Enhancing Gain Performance of Dielectric Resonator Antenna via Director Embedding Without Size or Weight Increase

This comunication presents a novel technique to enhance the gain performance of a dielectric resonator (DR) antenna (DRA) operating in its fundamental radiation mode without increasing the antenna size or weight by embedding an M-dipole or ME-dipole director within the DRA. A U-shaped groove, forming the embedded M-dipole director, is carved on the rectangular DR’s top surface and coated with an adhesive metallic copper layer, achieving smaller size and minimal weight compared to bulky metal plate directors. The peak gain of the rectangular DRA with the embedded M-dipole director reaches 9.68 dBi, more than 3 dB higher than a reference DRA of the same size, and slightly exceeds a binary array of the reference DRAs. For wideband and stable gain characteristics, a rectangular DRA embedded with an ME-dipole director is also designed, exhibiting an impedance bandwidth of 30.5% and a 1 dB gain bandwidth of 24.9%. It has a simulated average gain of 7.93 dBi which is a 2.3 dB improvement over a reference DRA of the same size. Both designs were fabricated and measured, validating the effectiveness of the proposed director embedding technique in enhancing DRA gain without increasing size or weight.