# phase

Incommunications engineering, the phase is the angle of a signal part. It is specified in angular degrees and represents the reference to the reference value of the complete signal.

For periodic signals, the total phase angle of a period is 360 degrees and corresponds to the period duration. For example, if this is 1 ms, then 1 degree of phase angle corresponds to a value of 1 ms divided by 360 degrees, i.e. 2.77 µs.

The time course of a signal oscillation can be determined on the basis of individual phase angles. For sinusoidal signals, a phase angle of 90 degrees corresponds to the highest positive amplitude, one of 180 degrees to the zero crossing from the positive to the negative half-wave, one of 270 degrees to the highest negative amplitude and one of 360 degrees to the zero crossing from the negative half-wave to the positive.

The vector underlying a particular phase position is called a phasor and can be measured with a vector meter.