Patent · US Expired

Frequency modulated modem transmitter

US4670888A · kind A · utility

18Cited by
4References
2Claims
0Family size

Assignee

Inventor

Key dates

Filing dateNov 7, 1985
Grant dateJun 2, 1987
Priority date
Expiry dateNov 7, 2005

Classification

  • Technology area (CPC H)Electricity
  • CPC primaryH04L27/12
  • WIPO fieldBasic communication processes
  • WIPO sectorElectrical engineering

Abstract

A frequency modulated transmitter including a reference frequency source providing a reference frequency to a phase locked loop circuit. The phase locked loop circuit provides a frequency output signal stabilized in accordance with this reference frequency and in accordance with a feedback signal. The phase locked loop circuit further includes a data input circuit that adjusts the output frequency in accordance with input data. Also included is the feedback circuit that provides the feedback signal to the phase locked loop circuit. This feedback circuit is derived from the frequency output signal. A synchronization circuit is connected to the feed back circuit and synchronizes the output of the feedback circuit with the reference frequency signal and the input data.

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