Passive microwave devices and high-T/sub c/ superconductors

At STI, fabrication of high-T/sub c/ thin films with low losses in under process at microwave frequencies - up to 20 times lower than copper at 10 gigahertz (GHz) at 77K. These films offer microwave design engineers an important new tool for improving system performance. Initially, they are concentrating on components where the payoff is high and the technical challenge is relatively easy: passive microwave devices. A passive microwave device derives its usefulness solely from its geometrical shape and its high-frequency electrical transport properties. In this article, the author describes three passive microwave devices and explain how high-T/sub c/ superconductors promise to improve their performance. The author will start by discussing microwave technology in general terms.