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 f1 (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 f1 (t) will always be zero.