3D Printable Inhomogeneous Dielectric Resonator Antenna with Cardioid Shaped Pattern

This paper presents the design and simulation of rectangular dielectric resonator antennas (DRAs) that radiate linear polarization with a cardioid-shaped pattern at 2.45 GHz, without the use of a ground plane. The antenna structure allows the balanced excitation of TE and quasi- TM modes by coaxial probe feeding, resulting in orthogonal electric and magnetic dipo-lar contributions. Material inhomogeneity is introduced within the scope of additive manufactory possibilities, by the means of separate regions with homogeneous permittivity, in order to control resonant frequencies and quality factors of modes in spectral proximity. The proposed DRAs are numerically analyzed with eigenmode and far-field simulations using Ansys HFSS. The inhomogeneous DRA achieves a maximum gain of 5.2 dBi at the operating frequency and a 5% operational bandwidth (OBW).