De-Embedding Methodology to Characterize Linearity of Active Filters Under Process Variations

This brief presents a new method to characterize the linearity of on-chip filters with accurate characterization of the filter’s transfer function (TF) in both its bandpass and stopband. Unlike conventional methods, this approach uses only one buffer, simplifying the design and improving accuracy. The filter and buffer are designed using GlobalFoundries (GF) 22-nm FDX technology, incorporating a back-gate biasing tuning mechanism in the buffer design that aims to maintain the performance of the buffer under process variation. The postlayout simulations demonstrate that the new method achieves a filter linearity of $\text {IIP3}=10.46~\text {dBm}$ , with an accuracy of 99.4% compared to the standalone filter’s linearity. Similar consistency is observed across process corners.