Modeling and characterization of self-biased circulators in the mm-wave range

The development of future telecommunication systems requires the miniaturization of circulators. Apart from using planar technologies, removing magnets appears as one of the main solutions to improve the integration of circulators. This technological step requires the use of oriented hexaferrites in their remanent state. Thus, the unusual properties of these materials were used to design and realize a millimeter-wave self-biased circulator in rectangular waveguide. Without magnets, insertion losses of 1.79 dB and an isolation level of 28.1 dB were measured at 41.4 GHz. These results demonstrate the strong potential of these materials for the design of self-biased circulators.