Low Power Superconducting Microwave Applications and Microwave   Microscopy
  We briefly review some non-accelerator high-frequency applications of superconductors. These include the use of high-Tc superconductors in front-end band-pass filters in cellular telephone base stations, the High Temperature Superconductor Space Experiment, and high-speed digital electronics. We also present an overview of our work on a novel form of near-field scanning microscopy at microwave frequencies. This form of microscopy can be used to investigate the microwave properties of metals and dielectrics on length scales as small as 1 mm. With this microscope we have demonstrated quantitative imaging of sheet resistance and topography at microwave frequencies. An examination of the local microwave response of the surface of a heat-treated bulk Nb sample is also presented. 
Steven M. Anlage, C. P. Vlahacos, D. E. Steinhauer, S. K. Dutta, B. J.   Feenstra, A. Thanawalla and F. C. Wellstood