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:
Jan. 13, 1976
Filed:
Oct. 18, 1974
Applicant:
Inventor:
Paul Anthony Spencer, London, EN;
Assignee:
Dolby Laboratories, Inc., New York, NY (US);
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
H04B / ;
U.S. Cl.
CPC ...
328167 ; 178D / ; 330126 ; 333 / ;
Abstract
A filter performs a dual filtering function by connecting an input terminal through a first impedance such as a resistor to a first output terminal. The input terminal is connected to a virtual earth at the input to a current amplifier through the first impedance and a second impedance such as a tuned circuit. The output of the amplifier is connected to a second output terminal and also to ground through a third impedance such as a resistor. The characteristics at the first and second output terminals may be complementary band stop and band pass characteristics.