Technique to Decompose Near-Field Reflection Data Generated From an Object Consisting of Thin Dielectric Layers

Extracting properties of hidden structures using ultra-wideband (UWB) radar is evolving into a promising technology. For these applications, a short-duration electromagnetic wave is transmitted into an object or structure of interest and the backscattered fields that arise due to dielectric contrasts at interfaces are measured. The time-of-arrival (TOA) between reflections and the amplitude of the reflections may be used to infer the geometrical and dielectric properties of hidden structures or objects. For electrically thin layers, the limited bandwidth of the illuminating signal typically gives rise to overlapping reflections, necessitating the use of high-resolution techniques. We investigate an iterative nonlinear parameter estimation technique that may be used for near-field applications. The effectiveness of the algorithm to decompose the reflection data is evaluated using numerical data generated from 2D and 3D dielectric slabs and experimental data from multi-layered slabs.