Measurements and characterization of ultra wideband propagation within spacecrafts

Ultra wideband (UWB) propagation was measured and characterized within spacecrafts, with a view to partly replacing onboard data buses with wireless connections. Spatial distributions of UWB and narrowband propagation in frequency (from 3.1 to 10.6 GHz) and time domains were measured with a microwave vector network analyzer. While narrowband resulted in a number of dead spots (deep fading points) within the conductive enclosures, UWB yielded none. This implies the UWB systems have an advantage over narrowband ones from the viewpoint of reducing fading margins. It was also found that delay spreads can be suppressed by partially panelling a radio absorber on the inner surfaces to facilitate high data rate transmission.