Radiation In The Electromagnetic Environment Of The Non-standard Target Fast Reconfigurable Mechanism Described

With the development of high speed print circuit board, radio frequency identification system and radio frequency device, radiated electromagnetic interference (EMI) is generated by electronic device. And many other devices are influenced seriously, even electrical miss-operation fault. Nowadays, the standard EM environment measurement as anechoic chamber can obtain the radiated EMI noise. However, the standard EM environment is complicated and can't identify the radiated EMI mechanism. On the other hand, civilian industrial devices can't afford the standard EM environment due to economical and technical conditions. Therefore, "low-end device, high-end technology" has been presented in EMC field.In this paper, fast reconstruction and mechanism description for radiated targets were researched by employed non-standard EM environment, including three parts:(1) Fast reconstruction method for radiated targets was presented by using non-standard EM environment measurement. According to PCB circuit and EM field analysis, the closed-forms of PCB distributive capacitance, radiation cable in-put capacitance and CM impedance were modified. Furthermore, the full-wave model of common mode (CM) current was proposed in the radiation cable.(2) Radiated EMI mechanism description method for radiated targets was put forward by employed the non-standard EM environment. The CM radiation model and differential mode (DM) radiation model were proposed. Moreover, with the Helmholtz equation, Lorentz condition and wave impedance principle, CM/DM radiation characteristic and mechanism can be obtained.(3) Radiated EMI noises generated by RFID based system, power line communication device, wireless communication instrument, wireless speaker and \electronic scale were analyzed by utilizing the suggest method. Meanwhile, the radiated EMI noise filters were designed in the paper.The theory and experiment results show that the radiated EMI characteristic and mechanism can be obtained efficiently by employed the suggest method. By using radiated EMI filter, radiated EMI noise can be reduced obviously and pass GB9254.