A fast wavelet collocation method for high-speed VLSI circuit simulation

This paper presents a fast wavelet collocation method (FWCM) for high-speed circuit simulation. The FWCM has the following properties: (1) It works in the time domain, so that the circuit nonlinearity can be handled, and the accuracy of the result can be well controlled, unlike the method working in the frequency domain where the numerical error may get uncontrolled during the inverse Laplace transform; (2) The wavelet property of localization in both time and frequency domains makes a uniform approximation possible, which is generally not found in the time marching methods; (3) It is very effective in treating the singularities often developed in high-speed ICs due to the property of the wavelets; (4) Calculation of derivatives at all collocation points is optimal and takes O(n log n), where n is the number of collocation points; (5) An adaptive scheme exists; and (6) It has an O(h/sup 4/) convergence rate while the most existing methods only have an O(h/sup 2/) convergence rate, where h is the step length. Numerical experiments further demonstrated the promising features of FWCM in high-speed IC simulation.