Analysis of Dispersion and Losses in Helically Corrugated Metallic Waveguides by 2-D Vector Finite-Element Method

Hollow metallic circular waveguides with helical corrugation of the inner surface (helical waveguides) attract considerable interest for various applications such as interaction regions in gyrotron traveling-wave tubes and as a dispersive medium for passive microwave pulse compression. In this paper, we employ a vector finite-element method in 2-D formulation for computation of the dispersion, attenuation characteristics, and the distribution of electromagnetic fields of eigenwaves of helical waveguides. As shown by comparison with the results of previously performed 3-D calculations, the presented method provides sufficient accuracy of calculating the characteristics of helical waveguides for a number of practically important cases at much lesser consumption of computer resources.