A 1.2V reactive-feedback 3.1-10.6 GHz low-noise amplifier

Abstract—A 15.1 dB gain, 2.1 dB (min.) noise figure low-noise amplifier (LNA) fabricated in 0.13 m CMOS operates across the entire 3.1–10.6 GHz ultrawideband (UWB). Noise figure variation over the band is limited to 0.43 dB. Reactive (transformer) feed-back reduces the noise figure, stabilizes the gain, and sets the ter-minal impedances over the desired bandwidth. It also provides a means of separating ESD protection circuitry from the RF input path. Bias current-reuse limits power consumption of the 0.87 mm2 IC to 9 mW from a 1.2 V supply. Comparable measured results are presented from both packaged and wafer probed test samples. Index Terms—Bias current-reuse, broadband amplifier, low-noise amplifier, monolithic transformer, reactive feedback, ultrawideband. I