Study of C-Band Bi-Periodic Sheet Beam EIO Based on Interaction Gap Width Tapering

A C-band bi-periodic extended interaction Oscillator (EIO) that has attributes of miniaturization and high efficiency is designed and simulated. Bi-periodic structure offers better interaction impedance and mode separation. In addition, interaction gap width tapering technique is adopted, which is characterized by linearly increasing gap width from the middle gap towards beam source and linearly decreasing towards collector side. This contributes to uniformity and increase of axial electric field, consequently, beam-wave interaction is enhanced. Eigenmode analysis is done to get normalized beam conductance and electric field distributions. In 3D particle-in-cell simulation, a power of 4.8MW at 5.83GHz is obtained by applying 85kV voltage, 100A current and 0.6T magnetic field. The peak power efficiency of designed structure is 56%.