High-Q microwave dielectric in the (1-x)MgTiO3-xCa0.6La0.8/3TiO3 ceramic system with a near-zero temperature coefficient of the resonant frequency

The microwave dielectric properties and microstructures of the new (1-x)MgTiO3-xCa(0.6)La(0.8/3)TiO(3) ceramic system, prepared using a mixed oxide route, were investigated. Combination of MgTiO3 (MT) and Ca0.6La0.8/3TiO3 (CLT) forms a two-phase system and leads to a near-zero tau(f). With increasing x, the microwave Q x f decreased and epsilon(r), increased. A microwave dielectric material having a epsilon(r), of 25.45, a Q x f of similar to 82,500 GHz (at 8.5 GHz), and a tau(f) of similar to 0.5 ppm/degrees C can be obtained from the compound 0.85MgTiO(3)-0.15Ca(0.6)La(0.8/3)TiO(3) sintered at 1275 degrees C for 4 It. It is proposed as a candidate material for ISM band components and GPS antennas. (c) 2008 Elsevier B.V. All rights reserved.