In this work, composites based on the ceramic matrix Ba2CoNbO6 (BCNO)(1-x) - CaTiO3(CTO)(x) were fabricated using the solid-state reaction method. X-ray diffraction and scanning electron microscopy were used for structural and morphological characterization of the material. The dielectric properties of the composites in the microwave and radio frequency ranges were analysed, as well as the temperature dependence, using the Hakki-Coleman and Silva-Fernandes-Sombra methods for microwave analysis and complex impedance spectroscopy for radio frequency analysis. A cylindrical resonator was fabricated from a mixture of Ba2CoNbO6 and CTO using 0, 5, 12, 20 and 37 wt. % of CTO and sintering of these composites. CTO insertion improved the thermal stability of the material and showed interesting results in the radio and microwave frequency ranges. Tests of the samples operating as an antenna were performed and showed that all samples were operating in the range of 3-5 GHz.