balanced signal
The term balanced signals is mainly used in audio technology and acoustics, whereas in cabling technology and buses one speaks of differential signals. Both signals are in phase opposition and are also referred to as balanced.
This type of signal routing uses two signal-carrying conductors on which signals are transmitted that are in phase opposition but identical in level, and an earth conductor. The sum of both signals is zero at any time.
When an interference signal occurs, both signals are equally superimposed by the interference signal. Since balanced signals are fed as input signals to a differential amplifier, the interference signals become zero in the differential amplifier because they are in phase opposition and subtract from each other. Balanced signals are generated from unbalanced signals via transformers. In this case, the asymmetrical signal is on the primary side of a transformer. On the secondary side, the transformer has a center tap that is connected to ground. The balanced signals are tapped on the secondary side at the winding ends and are in phase opposition.
A well-known component for balancing is the balun, a wideband transformer. Balun stands for balanced and unbalanced and converts balanced RF signals into unbalanced ones. In the past, there were also balun converters in the antenna crossovers, since balancing from balanced antenna cable to unbalanced coaxial cable often had to be performed.