Wideband simple cylindrical dielectric resonator antennas

Bandwidths of the coaxial fed and aperture coupled cylindrical dielectric resonator antennas (DRAs) with broadside radiation patterns are enhanced by exciting the HEM_11Δ (1<Δ<2) mode at a frequency close to the HEM_11δ (0<δ<1) mode. Both HEM_11δ and HEM_11Δ modes have similar broadside radiation patterns. Measured impedance bandwidths as much as 26.8% (S₁₁<-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_11Δ 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.