Strip-fed shaped dielectric resonator antenna for improved radiation characteristics through mode filtering

A shaped cylindrical dielectric resonator antenna (CDRA) has been investigated for the first time with a view to improving its radiation characteristics. The CDRA is fed by a microstrip line. The shaping is done by introducing a central hole protruded through the bottom of the DRA. This helps in mode filtering and thus by reducing cross-polarized fields without causing any deterioration in the principal plane radiations. Isolation between co-to-cross-polarized fields increases from 26 dB (for conventional geometry) to 42 dB (for proposed configuration) using a commercially available material with ε_r = 10.