A Highly Linear Broadband CMOS LNA Employing Noise and Distortion Cancellation

Abstract

<para xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> A broadband inductorless low-noise amplifier (LNA) design that utilizes simultaneous noise and distortion cancellation is presented. Concurrent cancellation of the intrinsic third-order distortion from individual stages is exhibited with the common-gate and common-source cascade. The LNA <formula formulatype="inline"> <tex>${\hbox{IIP}}_3$</tex></formula> is then limited by the second-order interaction between the common source and common gate stages, which is common in all cascade amplifiers. Further removal of this third-order distortion is achieved by incorporating a second-order-distortion-free circuit technique in the common gate stage. Implemented in 0.13 <formula formulatype="inline"> <tex>$\mu$</tex></formula>m CMOS technology, this LNA achieved <formula formulatype="inline"> <tex>${+}$</tex></formula>16 dBm <formula formulatype="inline"><tex>${\hbox{IIP}}_3$</tex> </formula> in both the 900 MHz and 2 GHz bands. Measurements demonstrate that the LNA has a minimum internal gain of 14.5 dB, noise figure of 2.6 dB from 800 MHz to 2.1 GHz while drawing 11.6 mA from 1.5 V supply voltage. </para>