ELIMINATING REDUNDANT DC EQUATIONS FOR ASYMPTOTIC WAVE-FORM EVALUATION

Asymptotic Waveform Evaluation (AWE) is a waveform estimation techniqu e which involves the computation of moments from a linear circuit foll owed by the generation of waveform estimates based on those moments. D uring moment computation a special case arises if there are capacitor cutsets or inductor loops. Methods proposed for handling these cases i nvolve identifying the cutsets and loops and replacing one of the capa citors (inductors) with a dependent source. This note describes a diff erent formulation of the problem. The elimination of redundant equatio ns in order to compute moments can be viewed as the dual of the proble m of reducing circuit equations to normal form. This formulation has a couple of interesting theoretical properties: (1) it formally handles all circuit topologies, including circuits with dependent sources for which the redundancies may be undetectable from an inspection of the circuit topology, and (2) it predicts that even networks without indep endent sources may have ''hidden'' particular solutions consisting of polynomials in t.