Investigation of 140GHz double-grating extended interaction oscillator

In this paper, A 140GHz double-grating sheet beam extended interaction oscillator (SB-EIO) is designed. The high- frequency characteristics and transmission characteristics are calculated by a three-dimensional electromagnetic simulation software. The resonant cavity structure is simulated by using the eigenmode solver. And the electric-field distribution satisfies TM110 mode. From the cold cavity simulation results, we can draw the dispersion curve by observing the electric-field distribution under different working modes of the single-period structure. And then, the working frequency of the hot cavity is 143 GHz by combining the voltage line and the dispersion curve's ordinate at 2π working point. With voltage 43.7 kV and current 2.5 A, it can be find that the peak power of output port is 30.11kW, and the beam-wave interaction efficiency is 27.56%.