The evolution of ferrite and other passive control components: A personal account

This Paper begins with a brief discussion of the state of passive components in the 1960 time frame. At this time available control components were realized in waveguide format with a few components being realized in balanced strip transmission line. Work on ferrite isolators and phase shifters at the Sperry Microwave Electronic Co. are reviewed. Work at other organizations are reviewed also. Developments in the mid 1960's, on toroidal non-reciprocal phase shifters (latching phase shifters) are optimized for use in microwave passive arrays. Applications are presented. Later efforts on reciprocal dual mode phase shifters are described. In the dual mode phase shifters fully filled circular waveguide are used in a unique geometrical layout. The present wide usage of these in both ground based and air borne arrays are highlighted.