“…A number of articles on theory and design of three-port circulator can be found in the literature. The emphasis is on performance improvement in terms of insertion loss [15][16][17], wide band operation [20,22,28,29], temperature stabilization [29,30], isolation bandwidth [15,16,23], miniaturization [28,[30][31][32], isolation [17,24] and high power operation [19,21,26,30]. Isolation performance is critical in some radar systems.…”