PURPOSE: To obtain a bipolar pulse generator which actuates a Josephson element at a high speed by combining a differential pulse generating circuit using an npn transistor TR and another differential pulse generating circuit using a pnp TR.
CONSTITUTION: When the base voltage of an npn transistor TR210 is higher than the 1st reference voltage VB1, an npn TR211 is cut off and the current flowing through a constant current source 230 is grounded via the TR210. When the base voltage of the TR210 is lower than the voltage VB1, the TR210 is cut off. Then the current flowing through the source 230 is supplied to an output terminal 250 via the TR211 and then to an earth via a termination resistance 301. The 2nd pulse generator 202 has the same actuation as the 1st pulse generator 201. However the generator 201 uses the npn TR and therefore the load current flows to the terminal 250 from the earth. While the generator 202 uses the pnp TR and therefore the load current flows to the earth from the terminal 250. As a result, a bipolar (positive and negative) pulse can be obtained with combination of both generators 201 and 202.
KAJI TETSUNORI
HATANO YUUJI
