An efficient algorithm for transient and distortion analysis of mildly nonlinear analog circuits

This work presents an effective approach to transient and distortion for mildly nonlinear analog circuits. Our method is based on Volterra functional series representation of nonlinear circuits. It computes the nonlinear responses using nonlinear current method which recursively responses using linear Volterra circuits to obtain linear and higher-order responses of a nonlinear circuit. The linear Volterra circuits are solved in frequency domain using an efficient graph-based technique, which can derive transfer functions of any large linear network very efficiently. The harmonic distortion can be directly obtained in the frequency domain while the transient responses are obtained via inverse Laplace transformation. The algorithm takes advantage of the identical Volterra circuits for second and higher order response, which results in significant saving in deriving the transfer functions. Experimental results for a number of nonlinear circuits are obtained and compared with SPICE3 to validate the effectiveness of this method.