Microwave Properties of Low‐Temperature Co‐Fired Ceramic Systems

Co-fired, patterned multi-layer ceramic structures permit the design of compact, dense microwave circuits, components and devices spanning the frequency range from 800 MHz to 77 GHz. Critical parameters affecting the performance of these low-temperature co-fired ceramic (LTCC) systems, are the dielectric properties of the co-fired ceramic and the metal loss occurring-in the patterned circuit. These parameters have different frequency and temperature dependence, and therefore their contributions to total insertion loss change as a function of application frequency and temperature. The contributions to microstrip attenuation loss of each of these critical parameters are analyzed at 10 GHz. Various dielectric resonator methods are used for accurate determinations of the substrate intrinsic dielectric, properties and the metal surface resistance. These data were used to evaluate individual contributing factors of attenuation loss. The total computed attenuation loss compared well with that measured with a microstrip ring resonator. This characterization aids the optimal development of multi-layer electronic circuits for the application frequency. It also provides the material scientist with the necessary focus on important dielectric, metallization, and fabrication processing issues encountered in the development of high-performance LTCC high-frequency application packages..