Second harmonic injection for restraining third-orderintermodulation in traveling wave tube

Harmonic injection is an effective solution for suppressing the harmonic and cross-modulation signals inspired by nonlinear distoration of traveling wave tube(TWT). In this paper, Christine 1D nonlinear beam-wave interaction model is used to simulate the 2nd harmonic injection. The results show that harmonic injection can suppress the 3IM signals inspired by nonlinear distoration effictively and reduce the output power of 3IM of TWT. The experimentation of harmonic injection is introduced whose results agree well with those of simulation agree well.