Ricerc@Sapienza

This chapter deals with the vector network analyzer systems used for the study of the electromagnetic properties of materials. The focus of the chapter is not the device itself, about which plenty of literature is available, but its application in materials characterization at the microwave and millimeter wave levels. Some interesting measurement techniques are presented and discussed in detail with the help of numerous experimental results. Moreover, the measurement criteria are commented on as a function of the materials under test. The waveguide, coaxial air line, Naval Research Laboratory Arch bistatic system, free-space, and reverberation chamber methods are presented and analyzed. Examples of measurements of conventional materials used in architectural building up to advanced foam and nanocomposite materials considered in defense and aerospace applications are presented. The authors have tried to transfer their wide laboratory expertise in this chapter, with the aim to be useful to other researchers in the field of electromagnetic characterization of materials.