330 MHz SQUID amplifier coupled to a capacitive transducer for gravitational wave experiments

Abstract A low noise high frequency r.f. SQUID is used for detecting the current flowing in a superconducting inductance coupled to a capacitive resonant displacement-voltage transducer. The SQUID output power spectrum for the whole system shows a noise performance only a factor two worse than in the uncoupled configuration. An upper limit for the predicted SQUID negative resistance has been found.