Wideband frequency tunability of CaCu3Ti4O12-based dielectric resonator antennas via the addition of glass

Abstract

In this study, DRAs produced using CaCu3Ti4O12(CCTO) as a high dielectric material (εr) was added with BaO–SrO–Nb2O5–B2O3–SiO2 (BSNBS) glass for possible tunability in a wideband frequency range. BSNBS glass (0.01-1 wt%) was mixed with CCTO powders (calcined) and compacted at 250 MPa into mixed-powder pellets. All the green body samples were then sintered at 1040°C for 10 hours. The wideband frequency tunability, measured using a network analyzer, showed that the addition of ≤0.05 wt% BSNBS glass decreased the resonance frequency from 9.51 to 9.33 GHz; later, the values increased to 9.89 GHz when BSNBS content was > 0.05 wt%. The εr of each sample was around 11-36 when measured at 9.5-11.8 GHz. The radiation pattern of CCTO for each sample that had been set up as a DRA radiated the signal equally or nearly identical to each other. Furthermore, the addition of BSNBS glass produced micrographs with finer grains, improved the density and reduced the porosity of the composite. Therefore, the addition of the BSNBS glass is a successful aid in the wideband frequency tunability of pure CCTO-based ceramics when used as DRAs.