ABSTRACT
Vacuum microelectronics is a new technology that uses micron-sized field emitter arrays (FEAs) as novel sources of electrons. FEAs have the potential to revolutionise free-electron microwave devices since electron emission can, in principle, be modulated by small voltages (10V) at very high frequencies (GHz) to effectively pre-bunch an electron beam for microwave generation. Moreover, FEAs are ‘cold’ emitters (requiring no heater current) which permit high current densities with spatial and temporal control and have a fast turn-on capability. This unique combination of properties makes possible smaller, lighter and more efficient microwave devices. FEA development at research centres around the world is proceeding with applications in display technology and microwave devices. This paper presents an overview of vacuum microelectronics for microwave power amplification, describes some recent advancements and briefly addresses future prospects.
