A progammable baseband anti-alias filter for a passive-mixer-based, SAW-less, multi-band, multi-mode WEDGE transmitter

A programmable baseband anti-alias filter (AAF) for a passive-mixer-based, 1.8V, SAW-less, multi-band, multi-mode WEDGE (WCDMA/HSUPA/EGPRS) cellular transmitter (TX) is described. This paper presents an AAF which results in ultra-low, −170dBc/Hz, receive-band noise, and enables the first single-mixer-based, multi-mode, SAW-less TX. By providing the noise and linearity performance only on-demand from system requirements, the presented AAF enables power savings of 14mW, or 34% of the total 41mW TX power. The AAF has been fabricated as part of a single-chip 0.13µm CMOS transceiver.