Effect of LVDS link speed and pattern length on spectrum measurements of a Spacewire harness

Abstract

Link speed and code word length in spacecraft digital systems have a critical effect on equipment design in terms of operation and electromagnetic interference. In this work the behavior of a Low Voltage Differential Signaling / Spacewire link is evaluated through radiated as well as signal spectrum measurements. Various pulse frequencies and pattern lengths were tested and the results indicate that higher pulse frequencies increase the radiated emissions of the system. Radiated emissions are also affected by pattern length, due to the fact that the magnitude and the spacing of the spectral lines vary as the code word length increases.