US Patent 9509274 Superconducting phase-shift system

One example includes a superconducting phase-shift system. The system includes an all-pass filter comprising at least one variable inductance element. The all-pass filter can be configured to receive an input signal and to provide the input signal as an output signal that is phase-shifted relative to the input signal based on a variable inductance provided by each of the at least one variable inductance element. The system can further include a phase controller configured to provide a phase-control current to control the variable inductance of the at least one variable inductance element based on a characteristic of the phase-control current.