  In this study, we investigated the performance of two 2D superconducting
quantum interference filter (SQIF) arrays fabricated from YBCO thin films at a
temperature of 77 K. Each array consisted of 6 Josephson junctions (JJs) in
parallel and 167 in series. We conducted both experimental and theoretical
analyses, measuring the arrays' voltage responses to an applied magnetic field
and their voltage versus bias-current characteristics. To properly model the
planar array layouts, our theoretical model used the stream function approach
and also included the Johnson noise in the JJs. The model further divides the
superconducting current density of the arrays into its Meissner current,
circulating current, and bias current parts for practicality. Since the
fabrication process of YBCO thin films cannot produce identical JJ critical
currents, we assumed a log-normal distribution to model the JJ critical current
disorder. Our model predictions, with a JJ critical current spread of 50%,
agreed well with our experimental data. Using our model, we were able to study
the dependence of the voltage modulation depth on critical current disorder and
London penetration depth. We also analyzed the observed reflection asymmetries
of the voltage versus magnetic field characteristics, which might provide
insight into the degree of critical current disorder. Overall, our findings
suggest that the use of YBCO thin films in SQIF arrays is promising, despite
the critical current disorder inherent in their fabrication process. Our study
highlights the importance of theoretical modeling in understanding the
performance of superconducting devices and provides insights that could inform
the design of future SQIF arrays.
