Optimal design method for microwave device using time domain method and design sensitivity analysis. I. FETD case

In this paper, a new optimal shape design method for microwave passive devices for better performances in a broadband is proposed, which is based on vector finite element time domain (FETD) method and design sensitivity analysis (DSA). The design sensitivity is evaluated using an adjoint variable method. While the original field equation is an initial-value problem, the adjoint equation is an terminal-value problem. To transform the terminal-value problem into a initial-value problem, a backward time scheme is used. To verity its usefulness, a two-dimensional E-plane waveguide T-junction is analyzed.