Rotating propagation magnetic bubble memory - has pairs of oppositely facing miniature plates contg. tracks and experiencing propagation and polarisation field

摘要

The memory comprises four pairs of miniature plates placed face-to-face. The propagating magnetic field provided by an external coil (10) and four internal coils (11) disposed orthogonally about the external coil (10). Each of the miniature plates (12,13) includes a substrate bearing a magnetic storage layer, separated by a thin insulating layer, and tracks forming a herring-bone pattern. Pref. the polarisation field is slightly included w.r.t. the perp. axis from the layers of the miniature plates, in order to provide components aligned with the field and rotating about the origin. Each miniature forming a pair is angularly displaced by 180 degs. w.r.t. its respective plate. The magnetic field intensity is of between 150 and 250 Oersteds and the rotating component of the field has an intensity of between 20 and 50 Oersteds. The conductors (14) leading to the tracks on the plates (12,13) have a thickness of a few tenths of a millimeter.