Microwave Ferrites, Part 1: Fundamentals and self biasing

摘要: Ferrimagnets having low RF loss are used in passive microwave components such as isolators, circulators, phase shifters, and miniature antennas operating a wide range of frequencies (1–100 GHz) magnetic recording media owing to their novel physical properties. Frequency tuning these has so far been obtained by external fields provided permanent magnet or passing current through coils. However, for high frequency operation the part bias should be possible, which requires large magnets resulting relatively size cost components. A promising approach circumvent this problem is use hexaferrites, BaFe12O19 SrFe12O19, have effective internal anisotropy that also contributes bias. Such self-biased material remains magnetized even after removing applied field, thus, may not require an