A Gaussian-Like Beam Output System for High-Power Ka-Band Gyro-TWT

作者：Wu, Zewei^*; Pu, Youlei; Liu, Guo; Jiang, Wei; Wang, Jianxun; Li, Hao; Luo, Yong

来源：IEEE Transactions on Electron Devices, 2018, 65(4): 1535-1541.

DOI：10.1109/TED.2018.2803075

• Broadband
• Gaussian-like beam
• gyrotron traveling-wave tube (gyro-TWT)
• high power amplifier
• Ka-band

An output system, consisting of a waveguide taper, a 90 degrees waveguide bend, a corrugated waveguide horn, and an RF output window, which can output a Gaussian-like beam rather than a circular waveguide TE0,1 mode in a broadband for a Ka-band gyrotron traveling-wave tube (gyro-TWT) has been developed and tested. The conversion process in each section is displayed, and the working principles are discussed in detail. The output mode purity at different frequencies is investigated by analyzing the measured radiation pattern, and the results show that the Gaussian mode contents of the output field is at least 98.5% from 32 to 39 GHz. The high-power performance of the proposed output system is investigated by replacing the traditional output structure of a Ka-band gyro-TWT, and the results show that the device work stable with a maximum power of 150 kW. The obtained Gaussian-like beam at the output window is directly usable for low-loss transmission as well as for effective antenna feed; no extra oversized mode converters are needed. The results obtained demonstrate the possibility of developing a compact, high-efficiency, and low-cost high-power millimeter-wave system based on the gyro-TWT.

• 出版日期2018-4
• 单位电子科技大学