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 HEM11 Delta (1 < Delta < 2) mode at a frequency close to the HEM11 delta (0 < delta < 1) mode. Both HEM11 delta and HEM11 Delta modes have similar broadside radiation patterns. Measured impedance bandwidths as much as 26.8% (S-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 HEM11 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.