A Reconfigurable DCS1800/W-CDMA LNA: Design and Implementation Issues

We present in this article a dual-standard dual-mode low-noise amplifier (LNA) for DCS1800/W-CDMA-FDD applications. In order to save die area compared to conventional parallel LNAs, we have used an alternative circuit configuration. It consists of sharing the most die consuming elements (inductances) in both operation standards, enabling a more compact solution. The mode and standard selection is performed through a bias scheme (MOS switches) that allows alternating between the two involved standards. The LNA die area is 1.0times1.2 mm
²
and it consumes 6.8 mW (3.8 mA under 1.8 V), including bias circuitry