Wideband simple cylindrical dielectric resonator antennas

Abstract

Bandwidths of the coaxial fed and aperture coupled cylindrical dielectric resonator antennas (DRAs) with broadside radiation patterns are enhanced by exciting the HEM/sub 11/spl Delta// (1</spl Delta/<2) mode at a frequency close to the HEM/sub 11/spl delta// (0</spl delta/<1) mode. Both HEM/sub 11/spl delta// and HEM/sub 11/spl Delta// modes have similar broadside radiation patterns. Measured impedance bandwidths as much as 26.8% (S/sub 11/<-10 dB) are achieved for the coaxial fed DRA and 23.7% for the aperture coupled DRA. These bandwidths are comparable to those obtained using stacked DRAs. The resonant frequency of the HEM/sub 11/spl Delta// mode can be adjusted by the radius (r) to height (h) ratio of the cylindrical DRA. A wide bandwidth is obtained when this ratio equals to 0.329.