PREAMPLIFIERS

A preamplifier (also known as "preamp" or "pre") is an electronic amplifier that converts a weak electrical signal into an output signal strong enough to be noise-tolerant and strong enough for further processing. 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 increases the power of both the signal and the noise present at its input. LNAs are designed to minimize additional noise.

Designers minimize noise by considering trade-offs that include impedance matching, choosing the amplifier technology (such as low-noise components) and selecting low-noise biasing conditions.