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Two Dimensional Field Access Scheme for Bubble Memories

IP.com Disclosure Number: IPCOM000085551D
Original Publication Date: 1976-Apr-01
Included in the Prior Art Database: 2005-Mar-02
Document File: 2 page(s) / 50K

Publishing Venue

IBM

Related People

Voegeli, O: AUTHOR

Abstract

A field access scheme is described in which the direction of bubble propagation can be controlled with the externally applied drive field. This is achieved by using an in-plane drive field having uniaxial symmetry in combination with a permalloy overlay pattern having more than one translation axis. The direction of propagation is selected by aligning the field's drive axis with a particular translation axis of the pattern.

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Two Dimensional Field Access Scheme for Bubble Memories

A field access scheme is described in which the direction of bubble propagation can be controlled with the externally applied drive field. This is achieved by using an in-plane drive field having uniaxial symmetry in combination with a permalloy overlay pattern having more than one translation axis. The direction of propagation is selected by aligning the field's drive axis with a particular translation axis of the pattern.

Bubble lattices are translated with a dot overlay pattern, as is shown in Fig. 1. The pattern has the same symmetry and spacings as the bubble lattice. The three translation axes alpha-1 to proportional to -3 correspond to lattice symmetry axes and are rotated 120 degrees from each other.

Isolated bubbles are translated with a square overlay pattern as is shown in Fig. 2, which has two orthogonal translation axes.

Fig. 3 depicts the translation mechanism for the two patterns when driven with a figure-eight drive field, as shown in Fig. 4. This field configuration is generated with two orthogonal alternating fields at frequencies 1 omega and 2 omega. The field's drive axis can be aligned with any translation axis of the overlay pattern, by changing relative amplitudes of the 1 omega and 2 omega drive currents in two orthogonal drive coils.

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