This final report summarizes the development work under the contract and the results obtained. Techniques were developed and applied culminating in several practival wideband amplifiers. The highest overall gain noted was 45 db at band center (93.75 Gc) with best noise figure at 16 db. Operation from 68 to over 100 Gc was demonstrated but the practical instantaneous bandwidth was limited to 15 or 20 Gc in each case due to dispersion. Continuance toward a field-type model is strongly recommended on the basis of the demonstrated feasibility and present radiometric need. Extension of this development of the 1-2 mm region is now entirely practical. In addition, cryogenic operation can remove the criticalness from the focusing components and conceivably result in a 6 db noise figure device with 45 Gc bandwidth centered at the 3.2 mm atmospheric window. (Author).