Static induction transistor (SIT) is a high power, high frequency transistor device. It is a vertical structure device with short multichannel. Being a vertical device, the SIT structure offers advantages in obtaining higher breakdown voltages than a field-effect transistor (FET). For the SIT, it is not limited by the surface breakdown between gate and drain, and can operate at a very high current and voltage. This device is also known as a V-FET, and can be found in some of the more upmarket amplifiers from Sony back in the late 1970s and Yamaha from 1973 - 1980.
An SIT has: