(1-x)CaTiO3-x(Li0.5Nd0.5)TiO3 for ultra-small dielectrically loaded antennas

Microwave (MW) dielectric ceramics based on the solid solution (1 - x)CaTiO3-x(Li0.5Nd0.5)TiO3 (0.25 a parts per thousand currency sign x a parts per thousand currency sign 1.0) were prepared by conventional solid-state synthesis using the mixed oxide route. Compositions closest to zero tau(f) (+65 ppm/A degrees C) were obtained at x = 0.8 where epsilon(r) = 110 and the microwave quality factor, Qf (0) a parts per thousand... 2600 GHz for samples sintered at 1300 A degrees C. To reduce the sintering temperature and compensate for any Li2O loss during fabrication, a parts per thousand currency sign0.5 wt% 0.5Li(2)O-0.5B(2)O(3) was added as a sintering aid in the form of raw oxides (LBR) and also as a pre-reacted glass (LBG). 0.5 wt% LBR was the most effective, reducing the temperature to achieve optimum density by similar to 50 A degrees C with no significant deterioration of microwave properties (epsilon(r) = 115, tau(f) = +65 ppm/A degrees C and Qf (0) a parts per thousand... 2500 GHz). The high permittivity and relatively low sintering temperatures (1250 A degrees C) are ideal for the development of low cost ultra-small dielectric loaded antenna, assuming the system can be tuned closer to zero by fractionally increasing x.