The Self-Biased Circulator: Ferrite Materials Design and Process Considerations

A strategic goal of next-generation transmit and receive modules used in radar and communication platforms is the continued miniaturization of semiconductor based electronics in conjunction with their integration with ferrite control elements, chief among them, the circulator. Here, we address the singular goal of efforts to transform the circulator, in its present form a three dimensional construct, to a two-dimensional device. Key to this transformation is the development of self-biased ferrite materials that are necessary for the breaking of time reversal symmetry and nonreciprocal performance of circulators and isolators. A discussion of efforts to integrate this new two-dimensional device with semiconductor-based active components will be addressed.