Sensitivity analysis of iterative adjoint technique for microstrip circuits optimization

This paper presents an accurate and efficient full-wave method, combined with iterative adjoint technique, for analyzing sensitivities of planar microwave circuits with respect to design parameters. Method of moments (MoM) in spatial domain is utilized, and generalized conjugate residual iterative scheme is applied to solve the linear matrix equations with fast convergence. Green’s functions for multilayer planar structures in DCIM form are employed to simplify the spatial domain manipulation. In the present method, a conventional integration model and the corresponding adjoint model are solved by MoM respectively. The adjoint technique, with the aid of iterative schemes, could significantly reduce the computational requirements, especially for the large electrical size device with many perturbing design parameters. Numerical results of S-parameter sensitivities of a low-pass microstrip filter by the present method are presented. Accuracy and efficiency are validated. © 2007 Wiley Periodicals, Inc. Microwave Opt Technol Lett 49: 607–609, 2007; Published online in Wiley InterScience (www. interscience.wiley.com). DOI 10.1002/mop.22204