Ricerc@Sapienza

The electromagnetic (EM) absorbing cross section (ACS) of carbon foams in the mm-wave frequency range 50–70 GHz is analyzed by means of a reverberation chamber (RC) set-up. Carbon foams are lightweight cellular materials which are believed to provide benefits in EM interference/compatibility (EMI/EMC) issues, due to their significant thermo-mechanical and electrical properties. With respect to usually employed microwave test set-up, the range of frequency investigated allows to analyze the details of the foam bulk structure using shorter wavelengths.

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.