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

HYPRES proposes to develop a novel delta-sigma analog-to-digital converter (ADC) for use in military satellite communications (MILSATCOM) receivers. This ADC will directly digitize a 20 GHz microwave signal with a bandwidth of 1 GHz, using ultrafast rapid-single-flux-quantum (RSFQ) superconductor integrated circuits (ICs), providing performance which is not achievable in any other technology. Such an ADC enables the replacement of multiple analog mixers, filters, and amplifiers with lower-noise, programmable digital components. During Phase I, a novel circuit architecture was developed that assures the near-term demonstration of these aggressive performance specifications using available IC fabrication technology. In Phase II, we will implement a complete single-channel bandpass digital receiver, comprising a Ka-band (20.2-21.2) ADC modulator, digital in-phase and quadrature (I&Q) mixers and two 16-bit decimation filters, operating at a clock speed of at least 27.6 GHz. We will also implement a multi-rate digital filter that will enable higher performance with higher ADC sampling rate. This project complements and leverages other HYPRES development projects for the DoD involving digital receivers at lower frequencies, as well as cryogenic integration demonstration projects.