3D-printed Wideband Rectangular Dielectric Resonator Antenna

A 3D-printed wideband rectangular dielectric resonator antenna (DRA) with omnidirectional radiation patterns is investigated. It is a multilayered design with four concentric square dielectric rings, which have progressively decreased effective dielectric constants in the azimuthal direction. To facilitate the 3D printing, a unit cubic cell that can be easily adjusted to provide different effective dielectric constants is used in our design. Three quasi transverse magnetic (TM) modes (quasi-TM01δ, quasi-TM02δ, and quasi-TM03δ) of the DRA are simultaneously excited by a centrally penetrated coaxial probe. By merging these quasi-TM modes together, the DRA with a wide impedance bandwidth is obtained. For demonstration, a prototype working in C-band is designed and printed. Measured results show that our design has a wide 10 dB impedance bandwidth of 44.8% (5.20-8.20 GHz), fully covering the current 5.8 GHz WLAN band (5.725-5.875 GHz). Also, fairly stable radiation patterns can be observed across the impedance passband (5.20-8.20 GHz).