Evolution of the Zero-Degree Hybrid

the zero-degree hybrid. In one direction, the signal is divided into two equal outputs, while in the opposite direction, two inputs are combined into a sin-gle output. The phase shift from the common port to each of the two divided ports is the same, so the rela-tive phase between those two ports is zero degrees. The configurations presented here also provide iso-lation between the two divided ports, as indicated by the term “hybrid,” which was first used in the tele-phone industry to describe special transformers with this isolation characteristic.