Symbolic noise analysis in analog integrated circuits

A novel symbolic analysis method to compute noise figure (NF) in analog circuits, is presented. The proposed method is based on manipulating data structures representing the interconnection relationships (IRs) of conductances, resistances and MOSFETs modelled by nullators and norators. It is demonstrated that the formulation of the system of equations being improved by computing the Cartesian product of the indexes associated to the IR of norators and nullators. The proposed noise analysis method is highlighted by including several examples which show the feasibility of the technique. Finally, it is shown that the suitability is in good agreement compared to HSPICE noise simulations.