The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Mar. 30, 1993
Filed:
Dec. 12, 1991
John X Przybysz, Penn Hills, PA (US);
Donald L Miller, Penn Township, Westmoreland County, PA (US);
Eric H Naviasky, Baltimore, MD (US);
Westinghouse Electric Corp., Pittsburgh, PA (US);
Abstract
A two-loop superconducting sigma-delta analog-to-digital converter includes a first superconducting inductor to which the analog signal is applied. A resistor converts to current in the first inductor to a voltage which is applied to a second superconducting inductor. The current in the second inductor, which increases quadradically with time, is applied to an overdamped Josephson junction which kicks back a single quantum voltage pulse each time its critical current is exceeded. This pulse reduces the current in the second inductor and serves as a digital ONE output. The pulses are also applied to an underdamped Josephson junction in a feedback pulse generator which latches at its gap voltage for the remainder of a half cycle of an ac bias current. This provides a voltage source for the primary of a superconducting transformer having a mutual inductance which produces sufficient flux in the secondary to cause a SQUID to generate in response to each pulse from the quantizer a selected number of feedback pulses which are applied to the first inductor.