Origins of high Q on microwave tungstenbronze-type like Ba6-3xR8+2xTi18O54 (R : rare earth) dielectrics based on the atomic arrangements

Microwave dielectrics are key materials for wireless communications, which have been tremendously developed in ubiquitous age. On the microwave dielectrics, there are three important properties, such as quality factor Q, dielectric constants epsilon(Gamma) and temperature coefficients of resonant frequency tau(f). The utilizable region for the frequency is expanding to higher frequency. Since the dielectric losses increase at higher frequencies, microwave dielectrics with high quality factor Q are of considerable interest. In this paper, we research the origin of high Q for the next generation dielectrics. We summarize the cases with high Q and state the origin of high Q on the tungstenbronze-type like solid solutions, which we have studied. (c) 2006 Elsevier Ltd. All rights reserved.