A fully differential low noise amplifier with real-time channel hopping for ultra-wideband wireless applications

In this paper, a CMOS low noise amplifier (LNA) employing the switched-capacitors is proposed to perform multi-band tuning for an MB-OFDM ultra-wideband (UWB) hopping system. By using the fully differential topology, the switching noise generated during each frequency transition interval is greatly suppressed. The proposed UWB LNA is implemented in a standard 0.18-/spl mu/m CMOS process. The simulation results show that it is capable of performing the fast switching with a settling time of less than 3 ns. Furthermore, the switching noise voltage at the output is rapidly reduced to less than 1 /spl mu/V within 5 ns. The designed circuit is optimized in each center frequency, achieving the maximum power gain of 16.2 dB and the minimum noise figure of 2.63 dB.