An efficient variable gain homotopy method using the SPICE-oriented approach

Homotopy methods are known to be effective methods for finding DC operating points of nonlinear circuits with the theoretical guarantee of global convergence. There are several types of homotopy methods; as one of the efficient methods for solving bipolar circuits, the variable gain homotopy (VGH) method is well-known. However, in the conventional VGH method, the initial point is sometimes far from the solution because it is given as a solution of a diode circuit. In this paper, we propose an efficient VGH method using the SPICE-oriented approach. The proposed method can be easily implemented on SPICE without programming, although we do not know the homotopy method well. Moreover, since we can use a good initial point, the path following tends to become smooth and efficient.