ABSTRACT
Analytical investigations of the transient behaviour of electromag-
netic waves in waveguides have a long history when considering
only empty waveguides with conductive walls [1-4]. In these
early works straight waveguides were considered in which the
phenomenon is described by a 1D equation in the time or frequency
domain because the transverse field components are determined via
the longitudinal ones in the general formulation. Using a Fourier
integral transform some aspects of the general nature of transient
propagationwere investigated. It was shown that the normal steady-
state structure does not exist in the transient phase since the
different field components propagate in a non-identical manner that
is characterised by the group velocity.