An RF Directional Coupler serves as a passive device utilised in the field of radio frequency (RF) design. It operates by coupling the power of a signal travelling along a line and making it available at another RF port. The RF Directional Coupler is designed to couple a certain amount of electromagnetic power in a transmission line to a port, enabling the signal to be used in another circuit. This function is typically employed in power amplifiers, antennas, signal distribution, and measurements. The device's main advantage lies in its ability to separate and isolate signals moving in different directions. This feature is crucial in applications such as line monitoring and signal distribution, where it is essential to distinguish between forward and reflected power.