An efficient method for calculating bounces in the irregular power/ground plane structure with holes in high-speed PCBs

The eigenmode expansion method (EEM) is a convenient technique for characterizing a power/ground (P/G) plane pair structure. The requirements of the plane pair´s shape, however, and a double-infinite series in its equation limit its applications. To overcome its disadvantages and extend its applications, this paper proposes some techniques for the EEM and makes some modifications to it. First, by employing the newly presented inverted composition method and the segmentation method, the improved EEM can be used to characterize a holey P/G plane pair with irregular shapes. Second, by employing a trigonometric Fourier series and a particular Pade approximation method-the η-algorithm, the double-infinite series in EEM can be changed into a single one and its convergence can be accelerated apparently so that the computation efficiency of the EEM is greatly improved. An example is considered to compare the numerical data of the new EEM with corresponding measurement results, thus demonstrating the good accuracy. The computation time of the proposed method is compared with that of the finite-element method (FEM), which shows that the new method has higher efficiency.