It can be seen that after the interaction process of beam-wave, the input signal of 0.33 V is amplified to 41.97 V with electron efficiency
However, the previous investigations on FWG-TWTs reveal that their electron efficiency are relatively low, which are mainly limited by the beam-wave interaction impedance [8-13].
In the future, in order to increase the electron efficiency of the interaction, it is feasible to search other novel slow-wave structures which are related to SFWG-SWS.
Figure 15(b) gives the saturated electron efficiency
versus the frequency, from which we can see that the saturated electron efficiency
is greater than 15.9% across the bandwidth of 58-64 GHz.