Demonstration of a 20 GHz phase shifter using high-temperature superconducting SNS junctions

We have achieved a figure-of-merit of 90/spl deg//dB from a Co-doped Superconductor-Normal-Superconductor junction series array phase shifter, with 300 junctions The maximum observed phase shift was 25/spl deg/ from a 900 junction array. The entire device fits on a die size of 0.5/spl times/0.5 cm/sup 2/, which is suitable for integration into a phased array. However, the performance of this high-temperature superconductor device is still below the 150/spl deg//dB for a conventional shifter. In simulations, we see that an improved performance of 150-200/spl deg//dB is possible. If this performance can be achieved, the reduced base loss in addition to the reduction in loss from the antennas and feed lines in an integrated antenna array would lead to a system-wide performance advantage for a superconducting system.