Transmission characteristics with second order approximations of elliptic-groove waveguide

In this paper, the transmission characteristics for the dominant mode H-e11 ((1)) in the vertical-flat elliptic-groove guide are analysed by using the mode-matching method and Mathieu function. The characteristic equations wit h the 1st and 2nd order approximations and their solutions for the dominant mode of the elliptic-groove guide are also obtained by a great quantity of theoretical analyses and numerical computations. The cut-off, dispersion a nd attenuation characteristics are in good agreement with those in the rele vant references under limiting conditions and are discussed in detail. The obtained results are of important significance for theoretical researches a nd actual applications of elliptic-groove guides for millimeter and submill imeter waves.