Topwave directional couplers are passive devices, which are used to couple part of the transmission power in the transmission line. The bandwidth, high directivity and high power of the directional coupler we provide can meet the needs of designers in demanding applications. Radio frequency directional couplers usually use two transmission lines close together so that energy passing through one transmission line can be coupled to another transmission line. https://www.topwavetelecom.com/directional-coupler/4-3-10-directional-coupler.html