Near- and far-fields test system of portable radios EMI to electronic devices

A new EMI (electromagnetic interference) test system to estimate the immunity of electronic devices is proposed. This system directly exposes the devices to the near- and far-fields generated by a dipole antenna and/or actual mobile phone. In addition, an in-vitro experimental system for pacemaker EMI investigation is introduced. This method uses the antenna input power and the distance between antenna and device-under-test as the test parameters instead of E-field strength. The transmitting signal properties of present mobile phones in Japan (800 MHz- and 1.5 GHz-PDC, 1.9 GHz-PHS, etc.,) are clarified to analyze EMI due to mobile radio wave exposure. A practical test procedure is also described. The summarized experimental results of EMI tests conducted on 228 pacemakers and 499 medical devices are shown to confirm the fact that the proposed system is indispensable for the EMI assessment of mobile phones.