High Directivity in the Narrow Band of Spherical Dielectric Antennas in GHz and THz Ranges

The article presents the results of numerical simulation by the finite element method of a spherical dielectric resonator with a dipole antenna placed inside. The directional properties of this type of antenna in the 2–4 GHz and 0.2–0.35 THz bands are calculated. It is shown that in a narrow band due to high order Mie resonances, the peak directivity of the antenna can reach values of 12.5 dBi with radiation efficiency of 0.9 and a sphere size of the order of 1.2λ. A variant of the antenna for the 0.2–0.35 THz range with its placement on a dielectric substrate is proposed, and the dimensional ratios of the structural elements for the narrowband mode with maximum gain are presented.