Frequency characteristic of an EBG structure for SSN suppression

The frequency characteristics of an Electromagnetic bandgap (EBG) structure composing of regular hexagonal patches for simultaneous switching noise (SSN) suppression in high-speed printed circuit board (PCB) is studied by analysis and simulation. First, the effects of the side length of patches and the slit width between patches on the band-gap parameters and transmission characteristics are analyzed. Based on the analysis, the mathematical expressions to estimate accurately the lower and upper cutoff frequency and the bandwidth of the band gap for different side length are given and verified by experiments. Finally, the distinct influence of the slit width on the left and right part of the band-gap is studied. High transmission performance of the EBG structure is shown by comparing with the ideal transmission characteristic.