Device-oriented review of recent Japanese developments in magnetic materials for gyromagnetic applications

A review is presented on the research and development conducted in the past three years in Japan in the field of microwave ferrites. The review is divided into six topics as follows: a) circulators and isolators comprising conventional ferrites and garnets, b) polycrystalline CaVGs, their preparations, characterizations and applications, c) large size single crystalline YIGs and their application to circulators, d) conventional YIG materials tailored to digital phaser designs and fabrications, e) lithium ferrite and its applications, and f) highly anisotropic Ba and Sr ferrites tailored for millimeter-wave resonance isolators. The review is concluded with a forecast of future research activities in this area in Japan.