Co-design of SAW duplexer and LNA in RF transceiver IC for reducing total noise figure in RF front-end of cellular systems

The co-design of a SAW duplexer and a low-noise amplifier (LNA) for reducing the total noise figure of the Rx chain in the RF front-end of current multi-band cellular handsets is presented in this paper. The co-design procedure is proposed and one case study for the UMTS Band2 is demonstrated. The key point of the co-design is designing a duplexer and an LNA at the optimum impedance, instead of the standard 50 Ω impedance interface, while taking the matching circuit loss into account. The possibility of reducing the total noise figure is shown in the case study simulation.