20.8 A 20mW GSM/WCDMA receiver with RF channel selection

Recent work on RF receivers has exploited N-path filters to address two critical issues, namely, blocker tolerance and high RF selectivity [1,2]. However, these designs face three drawbacks: (1) the low-noise amplifier (LNA) incorporates a G
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stage that, even with a virtual ground at its output nodes, must still withstand strong blockers at its input; (2) the low-order filter transfer function does not provide sufficient selectivity in narrow-band applications such as GSM or WCDMA; (3) they consume roughly 60mW around 2GHz.