Josephson Junctions Based Low Temperature Superconducting Phase Shifter for X- and K-Band using MIT-LL SFQ5ee Process

This paper presents results for a low temperature superconductor (LTS) based phase shifter realized by coupling an array of Superconducting Quantum Interference Devices (SQUIDs) to a transmission line. The phase is controlled by the use of a dc control voltage applied to the transmission line. A phase shifter having an array of 2256 rf-SQUIDs is analyzed and experimentally demonstrated. The measured results show a controllable phase shift of 130◦ in the X-band and 328◦ in the K-band with an insertion loss variation of 0.46 ±0.23 dB and 2.5 ±1 dB, respectively. The device is realized using MIT Lincoln Laboratory eight niobium layer fabrication process with a chip footprint of 2.5 mm × 1.6 mm.