Signal coupling refers to the process of transferring signals between different components in a system, such as electronic circuits. This can occur through various methods, including direct electrical connections or through electromagnetic fields. The goal is to ensure that the signal maintains its integrity while moving from one part of the system to another. There are two main types of signal coupling: direct coupling and capacitive coupling. Direct coupling involves a physical connection, allowing signals to pass without significant alteration. In contrast, capacitive coupling uses capacitors to transfer signals, which can filter out certain frequencies and prevent direct current (DC) from passing through, thus protecting sensitive components.