A Cellular-Band CDMA 0.25-<tex>$mu$</tex>m CMOS LNA Linearized Using Active Post-Distortion

Abstract

The theory of a linearization method using active post-distortion (APD) is explained for low-frequency and high-frequency applications. The low-frequency cancellation is explained in power series format and the high-frequency cancellation is explained in Volterra series format. The method is utilized for a cellular band (869-894 MHz) CDMA low-noise amplifier (LNA), which is implemented in 0.25-/spl mu/m CMOS process. The LNA achieves 1.2 dB NF, 16.2 dB power gain, and +8 dBm IIP3 while consuming 12 mA current from 2.6 V supply voltage. It shows 13.5 dB of IM3 product reduction with 0.15 dB NF penalty in comparison with an LNA which does not use the APD method.