Integration Concept for a Self-Biased Ka-Band Circulator

Abstract

This paper studies an integration concept fora self-biased Ka-band circulator. Non-reciprocity is achievedby means of a pre-sintered scandium substituted bariumhexaferrite which, as a hard-magnetic material, does notrequire external magnetic biasing. The ferrite is integratedinto a microstrip circuit on a RO4000 laminate. This yieldsa compact and potentially low-cost circulator. The basicfunctionality is demonstrated in a first experiment. Theresults are still quite preliminary, though. Yet, some importantconclusions can be drawn regarding the required designoptimization measures.