Annular Column Loaded Cylindrical Dielectric Resonator Antenna for Wideband Conical Radiation

A wideband cylindrical dielectric resonator antenna (CDRA)-loaded with an annular column, namely the LCDRA, is proposed and analyzed. The antenna comprises two components-an inner cylindrical dielectric and a loaded concentric column dielectric. The proposed antenna is centrally fed by a coaxial probe, and has a low profile of 0.175 λ₀ (λ₀ is the wavelength of the center frequency). Four conical radiation pattern modes (TM_01δ, TM_02δ, TM_03δ, and TM_04δ modes) are excited and merged, providing an impedance bandwidth of 56% (3.14-5.56 GHz). A prototype of the proposed antenna is built and tested. Good agreement between the simulated and measured results, including the reflection coefficient and radiation patterns, is achieved.