ABSTRACT
This chapter explains the design and development of radio frequency and electro-optical devices incorporating rare earth materials. Solid state devices that include rare earth materials are gallium arsenides MESFETs, high electron mobility transistors, gallium nitride (GaN) high-power devices, silicon diodes, Li-Ni crystals, Hg:Cadmium:Te long wavelength detectors, erbium - and ytterbium -doped optical fibers. The chapter describes solid state amplifiers using GaAs MESFET and GaN devices, which deploy rare earth materials. Amplifier design engineers and solid state scientists claim that most research on GaN Wide-band power amplifiers should be undertaken with emphasis on Monolithic Microwave Circuit technology compared to hybrid MIC technology. Solid state device scientists recommend lower drain voltage, say 48 V for stress tests, in order to get reliable MTBF data at higher operating temperatures ranging from 300 to 350°C. Solid state scientists have performed comprehensive research studies which have reported on heat-flux cooling techniques for high-power microwave monolithic amplifiers.
