Editing Low-noise amplifier (section)

{{short description|Signal amplifier that doesn't significantly degrade the signal-noise ratio}}
{{more citations needed|date=November 2015}}
{{Use mdy dates|date = March 2019}}
{{Use American English|date = March 2019}}

A '''low-noise amplifier''' ('''LNA''') is an electronic component that amplifies a very low-power [[signal]] without significantly degrading its [[signal-to-noise ratio]] (SNR). Any [[electronic amplifier]] will increase the power of both the signal and the [[Noise (electronics)|noise]] present at its input, but the amplifier will also introduce some additional noise. LNAs are designed to minimize that additional noise, by choosing special components, operating points, and [[Circuit topology (electrical)|circuit topologies]]. Minimizing additional noise must balance with other design goals such as [[power gain]] and [[impedance matching]].

LNAs are found in [[Radio|radio communications]] systems, [[Amateur Radio]] stations, medical instruments and [[electronic test equipment]]. A typical LNA may supply a power gain of 100 (20&nbsp;[[decibels]] (dB)) while decreasing the SNR by less than a factor of two (a 3&nbsp;dB [[noise figure]] (NF)). Although LNAs are primarily concerned with weak signals that are just above the [[noise floor]], they must also consider the presence of larger signals that cause [[intermodulation distortion]].