Normal Modes in Overmoded Dielectric-Lined Circular Waveguide

The propagation constants (loss and phase) are determined for the normal modes in dielectric-lined overmoded (guide radius » wavelength) circular guide by numerical solutions of the appropriate characteristic equations. It is shown that the heat loss of the TMpnmodes is quite low and decreases with increasing frequency in contrast to the increase in heat loss predicted by the perturbation theory for thin linings. The primary effect of the low-loss TMpnmodes on a transmission system using the TE01mode is a reduction in the route bend losses.