Accurate power detector and dual directional coupler with self-calibration in 65nm CMOS

This work describes an autonomous detector which does not require any calibration during production and still maintains an accurate power reading of less than ±0.5dB under PVT and another ±0.4dB error for VSWR up to 2.6:1 change. The solution is based on self-compensated power detector with an integrated directional coupler having directivity of more than 20dB and 0.2dB loss with internal calibrations that are done during normal operation. The detector described in this work was designed for a WiFi system in 65nm CMOS. The whole detector size including the calibration and analog circuits is 0.1 mm2.