Microwave tomography is an active, developing research area. The objective is to visualize hidden, subsurface features through application of microwave radiation. Applications include ground penetrating radars (GPR) , defect spectroscopy in materials, fault detection in construction and manufacturing, and the detection of hidden objects at secure access points. Recently, significant effort has been devoted to microwave tomography for medical applications - and frequency-dependent, mechanical metrology of defects. In spite of this broad effort, microwave tomography at the nanoscale is in its infancy. One significant challenge is that measurements at the nanoscale are done mostly in the near field, as is also the case in GPR and some biological applications, but with the additional requirement that the nanoscale, electromagnetic interaction of microwave radiation with materials must be understood. These unique interactions with nanoscale systems usually differ significantly from corresponding interactions with macroscopic objects. In this chapter, we will discuss basic principles of nanoscale microwave tomography and some initial tomographic measurements with near field scanning probe microscopes.
Measurement Techniques for Radio Frequency Nanoelectronics