Simple estimation of relative permittivity of wall by UWB radar system

This paper describes a simple method for the relative permittivity estimation of the wall by an UWB (ultra wideband) impulse radar system. It is non-invasive reflected free space method for data gathering just from the single side of the wall. There is just one condition also by which we can achieve the best possible accuracy. It is a short time window of monitored signal, while there is an undesired reflection from the other side of the wall. Frequency dependence of the relative permittivity is then obtained from the reflection coefficient of the transmitted TEM (transverse electromagnetic) wave. The paper describes two demonstrative measurements and verification of the measured data by the transmission method.