METALLIC QUANTUM TUNNELLING VARISTOR DEVICES

FOR FAST RISE TIME PULSES AND HIGH POWER MICROWAVE APPLICATIONS, A NEW CLASS OF VARISTOR DEVICES IS NEEDED THAT SURPASSES THE PERFORMANCE OF PRESENT DEVICES. CURRENTLY AVAILABLE VARISTOR MATERIALS DEPEND ON SEMICONDUCTOR JUNCTIONS, AVALANCHE MECHANISMS, OR ZENER ACTION, OR A COMBINATION OF THESE EFFECTS. AN ALTERNATIVE THAT OFFERS SIGNIFICANT ADVANTAGES IN TERMS OF RESPONSE CHARACTERISTICS, RELIABILITY, AND TEMPERATURE STABILITY IS TO USE METALLIC QUANTUM TUNNELLING TO PRODUCE THE DESIRED NONLINEAR CHARACTERISTICS. ALTHOUGH THERE ARE MATERIALS THAT ARE PURPORTEDLY OF THE METALLIC TUNNELLING VARIETY, WE BELIEVE THE TUNNELLING REGIME HAS NOT BEEN ACHIEVED NOR HAS THERE BEEN AN APPROPRIATE EMPIRICAL QUANTUM TUNNELLING SIGNATURE USED IN EVALUATING THESE MATERIALS. THE OBJECTIVES OF THIS PROJECT ARE TO: DEVELOP A CORRECT EMPIRICAL SIGNATURE INDICATING WHETHER OR NOT A VARISTOR MATERIAL IS OPERATING IN THE METALLIC TUNNELLING REGIME; DETERMINE MATERIAL PARAMETERS TO ASSURE THE TUNNELLING REGIME IS ACHIEVED; FABRICATE METALLIC TUNNELLING VARISTORS APPROPRIATE FOR PROTECTION OF HF, VHF, AND UHF COMMUNICATIONS EQUIPMENT FROM UPSET OR FAILURE CAUSED BY "FRONTDOOR" EMP INTRUSION; TEST THE DEVICES UNDER LABORATORY CONDITIONS.