Abstract :
Since the beginning of the use of ferrites for microwave applications, commercially available materials have been used with success at wavelengths of 3 cm and less. However, it has been felt that at 3 cm, and even more at longer wavelengths, the properties of these materials are not the best obtainable. Therefore, a number of investigations have been made of the influence on the microwave properties of varying ferrite composition. The introduction of a significant quality, called `specific attenuation¿, has made it possible to find optimum compositions with respect to insertion loss in applications. Results hitherto obtained with three-component systems at wavelengths of 3, 6 and 10cm are presented graphically, together with recommendations as to how the performance of the best materials can be further improved by the inclusion of a fourth component, in case such a procedure were found expedient.