An efficient characterization approach of radiated electromagnetic field analysis for PCBs+

Radiation characterization is composed of radiation mechanism diagnosis and radiated electromagnetic (EM) field estimation. Based on not only the internal relationship between radiated EM field and wave impedance, but also the inner relationship between wave impedance and measurement distance, a new near-field method is proposed for diagnosis of radiation mechanism, including common mode (CM) and differential mode (DM). Furthermore, by employing radio frequency (RF) circuit parameter measurement, a simple approach is presented for estimation of radiated EM field generated by RF current in the cable. The experimental research shows that radiated noises decrease obviously after circuit improvement, meanwhile, the radiation mechanism is achieved by the near-field method; in addition, the results of RF circuit parameter measurement agree well with 3-m chamber measurement results. Therefore, the presented approach is efficient and effective.