A Robust CMOS RF Front-end Design for 3.1-4.8GHz MB-OFDM UWB Svstem

摘要

This paper presents a robust RF front-end for 3.1-4.8-GHz direct-conversion Ultra-wideband (UWB) applications such as the MB-OFDM UWB. The circuits contain a gain controllable low-noise amplifier (LNA) with resistive feedback,a merged quadrature mixer with static current injection,and local oscillator (LO) buffers. Post-layout simulations show that the fully differential front-end achieves a maximum conversion gain of 25.5dB and a minimum of 16.5dB,an input return loss of better than -8dB,a minimum noise figure of 4.5dB in high-gain mode and an input referred 3rd intercept point (IIP3) of -4.3dBm in low-gain mode while drawing 26.3mA current from a 1.8-V supply without the buffers. The ESD protected chip is implemented in a 0.18-μm CMOS technology with an active area of 0.48mm2.