Bandwidth Enhancement of a DRA Based on Characteristic Modes Analysis

This work investigates the improvement of the radiation bandwidth of a dielectric resonator antenna (DRA) by integrating an air cone into its structure. Using Characteristic Mode Analysis (CMA), it is demonstrated that the introduction of the air cone modifies the radiation of secondary modes and consequently broadens the bandwidth of the dominant mode. Simulation results show that the realized gain bandwidth improves from 30% to 36%, leading to a more stable gain in the operating frequency range and a noticeable reduction in the level of the higher-order mode.