Definition
A form of signal amplification in which the output signal is an exact, larger copy of the input signal. The shape and proportions of the waveform are preserved; only its amplitude (strength) is increased.
Plain English
Making a signal stronger without changing its shape. Whatever goes in comes out the same — just bigger.
Context Anchor
Seen in aircraft radio, navigation, and avionics discussions, especially when describing how a transmitter or receiver handles a signal.
Derivation
Linear comes from the Latin linearis, meaning 'of or belonging to a line.' In a graph of output versus input, a linear amplifier produces a straight line — output rises in direct proportion to input. Amplification comes from the Latin amplificare, 'to make larger.' Together: making something larger in a straight-line, proportional way.
Why Pilots Care
Linear amplification matters in radio transmitters and audio systems because it keeps voice transmissions and data signals undistorted. Non-linear amplification can garble communications or corrupt navigation signals.
Analogy
It is like turning up a clean speaker. The sound gets louder, but the words and tone stay the same. If the speaker starts buzzing or breaking up, that is no longer clean linear amplification.
Intuition Check
Linear does not mean the signal travels in a straight physical path. Here it means the output increases in the same proportion as the input, so the signal stays faithful to the original.
Example Sentence 1
The transmitter uses linear amplification so that the pilot's voice reaches the controller clearly, without distortion.
Example Sentence 2
Linear amplification in the audio panel keeps ATC transmissions clear and undistorted at any volume setting.