PURPOSE: To prevent an oscillation when the electric characteristic of an elemen tal transistor is measured by a method wherein the abnormal oscillation of the transistor is absorbed by a series circuit which is composer of a capacitance and of a resistance equivalent to a constant impedance in a distributed constant line.
CONSTITUTION: The title circuit is provided with the following: distributed constant lines 14, of a constant impedance, which are connected to an input terminal at a transistor; a terminal 34, for measurement use, which is extended from an arbitray position in the distributed constant lines 14 and which is provided with a reactance component; and a series circuit which is connected to the opposite side of an input terminal for the distributed constant lines 14 and which is composed of a capacitance 44 and of a resistance 64 equivalent to a constant impedance in the distributed constant lines 14. Thereby, since an oscillation frequency can be absorbed up to a frequency whose constant impedance is guaranteed, it can be suppresses perfectly.
ISHIKAWA OSAMU
AZUMA CHINATSU
