Low loss self-biased ferrite materials for size and weight sensitive circulator applications requiring high power handling and high temperature stabil

Self-biased ferrite circulator devices have been demonstrated and thus far exhibit high loss and poor isolation, making them unsuitable for practical applications. The main reason for less than satisfactory performance and high frequency of operation lie in the unacceptable quality of hexagonal ferrite materials. Metamagnetics’ researchers have developed novel materials fabrication and orientation techniques that lead to exceptionally low magnetic losses. Further, these orientation techniques have been successfully applied to substituted hexagonal ferrite materials that possess low uniaxial anisotropy, allowing self-biased devices over 2 to 20 GHz. Building upon these advances, in this proposal, the development of self-biased ferrite materials and device concepts for the 2 to 20 GHz frequencies is pursued. This program’s technical objectives can be summarized as: (i) develop low loss self-biased ferrite materials for size and weight sensitive circulator and isolator applications requiring high power handling and high temperature stability, (ii) numerically develop and optimize performance of self-biased circulator and isolator designs using material properties of advanced ferrite materials, and (iii) conduct initial experimental studies to confirm the numerical models, including self-biased or very low bias field circulation at design frequency and at elevated temperatures.