A Hardware Prototype of Wideband High-Dynamic Range ADC

Abstract: Key parameters of analog-to-digital converters (ADCs) are their sampling rate and dynamic range. Power consumption and cost of an ADC are directly proportional to the sampling rate; hence, it is desirable to keep it as low as possible. The dynamic range of an ADC also plays an important role, and ideally, it should be greater than the signal's; otherwise, the signal will be clipped. To avoid clipping, modulo folding can be used before sampling, followed by an unfolding algorithm to recover the true signal. In this paper, we present a modulo hardware prototype that can be used before sampling to avoid clipping. Our modulo hardware operates prior to the sampling mechanism and can fold higher frequency signals compared to existing hardware. We present a detailed design of the hardware and also address key issues that arise during implementation. In terms of applications, we show the reconstruction of finite-rate-of-innovation signals which are beyond the dynamic range of the ADC. Our system operates at six times below the Nyquist rate of the signal and can accommodate eight-times larger signals than the ADC's dynamic range.