An extension of the time-domain Friis equation

The time-domain Friis-type antenna equation is in the literature standardly limited to a rather special class of antenna systems whose radiation impedance or/and load show (electromagnetically) instantaneously-reacting behavior. In this paper, this limitation is removed thereby generalizing the time-domain Friis equation. An illustrative example is given for pulsed-field interaction between two electrically-small thin wires.