Electrically-Small Superconducting Wide-Bandwidth Receiver Based on Series Arrays of Nano-Josephson Junctions

ABSTRACT: There is currently a large widespread research effort to develop physically and electrically small antennas with ultra-wide-bandwidth to replace the many antennas operating on communication and signals intelligence- SigInt- systems at different frequencies with a single compact unit. Such an antenna would substantially increase the communication and detection abilities of aircraft and small direction-finding mobile platforms. The leading technology involves using arrays of superconducting quantum interference devices (SQUIDs). These devices boast the large bandwidths necessary for this application and also possess high sensitivity. Great progress has been made in the realization of SQUID based antennas but they are difficult to fabricate because non-uniformity in junction parameters quickly degrade performance. Especially important is the linearity which is crucial for detecting a small signal in the presence of nearby interfering signal without mixing them together. One additional concern with SQUID based receivers is that the dynamic range is small and may be overloaded by larger signals. Here we propose an alternative device based on long Josephson junctions which are conceptually simpler, possess intrinsic high linearity, very large dynamic range, and have potentially greater signal to noise. They are also much easier to manufacture because of their robustness to Josephson junction parameter spread.; BENEFIT: We propose to apply our now well-established Josephson technology to increase the voltage and hence the sensitivity while improving the signal-to noise of a Fraunhofer device well beyond that obtainable from SQUID devices. We propose a state-of-the-art electrically small ultra-wideband antenna based on Josephson junction arrays which may have wide bandwidth, linearity and dynamic range unsurpassed by any current technology.