A look at the emissions of three low-power wireless charging devices

We examined the electromagnetic (EM) emissions of three commercially available systems that charge remote devices by use of inductive wireless power transfer (WPT) in the Low-Frequency (<;300 KHz) range. All devices have passed applicable emissions regulations We measured the temporal and spectral characteristics of the char ging and information exchange between the charger and load. The basic WPT characteristics of each device are examined. We performed a simple interference test between these devices and a 13.56 MHz Radio Frequency Identification (RFID) reader to investigate possible interference potential posed by fundamental power transfer and the data modulation produced by WPT devices Results imply that interference potential of the lower-power, data signals maybe greater than the higher-power WPT transfer signal.