General analysis of millimetric wave H guides

A mathematical model, describing the wave modes in an idealized H guide, is presented. The H guide is a dielectric plate limited by two parallel conducting surfaces of infinite extension. The wave propagation conditions, the attenuation coefficients, the dielectric losses and the conduction losses are obtained from a single parameter which is a function of the waveguide geometrical data. It is shown that the H guide performs efficiently at frequencies greater than the usable range of the traditional rectangular waveguides. It is suggested to employ LSM1 mode because of lower attenuation than the LSE1 mode, and compatibility with rectangular guides.