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:
Aug. 07, 1984
Filed:
Nov. 30, 1982
Applicant:
Inventor:
Daniel G Jablonski, Bethesda, MD (US);
Assignee:
The United States of America as represented by the Secretary of the Navy, Washington, DC (US);
Primary Examiner:
Int. Cl.
CPC ...
H03F / ;
U.S. Cl.
CPC ...
330426 ; 330306 ; 328167 ;
Abstract
A plurality of passive filters in combination with a corresponding plurality of operational amplifiers form an individual series of quasi low-pass, bandpass, and quasi high-pass filters which when their outputs are summed in an operational amplifier summer, constitute a 'semi-active' notch filter having a low frequency phase shift of substantially zero, and a notch frequency which can be adjusted independently of the low frequency phase shift. The existence of the notch is also independent of the properties and limitations of the operational amplifiers used.