Diffraction on two opposite parallel PEC half-planes at skew incident

The diffraction of an arbitrary incident plane wave on two opposite PEC half-planes is formulated in terms of Wiener-Hopf equations. The factorization of the 4x4 matrix kernel is reduced to the factorization of a 2x2 matrix kernel. The factorization of the kernel is obtained by the solution of a Fredholm equation of second kind that provides very accurate results.