Self Biased Y-Junction Circulator at ${\rm K}_{\rm u}$ Band

A self-biased microstrip Y-junction circulator was designed, fabricated and tested at K_u band utilizing strontium M-type barium ferrite. The junction circuit consisted of a dielectric slab resting upon a polished thin composite plate of bulk strontium M-type hexaferrite. This approach proved to be mechanically rigid and compatible with the fabrication of integrated circuits yielding practical electrical characteristics of a circulator circuit. The measured isolation was 21 dB, and the insertion loss was 1.52 dB at 13.6 GHz. The measurements matched well with the HFSS simulation of the composite circulator design.