Granted Patent
Utility
US 5,663,676 · App. 08/603,259
Active filter independently controlling cut-off frequency and quality factor
Inventor:
Hiroko ITOH
Patented Case
View Patent ↗
Granted: Sep 2, 1997
Filed: Feb 20, 1996
Inventor
Hiroko ITOH
Assignee (at issue)
NEC CORPORATION
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.