Wideband Frequency Selective Limiter

A concept for a novel wideband Frequency Selective Limiter (FSL) using High Temperature Superconductors (HTS) is proposed. The device selectively limits the level of narrow band high power signals over a relatively wide frequency band without appreciable effect on the weak signals. Thus high dynamic range can be maintained for receiver systems designed to intercept weak signals over a wideband, which otherwise could be masked by the strong signal saturation effects. The operation of the FSL device is based on channeling of the total signal frequency components to sub-bands with subsequent attenuation of the band limited strong signals individually. Due to the frequency separation, weak signals sufficiently separated in frequency from the interfering signals are practically unaffected. Thus the dynamic range of the system is maintained while the weak signals are preserved. Superconductor technology allows devices with high selectivity to be built, as a result of the extremely low loss of circuits using HTS. Low to moderate performance devices can be implemented using conventional technologies albeit with lower selectivity and possibly higher insertion loss.