Noise analysis of the quantum flux parametron

An analysis of the limitations imposed by thermal noise on the application of the quantum flux parametrons (QFPs) as current comparators and timing discriminators is presented. At low operational frequencies, a thermal activation approach is used, while at high frequencies a circuit simulation method is required. At frequencies greater than the Josephson junction plasma frequency, an approximate expression for the noise is given. The calculations are in good agreement with the approximations and the experimental results.<>