Hybrid Coupler Basics

This is an application note from MECA which goes over the basics of Hybrid couplers. 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 ports or to combine two signals while maintaining high isolation between the ports.

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 ports or to combine two signals while maintaining high isolation between the ports.