A wideband input/output structure for the staggered double grating sheet beam travelling wave tube

A wideband input/output structure for the staggered double grating sheet beam traveling wave tube (SBTWT) is designed, which has the merits of simple structure, low reflection and high isolation in a wide frequency band. A design example is given for a 94GHz sheet beam travelling wave tube, the CST-MWS simulation results show the S parameters are satisfactory.