Definition
This phrase is not a standalone aviation term. It is a fragment of a longer definition, most likely describing a carrier wave or signal that can be altered (modulated) so it carries information or data from one point to another. In aviation electronics, modulation is the process of varying a property of a radio wave — such as its amplitude or frequency — so that it conveys voice, navigation signals, or digital data.
Plain English
It describes a signal — usually a radio wave — that can be changed in a controlled way so it carries useful information like voice or data.
Context Anchor
Seen in radio, navigation, and aircraft electronic system discussions where signals are used to carry information.
Derivation
Modulate comes from the Latin modulari, meaning to regulate or measure. In radio, it means to regulate a wave's shape so it carries a message rather than just existing as a plain tone.
Why Pilots Care
Every radio call, VOR signal, ILS course, and datalink message a pilot uses depends on a carrier wave being modulated with information. Without modulation, a radio just produces a steady, useless tone.
Analogy
Think of a steady whistle being changed into short and long sounds to send a message. The sound itself is being varied so it can carry meaning.
Grounding Statement
A plain radio wave is like a blank page; modulation is the writing on it that turns it into a message.
Intuition Check
Do not read “modulated” as simply “adjusted.” Here it means changed in a planned pattern so information or data can ride on the signal.
Example Sentence 1
A VHF carrier wave that can be modulated with information or data allows the pilot's voice to be transmitted to the tower.
Example Sentence 2
Modern data link systems rely on signals that can be modulated with information or data to deliver weather and traffic updates directly to the cockpit.