High-Speed Analog Signal Processing with Superconductive Circuits

A new technology utilizing superconductive circuits to provide wideband analog signal processing is described. The function of a canonical signal processor is reviewed, followed by a description of the structure and performance of recently implemented superconductive tapped delay lines and convolvers. The technology has two key features: low-loss and low-dispersion electromagnetic striplines.which provide tapped delay on compact substrates; and superconductive tunnel junctions,which provide efficient low-noise mixing and high-speed sampling circuits. As a demonstration of the utility of this new class of superconductive devices, an ultrawideband chirp-Fourier spectrum analyzer has been developed,which provides a 60-channel analysis of a 2.4-GHz band in 40 ns. Projections based on these results indicate that superconductive technology should support analog device bandwidths of at least 10 GHz with time-bandwidth products up to 1000. Such circuits will provide real-time signal-processing functions with the digital equivalent of up to 1012 operations/sec. In addition to pure analog structures, superconductive technology supports high-speed digital components and thus offers the potential for integrated analog/digital signal processors of greater efficiency, speed and processing gain than would be achievable by either approach in isolation.