A SAW-less GSM/GPRS/EDGE receiver embedded in a 65nm CMOS SoC

Over the last decade, significant progress has been made towards increasing integration and reducing bill of material (BOM) for GSM/GPRS/EDGE cellular systems. In modern cellular phones, transmit SAW filters have been largely eliminated with innovative TX architecture and circuits [1] while receive SAW filters are still present. This remains as one of the few bottlenecks in achieving a true low-cost single-chip solution which offers a genuine advantage for high-volume applications. The main challenges of eliminating SAW-based bandpass filters from multiband 2G/2.5G receivers lie in noise-figure (NF) degradation and gain desensitization induced by 0dBm blockers at merely 20MHz away from the −99dBm in-band signal at GSM850/900 band. Furthermore, these unfiltered inter-ferers cause a strong reciprocal mixing effect and result in additional SNR degradation. Therefore, a SAW-less RX is required to have an extremely high dynamic range while maintaining best-in-class NF, LO wideband phase noise (PN) and spur performance.