The document describes an RF broadband power amplifier using 2x SD2933 N-channel enhancement-mode lateral MOSFETs. It has excellent thermal stability and operates over the frequency range of 1.6 to 54 MHz. The amplifier has a supply voltage of 48V, typical output power of 400W, and maximum input power of 10W. The efficiency is between 57% and 76%. The IMD at 300WPEP is less than -26dBc and the load mismatch is 3:1 for all phases.