Development of Advanced Microwave Components and Techniques - Planar Hexagonal Ferrites and Devices

摘要

Studies were made of the effect of various processing variables on the dielectric loss of the planar hexagonal ferrites. Loss tangents which are of the order of 0.02 are the most severe limitations of the materials. Linewidths of approximately 290 oersteds were obtained on the Cu0.75Zn 1.25 Y compound. Attempts at orienting the grains of cubic polycrystalline materials produced yttrium iron garnet with aa linewidth of 18.5 oersteds, yttrium gadolinium iron garnet with a linewidth of 156 oersteds, and nickel ferrite (NiFe2O4) with a linewidth of 379 oersteds. Measurements and analysis of the application of planar hexagonal ferrites in isolator performance are reported. While the anisotropy field of the planar ferrite reduces the external field required for resonance, it is also shown to adversely effect some isolator characteristics. Measurements were made on both E and H-plane configurations. (Author)