This Small Business Innovation Research Phase I project will investigate an innovative design of planar microwave and millimeter wave (MMW) circulators compatible with integrated circuits. Traditionally, ferrite circulators are made using bulk materials in which holes need to be drilled to a very small tolerance in the dielectric substrates, and, hence, the fabrication cost are high. In addition, the need for permanent magnets further impedes the development of circulator designs toward monolithic microwave/MMW circuits. During Phase I, potential circuit geometries for designing practical planar microwave/MMW circulators will be identified, proof-of-concept experiments will be completed, and a commercialization strategy will be outlined. During Phase II, a prototype thin-film circulator will be designed, fabricated and tested and self-biasing circulators employing hexagonal ferrite films will be developed. Major cost and applicability issues associated with commercialization of the proposed circulator designs will be explored. This research and development will seek to provide low cost production of circulators that will facilitate their commercialization so that high performance circulators can find direct commercial applicability in the radar and communication industries. The results of this research effort will enhance U.S. competitiveness by advancing the state-of-the-art in the knowledge and understanding of microwave/MMW integrated-circuit circulators.
