Self-biased CPW Circulator with Low Insertion Loss

A self-biased CPW circulator with low insertion loss is proposed for operation in the Ku frequency band. A new composition of La-Co substituted hexaferrite with high remanent magnetization and strong magnetocrystalline anisotropy has been developed for self-biased nonreciprocal devices. The proposed circulator design employs a hexaferrite puck placed on the top of a junction resonator printed on alumina substrate together with the tapered CPW matching transformers. The circulator insertion loss is less than 0.5 dB at isolation over 20 dB across 3% band. The presented novel architecture of compact low-loss self-biased CPW circulator enables its integration with modular design of modern RF front-end and active antennas of the communications systems.