For 2026, the FDIM Design Challenge took a different twist – the goal was to demonstrate a 40M QRP transmitter having the highest DC to RF conversion efficiency. We had many entries using a number of PA designs and topologies. The winning entry was designed by Mark Frost AC9VC, demonstrating a DC to RF efficiency of 86.0%
Mark’s innovative design used a Gallium Nitride mosfet as the power amplifier device, very impressive!
Congratulations to Mark!