Higher-order MoM combined waveport analysis of circular waveguide problems

In this paper, the radiation problem of circular waveguide is analyzed using higher-order Method of Moments (MoM). The difficulty of the problem is the lack of matched excitations and loads. The method of mode matching is used to construct ideal waveports, which can provide not only excitations as sources but also perfectly matched loads. The involvement of Bessel functions makes the circular wave port more complicate. Numerical results demonstrate that the proposed method can accurately and efficiently solve the circular waveguide problems. Finally, an electrically large reflector antenna is solved.