The present status of microwave Ferrite materials and devices in China

The recent research, development, and production of the microwave ferrites and devices in some dozen of institutions in China are discussed. The improvement of microwave ferrites through the study of ionic substitution, ionic distribution, solid-state reaction, mechanisms of loss, as well as preparation technologies are given. Also presented in the paper are the theoretical and experimental studies which have resulted in the enhancement of the performance of microwave ferrite devices, such as lumped element circulators and isolators, low-temperature and low-loss circulators, yttrium iron garnet (YIG) tuned filters, etc. Magnetostatic wave delay lines now under investigation are discussed.