Plane wave diffraction by two half-planes joined by a step is studied
in the case where the half-planes and the step are characterized by di
fferent surface impedances. The diffraction problem is first reduced t
o a modified Wiener-Hopf equation of the second kind whose solution co
ntains an infinite set of constants satisfying an infinite system of l
inear algebraic equations. A numerical solution of this system is obta
ined for various values of the surface impedances and the height of th
e step, through which the effect of these parameters on the diffractio
n phenomenon is studied.