Dielectric measurements by time domain reflectometry
Robert H. Cole · 1975
Transient or “time domain” methods have become of considerable interest in the last few years because of the availability of fast pulse generators and sampling oscilloscopes permitting measurements in the range 10−11to 10−7seconds, corresponding to frequencies from a few megahertz to a few gigahertz. The voltage pulse reflected from a dielectric sample in a coaxial line after arrival of an incident pulse with short rise time (ca. 40 psec) resembles the dielectric current response to a step voltage, but is distorted by effects of finite amplitude of the reflected pulse, propagation in the sample, and the sample termination, all of which must be taken into account in a proper analysis.