New Transistor Operating for High Frequency and High Power

The main mechanism of operation of a new transistor which shows exponential I-V character, is based on the static induction and is called SIT (Static Induction Transistor). SIT is a promissing device also for higher frequency operation because of (1) short channel length, (2) lower gate series resistance, (3) small gate-source capacitance, (4) small gate-drain capacitance. Si SIT exhibits GHz operation: 200 MHz-40 watts, 1 GHz-5 watts, cut-off frequency is more than 2.0 GHz. Further developments of higher frequency and, higher power devices can be realized in distributed structure and travelling-wave operation of SIT. It will be soon possible to prepare an SIT which operates 100 watts out-put power at GHz frequencies.