An Inductor-less Current-Reuse CS LNA with Resistive-Feedback for Low-Noise Applications

This paper presents an inductor-less CMOS current-reuse common-source ultrawideband amplifier, operating in the 1.5-9.3-GHz range. The LNA uses resistive feedback for wideband input matching thus forming a self-biased inverter-based amplifier; however, a novel buffering scheme is used in conjunction with the amplifier to avoid loading from the resistive feedback. The LNA was designed using the tsmc 65-nm process and it achieves ($S_{11}$) of better than −11.6 dB across the entire bandwidth, maximum $S_{21}$ of 13.2 dB with 3-dB bandwidth of 7.8 GHz, noise-figure of 1.9-2 dB with only 0.1 dB variation across the entire bandwidth of 1.5-9.3-GHz, $IIP_{3}$ of −4.6 dBm at 6 GHz fundamental frequency with 100 MHz tone separation. The power consumption is limited to 4.5 mW while operating under 1-V supply.