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 spatiotemporal modulation, which are analyzed 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.
|Number of pages||8|
|Journal||Physical Review A (Atomic, Molecular and Optical Physics)|
|Publication status||Published - 2009|
- journal letters, notes, etc.
- CWTS 0.75 <= JFIS < 2.00