Patent · US Expired

RF wide bandwidth lossless high performance low noise transmissive link

US6175672A · kind A · utility

33Cited by
2References
20Claims
0Family size

Assignee

Inventors

Key dates

Filing dateJun 18, 1999
Grant dateJan 16, 2001
Priority date
Expiry dateJun 18, 2019

Classification

  • Technology area (CPC H)Electricity
  • CPC primaryH04B10/2575
  • WIPO fieldTelecommunications
  • WIPO sectorElectrical engineering

Abstract

A substantially lossless transmissive link, such as an RF fiber optic link, that selectively employs a number of techniques to improve various link parameters. The link may be structured to comprise a high power light source, such as a laser, that provides light output having a high level of optical power. A feedback circuit may be disposed around the light source that reduces relative-intensity-noise levels produced by the light source at low frequencies. A modulator is provided that modulates the light output of the light source. Preferably, a dual output modulator may be used to provide two modulated optical signals whose respective RF modulation is "effectively" 180 degrees out of phase. An optical fiber that transmits the modulated optical signal(s). A photodetector without a load resistor directly on its output that is operable at the high level of optical power, receives the modulated light and recovers the RF signal. A dual balaniced photodetector that is used in conjunction with the dual output modulator. An RF component, such as an amiplifier, that is coupled directly to an output of the photodetector that provides a load resistance for the link.

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