Comparison and IIP2 analysis of two wideband Balun-LNAs designed in 65nm CMOS

Abstract

Two wideband Balun-LNA configurations have been designed in 65nm COMS technology. Both of them employ a single-to-differential (S-to-D) conversion topology composed of a common gate (CG) amplifying stage and a common source (CS) stage, providing output balancing and noise and distortion cancelling. One is inductorless and the other one exploits gain-boosting current-balancing topology. With 2.5V and 2.5V/1.8V supply the LNAs achieve voltage gains of 24.5dB and 22.8dB, noise figures of below or close to 3dB, input second-order intercept points (IIP2) of 31dB and 41.8dB, respectively. In addition, the sensitivity of IIP2 is deeply investigated.