A Dielectric Resonator Antenna With Enhanced Gain Bandwidth

This communication presents a wideband dielectric resonator antenna (DRA) with a stable gain in-band. Four modes are excited in the DRA, including the fundamental mode T-E111(y) and higher order modes T-E113(y), T-E122(z), and T-E115(y), which are combined to provide a wide impedance bandwidth. However, this combination of modes introduces severe gain drops at specific frequencies, resulting in a fluctuating gain across the wide impedance bandwidth. To improve the gain bandwidth, the electric filed distributions at these specific frequencies are analyzed and reconstructed using the proposed approaches. For demonstration, a practical prototype of the proposed antenna is fabricated and measured. Reasonable agreement between the measured and simulated results is observed. The prototype exhibits a wide measured 10-dB impedance bandwidth of 64.6% (5.85-11.48 GHz) and a 1-dB gain bandwidth of 57.5% (6.35-11.48 GHz), with stable broadside radiation patterns in-band. Additionally, the maximum gain can reach 7.2 dBi.