mesfets are usually constructed in compound semiconductor technologies lacking high quality surface passivation such as gallium arsenide, indium phosphide, or silicon carbide, and are faster but more expensive than silicon-based jfets or mosfets. production mesfets are operated up to approximately 45 ghz, and are commonly used for microwave frequency communications and radar. the first mesfets were developed in 1966, and a year later their extremely high frequency rf microwave performance was demonstrated.