Hemispherical Dielectric Resonator Antenna Based on Apollonian Gasket of Circles-A Fractal Approach

A novel, compact hemispherical dielectric resonator antenna based on Apollonian Gasket of circles is proposed. The Apollonian Gasket is a fractal generated from triplets of circles, where each circle is a tangent to the other two. The dielectric material used is Rogers TMM 10, which is a ceramic thermoset polymer composite material having a dielectric constant of epsilon(r) = 9.2. The fractal geometry offers a wide impedance bandwidth of around 1.68 GHz (47%) for S-11 < -10 dB at a resonant frequency of 3.6 GHz. Experiments have been conducted up to the third iteration of fractal. Two modes have also been investigated which show presence of both TM101 like and TE111 like modes. For TM101 like mode, the antenna radiates with a gain of around 6.5 dBi whereas for TE111 like mode, the antenna radiates in the broadside direction with a high gain of 8.5 dBi.