Wideband Balun-LNA With Simultaneous Output Balancing, Noise-Canceling and Distortion-Canceling Stephan C. Blaakmeer , Member , IEEE, Eric A. M. Klumperink , Senior Member , IEEE

Abstract

An inductorless low-noise amplifier (LNA) with active balun is proposed for multi-standard radio applications between 100 MHz and 6 GHz. It exploits a combination of a common-gate (CG) stage and an admittance-scaled common-source (CS) stage with replica biasing to maximize balanced operation, while simul- taneously canceling the noise and distortion of the CG-stage. In this way, a noise figure (NF) close to or below 3 dB can be achieved, while good linearity is possible when the CS-stage is carefully op- timized. We show that a CS-stage with deep submicron transistors can have high IIP2, because the cross-term in a two-di- mensional Taylor approximation of the /40 /41charac- teristic can cancel the traditionally dominant square-law term in the /40 /41relation at practical gain values. Using standard 65 nm transistors at 1.2 V supply voltage, we realize a balun-LNA with 15 dB gain, NF 3.5 dB and IIP2 /4320 dBm, while simul- taneously achieving an IIP3 0 dBm. The best performance of the balun is achieved between 300 MHz to 3.5 GHz with gain and phase errors below 0.3 dB and 2 degrees. The total power con- sumption is 21 mW, while the active area is only 0.01 mm /50.