A TE(21) second-harmonic gyrotron backward-wave oscillator with slotted structure

作者：Chen N C^*; Yu C F; Chang T H

来源：Physics of Plasmas, 2007, 14(12): 123105.

DOI：10.1063/1.2816984

Second-harmonic gyrotron backward-wave oscillator (gyro-BWO) with a reduced magnetic field strength is a tunable source in the millimeter wave regime, but it has long been impeded by the severe mode competition as a result of low efficiency and narrow bandwidth. This study employs a slotted structure functioning as a mode selective circuit to suppress the lower order transverse modes. In addition, a two-step tapered waveguide is adopted to stabilize the higher-order transverse modes and axial modes. Some important characteristics of the slotted gyro-BWO will be analyzed and discussed. As a calculated result, the interaction efficiency is improved and the stable tuning range is broadened. A stable, Ka-band, slotted second-harmonic gyro-BWO is capable of producing an efficiency of 23% with a 3 dB tuning bandwidth of 9% at 5 A and 100 kV.

• 出版日期2007-12
• 单位清华大学