D.c. Coupling Patents (Class 330/163)
  • Patent number: 5321710
    Abstract: A predistortion circuit reduces composite second order intermodulation distortion products inherently generated by a laser diode. A radio frequency signal is split into a primary and secondary signal, and the secondary signal is amplified by an amplifier biased at a starvation current level so as to produce intermodulation distortion products having an amplitude relatively large compared to an amplitude of a fundamental generated by the amplifier. The amplitude and phase of composite second order intermodulation distortion products generated by the amplifier are adjusted so as to substantially match those inherently generated by the laser diode by the primary electrical signal, with the products being about 180.degree. out of phase relative to those generated by the laser in response to the primary signal.
    Type: Grant
    Filed: April 19, 1993
    Date of Patent: June 14, 1994
    Assignee: Raynet Corporation
    Inventors: Peter W. Cornish, Barry Duncan