Granted Patent
Utility
US 4,639,680 · App. 06/722,624
Digital phase and frequency detector
Inventor:
Alec L. Nelson
Patented Case
View Patent ↗
Granted: Jan 27, 1987
Filed: Apr 12, 1985
Inventor
Alec L. Nelson
Assignee (at issue)
Sperry Corp.
This patent predates the USPTO's electronic file wrapper — prosecution documents from this era exist only in the Patent Office's paper records. A certified copy of the file history can be ordered from the USPTO's paper archives.