Mixed signal integrated circuits based on GaAs HEMTs

During the past five years numerous mixed signal integrated circuits (IC's) have been designed, processed, and characterized based on our 0.2 mu m gate length AlGaAs/GaAs quantum well HEMT technology. Utilizing the inherent advantages of the AlGaAs/GaAs material system, optical, analog, microwave, and digital functions have been integrated monolithically. Examples are a chip set for 40 Gb/s optoelectronic data transmission systems, 15 and 34 GHz PLL's, a 35 GHz phase shifter for phased array antenna applications, a 2-kb ROM with subnanosecond access time for direct digital signal synthesis, and a 6-k gate array