Analysis of corrugated wave-guides by coupled integral equation technique and other numerical techniques

The disc-loaded corrugated waveguides have been investigated by many techniques, due to their importance in antennas, mode converters, phase shifters, polarizers, slow wave structures and even transmission systems. In this paper, the propagation characteristics of a periodically disc loaded waveguide for the axially symmetric TM_0n mode are determined based on the COUPLED INTEGRAL EQUATION TECHNIQUE (CIET). The CIET has the analytical content of the MODE MATCHING TECHNIQUE (MMT), with the inclusion of edge conditions, and solution using the METHOD OF MOMENTS (MoM). In this technique, a set of coupled integral equations in the tangential electric fields at the gaps of the interfaces are derived and solved by the moment method using basis functions, which include the edge conditions. This method used by Amari etal., [1] for TE_0n mode has been extended to TM_0n mode, which is mainly used in the slow wave structure for linear accelerators, BWOs and TWTs. The dispersion characteristics of the disc-loaded corrugated slow-wave structure for linear accelerator was computed for the TM₀₁ mode propagation using the CIET technique. This result is validated against the results published in the literature, using the mode-matching technique and both the techniques agree very closely. The dispersion characteristic for the same slow wave structure with finite thickness corrugation is also computed with the three dimensional electromagnetic software packages: HFSS¹, MAFIA² and Microwave studio² and the results in terms of simulation time and memory are compared.