Interconnect model reductions by using the AORA algorithm with considering the adjoint network

This work proposes a hybrid method for interconnect model-order reductions. First, the adaptive-order rational Arnoldi (AORA) method is investigated. An extension of the classical multi-point Pade approximation by using the rational Arnoldi iteration approach are studied. The adaptive-order can be achieved by choosing the expansion frequency corresponding to the maximum output moment error. Secondly, the adjoint network technique is studied. By exploring symmetric properties of the MNA formulation, the computational cost of constructing the congruence transformation matrix can be reduced by 50% compared with the conventional methods.