Design of Dynamic Variable Power with High Efficiency and Reliability for Ku-Band TWT

The traditional way to achieve the adjustment of the output power of the traveling wave tube(TWT) is to reduce the input power and keep the TWT in small signal working state, but it significantly affects the efficiency of the TWT.It is of great value to use the method of reducing cathode current to realize the high efficiency of both the state of saturation and the state when the power backs off the half of the state of saturation (the power back-off 3dB). When the emission current changes,the working state of the traveling wave tube changes, the efficiency of TWT may get worse, it has to make the electronic energy similar at the situations of large current and the small one. In this paper,an example of radiant cooling space TWT for Ku-band is presented, the total efficiency of traveling wave tube in the state of saturation is above 68.81%, and when the power backs off the half of the state of saturation, The total efficiency is above 61.42%.