RFI 3-Port Directional Couplers are used in a variety of RF combining, sampling and power splitting applications, typically used in DAS (Distributed Antenna Systems) for sampling RF for fiber-fed systems and distributing power throughout feeder cable networks. Using directional couplers suitable for covering UHF to high-end cellular frequencies saves on the cost of upgrades when public safety radio coverage may have to be accommodated on a DAS designed for cellular coverage. The RFI multiband directional couplers are available in a range of coupling values which gives the network designers and planners the ability to optimize and balance RF levels throughout a DAS network.