High Q Dielectric Titanium Tellurite Thick Films on Alumina Substrates for High Frequency Telecommunications

The vital role of high-quality-factor (Q) high-frequency (f) dielectric resonators in the growing microwave telecommunication, satellite broadcasting and intelligent transport systems has long motivated the search for new, small size, and lightweight integrated components and packages, prepared by low cost and sustainable processes. One approach is replacing the currently used bulk ceramic dielectrics by thick films of low-sintering-temperature dielectrics fabricated by affordable processes. Here we demonstrate the fabrication of high-Q TiTe₃O₈ thick films directly on low loss Al₂O₃ substrates by electrophoretic deposition using sacrificial carbon layer. Nineteen-micrometre-thick TiTe₃O₈ films on Al₂O₃ sintered at 700 °C are found to have a relative permittivity ε_r of 32 and Q × f > 21,000 GHz. Being thus able to measure and provide for the first time the microwave dielectric properties of these films, our results suggest that TiTe₃O₈ films on Al₂O₃ substrates are suitable for microlayer microstrip array applications.