A 2.3 kW 80% Efficiency Single GaN Transistor Amplifier for 400.8 MHz Particle Accelerators and UHF Radar Systems

RF Power Amplifiers (PA) based on single GaN/SiC High Electron Mobility Transistors (HEMT) operating at 100 VDC in CW or 145 V in pulse mode are reported here with 2x 50 mm gate periphery which achieve 1.2 kW CW and 2.3 kW with a pulse width of 100 s and 5% duty cycle, both with 80% drain efficiency. The amplifier design employs harmonic tuning to achieve high efficiency and patented thermal enhancement techniques that help mitigate heat dissipation in such high-power density transistors. These devices and circuits have been designed to operate at 400.8 MHz for potential interest at CERN for the proposed High Luminosity Large Hadron Collider (LHC), or for UHF high power radar systems. The technology allows for single transistors with power levels of 2 kW CW or 4 kW pulsed and efficiency >70% which reduce the number of combiners and related losses to achieve MW power levels.