Patent · US Expired

Lowpass filter with electronic control of cutoff and resonance

US4404529A · kind A · utility

9Cited by
2References
15Claims
0Family size

Inventors

Key dates

Filing dateDec 30, 1980
Grant dateSep 13, 1983
Priority date
Expiry dateDec 30, 2000

Classification

  • Technology area (CPC H)Electricity
  • CPC primaryH03H11/1213
  • WIPO fieldBasic communication processes
  • WIPO sectorElectrical engineering

Abstract

A lowpass filter circuit having an electronically controllable cutoff frequency and utilizing a feedback current mirror circuit as a variable impedance element. The filter circuit employs low noise, low distortion output circuitry and includes means for electronically controlling resonance.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.