Abstract: In order to eliminate the false singularities in the Fringe Components of Equivalent Edge Currents expressions, this paper extends the treatment of false singularities of diffraction coefficients in the Physical Theory of Diffraction into the Fringe Components of Equivalent Edge Currents expressions. The part which may produce singularity is departed from the original ones, and then is transformed into more steady expressions in the neighbourhood of singularity points by using the trigonometry exchanging and variable substitution. The reformulated Fringe Components of Equivalent Edge Currents expressions are obtained, thus increasing the numerical stability in neighbourhood of singularity points and eliminating the singularity. Numerical results testifies the validity of the method.

Key words: equivalent edge current, false singularities, physical theory of diffraction