Hybrid Couplers are a class of passive component which perform lossless combining and coupling of multiple inputs onto multiple outputs. They comprise of 2×2, 3×3, and 4×4 coupling matrices, providing 3, 4.8, and 6 dB coupling respectively. The component can also be referred to as a Hybrid Combiner and Hybrid Matrix, although there are nuances to be aware of.
Compared to using a Power Divider as a ‘combiner’, hybrids are considered ‘lossless’, in that they incur the same losses of a Power Divider but provide additional output ports. As they also provide higher isolation and power handling than ordinary Power Dividers, Hybrids often substitute their use in high performance system designs.
They are most prominently found in Distributed Antenna Systems used to provide neutral-host in-building coverage for multiple network operators. Because of their importance they are subject to stringent quality conditions to prevent any adverse impact to the macro networks which they combine.