螺旋行波管衰减器炭涂层的特性表征

Characterization of carbon-attenuator coatings for helical traveling wave tube applications

分别采用热解沉积、胶体石墨涂刷和电弧放电法在行波管(TWT)刚玉支撑杆上涂覆了吸波炭涂层,以改善TWT稳定性。通过一种带孔窄频—高波—道管的实验装置,应用无向量网络解析器实施反射和透射波测量,测得6.0GHz频段涂层杆的衰减程度。并利用一种软件高频结构模拟器(HFSS)进行了模拟。结果表明:胶体石墨涂层显示出最大的损失或吸光率,是适宜的衰减器涂料。HFSS模拟的结果与实验结果吻合。

Attenuator coatings of carbon were deposited on alumina support rods by pyrolytic deposition, aquadag coating and arc discharge to absorb the reflections and to improve the stability of a helical traveling wave tube. An experimental set up involving a narrow-height wave-guide with a hole was used to measure the attenuation of the coated rods at 6.0 GHz frequency by carrying out reflection and transmission measurements using a scalar network analyzer. The same structure was also simulated by using a high frequency structure simulator （HFSS）. Results indicate that the aquadagcoated films provide a maximum loss or absorbance and are suitable as the attenuator coating. The simulated results by HFSS agree well with the experimental observations.