Faasiinversio

Faasiinversio, or phase inversion, is the process of reversing the phase of an electrical signal by 180 degrees. In a phase-inverted signal, the waveform is the mirror image of the original with inverted polarity: voltage peaks become troughs and vice versa. In electronics, phase inversion is most commonly achieved with an inverting amplifier configuration using an operational amplifier, where the output is proportional to the negative of the input (output = -(Rf/Rin) × input). Passive networks and all-pass filters can also produce a near-180-degree shift within a specific frequency range.

Uses and purpose: Phase inversion is used to correct polarity mismatches between audio devices, microphones, and loudspeakers. When two signals that are nominally the same are combined, incorrect polarity can cause partial cancellation or reinforcement depending on the phase relationship, affecting perceived loudness and timbre. A polarity or phase switch on mixing consoles and some microphones allows engineers to align signal polarity. Phase inversion is also used in sound design and for testing phase-related effects.

Limitations: Real-world circuits have finite bandwidth and may introduce additional phase shifts that vary with frequency, so inversion is exact only within a specified range. When combining multiple signals with different amplitudes and delays, simple polarity inversion cannot fully cancel or align them.

See also: Polarity, Phase (wave physics), All-pass filter, Inverting amplifier.