Efficient computation of nonparaxial surface fields excited on an electrically large circular cylinder with an impedance boundary condition

An alternative numerical approach is presented for the evaluation of the Fock-type integrals that exist in the uniform geometrical theory of diffraction (UTD)-based asymptotic solution for the nonparaxial surface fields excited by a magnetic or an electric source located on the surface of an electrically large circular cylinder with an impedance boundary condition (IBC). This alternative approach is based on performing numerical integration of the Fock-type integrals on a deformed path on which the integrands are nonoscillatory and rapidly decaying. Comparison of this approach with the previously developed one presented in [1], which is based on invoking the Cauchy's residue theorem by finding the pole singularities numerically, reveals that the alternative approach is considerably more efficient.