Low Noise Amplifier Architecture Analysis for OFDM-UWB System in 0.18μm CMOS

This paper analyzes architectures of the low noise amplifier (LNA) for orthogonal-frequency-division-multiplexing ultra-wideband (OFDM-UWB) application. Until now, most UWB LNA implementations are focusing how to realize a single LNA covering the whole frequency band. In this work three popular wide-band LNA architectures are compared to a proposed parallel LNA architecture in which different amplifiers cover different frequency bands. Our study reveals that by reusing the source degenerated inductor between the different frequency bands, the parallel LNA architecture can achieve better performance than the single wide-band LNA (S11≪-10 dB, voltage gain≫15 dB, NF≪4.5 dB, power consumption≪10 mW) at the expense of a slightly increased circuit area.