A GHz-band ceramic multi-layer substrate and its application to a hybrid IC

A novel ceramic multilayer substrate for mobile communication using alumina-glass composite ceramics and cofired copper conductors is presented. Electrical characteristics at gigahertz frequencies of the substrate, copper conductor, transmission line, and via hole were evaluated. Hybrid integrated circuits such as an antenna switch were demonstrated using the substrate. The results showed that the ceramic multilayer substrate has electrical characteristics sufficiently good for gigahertz-band applications. Using the substrates, one can greatly reduce the size of RF circuit boards for mobile communication equipment. An RF antenna switch circuit for mobile portable telephones operating at 1.5 GHz has been demonstrated.<<ETX>>