3D analysis of helical slow-wave structures for space TWTs: critical comparison of Ansoft HFSS and CST Microwave Studio

3D EM simulators allow to model any type of 3D structure without analytical approximations or experimental errors. The objective of this study is to evaluate the capabilities of two of these simulators (based on finite element and finite difference approaches) and to perform a critical comparison (in terms of CPU-time and accuracy) for a typical space helix TWT in Ku-band. Two commercially available simulators were used for this study: Ansoft-HFSS, and CST Microwave Studio.