This paper presents a 2.4GHz, reconfigurable RF LNA using on-chip peak detection and calibration to measure and optimize its input impedance (S 11) and gain (S21) in-situ, compensating for the unpredictable effects of process, voltage and temperature (PVT) variations. Measurement results show that the calibration of the LNA across PVT corners improves the S11 by 5.1dB, S21 by 3dB, while not significantly degrading the Noise Figure (0.22dB degradation) and linearity (1.7dBm degradation). © 2010 IEEE.