All-digital 1-bit RSFQ autocorrelator for radioastronomy applications: design and experimental results

We present the design of a rapid single-flux-quantum all-digital 1-bit autocorrelator for submillimeter spectrometry applications, featuring 4-GHz input signal bandwidth, double oversampling quantizer, and 16-Mb/s-per-channel output rate. The correlator consists of a digital delay line with multiplication and an array of accumulators with parallel readout. We report experimental results for a three-stage delay line (294 Josephson junctions) and a 4/spl times/4 array of accumulators (288 Josephson junctions) fabricated in HYPRES' standard 3.5-/spl mu/m 1000-A/cm/sup 2/ Nb-trilayer process.