Electromagnetic waves generated by line exponentially decaying current pulses

Electromagnetic pulses emanated by exponentially decaying currents propagating along a finite line segment with subluminal and luminal velocities are considered. Corresponding electromagnetic problem for the decaying unit-step current is solved by incomplete separation of variables and the basic solution is obtained for the magnetic field strength. This solution is a sum of an analytical expression and a quadrature term, the latter admitting good analytical approximation in the far zone (r/lgsim10), where the entire electromagnetic field can be assessed. Eventually, the results of this work represent feasible analytical expressions for the electromagnetic-pulse durations and maximum amplitude for different configurations of the source, including such practical models as a bipolar current and a current pulse partially reflected from the radiator end