Accuracy-Controlled Combined Adaption- Optimization Scheme for Finite-Element Analysis of 3-D Microwave Devices

Greater reliability and large computational savings can be achieved by linking the adaptive iteration of a computational analysis with the outer, optimization iteration, so that at each optimization step, the analysis performed is as accurate as it needs to be, and no more. Earlier work in this area involving scattering parameter calculation of 2-D waveguide structures is extended to 3-D with certain modifications. A more robust error estimator is used, as well as a different direct optimization strategy that better exploits the ready availability of gradient information. Results for two rectangular waveguide components, a transformer and an E-plane U-bend, confirm the efficiency of the method