2200W High-Efficiency Amplifier Module Covering 325MHz and 352MHz Applications

After developing a 352 MHz 1600 W RF power amplifier with the ART2K0FE LDMOS transistor from Ampleon, the question was whether we could increase this power with the newer ART2K5TPU transistor from Ampleon with a comparable efficiency. In addition to the 352 MHz target, there is also a desire to find a configuration for 325 MHz, and if possible even a combination of both frequencies. The amplifier section of the modular LE029 amplifier platform is used as a starting point. The LE029 platform is designed for highly accurate reproduction, which is beneficial for power balancing in multi-unit amplifier systems. During many tests and experiments it has become apparent that the circuit can be optimized to such an extent that a frequency range from 325 MHz to 352 MHz can be covered with an efficiency of more than 70%. An observation has been made for 330 MHz, where a power of more than 2500 W can be achieved at 74% efficiency. Further research showed that the planar balun structure appears to be responsible for this. A planned follow-up study will further investigate the extent to which this extreme optimum can be tuned to other frequencies.