Digital Iterative Harmonic Rejection and Image Cancellation for LPF-Less Frequency-Interleaved Analog-to-Digital Converters

The frequency-interleaved analog-to-digital converter features large bandwidth, high speed, medium-to-high resolution with respectable jitter robustness, albeit suffering from circuit impairments such as spectral leakages, harmonic interferences, in-phase/quadrature and aliasing images. For the first time, a digital compensation framework is introduced to minimize these impacts simultaneously. In this framework, channel recombination is performed before calibration. It circumvents the needs for analog harmonic rejection and channel separation, thus enabling significant simplification of the complex analog frontend design. A comprehensive system model that incorporates all the aforementioned distortions is formulated and leads to an iterative solution. Given the mismatch parameters, simulation outcomes validate the feasibility of this proposed framework and promise impressive performance benefits.