Many Octave, Ultra-Sensitive Low Frequency Receivers

The proposal aims at developing super-resolution (26-bits) analog-to-digital converters (ADCs) having an instantaneous bandwidth of 20 MHz by using "derivative-sampling" that breaks the Shannon-Nyquist criteria of sampling. Derivative sampling would sample the signal and its higher-order derivatives at sub-Nyquist to achieve larger bandwidth and resolution. The sub-Nyquist samples of the signals and its derivatives would then be digitally processed using digital filter-banks to generate the requisite samples at Nyquist rate. The derivative of the signals will be generated by using various order high-pass filters. Thus to achieve the desired performance the proposal would build high-pass filters and ADCs. The proposal will explore 3 different architectures, viz., 1. Semiconductor high-pass filters and semiconductor ADC, 2. Super-conductor high-pass filters and ADC, and 3. Hybrid, i.e., Superconductor high-pass filters and semiconductor ADC. The best of the three architectures would then be designed, fabricated, and tested in the later phases.