Design and Analysis of the Coaxial-fed Cavity-backed Annular Slot Antenna

This article presents the design and analysis of a coaxial-fed cavity-backed slot antenna. The use of a parasitic annular slot for the annular-slot-excited dielectric resonator antenna (DRA) with a backing cavity is theoretically studied. Based on the finite element methods (FEM), the VSWR, input impedance, radiation characteristics and the parameters of the antenna were analyzed. The numerical calculations emphasize narrow slots and shallow cavities. Resonance frequency, bandwidths, and radiation patterns were studied with respect to a slot width, a cavity depth and the coaxial-fed position. By optimizing the parameters of the antenna, circular polarization and the bandwidth arranged from 250 MHz to 400 MHz with VSWR5.0 were obtained.