A low-noise amplifier (LNA) is an electronic amplifier that amplifies a very low-power signal without significantly degrading its signal-to-noise ratio. An amplifier will increase the power of both the signal and the noise present at its input, but the amplifier will also introduce some additional noise. LNAs are designed to minimize that additional noise. Designers can minimize additional noise by choosing low-noise components, operating points, and circuit topology. Minimizing additional noise must balance with other design goals such as: power gain and impedance matching.
A LNA is an electronic amplifier that is used to amplify signals of very low strength, usually from an antenna where signals are barely recognizable and should be amplified without adding any noise, otherwise important information might be lost. LNAs are one of the most important circuit components present in radio and other signal receivers.
LNAs are found in radio communications systems, It's a significant part of a receiver circuit whereby the received signal is processed and converted into information. LNAs are designed to be close to the receiving device so that there is minimum loss due to interference. As the name suggests, they add a minimum amount of noise (useless data) in the received signal because any more would highly corrupt the already weak signal. When the signal-to-noise ratio (SNR) is high and needs to be degraded by around 50 percent and power needs to be boosted, a LNA is the first component of a receiver to intercept a signal, making it a vital part in the communications process.