Assessment of radiated immunity of C-band satellite TV receiving station in Hong Kong local environment due to UWB interference

摘要

The frequency spectrum of ultra-wideband (UWB) covers from 3.1 to 10.6 GHz in accordance with the Federal Communications Commission (FCC) definition [1] and European Union Commission decision [2]. The UWB technology is basically a time-domain pulse transmission with small pulse duration. The short pulses would have a wide bandwidth, which is generally larger than 500 MHz, and overlaps several existing radio communication services. Based on this characteristic, the concern of UWB interference on existing narrowband wireless systems has been raised, since the same frequency spectrum has been utilized. In the United States, the average emission mask for a UWB device is 500 μV/m measured in 3 m which is equivalent to an effective isotropic radiated power (e.i.r.p.) of -41.3 dBm/MHz [3]. However, there have been studies carried out by the International Telecommunication Union (ITU) [4] and Electronic Communications Committee (ECC) [5] which suggest that this e.i.r.p. limit could not sufficiently protect some of the existing systems from UWB interference. The "noise-like" propagating UWB pulses raise the thermal noise floor of other systems, which could eventually degrade their overall performance.