, wider bandwidth, and consistent radiation patterns over the operating frequency band. It makes the proposed designs suitable for ultra-wideband (UWB) applications. © 2024, Electromagnetics Academy. All rights reserved.