Electromagnetic radiation in a time-varying background medium
Abstract
Analytical solutions are presented for the electromagnetic radiation by an arbitrary pulsed source into a homogeneous time-varying background medium. In the constant-impedance case an explicit radiation formula is obtained for the synchronous permittivity and permeability described by any positive function of time. As might be expected, such a medium introduces significant spectral shifts and spatio-temporal modulation, which are analized here for the linear and exponential time-variations of the medium parameters. In the varying-impedance case the solution is obtained for the fourth-order polynomial time-dependence of the permittivity. In addition to the spectral shifts and modulation this spatially homogeneous medium scatters the field introducing causal echoes at the receiver location.
Cite
@article{arxiv.0906.0495,
title = {Electromagnetic radiation in a time-varying background medium},
author = {Neil V. Budko},
journal= {arXiv preprint arXiv:0906.0495},
year = {2009}
}
Comments
17 pages, no figures