A fast mode analysis for waveguides of arbitrary cross section with multiple regions by using a spectrum of two-dimensional solutions and asymptotic waveform evaluation

A fast mode analysis for waveguides of arbitrary cross section with multiple regions is presented in this paper. The analysis is based on a spectrum of two-dimensional (2-D) solutions with application of asymptotic waveform evaluation, which requires only several 2-D solutions in searching for the propagation modes and calculating the field distribution of the modes in waveguides. The boundaries of waveguides can be modeled by perfect electric conductors, perfect magnetic conductors, dielectric materials, and asymptotic strip boundary conditions. By this modeling, one can also analyze the waveguides with the soft and hard surfaces. The method is excitation dependent, which provides a tool to analyze the response of different modes to different excitations. No existence of spurious modes is experienced by using this method. The verification and comparison of the numerical results with analytical, published data, and measurements are also presented in this paper.