General radiation EMI/EMC design need to be considered at the same time, the radiated conduction (conducted) two aspects. The former belongs to the part of high frequency (> 30 MHZ) part of the latter is the relatively low frequency (< 30 MHZ). So not only pay attention to high frequency and low frequency part. A good EMI/EMC design must consider when layout at the beginning to the location of the device, the arrangement of the PCB lamination, important online games, devices, such as the choice of PCB optimal guest board remind if they didn't have a better arrangement in advance, after the solution will be wasted effort, increase the cost. Such as the location of the clock generator try not to close to the external connector, high-speed signal to go inside and pay attention to the characteristic impedance matching and reference layer to reduce the reflection in a row, signal devices by pushing the slope (slewrate) as far as possible little to reduce the high frequency components, the choice to coupling decoupling/bypass capacitor note its frequency response is in line with the requirements in order to reduce the noise power supply layer. In addition, pay attention to the high frequency signal of current return path as far as possible make the loop area small (that is, loop impedance loopimpedance small as far as possible) in order to reduce radiation. You can also use the division of strataTo control the range of high frequency noise. Finally, select the appropriate site (chassisground) for the PCB and enclosure.