High frequency characteristics for W-band multiple beam staggered double-vane traveling wave tube amplifier

A new micro-structure scheme was proposed by using three parallel pencil beams instead of the sheet beam for the W-band staggered double vane traveling wave tube amplifier, and detailed analysis and optimization were given for the high frequency characteristic with its input/output couplers. The results show that the structures have a good dispersion characteristic and very broad working bandwidth, the strong component of longitudinal electric field is very benefit to the interaction and exchange of the energy between the electron beam and the high frequency field. Keep the diameter of the pencil beam tunnel as the same of the height of the sheet beam tunnel, the interaction impedance of the structures can achieve 2-3 times as high as the sheet beam scheme to obtain the high interaction efficiency and high output power. In order to match the staggered double-vane high frequency system, we present a more simple and easy input/output coupler structure. Just using three periods of transition structures, the input/output structures of the traveling wave tube amplifier can achieve a low reflection loss below the -20 dB in a broad bandwidth with more suitable application in the devices later.