Novel 0.22-THz Extended Interaction Oscillator Based on the Four-Sheet-Beam Orthogonal Interconnection Structure

Numerous terahertz vacuum electronic devices (TVEDs) have been proposed. Among these devices, extended interaction oscillators (EIOs) exhibit small-volume, lightweight, low-working-voltage, stable-working frequency, and high-power characteristics. The ladder-line slow wave structure exhibits strong coupling and can interact with the sheet beam to considerably improve the efficiency of beam–wave interaction. In this study, a novel high-frequency structure was proposed. Four conventional ladder-line slow wave structures were placed vertically to form a four-sheet-beam orthogonal interconnection structure (OIS) that considerably increased the coupling efficiency between the cavities, improved output power and efficiency, and interacted perfectly with the TM81 mode. In this study, the dispersion characteristics and field distribution were studied through numerical and simulation calculations, and the optimal working parameters and output structure were analyzed using particle-in-cell (PIC) software. Next, a 0.22-THz extended interaction oscillator based on four-sheet-beam OSI was designed. Simulation results have shown the achievement of the output power of 0.22-THz wave over 500 W with four sheet beams at 16.6 kV and each current of 0.8 A. Finally, preliminary processing and cold tests of the structure were performed. This novel structure provided an alternative for the development of terahertz EIOs.