Improved efficiency of spatial mixed-potential Green´s function computation for coated cylinders

Expressions for the spectral domain electric mixed-potential (MP) Green´s function for a substrate-covered circular cylinder are derived in terms of the spectral dyadic Green´s function for the electric field. The spectral properties of the derived function are exploited in the transformation to the space domain, extracting its regularized spectral asymptotic behavior. The extracted asymptotic functions can be transformed analytically. Recently, the computation of the spatial domain MP Green´s function has been significantly accelerated by an adaptive interpolation of the spectral Green´s function and application of numerical Filon integration in the inverse Fourier transformation. Several important issues of software implementation, numerical stability and accuracy are discussed and numerical results are presented.