Microwave Applications Of High Temperature Superconductivity

High quality high temperature superconducting (HTSC) thin films can have approximately 100 times lower microwave losses at 77K than the best normal metals. Because of this they can be used to fabricate microwave stripline devices and circuits with 100 times higher line-Q than is possible with normal metals. We have fabricated T1/sub 2/Ba/sub 2/CaCu/sub 2/O/sub 8/ superconducting thin films on LaA1O/sub 3/ substrates and measured their surface resistance at 9.55 GHz as a function of temperature and microwave power. In addition, we have fabricated microstrip devices with these films that can perform 100 times better than normal metal circuits at practical power levels in a broad range of microwave applications.