TRANSIENT CURRENT ON A WIRE PENETRATING A CAVITY-BACKED CIRCULAR APERTURE IN AN INFINITE SCREEN

The problem considered is that of a wire penetrating a circular aperture in an infinite conducting screen and entering a circular cylindrical cavity. Results for the transient current propagating along the wire both inside and outside the cavity are presented. The current in both regions is evaluated in the frequency domain by the method of moments (MOM). An approximate method for evaluating the exterior current at an observation point far from the aperture is also discussed. To obtain the transient response, a numerical inverse Fourier transform is used. The current response is examined as a function of cavity and aperture dimensions. Results obtained with the approximate method are compared with the MOM solution. It appears that information concerning the interior cavity dimensions is present in these exterior observations. © 1990 IEEE