MICROWAVE-ACOUSTIC RESONATORS AND FILTERS FOR MMIC MODULES

THE TRI-SERVICE MMIC PROGRAM HAS ACHIEVED GOOD SUCCESS IN DEVELOPING MOST OF THE KEY ELEMENTS WHICH ARE NEEDED FOR MONOLITHIC MICROWAVE CIRCUITS. FOR EXAMPLE, AMPLIFIERS, MIXERS, FREQUENCY MULTIPLIERS, FREQUENCY DIVIDERS, MODULATORS, AND DEMODULATORS HAVE ALL BEEN SUCCESSFULLY DEMONSTRATED. HOWEVER, TWO KEY FUNCTIONS HAVE BEEN MISSING, NAMELY FREQUENCY FILTERS AND FREQUENCY SETTING ELEMENTS (FOR OSCILLATORS). CURRENT MMIC RESEARCH AS STILL RELIED ON OLDER (NON-MONOLITHIC) TECHNOLOGIES FOR PROVIDING THESE TWO CRITICAL FUNCTIONS WHICH ARE NECESSARY FOR COMPLETE MMIC SUBSYSTEMS. IF A SIGNIFICANT IMPROVEMENT IN RF AND MICROWAVE SUBSYSTEM SIZE IS TO OCCUR AS A RESULT OF THE MMIC EFFORT, A MAJOR ADVANCE MUST BE MADE TO ACHIEVE MONOLITHIC IMPLEMENTATION OF THESE TWO CRITICAL FUNCTIONS. FOR FREQUENCIES BELOW 1 GHZ, SURFACE ACOUSTIC WAVE (SAW) AND BULK ACOUSTIC WAVE (BAW) TECHNOLOGIES HAVE PROVIDED EXCELLENT MONOLITHIC IMPLEMENTATIONS OF THESE TWO FUNCTIONS. THE PROPOSED PROGRAM WILL EXTEND THE FREQUENCY RANGE OF THESE ACOUSTIC TECHNOLOGIES BY A FACTOR OF 10 THROUGH THE DEVELOPMENT OF AN INNOVATIVE NEW CLASS OF ACOUSTIC PROPAGATION MODES WHICH HAVE PHASE VELOCITIES THAT ARE UP TO 10 TIMES LARGER THAN CONVENTIONAL ACOUSTIC WAVE VELOCITIES. SUCCESSFUL COMPLETION OF THIS EFFORT WOULD MAKE A MAJOR BREAKTHROUGH FOR MICROWAVE FILTER AND RESONATOR TECHNOLOGY.