Multi-band, multi-mode, low-power CMOS receiver front-end for sub-GHz ISM/SRD band with narrow channel spacing

This paper presents a narrow channel bandwidth, ultra low power receiver front-end for 170/433/868/915/950 ISM/SRD bands with channel spacing down to 12.5kHz. A gm-boosted CG-CS current-reuse inductorless LNA provides high linearity and low current capability over wide bandwidth. Passive mixer implemented with non-overlapping clock waveforms reduces RF loading to the LNA, and reduces close in 1/f noise. The IF amplifier uses multi-tanh technique to achieve high linearity at low current consumption. The IC uses various power saving modes and achieves a 39dB voltage conversion gain, 6.5dB NF, -14dBm IIP3, 64dB adjacent channel selectivity at 12.5kHz offset, and 91dB blocker rejection at 10Mhz offset. The front-end consumes 2.8mA from 1.8V regulated supply using 180nm CMOS technology.