The Study of Very Low Voltage Planar Slow Wave Structure For Compact TWT

One kind of low operating voltage planar novel slow wave structure for compact travelling wave tube is proposed in this paper. Instead of the high voltage of traditional TWT such as 10∼20kV, the proposed dielectric rods supporting meander metal line planar SWS could achieve 3∼5kV operating voltage at Ka-band without dielectric substrate supporting not like microstrip SWS. All along the traditional microstrip SWS has been suffered from electric charge accumulation on dielectric substrate inevitably and energy lose caused by dielectric. In this paper, by using the dielectric rods supporting metal lines on the both sides, the proposed SWS could overcome the problems mentioned above. In addition, by adjusting the structure parameters, the operating voltage and working frequency could be changed easily and effectively. One kind of low voltage SWS for Ka-band TWT is designed, in which the corresponding voltage is 3600V. According to particle-in-cell simulation results, the low voltage TWT can get an output power of 128 W at 38 GHz under the case of 0.2 A beam current. The corresponding maximum gain and electron efficiency is 21.1 dB and 17.7%.