Embedded ARM-based automatic gate bias control system for LDMOS RF power amplifiers

An intelligent gate voltage control system is proposed in accordance with changes of temperature and drain current. The system is implemented in an embedded ARM platform ADuC7026 (ARM7), in which the uC/OS-II operating system is utilized to the control the compensation process for the deterioration of the LDMOS power amplifier (PA) at different temperatures in real-time. With the interrelation of temperature, bias gate voltage and drain current, the parameters of LDMOS PAs could be changed automatically in accordance with external conditions and drain current through real-time monitoring the working status of the power amplifier so as to maintain its linear stability. Finally, the effectiveness and reliability of the system are verified directly by the good performance of the simulation and hardware experiments.