Rapid design closure of microwave components by means of feature-based optimization and adjoint sensitivities

Abstract

In this article, fast design closure of microwave components using feature-based optimization (FBO) and adjoint sensitivities is discussed. FBO is one of the most recent optimization techniques that exploits a particular structure of the system response to “flatten” the functional landscape handled during the optimization process, which leads to reducing its computational complexity. When combined with gradient-based search involving adjoint sensitivities, the design cost becomes even lower, allowing us to find the optimum design using just a few electromagnetic (EM) simulations of the structure at hand. Here, operation and performance of the algorithm is demonstrated using a waveguide filter and a miniaturized microstrip rat-race coupler (RRC). Comparative studies indicate considerable savings that can be achieved even compared with adjoint-based gradient search. In case of RRC, numerical results are supported by experimental validation.