Development of a Subterahertz Folded-Waveguide Extended Interaction Oscillator

A novel type of two-section folded waveguide (TSFW) slow wave structure for the development of a subterahertz (sub-THz) extended interaction oscillator (EIO) is proposed in this paper. We focus on the development of sub-THz EIO, in which the key parts, including the electron optics system, the high frequency structure for beam-wave interaction, and output window, are fabricated and tested. Based on the key parts, the prototype of EIO is developed. The experimental results show that over 12-W output power at the frequency of 107.9 GHz at 2% duty cycle is achieved. This paper demonstrates that the feasibility of a high power THz oscillator can be obtained by the use of a prebunching electron beam produced by TSFW.