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:
Feb. 09, 1982
Filed:
Feb. 27, 1980
Alan J Greaves, Ipswich, GB;
Philip E Greenaway, Felixstowe, GB;
Charles Nightingale, Felixstowe, GB;
The Post Office, London, GB;
Abstract
A filter network that exhibits a bandstop response comprises a network of basically low pass or high pass structure. The network is developed by choosing a bandstop transfer function, a fourth-orderelliptic is disclosed, which is converted to a low pass function. This function describes a passive low pass LC ladder network including a negative impedance element. A Bruton transformation is applied to the passive LC network to give an active version including an ungrounded negative resistance network in a series arm and frequency-dependent negative resistances in shunt arms without requiring inductance coils for its implementation.