Electromagnetic Field Calculated by a New Method of Spreading Variable

Harmonic series representations are frequently used for calculating electromagnetic fields scattered by a circular conducting cylinder. The harmonic representations are obtained by a method of separating variables in the cylindrical coordinates. Residue series representations are also used for calculating electromagnetic fields scattered by the circular conducting cylinder. The residue series are obtained by Watson's transformation. In this paper, it is shown that the residue series representations can also be obtained from another method of separating variables, and various distinguishing characteristics of the eigenfunction used in this method are made clear. The authors discuss the advantages and the distinctive features of the residue series representations in the comparison with the harmonic series representations.