Analysis of an inhomogenously ridge-loaded helix SWS used in MPM

In this paper, the ridge-loaded helix slow-wave-structure (SWS) used in microwave power module (MPM) is presented. Based on the finite vane model, the loaded ridge and the support rod in ridge are equalized to the sector waveguides with regard to the helix tape thickness. The dispersion characteristic equation is newly derived. The calculation results meet the measurements very well.