Optimal equivalent‐time sampling for periodic complex signals with digital down‐conversion

Abstract Equivalent‐time sampling can improve measurement or sensing systems because it enables a broader frequency band and higher delay resolution for periodic signals with lower rates than Nyquist receiver. Meanwhile, digital down‐conversion (DDC) technique be implemented using straightforward radio (RF) circuit. It avoids timing skew in‐phase/quadrature gain imbalance instead of requiring high‐speed analog‐to‐digital converter to sample an intermediate (IF) signal. Therefore, when equivalent‐time DDC techniques are combined, significant synergy achieved. This study provides parameter design methodology optimal DDC.