平板筐体を利用した放射ノイズ抑制方法の検討

抄録

This paper describes changes in the characteristics of radiated emissions generated when the ground pattern of a two-layer PWB is connected to the sheet metal. Results of experiments revealed that the emission level deteriorated when the PWB was connected to the sheet metal under particular frequencies. The two reasons for this are that a standing wave is generated, and that a high-frequency current flows at the connection point. We took countermeasures to reduce the radiated emissions by regulating the impedance at the connection point, and confirmed their effectiveness in a wide frequency band.