Granted Patent
Utility
US 4,812,789 · App. 07/146,018
Ridged waveguide wide band diplexer with extremely sharp cut-off properties
Inventor:
Kuan M. Lee
Patented Case
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Granted: Mar 14, 1989
Filed: Jan 20, 1988
Inventor
Kuan M. Lee
Assignee (at issue)
Hughes Aircraft Company
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.