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.