Inductor-less PVT robust gain switching balun LNA for multistandard applications

摘要

An inductor-less single to differential low-noise amplifier (LNA) is proposed for multistandard applications in the frequency band of 0.2-2 GHz. The proposed LNA incorporates noise cancellation and voltage shunt feedback configuration to achieve minimum noise characteristics and low power consumption. In addition to noise cancellation, trans-conductance of common-source stage is scaled to improve the noise performance. In this way, noise figure (NF) of LNA below 3 dB is achieved. An additional capacitor C-c is used to correct the gain and phase imbalance at the output. The gain switching has been enabled with a step size of 4 dB for high linearity and power efficiency. The bias point of all transistors is chosen such that the variation in g(m) is not more than 10%. The proposed LNA is implemented in UMC 0.18-mu m RF CMOS technology. The core area is 182 mu m x 181 mu m. Moreover, the LNA has better ratio of relevant performance to area. The proposed balun LNA is validated by rigorous Monte Carlo simulation. The 3 sigma deviation of gain and NF is less than 5%. Finally, the proposed LNA is robust to unavoidable PVT variations.