High-Gain Dual-Band Waveguide-Fed Dielectric Resonator Antenna

A distinctive configuration of rectangular waveguide-fed hemispherical dielectric resonator antenna (HDRA) for high-gain dual-band operation is described in this letter. A cylindrical-shaped hard rubber with a circular slot and
$\epsilon_r = 3$
is inserted between HDRA and ground plane to achieve dual-band, excellent coupling, enhanced bandwidth, and high gain. The structure of the antenna is very simple to fabricate. Measured results show that the proposed antenna radiates in two bands with resonant frequencies 7.65 and 10.04 GHz. The first band provides a bandwidth of 4.98% and a high gain of 11.72 dBi with a broadside radiation pattern. The second band enables wideband operation with an impedance bandwidth of 12.68% and a gain of 11.5 dBi. The structure attains high coupling efficiency in both bands.