Superconductor ADC for WindSat

The ability to directly digitize high frequency analog radio frequency (RF) signals greatly simplifies multi-band microwave receivers. Superconductor analog-to-digital converters (ADC) offer discriminating advantages in both bandwidth and fidelity due to very high sampling rates and quantum-accurate digitization based on counting of magnetic flux quanta. Multiple digital-RF receiver systems incorporating superconductor ADCs have been in operation for over two years in field-ready configurations at Government laboratories, and have demonstrated direct digitization of RF signals above 20 GHz. We propose to increase sampling rates from 40 GHz in current ADCs proven in these delivered systems to 100 GHz and 200 GHz. These ADCs will be designed together with proportionately faster on-chip digital circuits and high-quality analog circuits that will allow us to not only design, but to build, and demonstrate hardware prototypes in Phase II. During Phase I, we will build circuit models and use state-of-the-art simulation tools to develop a roadmap of ADC designs with increasing speed and complexity to meet the needs of spaceborne microwave radiometry and other RF applications.