Physical aspects of microwave FETs (Review)

The characteristics of Schottky-barrier FETs for use in microwave devices are examined. Particular consideration is given to: the operating mechanisms of FETs; the smooth-approximation theory for transistors with a 1-micron gate length; the equivalent-circuit parameters; allowance for the strong-field domain and diffusion in two-dimensional analysis; transistors with a submicron gate length; noise characteristics; and stability. Attention is given to the physical properties of FETs which determine their efficiency in low-noise amplifiers in the upper part of the cm range and in the mm range.