Fast algorithm of Modal Expansion Method for Calculating Transfer Impedance of Arbitrary Shape Power Bus

This paper proposes a fast algorithm of modal expansion method for calculating the transfer impedance of two-dimensional isosceles triangular cavity. The fast algorithm is based on Fourier series formulas that simplify an infinite series summation to an analytic function. Therefore, the double summation of the modal expansion solution is reduced to single summation. Comparing with the double summation solution, the present method reduces 97.3% calculation time. Furthermore, a segmentation method is used to expand the isosceles triangular modal solution to arbitrary shape solution. Simulated and experimental results demonstrate the accuracy and efficiency of the present method.