1-port topology of the degree-1 and-2 terminated circulator

The equivalent circuit in the impedance plane at port-1 of a 3-port circula tor with ports 2 and 3 terminated in ideal resistive loads is a classic res ult. The purpose of the paper is to synthesise I-port topology in the admit tance plane in the case for which ports 3 and 3 are terminated in real resi stive loads and in that for which the ports are loaded by broadband matchin g networks. This is done in terms of the eigenvalues of the problem region under the assumption that the in-phase eigen-network may be idealised by a short-circuited boundary condition and an ideal 2-port gyrator circuit. The real part circuit and those at the split frequencies of the counter-rotati ng eigenvalues are also deduced as a preamble to realising the general circ uit. The properties displayed by these circuits are compatible with existin g experimental procedures for this class of device.