# phase

In communications engineering

, the phase is the angle of a signal component. 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

is360 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 characteristic 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 on which a particular phase angle is based is called a phasor and can be measured with a vector measuring device.