Semiconductor-Tuned High-Temperature Superconducting Filters for Ultra-Sensitive RF Receivers (SURF)

The goal of this program is to develop the technologies needed for the next generation of high-temperature superconducting (HTS) filters, enabling them to be tuned at microsecond speeds, and with other parameters (high quality factor "Q', low insertion loss, high out-of-band rejection, etc.) appropriate for their utilization by the armed forces. Tunable HTS filters are essential components for ultra-sensitive radio-frequency receivers, used for detecting weak signals in a competing environment of dense radio-frequency interference. There are several modalities. Tunable "notch" filters can suppress interference due to identifiable interferors, or self-interference due to friendly communication systems utilizing frequency band of interest, whose center frequency might change. These extraordinary new filters will be adaptable to a large set of missions, among them eliminating self-interference due to co-located transmitters, and detection of very weak signals which are unintended emissions characteristic of various threats.