nonstationary electromagnetic field
time-domain and frequency-domain integral equations
Diffraction of a nonstationary electromagnetic field is simulated with the use of time- and frequency-domain approaches based on time-domain integro-differential equations and frequency-domain integral equations, respectively, for the current flowing over the surface of a scatterer.
The numerical methods developed and comprehensively described in the author’s and her colleagues’ previous studies are applied to calculate currents induced on the surface of different bodies and scattered fields in the far zone. It is assumed that the incident field is the field of a plane wave and the considered scatterers are bodies of revolution located in a homogeneous lossless medium. Solution of time-domain integro-differential equations is an effective tool in the case when it is necessary to investigate diffraction of a video pulse by different bodies. Solution of frequency-domain integral equations is more suitable for the analysis of scattering of different pulses by the same body. The applicability of the aforementioned two approaches is demonstrated via simulation of scattering of different pulses by certain bodies of revolution. Thus, the time-domain approach is used to calculate the currents induced on the surface of a finite circular perfectly conducting cylinder illuminated by a Gaussian video pulse propagating perpendicularly to the axis of symmetry. The frequency-domain approach is used to analyze the responses of such a cylinder to radio and video pulses. In addition, the frequency-domain approach is applied to investigate the mechanisms of diffraction of a Gaussian video pulse by a perfectly conducting cone covered by a dielectric layer.