Sine Waves

Also known as sinusoidal wave.

The sine wave is the most fundamental form of a periodic analog signal. When we visualize it as a simple oscillating curve, its change over the course of a cycle is smooth and consistent, a continuous, rolling flow. Each cycle consists of a single arc above the time axis followed by a single arc below it.

A sine wave can be represented by three parameters: the peak amplitude, the frequency, and the phase. These three parameters fully describe a sine wave.

The peak amplitude of a signal is the absolute value of its highest intensity, proportional to the energy it carries. For electric signals, peak amplitude is normally measured in volts.

sine wave

Applications of Simple Sine Waves

  • power company sends a single sine wave with a frequency of 60 Hz to distribute electric energy to houses and businesses (sine wave carrying energy)

  • send an alarm to a security center when a burglar opens a door or window in the house (sine wave is a signal of danger)

In data communication, if we had only one single sine wave to convey a conversation over the phone, it would make no sense and carry no information; just hear a buzz. A single-frequency sine wave is not useful in data communications; we need to send a composite signal, a signal made of many simple sine waves.