For at least eight of the first ten years of high-temperature supercon
ductivity it has been clear that one of the earliest areas of applicat
ion and commercialization of these materials is as passive devices for
microwave electronics. At the time of writing the first prototype pro
ducts are entering service in the mobile communications industry and a
wide range of other devices are at a relatively advanced stage of dev
elopment. in the further future one can see a cryogenic integrated tec
hnology based on HTS materials and the related functional materials wh
ich have emerged within the last ten years.