Hybrid Junction

a four-arm radio wave guide system in which the power entering any one arm is equally divided between two others and does not enter the fourth arm; when coherent oscillations are fed to any two of the arms, their sum will be detected at a third arm and their difference at the fourth.

Hybrid junctions are used in superhigh-frequency technology: in dividers and power splitters to add and subtract oscillatory powers, in balanced mixers to suppress the noise of a receiver heterodyne, and in bridge circuit measuring devices to determine impedances and reflection coefficients. The great variety of hybrid junctions reduces to three simple forms: the hybrid ring type, the hybrid tee, and the directional coupler with a 3-decibel coupling. The ring hybrid junction, or hybrid ring, consists of a segment of a radio-frequency wave guide that is closed upon itself and has connecting arms. The circumference (along a mean radius) of the hybrid ring is made equal to a multiple of half the design wavelength of the electromagnetic oscillations within it, and the distance (along the same circumference) between the individual arms is a multiple of a quarter wavelength.