A 0.1–1.1 GHz inductorless differential LNA with double g_m-boosting and positive feedback

A 0.1–1.1 GHz wideband low-noise amplifier (LNA) is proposed in this paper. The LNA is a fully differential common-gate structure. Large equivalent transconductance (g_m) is realized by active g_m-boost and capacitive cross-coupling. By introducing a positive feedback path, the circuit increases design freedom. It alleviates the tradeoff between input matching, gain and noise performance. The proposed LNA avoids the use of on-chip inductors to save area and cost. A prototype is implemented in standard TSMC 180-nm CMOS technology. From the measurement, the proposed LNA shows a 19 dB voltage gain with a 1 GHz 3-dB bandwidth. The minimum noise figure (NF) is 3.1 dB. The LNA achieves a return loss greater than 10 dB across the entire band and the third-order input-referred intercept (IIP3) is better than -2.9 dBm. The core consumes 3.8 mW from 1-V supply occupying an area of 0.03 mm ². © 2017, Springer Science+Business Media, LLC.