On the Two Segmented and High Aspect Ratio Rectangular Dielectric Resonator Antennas for Bandwidth Enhancement and Miniaturization

The goal of this communication is to maintain wide impedance bandwidth while miniaturizing a microstrip-fed dielectric resonator antenna (DRA). The approach of using high aspect ratio structures is proposed, discussed, and compared with the two segmented structures approach. Finite element method parametric study of high permittivity high aspect ratio structures is used to demonstrate how two appropriate resonant modes can be merged to obtain miniaturized antennas with broadband operation, stable radiation patterns, and low cross polarization levels. To show the effectiveness of the approach, a set of microstrip-fed two segmented and high aspect ratio DRAs is fabricated, characterized, and the results are compared with Ansoft HFSS simulations. A high aspect ratio DRA with cross section as small as 0.08lambda by 0.12lambda has better than 11 percent bandwidth and is especially attractive for compact array applications.