Closed-form analytic expressions for the pulsed-source radiated electromagnetic field in a class of media with time-varying wave speed

•The pulsed electromagnetic radiation in a class of time-varying media is analyzed.•Analytic expressions are derived via a novel ‘Ansatz’ approach.•Tentative application: analysis of pulsed echo returns in weather radar measurements.•The analytic results can serve as a benchmark in computational procedures.

Closed-form analytic expressions are arrived at for the pulsed-source radiated electromagnetic field in a homogeneous, isotropic, lossless medium with constant wave impedance/admittance, but with time-varying wave speed. A particular choice of the excitation solves the corresponding initial-value problem. The results can be used to benchmark purely computational investigations.