Patent · US Expired

Notch filter

US4577168A · kind A · utility

61Cited by
4References
35Claims
0Family size

Assignee

Inventor

Key dates

Filing dateDec 3, 1984
Grant dateMar 18, 1986
Priority date
Expiry dateDec 3, 2004

Classification

  • Technology area (CPC H)Electricity
  • CPC primaryH03H7/1708
  • WIPO fieldBasic communication processes
  • WIPO sectorElectrical engineering

Abstract

An improved notch filter having a single port, surface acoustic wave transducer in parallel with an inductor and forming a first circuit which primarily blocks the signal frequency at all frequencies except the notch frequency at which point the first circuit becomes essentially resistive and at that point is cancelled by a signal from a second circuit in parallel with said first circuit and which is 180.degree. out-of-phase thereby providing a notch filter.

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