Dielectric Study in the Microwave Range for Ceramic Composites Based on Sr^sub 2^CoNbO^sub 6^ and TiO2 Mixtures

In this work, we fabricated ceramic composites based on the composite matrix Sr2CoNbO6 (SCNO)-TiO2. The SCNO was synthesized by solid-state reaction, and x-ray diffraction was used for the structural characterization of this synthesis. We measured the dielectric properties in the microwave range by using the Hakki-Coleman method, as well as the thermal stability of these composites in this frequency range. We inserted TiO2 in an SCNO ceramic matrix in order to improve the thermal stability of SCNO. The cylindrical dielectric resonators were fabricated using concentrations of 5 wt.%, 10 wt.%, 20 wt.%, 40 wt.%, 60 wt.%, and 80 wt.%. The insertion of TiO2 improved the thermal stability, dielectric loss, and permittivity of the SCNO-based ceramic. These ceramic composites were evaluated as dielectric resonator antenna, and the performance of these materials presented a reflection coefficient below -10 dB, gain above 2.5 dBi, and efficiency above 60%.