Granted Patent
Utility
US 4,652,844 · App. 06/779,586
Dual mode filters
Inventor:
Enrico Brambilla
Patented Case
View Patent ↗
Granted: Mar 24, 1987
Filed: Sep 24, 1985
Inventor
Enrico Brambilla
Assignee (at issue)
Telettra - Telefonia Elettronica e Radio S.p.A.
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.