A Catalog of Low Power Loss Parameters and High Power Thresholds for Partially Magnetized Ferrites

The low power loss and high power threshold properties have been measured on a number of candidate ferrite phase-shifting materials. The low power loss is characterized by μ₀´´, the imaginary part of the diagonal component of the permeability tensor for the completely demagnetized state. μsub 0/´´ was measured from 3.0 to 16.8 GHz. The high power properties are characterized by the parallel pump threshold at a bias field correspontig to H_i ≡ 0 and to 4πM ≡ 4πM_s. The threshold was measured between 3.0 and 16.8 GHz. For the purposes of computer calculation μ₀´´ and h_crit were fit to an equation of the form A (γ4πM_s / ω)^N. Translating μ₀´´ and h_crit to ΔH_eff and ΔH_k gives the YIG plus Al as the lowest loss and lowest threshold materials followed by the Gd garnets and MgMn spinels. The Ni spinels are very Iossy.