Higher-Order Modes in Dielectrically Loaded Rectangular Waveguides

The problem of propagation in a waveguide containing E-plane slabs of dielectric was considered previously by several authors. However, their treatment was limited to the TE_mo modes. A more general and complete derivation of the dispersion equations for all the modes existing in these structures is presented here. It is shown, on the basis of theoretical and experimental results, that the frequency bandwidth is much smaller than the values previously obtained, considering only the TE_mo modes, for many cases of practical interest