Using A GaN HEMT Pulsing Circuit

In many applications such as military, weather and marine radar, RF power amplifiers are used in pulsed mode. Typically, the RF signal is pulsed while the DC bias used to power the transistor to a set point is left constant. However, in other applications pulsing the DC bias allows for reduced interference to the receiving path, noise and power consumption. The main challenge of drain pulsing is the high current on the drain side and switching time that can be achieved. This application note provides an overview of a circuit used to achieve 1.9 uS turn on time for a high-power (20 A peak) device using drain pulsing.