Method of manufacturing ferromagnetic toroids used in ferrite phase shifters

A fabrication process for ferrite toroids which utilizes ferrite ceramic tape having an improved elongation characteristic. The process utilizes a set of rigid mandrels which are employed in the final lamination to support the rectangular cross section of the internal cavity of a respective ferrite tube, thereby reducing stress concentration and permitting the highest lamination pressure to be used in the final step. The mandrels are removed prior to panel densification. The tape and mandrels operate together to minimize cracks and pores in the toroids and provide an added advantage of maintaining high tolerances in the internal cavity dimensions as well as the cavity-to-cavity alignment.