Ferrite-superconductor microwave phase shifters

Experimental ferrite phase shifters that utilize superconductor circuits with very low conduction losses are described. Magnetic flux is confined to a closed path, thereby avoiding deterioration of the superconducting properties that occurs when magnetic fields enter the superconductor. X-band differential phase shifters with meanderline circuits fabricated from niobium superconductors operated at 4 K have produced figures of merit exceeding 1000 deg/dB. The designs are adaptable to high-T/sub c/ superconductors.>