Introduction of a phase difference of 180°. Note: Phase inversion may occur with a random or periodic, symmetrical or non-symmetrical waveform, although it is usually produced by the inversion of a symmetrical periodic signal, resulting in a change in sign. A symmetrical periodic signal represented by f (t) = Ae^{ jt}, after phase inversion, becomes f_{1}(t) = Ae^{ j(t+)}, where t is time, A is the magnitude of the vector, is angular frequency ( = 2f ), where f is the frequency and 3.1416 and e 2.7183. The algebraic sum of f (t) and f_{1}(t) will always be zero.