A novel half space time-domain measurement technique for one-dimensional microwave imaging

In this paper, the moisture content for cement based materials having different water to cement (w/c) ratios is measured using the microwave free space technique. The overall process is non-destructive and employs the time-domain measurement data. The measurement system consists of a vector network analyzer, a wide-band lens horn antenna, cement based material of having different water to cement (w/c) ratio and associated microwave components. The main focus here is to determine the permittivity, the effective conductivity and the thickness of test specimens under the situation, where only reflection measurements can be carried out due to the restricted access of the object from the other side. It is observed that the effective conductivity is directly proportional with the moisture content or the w/c ratios of these test samples.