Three junction squid mixer
AssigneeInternational Business Machines Corporation
InventorClaudia D. Tesche
Life of this patent
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Abstract
A three junction SQUID (superconducting quantum interference device) mixer circuit is disclosed wherein a nonlinear element such as a Josephson junction is coupled with a dc SQUID formed by two other nonlinear elements such as Josephson junctions and two input coils to provide a mixer circuit that can be employed for mixing two input magnetic flux signals. The mixer can be used for up-converting very low frequency signals, for minimizing and solving problems associated with quantum noise limitations, or for down-converting high frequency signals.
Claims7
A three junction superconducting quantum interface device mixer for mixing two input magnetic flux signals to enable heterodyning for up-converting low frequency signals or down-converting high frequency signals, to minimize noise in the superconducting quantum interference device, comprising:
- a) a dc superconducting quantum interface circuit comprising a series circuit pair of first and second nonlinear elements, each having current to voltage characteristic similar to a Josephson junction and first and second input coils for the dc superconducting quantum interface circuit;
- and
- b) a third nonlinear element having a current to voltage characteristic similar to a Josephson junction coupled in parallel with one of the input coils forming an additional or third shunting junction having a current flowing therethrough to provide a circuit that can be employed as a mixing device for mixing two input magnetic flux signals to enable heterodyning for up-converting low frequency signals or down-converting high frequency signals, to minimize noise in the superconducting quantum interference device.
Dependencies are inferred from the claim text.