S波段20kW平均功率正交场放大器研究

Development of an S-band 20kW Average Power Crossed Field Amplifier

针对S波段长脉宽、大工作比正交场放大器应用需求,仿真优化了短管支撑曲折线慢波结构的色散及耦合阻抗特性,提出了输能结构改进方案,对高频系统进行了优化设计,仿真结果与冷测结果具有较好一致性,冷测结果表明,该设计实现了高频系统的宽频带及高效率。首次采用99.5%细晶氧化铝陶瓷作为控制极与阴极间绝缘介质,解决了绝缘组件大平均电流下击穿问题。首次采用固态放大器和二级正交场放大器搭建了三级放大链测试系统,实现了S波段正交场放大器大工作比测试,热测结果表明,在脉冲宽度300μs、工作比8%条件下,该放大器在300 MHz带宽内脉冲功率大于250 kW,平均功率大于20 kW,全带宽内效率大于52%,该放大器使S波段大功率正交场放大器技术水平迈上了新台阶,也是当前国际上脉冲宽度最宽、工作比最大的正交场放大器产品。

According to the requirements of S-band crossed field amplifier（CFA） with long-pulse width and large-duty cycle,the dispersion and coupling impedance of the Stub-Supported Meander Line structure are optimized. Then,the high frequency structure and energy output structure are designed and improved. Compared cold test result with simulation result,the performances of broad bandwidth and high efficiency are attained. 99. 5% alumina ceramics is firstly used for insulation between control electrode and anode. This structure could avoid the breakdown phenomenon of insulation assembly during the condition of large average current. Based on Solid State Amplifier and two-stage CFA,triple amplifier chain system is applied for hot-test of large duty cycle S-band CFA. With the condition of a pulse-width of 300μs and a duty cycle of 8%,the pulsepower and average-power are more than 250 kWand 20 kW respectively,with the bandwidth of 300 MHz,the operation efficiency is larger than 52% in full bandwidth. Basing on the breakthrough of key technology of high-average power and longpulse width CFA in design and technological process,the technology of S-band high-power CFA is improved drastically.