Effect of split power/ground planes using stitching capacitors on radiated emission

In this paper, the radiated emissions generated by various split power/ground plane structures are studied. The magnetic field and electric field over the designed test pattern are simulated. Each of the results has different field pattern by bandwidth of signal frequency, gap space or gap location of the split ground gap. To reduce the radiated emission, the method for determining the gap space and the gap location are studied based on the return current distributions. Also, the magnetic near-fields are measured by the near field EMI scan over the test board with the different value and location of the stitching capacitors. These results show that the radiated emission on split power/ground structure can be reduced by optimizing its structure. Moreover, the values and locations of the stitching capacitor should be determined to minimize the discontinuity of the return current paths.