Field effect tube electrical characteristics

Field effect transistor and transistor in the electrical characteristics of the main difference is the following:Patch FET1: the field effect tube voltage control device, the conductive case depends on the gate voltage. Transistor is the current control device, the conductive case depends on the size of the base current.2: the field effect tube current IDS and the grid UGS Gm decided by the relationship between the transconductance, transistor current Ic and Ib by the relationship between amplification coefficient βdecision. That is to say, the field effect tube capable of amplifying Gm measure, transistor capable of amplifying the use of βmeasure.3: FET input impedance, input current is small; the transistor input impedance is very small, in the conductive when larger input current.4: the FET drain source static volt-ampere characteristic with gate voltage UGS variables, transistor characteristic curve to the base current of Ib variables.5: general field effect tube with small power, high power transistor.