Experimental investigation of the scattering of electromagnetic waves from a model random medium of discrete scatterers

摘要

The paper describes a new three-dimensional physical model of a random discrete-scatterer medium and presents the results of an experimental investigation to determine the suitability of the model in studies aimed at the evaluation of approximate scattering theory. In contrast to previous models in which the scatterer statistics were indirectly controlled by a physical process, the present model allows the statistics to be directly controlled as in a Monte Carlo computer simulation. It also permits considerable flexibility in the type of scatterers used. The experimental model investigated consisted of a layered slab region of polystyrene foam (142 × 76 × 27 cm) in which polyethylene spheres of 1.27 cm diameter were embedded at random positions. These positions were generated by computer from a uniform distribution. The medium was scanned by a narrow 35-GHz beam and the randomly varying transmitted field was recorded, sampled, and statistically analyzed. The accuracy of the first and second field moments, determined in experiments on the model with two different average densities of the spherical scatterers, is evaluated.