微波大功率变脉冲放大器的研制

针对基于悬浮平台微波凝视关联成像系统对变脉冲宽度和大峰值功率的需求,研制了一款 X 波段变脉冲固态功率放大器。描述该放大器组件中高速漏极调制及保护电路和射频开关的实现方案,分析大功率高速漏极调制电路输出电压脉冲的影响因素,优化调制电路的负载设计,并解决功放输出射频脉冲的包络凹陷问题。经试验验证:研制的功率放大器具有散热性好,稳定工作时间长,最窄脉宽 20 ns,上升下降沿均小于 3 ns,峰值功率大于 40 W 的射频脉冲输出等特点;其漏极调制电路输出 24 V电压脉冲,上升沿小于 20 ns,下降沿约 60 ns。

A Study and Design of Microwave High Power Amplifier with Variable Pulse Width

With the demand of variable pulse width and high peak power by the microwave staring correlated imaging system of suspended platform, an X-band variable pulse width solid-state power amplifier is designed in this paper. The implementation schemes of the high-speed drain modulation, protection circuit and the radio frequency ( RF) switch are described. Then the factors affecting the voltage pulse of the high power and high-speed drain modulation circuit are analyzed and the load of the drain modulation circuit is optimized. In addition, solutions are put forward for the problem that the envelope of the output RF pulse of the amplifiersags. Experiments demonstrate that the developed power amplifier can work stably for a long time and the most narrow output pulse width is 20 ns with more than 40 W peak power, and less than 3 ns rising and falling time. The rising time of the 24 V voltage pulse of the drain modulation circuit is less than 20 ns, and the falling edge is about 60 ns.