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:
May. 28, 1991
Filed:
Oct. 23, 1989
Applicant:
Inventors:
Robert DiBiase, Carlisle, MA (US);
Zvi Galani, Bedford, MA (US);
Raymond C Waterman, Jr, Westford, MA (US);
Assignee:
Raytheon Company, Lexington, MA (US);
Attorneys:
Primary Examiner:
Int. Cl.
CPC ...
H03H / ;
U.S. Cl.
CPC ...
333 171 ; 333207 ;
Abstract
A tunable bandpass filter for radio frequency energy with a phase-locked loop for tracking an input signal and to control the filter to keep the center frequency of the passband coincident with the frequency of the input signal is shown. Using a Yttrium Iron Garnet (YIG) filter as a frequency determining element and as a passive dispersive reference element for a frequency discriminator, the bandpass filter uses the output signal of the discriminator to form a fine tuning signal to control the center frequency of the passband of the YIG filter.