Pole-Converging Intrastage Bandwidth Extension Technique for Wideband Amplifiers

To overcome limitations on bandwidth extension in conventional design techniques, a novel pole-converging technique with transformer feedback for intrastage bandwidth extension is proposed and analyzed in this paper. For verification, a three-stage cascode low-noise amplifier (LNA) based on the pole converging and negative drain-source transformer feedback is designed and implemented in a 65-nm CMOS technology. Consuming 27 mW dc power from a 1.8 V supply, the fabricated prototype exhibits peak power gain of 18.5 dB, minimum noise figure of 5.5 dB, 3-dB bandwidth of 30 GHz, and fractional bandwidth of 38.7%. The bandwidth of the three-stage cascode LNA is significantly extended without increasing power consumption and die size.