70 MHz fiber optic transmission from satellite DBS receiving antenna

Abstract

A broadcast satellite signal after conversion into an intermediate frequency (IF) signal at 70 MHz has been transmitted through an optical fiber in order to distribute the signal to the DBS (direct broadcasting satellite) receiver in a remote location. Based on experiments, it was found that a fiber-optic link allowed the designers to have greater flexibility than coaxial cables, and that light emitting diodes were attractive not only in terms of cost-effectiveness but also in terms of simplicity. The optical transmitter and receiver circuits built for experimental use were inexpensive and simple in circuit configuration. The distortion factor of the audio signal was less than 1% with a signal-to-noise ratio (SNR) of 70 dB. The differential gain and differential phase of the fiber-optic transmission system were less than 1% and 1 degree, respectively, and the SNR of the video signal was 46 dB.<>