Fast Approximation of the Transient Response of Lossy Transmission Line Trees

An efficient technique for estimating the time-domain response of lossy tree-like interconnect structures is presented. The approach is based on approximating such structures by a tree of RLGC sections, and computing a low order approximation to its transfer function. Unlike the Asymptotic Waveform Evaluation approach, the reciprocal of the transfer function of the tree is expanded as a polynomial in s. Experimental results are presented which demonstrate the higher accuracy of this approach as compared to AWE. A generalization of the procedure for computation of capacitive crosstalk is also presented.