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.

17 pages, no figures

References in corpus (2)

• General Relativity in Electrical Engineering
• Observation of negative impulse velocity in free space

Cited by in corpus (9)

• Beyond the Bode-Fano Bound: Wideband Impedance Matching for Short-Pulses using Temporal Switching of Transmission-Line Parameters
• A Generalization of the Kramers-Kronig Relations for Linear Time-Varying Media
• Stationary Charge Radiation in Anisotropic Photonic Time Crystals
• Frequency converter implementing an optical analogue of the cosmological redshift
• Soft Temporal Switching of TL Parameters: Wave-field, Energy Balance, Applications
• Plasmonic Time Crystals
• Dipole polarizability of time-varying particles
• Electromagnetic fields in a time-varying medium: Exceptional points and operator symmetries
• Dispersion, Controlled Dispersion, and Three Applications