Symbolic analysis of analog and digital circuits

An efficient computer method for symbolic analysis of linear analog and digital circuits is described. The tableau formulation is used in the derivations but the mixed nodal tableau method is used in actual computations of analog circuits. One triangular factorization of the system matrix, followed by forward and back substitutions, is sufficient to generate all partial derivatives of the numerator and denominator of the immitance function in terms of variable elements. In the case of frequency dependent elements, the fast Fourier transform algorithm is used to obtain the polynomial coefficients. The computational cost is discussed and compared with that of other well-known symbolic analysis algorithms. Difficult programming sections are given. Little software is needed beyond that if a program for frequency analysis is available.