Class-E Silicon Carbide VHF Power Amplifier

Silicon carbide (SiC) Metal-Semiconductor Field Effects Transistors (MESFET) have been mostly employed in microwave and broadband radio frequency (RF) power amplifiers. This paper investigates an alternative use in high efficiency, class-E RF power amplifiers in the VHF range. Both simulation and experimental results are shown and demonstrate excellent agreement. A maximum drain dc to RF efficiency of 87% was predicted and 86.8 % achieved. The SiC MESFETs used in this project appear to offer significant advantages, particularly for space applications, over gallium arsenide (GaAs) transistors, which are inherently low voltage devices and more difficult to operate in class-E due to the high drain peak voltage occurring in this class of operation.