FAST AND ROBUST INEXACT NEWTON APPROACH TO THE HARMONIC-BALANCE ANALYSIS OF NONLINEAR MICROWAVE CIRCUITS

The letter discusses a novel approach to nonlinear microwave circuit s imulation by the harmonic-balance (HE) technique, The nonlinear system is solved by an inexact Newton method, and the GMRES iteration is use d at each step to find a suitable inexact Newton update, The peculiar structure of the Jacobian matrix allows the basis vectors of the Krylo v subspace to be computed mostly by the FFT, The resulting simulation tool is fast and robust, and outperforms conventional HE techniques wh en applied to large-size nonlinear analysis problems.