UWB car attenuation measurements

In the European regulatory domain the CEPT ECC working group TG3 on ultra wideband (UWB) has developed a broad framework for the regulation of the deployment of UWB devices in Europe. In the first draft of the regulation the deployment of UWB will be strictly restricted to indoor usage, prohibiting usage in cars, trains and planes in order to guarantee maximum interference mitigation towards incumbent services. Thus planned deployment of UWB in cars for different kind of application like sensor or car multimedia communications application would be prohibited under the existing regulation. The attenuation measurements presented in this paper should pave the way towards a less restrictive definition of the indoor usage model including the in-car usage. The measurements have been carried out at the premises of the Joint European Research Center (JRC) in Ispra, Italy in the European Microwave Signature Laboratory (EMSL). As a main result of the measurements it can be seen that the average worst case attenuation in the frequency range of interest of the evaluated cars is in the range of the assumed indoor to outdoor attenuation of 10 dB to 12 dB assumed in the CEPT ECC Report 64. These results are inline with the ITU recommendation ITU-R-P 679-1.