  We study vortex structure in three different models of long Josephson
junctions: exponentially shaped Josephson junction and Josephson junctions with
resistor and shunt inhomogeneities in barrier layer. Numerical calculations of
the possible magnetic flux distributions and corresponding bifurcation curves
have done. For these three models the critical curves ``critical
current-magnetic field'' are constructed. We develop an idea of the equivalence
of exponentially shaped Josephson junction and rectangular junction with
distributed inhomogeneity and demonstrate that at some parameters of shunt and
resistor inhomogeneities at the ends of the junction the corresponding critical
curves are very close to the exponentially shaped one.
