Patent · US Expired

Demodulator for frequency modulated signals

US4288876A · kind A · utility

2Cited by
4References
7Claims
0Family size

Assignee

Inventors

Key dates

Filing dateMar 28, 1977
Grant dateSep 8, 1981
Priority date
Expiry dateMar 28, 1997

Classification

  • Technology area (CPC H)Electricity
  • CPC primaryH03D3/22
  • WIPO fieldBasic communication processes
  • WIPO sectorElectrical engineering

Abstract

This new demodulator for frequency modulated signals separates the signals into two distinct paths and delays the signals in one of the paths, with reference to those in the other of said paths, by an integral odd multiple of a quarter of one wavelength of the center wavelength of the signals. A particular type of balanced mixer compares the outputs of said two paths and produces an output varying in amplitude according to the phase difference between the signals at the outputs of said two paths. The above improvement has peculiar advantages in FM receivers for the relatively weak, wide band (excess of 2MHz), frequency modulated, television signals received from satellites.

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