A DC-to-22 GHz 8.4mW compact dual-feedback wideband LNA in 90 nm digital CMOS

A dual-feedback topology to extend bandwidth of resistive feedback LNAs is proposed in this paper. Active source follower shunt-shunt feedback using a shunt peaking inductor to extend the 3-dB and input matching bandwidth is employed, combined with series-shunt feedback for extended impedance matching using a source inductor. A prototype in 90 nm digital CMOS achieves a high 3-dB bandwidth of 29 GHz while preserving adequate input matching up to 22 GHz. The miniature area (0.017 mm
²
) and low power consumption (8.4 mW) make the solution very attractive for low-cost very wideband LNA implementation.