Optimization of full‐wave EM models by low‐order low‐dimension polynomial surrogate functionals

A practical formulation for EM‐based design optimization of high‐frequency circuits using simple polynomial surrogate functionals is proposed in this paper. Our approach starts from a careful selection of design variables and is based on a closed‐form formulation that yields global optimal values for the surrogate model weighting factors, avoiding a large set of expensive EM model data, and resulting in accurate low‐order low‐dimension polynomials interpolants that are used as vehicles for efficient design optimization. Our formulation is especially suitable for EM‐based design problems with no equivalent circuital models available. The proposed technique is illustrated by the EM‐based design optimization of a Ka‐band substrate integrated waveguide (SIW) interconnect with conductor‐backed coplanar waveguide (CBCPW) transitions, a low crosstalk PCB microstrip interconnect structure with guard traces, and a 10–40‐GHz SIW interconnect with microstrip transitions on a standard FR4‐based substrate. Three commercially available full‐wave EM solvers are used in our examples: CST, Sonnet, and COMSOL. Copyright © 2015 John Wiley & Sons, Ltd.