Applications of symbolic network analysis

Symbolic network analysis is a formal technique, complementary to numerical analysis, to calculate the behaviour or a characteristic of a circuit with independent variable frequency, dependent variables voltages and currents and some or all of the circuit elements represented by symbols. The evaluation of the symbolic functions is much easier and faster than working repeatedly with a numerical simulator. A program for symbolic network analysis, of lumped linear or linearised time invariant circuits is presented. The network functions and their sensitivities with respect to the element values are computed with a matrix-based method, using symbolic manipulation of algebraic expressions. An interesting application of the symbolic network analysis is noise computation, one of the most difficult tasks that an analog engineer must perform. Symbolic expressions for the system noise measures are obtained.