DOMINANT MODE CHARACTERISTICS OF CIRCULAR GROOVE GUIDE

Circular groove guide is a hind of waveguide for millimeter waves with low loss, large dimensions, and low dispersion. In this gaper, the do minant mode characteristics of it is analysed, The technique that mode macthing method combines with point matching method is used to derive the Nth-order characteristic equation of the guide, The 1st order, 2n d order and 3rd order approximate curves that the normalized cutoff wa velength of circular groove guide varies with c/a are given. The atten uation curves are given at 1mm, 1.5mm and 3mm wavelength. The numerica l results are in well agreement with the experimental results publishe d.