Wide-Beam Dielectric Resonator Antennas Based on the Fusion of Higher-Order Modes

Geometry-induced resonant modes with intrinsic broad beam coverage are synthesized within step-shaped dielectric resonator antennas (DRAs). Following the idea of mode fusion, a synthesized mode inherits and combines the modal features from several conventional ones of regular DRAs. Superior flexibility and design freedom in beam shaping are thus obtained, leading to a 3 dB beamwidth exceeding 200° in both main planes. To form such a broad-beam mode, three regular higher-order modes from rectangular DRAs are chosen and merged. Their modal radiation patterns have fine complementation, meanwhile, they are readily excited by a shared feed. To further demonstrate the mechanism of mode fusion, the modal field distribution of the presented DRAs is analyzed. A design guide is presented as well.