General polynomial chaos‐based expansion finite‐difference time‐domain method for analysing electromagnetic wave propagation in random dispersive media

Abstract A new approach for using polynomial chaos‐based expansion finite‐difference time‐domain (PCE‐FDTD) is presented to calculate the uncertainty of electromagnetic wave propagation in dispersive materials. Based on the bilinear transform method, this approach performs polynomial expansion on random electromagnetic fields by PCE‐FDTD method. The proposed algorithm has a simple formulation and is very easy to extend to isotropic dispersive material. It has a general form for different types of random dispersive materials and can efficiently calculate the mean value and the SD of electromagnetic field components in a single run. Two examples of different dispersive media with two random variables are listed to show the generality of the algorithm, and a radar cross‐section of a perfectly conducting cylinder coated by a layer of random plasma is illustrated as an example to show the practicability of the approach. The results are validated by comparing it with the Monte Carlo method.