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. 03, 1976
Filed:
Sep. 27, 1974
John Mortimer Rollett, London, EN;
David Richard Wise, London, EN;
The Post Office, London, EN;
Abstract
A filter network particularly suitable for construction in micro-electronic circuitry for application in telephony systems is formed by simulating inductance in a circuit arrangement incorporating only resistance, capacitance and amplifying elements. The symmetry of the circuit arrangement and coupling into the filter network simplifies fabrication and reduces the number of amplifiers previously required to perform similar filter functions. The filter networks may be built up by coupling a chain of circuit arrangements each including two unity gain amplifiers having a series resistor/capacitor feedback network and a non-inductive element interconnecting the two amplifier feedback networks.