Rigorous analysis of iris coupling problem in waveguide

The authors present a new class of simple basis functions which explicitly take the edge conditions into consideration and use them for solving the waveguide iris coupling problem by the moment method. The good agreement between the present and previously published results for some special cases of parallel-plate and rectangular waveguides demonstrates the correctness of the choice of the basis functions. The basis functions introduced here are characterized by their simple form and generality, while having fast convergence behavior like previously published basis functions