High Frequency Bandpass ADC Technology for Digitization at Ka/EHF-Band RF

HYPRES proposes to develop a novel superconducting delta-sigma analog-to-digital converter (ADC) for use in a military satellite communications (MILSATCOM) receiver. This ADC will directly digitize a 20 GHz microwave signal with a bandwidth of 1 GHz, using ultrafast rapid-single-flux-quantum (RSFQ) Josephson junction technology, with a sampling rate above 80 GHz, which is far beyond the current state-of-the-art in any technology. Such an ADC provides the core of a software-defined radio (SDR) receiver, permitting the replacement of multiple analog mixers, filters, and amplifiers with digital counterparts. In addition to reducing the number of discrete components, the superconducting receiver reduces the system noise temperature, thus increasing the G/T factor and improving the overall communications link. This project complements and leverages other HYPRES development projects for DoD involving digital receivers at lower frequencies, including similar bandpass ADCs centered at 1 GHz, 5 GHz, and 7.5 GHz.