金刚石在太赫兹电真空器件中的应用

Application of diamond in Terahertz vacuum electron devices

金刚石材料具有低的介电常数、小的微波损耗、良好的导热性能,成为太赫兹电真空器件发展过程中非常有研究价值和应用价值的材料。它可以作为输能窗的介质窗片和高频结构的介质支撑材料。本文介绍了微波等离子体化学气相沉积(MPCVD)金刚石材料在太赫兹电真空器件中的具体应用实例,以及在W波段行波管中的实际应用情况,包括MPCVD金刚石的制备过程,及其与金属材料的封接工艺。研制出的W波段金刚石窗冷测结果显示其在75 GHz-110 GHz频段内性能良好:驻波系数(VSWR)≤1.5,传输损耗≤0.5 dB。这种窗已经成功用于W波段折叠波导连续波与脉冲行波管中。

Diamond is a kind of ideal dielectric material for terahertz vacuum electron devices due to its excellent properties, such as a lower dielectric constant, lower microwave loss and larger thermal conductivity. It can be used as transmission window material and dielectric supporting material for high frequency structure. This paper describes some applications of Microwave Plasma Chemical Vapor Deposition（MPCVD） diamond in terahertz vacuum electronic devices, including the fabrication process of MPCVD diamond, and diamond-metal sealing techniques. Cold testing results of the W-band diamond window show a good performance in a frequency region of 75 GHz-ll0 GHz, with a standing wave ratio （VSWR）≤ 1.5 and a transmission loss≤0.5 dB. The diamond window has been successfully used in W-band pulsed and CW TWTs.