Transmission modes of closed elliptic-groove waveguides for millimeter waves

In this paper, a new type of horizontal-flat and vertical-flat closed ellip tic-groove guides is firstly presented. The field components and characteri stic equations for some main transmission modes of the closed elliptic-groo ve guides are derived by with the help of the mode-matching method and Math ieu function. The variations of the cut-off wavelengths along with eccentri cities, widths and lengths of the parallel plates for a number of lower ord er transmission modes of the closed elliptic-groove guides are also analyse d in detail. The calculated results in good agreement with ones in the rele vant references are of very important values in theoretical researches and actual applications of closed elliptic-groove guides for millimeter and sub millimeter waves.