Numerical investigation of a broadband dielectric resonator antenna backed by SIW cavity

In this paper an slot excited cylindrical Dielectric Resonator Antenna (DRA) backed by a substrate integrated waveguide (SIW) cavity is numerically investigated based on Finite Element Method (FEM). It consists of a DRA placed on the conducting back plane of the SIW cavity. A resonator slot is used to couple energy from the cavity to the DRA. By merging two resonant frequencies of the slot and the DR, a wide operating bandwidth is achieved. A parametric study of the slot size, feed line length and dimensions of the DRA on the radiation performance of the antenna is carried out. Results show that the proposed structure exhibits as much as bandwidth of 26% for S₁₁<; -10 dB. Gain of the antenna structure is at least 5 dB over the whole operation band and its radiation efficiency is more than 95%.