Excitation of Dielectric Resonator Antennas by Loop Coupling

A loop-based excitation scheme for dielectric resonator antennas is presented. The proposed structure consists of a loop-shaped probe terminated in a short circuit. In this feeding technique, the magnetic field induced by the current loop excites the radiator of the antenna by means of electromagnetic coupling. The loop-coupling method is advantageous for the excitation of the TM 01δ mode in cylindrical dielectric resonator antennas since it does not require drilling the dielectric resonator, is suitable for antennas with radiator on a ground plane, and works for a variety of dielectric constants and aspect ratios for the dielectric resonator. The close agreement between measured and simulated results validates this feeding mechanism experimentally.