ACCURATE ANALYSES OF THE ON-AXIS FIELDS OF A CIRCULAR DISK BY TRANSIENT AND HARMONIC EXCITATION

The computation of near zone fields is very important in many practica l applications. Accurate analyses of the on-axis fields of a circular disk by transient and harmonic excitation show that there is an energy uprising zone on the axis rather than a non-decaying one, provided th at the disk is excited by a rectangular pulse, the duration of which i s less than the ratio of the radius to the light velocity, Similar res ults corresponding to the time-harmonic excitation are also given, whi ch are quite different from the conclusions derived by Silver.