An analog signal and its carrier wave are two distinct components of a communication system. Here's an explanation of each:
- Analog Signal: An analog signal represents continuous variations of a physical quantity, such as voltage or sound pressure, over time. It carries the information being transmitted. Analog signals can have an infinite range of values and are often used to convey audio, video, or other continuous data.
An analog signal is typically characterized by its amplitude (strength or intensity) and frequency (rate of variation). For example, in audio communication, the analog signal may represent the changing air pressure caused by sound waves.
- Carrier Wave: A carrier wave, on the other hand, is a high-frequency signal that is generated by a transmitter to carry the analog signal. It is often a sinusoidal waveform with a fixed frequency and amplitude. The carrier wave itself does not contain any information; it acts as a carrier for the analog signal.
The carrier wave's primary purpose is to provide a stable and consistent medium through which the analog signal can be transmitted efficiently. By modulating the carrier wave, which means altering its characteristics in response to the analog signal, the information from the analog signal is embedded onto the carrier wave.
Modulation techniques, such as amplitude modulation (AM), frequency modulation (FM), or phase modulation (PM), are used to impress the analog signal onto the carrier wave. These modulation techniques vary the amplitude, frequency, or phase of the carrier wave in proportion to the variations in the analog signal. This modulation allows the receiver to extract the original analog signal from the modulated carrier wave.
In summary, the analog signal contains the actual information being transmitted, while the carrier wave is a high-frequency signal that serves as a carrier for the analog signal, allowing it to be transmitted efficiently through a communication system.