Patent ID: 7242200

Claim:
A field-effect-transistor characteristic measuring system in which a pulse output from a pulse generator is applied to a gate of a field effect transistor to measure drain current flowing through the field effect transistor, the pulse having a voltage based on a set voltage, the measuring system comprising: a divider for dividing the pulse output from the pulse generator into a first pulse applied to the gate of the field effect transistor and a second pulse for voltage measurement; voltage measuring means for measuring a voltage of the second pulse; and set-voltage adjusting means comprising a terminating resistor connected to a transmission path for the first pulse, wherein said set-voltage adjusting means is for determining, based on the voltage of the second pulse, a target set voltage for the pulse generator to apply a pulse having a desired gate application voltage to the field effect transistor and for adjusting the set voltage to the target set voltage so that a voltage of the first pulse is equal to the desired gate application voltage.