Simulation and experiments of ultra-wideband radio propagation within closed boxes for replacing wired interface buses in spacecrafts

Ultra-wideband (UWB) signal propagation was simulated and experimented within closed boxes with various inner volume, with a view to replace (at least partly) wired onboard data buses with wireless communications. Since multipaths depend on inner volume, it is necessary to evaluate the propagation characteristics depending on volume. Frequency-domain responses (from 3.1 to 10.6 GHz) in some closed boxes emulating a small scientific satellite were simulated and measured with a vector network analyzer. The spatial distribution of UWB propagation and its parameters were derived from the measurements. The propagation gains did not apparently depend on the inner volume. On the other hand, delay spreads were found increase with the volume.