X波段300 kW正交场放大器设计

Design of an X band 300 kW crossed field amplifier

摘要:

首次提出采用高二次发射系数铂钡合金作为冷阴极，实现了X波段正交场放大器(CFA)宽脉冲和大工作比稳定工作。提出了双螺旋耦合翼片慢波结构与波导之间采用缝隙耦合加切比雪夫阻抗变换器输能结构设计方案。通过对慢波结构及高频系统仿真分析与设计，实现了慢波结构与输能组件间的宽频带良好匹配，电压驻波比及插损特性仿真结果与冷测结果具有很好的一致性。热测结果表明，放大器在1 GHz带宽内脉冲功率大于300 kW，效率大于57%，增益大于14 dB，填补了国内X波段宽带大功率正交场放大器的空白，是当前国际上脉冲宽度最宽、工作比最大的X波段正交场放大器产品。

Abstract:

The platinum-barium alloy with high secondary emission factor is selected as the cathode material for the first time. With this kind of cathode, the X-band Crossed Field Amplifier(CFA) could operate steadily with the condition of broad pulse-width and large duty ratio. The structure of the slot-coupled and Chebyshev transformer are proposed to connect the dual-helix coupled vane with output waveguide. Based on simulation analysis of RF system, the slow wave structure is perfectly matched with output waveguide; and the experimental results in VSWR and insertion loss are in agreement with simulation results. The test data shows that the device is able to deliver an output power of ~300 kW within 1 GHz bandwidth. In the full bandwidth, the efficiency and gain are more than 57% and 14 dB, respectively. This X-band crossed field amplifier is successfully manufactured for the first time in China. And so far, its pulse-width and duty ratio are the largest among the products of X-band crossed field amplifier in the world.