Large-signal analytical approach to a disc-loaded gyro-TWT amplifier

In the present study, large-signal analysis of a disc-loaded gyro-travelling wave tube amplifier has been presented. For this purpose, analytical theory for non-linear analysis of an arbitrary-shaped interaction structure has been extended for a disc-loaded interaction structure. Power profile results of the present theory, taking waveguide disc-hole radius equal to waveguide-wall radius where the structure becomes a smooth wall circular waveguide, closely matches with the published results of a circular waveguide. Comparison of already published small-signal theory results and the present large-signal theory has been done and a fair agreement (within 4%) has been achieved. Spatial power and efficiency profile for a disc-loaded gyro-traveling wave tube with structure parameters r_D/r_W = 0.6, L/r_W = 0.4 and T/r_W = 0.1 operating in TE₀₂-mode at 91.4 GHz has been presented.