2.4 A 0.028mm2 11mW single-mixing blocker-tolerant receiver with double-RF N-path filtering, S11 centering, +13dBm OB-IIP3 and 1.5-to-2.9dB NF

RF-tunable blocker-tolerant receivers (RXs) enhance the flexibility of multiband multistandard radios at low cost (Fig. 2.4.1). The mixer-first RX [1] delays the signal amplification to baseband (BB) by frequency-translating the BB lowpass response to RF as bandpass. This raises the out-of-band (OB) IIP3 (27dBm) at the expense of NF (5.5dB) and power (60mW) due to no RF gain. The noisecancellation RX [2] breaks such a tradeoff by paralleling a voltage-sensing RX with the mixer-first RX. This achieves a better pair of NF (1.9dB) and OB-IIP3 (13.5dBm), but sacrifices more die size (1.2mm) and power (<78mW) to accommodate the doubled RF and BB circuits. In [3], N-path RF filtering and noise cancellation are concurrently attained in one current-reuse RX. That approach saves die area (0.55mm) and power (16.2mW) at a high OB-IIP3 (17.4dBm), but requires a high VDD (2.5V) to widen the voltage headroom. Also, seeing that its NF (4.6dB) is handicapped by the input-impedance matching requirement (S11<-10dB), there is no flexibility to get better NF. Finally, as both [2] and [3] involve two mixing steps, the LO power is penalized.