A 3 dB 90° hybrid coupler is a four-port device that is used either to equally split an input signal with a resultant 90° phase shift between output signals or to combine two signals while maintaining high isolation between them. Hybrid couplers are designed to combine two operating frequencies to a single antenna feed or distribution cable. This requires the termination of one output port in 50 Ohm and results in a 3dB loss in each signal. In situations where two similar feeds are required, both outputs may be used eliminating the need for a termination and the 3dB loss.