High frequency oscillations in epitaxial layers of GaAs by circuit control of domain growth

The main objective of the work described here was to characterize the microwave circuit necessary to generate oscillations in the range 26 to 40 GHz from layers of epitaxially grown GaAs. Typically, layer thickness and doping concentrations were 10 µ and 2 × 10¹⁵/cm³. The layers used were of two types, n + + - n - n + (vapor regrown sandwich) and n + -n. They have been operated in both CW and pulse conditions with a bias field of 2-3 times the threshold value. Peak pulse power generated has been 450 mW at 28 GHz with an efficiency of 2.6%.