Effect of sintering temperature and time on microwave dielectric properties of CaNb2O6 ceramics

The microwave dielectric properties of CaNb 2 O 6 ceramics were investigated with a view to their application in mobile communication. The CaNb 2 O 6 ceramics were prepared by the conventional solid-state method with various sintering temperatures and sintering times. A maximum density of 4.67 g/cm 3 was obtained for CaNb 2 O 6 ceramic, sintered at 1,400 °C for 4 h. Dielectric constants ( ε r ) of 13.3–18.1 and quality factor ( Q × f ) of 12,200–50,000 GHz were obtained at sintering temperatures in the range 1,300–1,500 °C for 4 h. Dielectric constants ( ε r ) of 18.0–18.1 and quality factor ( Q × f ) of 44,300–50,000 GHz were obtained for sintering times in the range 2–6 h at a sintering temperature of 1,400 °C. A dielectric constant ( ε r ) of 18.1, a quality factor ( Q × f ) of 50,000 GHz, and a temperature coefficient of resonant frequency ( τ f ) of −54 ppm/°C were obtained when CaNb 2 O 6 ceramics were sintered at 1,400 °C for 4 h.