Efficient calculation of the Green´s function in rectangular waveguides

An efficient calculation method is proposed for the potential Green´s function in rectangular waveguides. The proposed method applies an efficient calculation method for the Green´s function on periodic structures to the image series representation of the waveguide Green´s function. As a result, exponential convergence has been achieved with increasing summation index. Several techniques are presented to minimize the number of terms to achieve a prescribed accuracy.