SAW-Less Analog Front-End Receivers for TDD and FDD

Abstract

A multistandard SAW-less receiver is designed exploring a current-mode architecture. A class-AB common-gate transformer-based low-noise transconductor amplifier (LNTA) is used to provide high linearity and harmonic filtering. A resonant passive mixer is adopted in order to allow the current-mode operation and improve the harmonic rejection. A low-power divider with intrinsic 25% duty-cycle is introduced to drive the passive mixer. A second-order Rauch biquad with complex poles makes-up the IQ blocker tolerant baseband. The receiver is designed to be suitable for SAW-less TDD and typical FDD applications with 3.8 and 1.9 dB of NF and > 18 and > 16 dBm of IIP3, respectively, using only 32 mW for each receiver.