LOW NOISE BROADBAND CURRENT AMPLIFIER BY USING SQUID

摘要

PURPOSE: A low noise broadband current amplifier by using a SQUID is provided to easily operate by simplifying a SQUID driving circuit and increasing a measurement bandwidth and a slewing velocity. CONSTITUTION: A low noise broadband current amplifier by using a SQUID includes a superconductive thin film(2) for increasing a resist value by rising a temperature thereof when an x-line pulse(5) is inputted to the superconductive thin film(2), an input coil(3), a bias resistor(4) connected to the superconductive thin film(2) for inputting for a direct current(6), a signal SQUID(14) for receiving a current pulse(7) through the input coil(3) and for applying a direct applying current(19), a reference junction(16), a direct current front amplifier(20), an integrator(21), a feedback resister(22) and a feedback coil(23). The low noise broadband current amplifier utilizes a double relaxation oscillation SQUID method and adopts a reference junction as well as a signal SQUID at the same time.