INDUCTIVE MATCHING TECHNIQUE FOR A FEED-FORWARD NOISE-CANCELING CMOS LOW-NOISE AMPLIFIER

摘要

An inductive matching technique is proposed for a noise-canceling CMOS low-noise amplifier (LNA). This composite LNA consists of a main amplifier and a feed-forward amplifier. The feedforward amplifier provides a noise canceling path to eliminate the noise at the output of the main amplifier. An inductor is used to tune out the remaining capacitive impedance at the output common node of two amplifiers, which provides the proper phase difference to cancel the overall noise voltage. For an optimum noise canceling bias, the measured noise figure is 2.5 dB, which is an improvement of 0.6 dB.