Near-Field Microwave Microscopy of Materials Properties
  Near-field microwave microscopy has created the opportunity for a new class of electrodynamics experiments of materials. Freed from the constraints of traditional microwave optics, experiments can be carried out at high spatial resolution over a broad frequency range. In addition, the measurements can be done quantitatively so that images of microwave materials properties can be created. We review the five major types of near-field microwave microscopes and discuss our own form of microscopy in detail. Quantitative images of microwave sheet resistance, dielectric constant, and dielectric tunability are presented and discussed. Future prospects for near-field measurements of microwave electrodynamic properties are also presented. 
Steven M. Anlage, D. E. Steinhauer, B. J. Feenstra, C. P. Vlahacos, F.   C. Wellstood