On the design and performance of a balanced-cascade LNA for FDD-WCDMA direct-conversion node-B RF receiver

Abstract

In this paper, the design requirements, design procedure, and performancc of a low noise amplifier (LNA) used in wideband code division multiple access (WCDMA) base station receiver, is illustrated. The amplifier design is aimed for a directconversion architccrurc. It simultaneously achieves good inputmatch, ultra-low noise figure and high linearity hi terms of low lliird order intermodulaiion (IMD3). The LNA achieves an overall gain OF 55 dB, noise figure (NF) better than 0.7 dB, IMD3 Icss than -67 &e. Devices used are E-pHEMT type with gate widths of 800um and 64ooum. Distribuled type quadraturehybrid is used for balanced confipralion with good amplitude and phase balance.