Properties of a high-T/sub c/ dc SQUID radiofrequency amplifier

We present an experimental investigation of a radiofrequency amplifier based on a bicrystal high-T/sub c/ dc SQUID designed for the frequency range 500-3000 MHz. The SQUID input coil comprises only one layer of a normal metal forming open-ended microstrip line. Both dc and microwave properties were investigated and analyzed. Maximum power gain was found to be 16 dB at 520 MHz for a SQUID with 8 turn input coil.