Immunity of Bluetooth-transmitters against interfering electromagnetic fields with high field-strengths

摘要

The wireless transmission standard Bluetooth has established its position within all areas of consumer electronics. More and more, the cheap and flexible wireless service for low up to medium data ranges is also used as a comfortable cable replacement within industrial environment. Although most environments pose no challenge for this robust standard, still some applications imply very noisy environments combined with high electric field strengths and modulated oscillations. This article examines the vulnerabilities of commercial available Bluetooth-transmitters exposed to electromagnetic fields with high electric field strengths with respect to the frequency and modulation factor. Both far-field and direct-coupled measurements are made, analyzing the transmission rate while exposing the modules to modulated and unmodulated radio signals between 10 MHz and 3 GHz.