Simulation and measurement of the propagation of Bluetooth signals in automobiles

Due to the low costs of Bluetooth digital radio, wireless communication according to this standard increases popularity in the future. An interference free operation of wireless devices in cars among themselves and between these devices and sensitive car electronics has to be assured. In this paper fields originated by Bluetooth transmitters in personal cars are examined. Field distributions according to different transmitter positions are simulated with the method of moments (MoM) in order to get worst case results of the field strength as well as to characterize the radiation pattern of such configurations. To compare with the simulation, measurements of the field strength and the radiation pattern are made. Finally, measurements of coupling into cables within the passenger cabin are performed. Due to their increasing use as basic hardware within portable computers, also the coupling of WLAN is observed in this context.