A 28.8MHz 21.1dBm-IIP3 3.2mW Sallen-Key 4th-Order filter with out-of-band zeros cancellation

A 4th-order 28.8MHz low-pass analog filter uses a modified version of Sallen-Key (SK) biquad that solves the standard SK cell critical aspect due to the out-of-band zeros (OoB). The proposed cell completely cancel the OoB zeros by means of a low-power auxiliary path and a specific design optimization.