Electromagnetic fields and the quasistationary approximation near amoving mirror

A detailed study of the electromagnetic fields generated by illuminating a plane mirror, in inertial motion, by a plane wave is described. A new and complete power series is obtained for the fields, and convergence conditions depending on the distance between the mirror and an observer are established. This series is shown to converge in bandpass systems provided the distance between the mirror and the observer is limited. The power series provides simple expressions for assessing the validity of quasi-stationary (QS) field approximations near the mirror. An example confirms that, with the exception of the immediate vicinity of wavefronts, QS approximations are valid under conditions arising in practical urban radio systems