Acceleration of Spectral Domain Approach for Generalized Multilayered Shielded Microstrip Interconnects Using Two Fast Convergent Series

A simple and versatile approach for the acceleration of the spectral domain approach for generalized shielded microstrip interconnects is presented. This approach uses asymptotic expansion for the Bessel´s function and the Green´s function followed by an approximation of infinite summation using two fast convergent sine cosine series. The asymptotic expansion coefficients of the Green´s functions are found by a combination of analytical and numerical approaches. The infinite summation involved in the computation of the elements of the Galerkin matrix is accelerated using two fast convergent sine cosine series. The use of a few entire-domain basis functions gives very accurate results for the propagation constants for any mode in the general case of a multilayered shielded microstrip line. In addition to this, closed-form expressions are developed to choose the number of terms and some parameters to adaptively accelerate the convergence of the second type of fast convergent series for a given accuracy. This approach can be extended to handle multiple interconnects in the same layer and in different layers and also to include the effect of finite thickness and conductivity.