TWT Folded Wave-Guide High-Frequency Losses Test and Simulation Based on Surface Roughness

This study introduces the W-band and G-band travelling wave tube (TWT) folded wave-guide (FWG) high-frequency losses (HFL) test and simulation. This is a method that does not require adjusting electric conductivity of the material during simulation. We respectively set the FWG E-plane and H-plane roughness based on test data, and then set the electric conductivity as the same with copper used in DC. The HFL simulation results obtained were matched with the test data at 91-101GHz and 195-225GHz. This indicates that the surface roughness of the material is the main source of HFL.