A superconducting 4 bit instantaneous frequency meter at 10 GHz with integrated resistors and air-bridges

A fully integrated device on a single 2″-MgO wafer for a 4 bit instantaneous frequency measurement between 9.5 and 10.5 GHz has been developed with coplanar delay lines and power dividers. Due to integration of power divider resistors and a large number of air-bridges, improved transmission characteristics are achieved in a more reproducible way than with surface mounted chip-resistors and ultrasonically bonded air-bridges. The passive integrated circuit has 4 output signals and after threshold detection yields a one step binary code with a maximum resolution of ±31.25 MHz at a bandwidth of ∼1 GHz and a center frequency of ∼10 GHz. A 4 bit test vehicle with Nb-delay lines on a 2″-MgO substrate yields a total nonlinearity of 1/5 LSB corresponding to 12 MHz. Another test vehicle with YBCO-delay lines on a 2″-MgO substrate will also be discussed.