EFFICIENCY ENHANCEMENT OF IMPATT DIODES

A NEW APPROACH FOR IMPROVING THE EFFICIENCY OF AN IMPATT DIODE HAS BEEN PROPOSED BY THE USE OF HETEROSTRUCTURES. THE GOAL FOR THE CONVERSION EFFICIENCY IS A MINIMUM OF 32%. THE HETEROSTRUCTURE WILL CONSIST OF A LOW BAND GAP MATERIAL (E.G. GAINAS) FOR THE AVALANCHE REGION AND A HIGHER BAND GAP MATERIAL (E.G. INP) FOR THE DRIFT REGION. A THEORETICAL ANALYSIS INCLUDING COMPUTER SIMULATION WILL BE PERFORMED FOR SELECTING THE PROMISING MATERIALS FOR THE FABRICATION OF IMPATTS. THE THEORETICAL STUDY WILL INCLUDE NOT ONLY THE DC CHARACTERISTICS (E.G. BREAKDOWN VOLTAGE, LEAKAGE ETC.) BUT RF PROPERTIES AS WELL. SOME OF THE SELECTED MATERIALS WILL BE GROWN EITHER BY MBE OR BY MOCVD. FOLLOWING CHARACTERIZATION, THE WAFER(S) WILL BE PROCESSED INTO CHIPS. AN ATTEMPT WILL BE MADE TO OBTAIN PULSED RF RESULTS BEFORE THE END OF PHASE I.