Dielectric materials for applications in microwave communications

Dielectric ceramic materials have been studied for decades due to both thei r application in important technologies and the fundamentally interesting r elationships among their crystal chemistry, crystal structures, and physica l properties. Recent dramatic changes in microelectronics and in particular wireless communications technologies have made the importance of materials with the unusual combination of high dielectric constant, low dielectric l oss and low temperature dependence of dielectric constant of great interest . In this review, the present state of knowledge of the chemistry, structur e, and dielectric properties of these materials, as well as examples of our own work, are described.