High-Dynamic-Range Digital-RF Receiver with Rapidly Tunable Notch Filters for Cosite Interference Reduction

HYPRES proposes a two-pronged approach to reducing co-site interference: (1) Tunable notch filters to track one or more narrow-band jamming signals. (2) The use of a sensitive digital-RF receiver with high spur-free dynamic range (SFDR), which can tolerate high inteference levels without saturation. Together, these techniques can reduce the inteference to an acceptable level. We further propose to evaulate the feasibility of implementing both of these using superconducting components. These include: (1) Thin-film RF analog notch filters based on high-temperature superconductors (HTS), rapidly tunable by either micromechanical, optical, or thermal means. (2) A digital receiver built using ultrafast low-temperature superconducting (LTS) digital integrated circuits, with SFDR greater than 100 dB. Several possible receiver architectures will be investigated, including active cancelation and subranging. Both HTS and LTS components can be integrated together using a compact, multi-stage cryocooler, so that the entire system can operate without the need for liquid cryogens. This builds on prior and continuing DoD programs at HYPRES developing digital-RF receiver systems using superconducting components.