Abstract-Dielectric Resonance in Ferrites for Sub-THz Signal-Processing Devices

Gopalan Srinivasan, Maksym A. Popov, Igor V. Zavislyak,

https://www.sciencedirect.com/science/article/pii/B9780124081307000101

This chapter discusses dielectric resonance in  type hexagonal barium and strontiumferrites and yttrium iron garnet (YIG) and their magnetic field-tuning characteristics. The dimensions of hexaferrites and YIG are chosen in such a way that the dielectric resonance occurs at a higher frequency than the traditional magnetic resonance in order to eliminate any hybrid modes. The samples in this study show dimensional resonance in the W-band (75–110 GHz). In the absence of an external magnetic field H, degenerate dielectric modes corresponding to clockwise and counterclockwise polarization of the microwave fields are observed. The mode degeneracy is lifted in H and the modes are magnetically tunable by ~ 1 GHz or more for nominal H-values. Theoretical estimates on magnetic field tuning are in reasonable agreement with the data. Possibilities for low-loss sub-THz isolators, resonators, filters, and phase shifters based on the dielectric modes are discussed.