Millimeter-Wave Spherical Dielectric Resonator Antenna Array

This work presents a new design technique to realize a microstrip resonator fed spherical dielectric resonator antenna (DRA) and
$2\times 2$
array at 36 GHz. The dielectric resonators can be placed on thin planar circuit board or on-chip. Vertical metallic walls around radiators eliminate the otherwise high sidelobes known for the spherical DRA. In the array, the metallic walls also contribute to a reduction of mutual coupling. Simulations, verified by measurements, show significant reduction of sidelobes and mutual coupling, while the impedance bandwidth of the in-phase fed
$2\times 2$
array reduces from 7.3% to 3.5%.