Modified hybrid reduction technique for the simulation of linear/nonlinear mixed circuits

This paper describes the modified hybrid reduction technique for the simulation of linear/nonlinear mixed circuits. First, a method for generating the projection matrix with the Krylov-subspace technique is described. The order of the circuit equation is reduced by congruence transformation with the projection matrix. The nonlinear reduction technique proposed previously has been directly inapplicable to the networks including the node to which no capacitors are connected. In order to cope with the above problem, the modified method generates the projection matrix by using the devices based on the backward Euler method and the approximation of nonlinear derivative. Consequently, the hybrid reduction technique would be applicable to more general networks. Finally, circuit simulations are performed for some example circuits using this technique and the validity and efficiency of the hybrid reduction technique are verified by comparing with the conventional transient analysis technique.