ABSTRACT This work investigates improving dielectric resonator antenna (DRA) radiation bandwidth through the integration of linearly graded permittivity profiles. Using Characteristic mode analysis (CMA), it is shown that such profiles broaden modal distribution, consequently extending the bandwidth of the dominant resonant mode. The proposed antenna design is enabled by additive manufacturing techniques, which allow precise control over material composition and geometry. Experimental results show a significant improvement in both modal and impedance bandwidth from 9.1% to 24,1%, leading to a more stable gain greater than 5 dBi across the operating frequency range.This study enhances the bandwidth of (DRAs by introducing a linearly graded permittivity profile. CMA reveals that this approach broadens the modal distribution and extends the dominant resonant mode bandwidth. Enabled by additive manufacturing for precise material and geometric control, the antenna achieves a bandwidth increase from 9.1% to 24.1% with a stable gain above 5 dBi.
Ammar et al. (Thu,) studied this question.