A 500-kw periodically focused S-band traveling-wave amplifier

This paper describes a developmental periodic permanent-magnet focused traveling-wave amplifier having up to 500 kw peak output power at S-band. The slow-wave circuit used is an extrapolation of the Hughes developed coupled-cavity structure which has been used previously in tubes at X- and C-band. In this structure the iron pole pieces used for focusing the beam are an integral part of the r-f circuit. The vacuum envelope consists of the iron pole pieces and alternating copper cavity walls. The higher power and lower frequency of the present tube has resulted in the largest size and highest power reported in a periodic permanent-magnet focused tube.