A General 180-Degree Hybrid Ring

It is shown that the familiar 180-degree (or "rat-race") hybrid ring is a particular case of a more general device which may be realized with a line of any impedance, provided it is less than ¿2 times the impedance required at the four ports. Although the ratrace presents the widest possible band, more general cases may be usefully employed especially in the UHF region where the instantaneous bandwidth required is usually small (a few percent).