PSEUDOMORPHIC HEMTS FOR MILLIMETER WAVE COMMUNICATIONS

ADVANCES IN SCIENTIFIC INSTRUMENTATION USED IN DEEP-SPACE MISSIONS HAVE GENERATED A NEED FOR HIGH DATA-TRANSMISSION RATES TO EARTH. IT MAY BE ECONOMICALLY FEASIBLE TO USE THE KA BAND (27-40 GHZ) FOR UP- AND DOWN-LINKING; THUS DEVELOPMENT OF MONOLITHIC MICROWAVE INTEGRATED-CIRCUIT PHASED ARRAY DISTRIBUTION SYSTEMS FOR MILLIMETER WAVELENGTHS IS DEMANDED. THE PSEUDOMORPHIC, HIGH-ELECTRON-MOBILITY TRANSISTOR (HEMT) IS UNEQUIVOCALLY THE BEST CANDIDATE FOR HIGH-POWER, HIGH-EFFICIENCY APPLICATIONS FROM 10-100 GHZ. ITS SUPERIOR LOW-NOISE PERFORMANCE PROVIDES THE OPPORTUNITY FOR INTEGRATION OF BOTH HIGH-POWER AND LOW-NOISE DEVICES ON THE SAME CHIP WITHOUT COMPROMISING THE PERFORMANCE OF EITHER COMPONENT. THE INNOVATION EXPLORED IN THIS PROJECT IS AN INVERTED, DOUBLE, HETEROJUNCTION HEMT WITH PULSE-DOPED DONOR AND PSEUDOMORPHIC CHANNEL LAYERS TO BE GROWN BY MOCVD, THE DEPOSITION TECHNIQUE OF CHOICE FOR HIGH-QUALITY PRODUCTION CAPABILITY. THE PHASE I PROJECT WILL DEMONSTRATE FEASIBILITY OF CONCEPT; PHASE II WILL RESULT IN AN OPTIMIZED STRUCTURE SUITABLE FOR PRODUCTION. ADVANCES IN SCIENTIFIC INSTRUMENTATION USED IN DEEP-SPACE MISSIONS HAVE GENERATED A NEED FOR HIGH DATA-TRANSMISSION RATES TO EARTH. IT MAY BE ECONOMICALLY FEASIBLE TO USE THE KA BAND (27-40 GHZ) FOR UP- AND DOWN-LINKING; THUS DEVELOPMENT OF MONOLITHIC MICROWAVE INTEGRATED-CIRCUIT PHASED ARRAY DISTRIBUTION SYSTEMS FOR MILLIMETER WAVELENGTHS IS DEMANDED. THE PSEUDOMORPHIC, HIGH-ELECTRON-MOBILITY TRANSISTOR (HEMT) IS UNEQUIVOCALLY THE BEST CANDIDATE FOR HIGH-POWER, HIGH-EFFICIENCY APPLICATIONS FROM 10-100 GHZ. ITS SUPERIOR LOW-NOISE PERFORMANCE PROVIDES THE OPPORTUNITY FOR INTEGRATION OF BOTH HIGH-POWER AND LOW-NOISE DEVICES ON THE SAME CHIP WITHOUT COMPROMISING THE PERFORMANCE OF EITHER COMPONENT. THE INNOVATION EXPLORED IN THIS PROJECT IS AN INVERTED, DOUBLE, HETEROJUNCTION HEMT WITH PULSE-DOPED DONOR AND PSEUDOMORPHIC CHANNEL LAYERS TO BE GROWN BY MOCVD, THE DEPOSITION TECHNIQUE OF CHOICE FOR HIGH-QUALITY PRODUCTION CAPABILITY. THE PHASE I PROJECT WILL DEMONSTRATE FEASIBILITY OF CONCEPT; PHASE II WILL RESULT IN AN OPTIMIZED STRUCTURE SUITABLE FOR PRODUCTION.