x(Mg0.7Zn0.3)0.95Co0.05TiO3-(1-x)(La0.5Na0.5)TiO3 ceramic at microwave frequency with a near zero temperature coefficient of resonant frequency

Dielectric properties of x(Mg0.7Zn0.3)(0.95)Co0.05TiO3-(1-x)(La0.5Na0.5)TiO3 ceramic were investigated at microwave frequencies. A nearly 0 ppm/degrees C temperature coefficient of resonant frequency was realized at x = 0.9. A two-phase system was confirmed by XRD analysis. A dielectric material applicable to microwave devices with a Q x f of 20,000-87,000 GHz and a dielectric constant of 21.27-26.2 was obtained at 1100 degrees C after 4 h of sintering. The microwave dielectric material 0.9(Mg0.7Zn0.3)(0.95)Co0.05TiO3-0.1 (La0.5Na0.5)TiO3 sintered at 1150 degrees C for 4 h has a dielectric constant of 24.56, a Q x f of 68,000 GHz, and a tau(f) value of 0 ppm/degrees C. It is proposed as a candidate dielectric for GPS patch antennas. (C) 2009 Elsevier B.V. All rights reserved.