An RF Directional Coupler is a specialized device used in the field of radio frequency engineering to selectively sample the power of a signal flowing in one direction without disturbing the flow of that signal. Typically employed in applications such as power monitoring, signal distribution, and network analysis, these couplers provide a critical function in ensuring signal integrity and system performance. The main characteristics of RF Directional Couplers include their ability to operate over a wide range of frequencies and their minimal insertion loss, which ensures that the primary signal's strength and quality are not significantly diminished. Common manufacturers of these components include Mini-Circuits, Pasternack, and Molex, among others.