A universal approximator of nonlinear functions based on CMOS analog circuits

A universal approximator which provides direct analog synthesis of nonlinear functions is described. For this purpose a mathematical approach, founded on rigorous theoretical results and able to approximate a continuous function with a given small error, is reported. It is shown that such functions can be implemented with CMOS analog circuits, on the basis of which the architecture of a universal approximator of nonlinear functions is defined. A series of results obtained with the SPICE circuit simulation show, through significant examples, the validity of the proposed approach