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

The microwave dielectric properties of CaNb2O6 ceramics were investigated with a view to their application in mobile communication. The CaNb2O6 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 CaNb2O6 ceramic, sintered at 1,400 A degrees C for 4 h. Dielectric constants (epsilon (r) ) of 13.3-18.1 and quality factor (Q x f) of 12,200-50,000 GHz were obtained at sintering temperatures in the range 1,300-1,500 A degrees C for 4 h. Dielectric constants (epsilon (r) ) of 18.0-18.1 and quality factor (Q x 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 A degrees C. A dielectric constant (epsilon (r) ) of 18.1, a quality factor (Q x f) of 50,000 GHz, and a temperature coefficient of resonant frequency (tau (f) ) of -54 ppm/A degrees C were obtained when CaNb2O6 ceramics were sintered at 1,400 A degrees C for 4 h.