Browse Prior Art Database

Magnetically Programmable Current Injection Interferometer Logic Device

IP.com Disclosure Number: IPCOM000048065D
Original Publication Date: 1981-Dec-01
Included in the Prior Art Database: 2005-Feb-08
Document File: 2 page(s) / 41K

Publishing Venue

IBM

Related People

Beha, H: AUTHOR [+2]

Abstract

A current injection interferometer is provided with additional magnetically coupled control lines which are galvanically isolated from the interferometer. Programmable control currents, coupled into the loop of the interferometer, effect the interference or threshold pattern of the directly injected input currents. This permits programmable changes of the logic function performed by the device.

This text was extracted from a PDF file.
At least one non-text object (such as an image or picture) has been suppressed.
This is the abbreviated version, containing approximately 85% of the total text.

Page 1 of 2

Magnetically Programmable Current Injection Interferometer Logic Device

A current injection interferometer is provided with additional magnetically coupled control lines which are galvanically isolated from the interferometer. Programmable control currents, coupled into the loop of the interferometer, effect the interference or threshold pattern of the directly injected input currents. This permits programmable changes of the logic function performed by the device.

Fig. 1 shows the equivalent circuit of a current injection junction interferometer that can be used. It comprises 3 junctions with different max. Josephson currents aI(o), bI(o), and cI(o). A control line current i(c) is coupled to the loop inductance L. The input currents i(A) and i(B) are injected at points A and B, respectively. The output load R(L) is connected to point C. For the parameter values indicated, the presence or absence of the control current i(c) determines the logic function performed on input signals i(A) andi(B). For i(c)=0, the device operates as an AND gate; for i(c)=2.8 I(o), as an OR-gate.

Fig. 2 schematically illustrates how the interferometer threshold characteristic is effected by programmable control currents i(c). The figure also demonstrates the operation of the device as an AND-gate and an OR-gate on applied input currents i(A) and i(B).

Other characteristics and logic functions can be obtained by changing the parameters, by employing different types of interferometers (d...