Space mapping surrogate-based microwave circuit design centering using a new statistical technique

Design centering is an optimal design process that seeks for the values of system parameters which maximize the probability of satisfying the design specifications (yield function). In this article, a derivative-free trust region (TR) optimization approach is combined with the generalized space mapping technique to develop a new space mapping (SM) surrogate-based statistical technique for design centering of computationally expensive microwave circuits. The TR optimization approach is well suited for expensive objective functions that have some uncertainty in their values or subject to statistical variations. The principal operation relies on building and successively updating quadratic surrogate models to be optimized instead of the objective function over TRs employing the truncated conjugate gradients. The approach constructs the initial quadratic surrogate model using fewer data points, then updates the surrogate model using a weighted least squares fitting that gives more emphasis to points close to the current center point. Integrating the TR optimization approach with the generalized space mapping technique results in a novel statistical design centering technique for the microwave circuits with a great reduction in computations and simulations needed for the yield optimization process. Design of practical microwave circuits is presented to indicate the effectiveness of the new design centering technique. Copyright © 2015 John Wiley & Sons, Ltd.