Characterization of layered dielectrics with short electromagnetic pulses

The use of picosecond duration bursts of electromagnetic radiation to study short-pulse wave propagation in layered dieletric materials is discussed. The radiation is generated using planar antennas that are switched photoconductively. The measurements are compared with time- and frequency-domain theoretical data. Issues associated with the windowing of time-domain results for highly resonant structures are addressed, as well as how the derived frequency domain data are influenced by the windowed Fourier transform. The accuracy of the time-domain results suggest that this technique may be a useful tool for characterizing layered materials.>