This Small Business Innovation Research Phase I Project will address the synthesis and processing of ceramic materials for microwave dielectric resonators used in mobile telephones and other telecommunications applications. Mission Research Corporation (MRC) proposes to conduct research on a new family of bismuth-based dielectric materials, with potential for reducing the size of ceramic resonators while improving resonator performance. These new dielectric ceramics also can be sintered at low temperature, thus allowing low-cost multilayer device fabrication and eventual integration into co-fired microwave integrated circuitry. In previous research, MRC identified a family of bismuth-based ceramic compositions that offer high permittivity, low microwave dielectric loss, and temperature-compensation of the resonant frequency. These properties are desired for the dielectric resonators used in mobile telephones. The primary objective of this Phase I project is to establish compositions and processing methods that provide low microwave dielectric loss in high-permittivity and temperature-stable dielectric ceramics. In this project, several ceramic compositions will be prepared and evaluated. The effects of composition and ceramic processing on the crystal chemistry, dielectric properties, and microwave dielectric loss of these ceramics will be determined. At the conclusion of this Phase I project, the feasibility of using these new dielectric ceramics in microwave dielectric resonator devices will be established. The Phase I research will provide a basis for further compositional and processing optimization and prototype resonator fabrication in Phase II.
