Equivalent circuit model of Terahertz folded waveguide traveling wave tube

In this paper, the transmission characteristics of the folded waveguide traveling wave tube (FW-TWT) is analyzed. The FW is equivalent as the transmission line. Both the bending part and beam tunnel are considered. According to the characteristics of two-port network, the S parameters can be calculated from the transmission matrix. The CST simulation is used to compare with the theory calculation. Both single period and multiple periods are considered in the calculation.