Research On EBG Structure For EMI Suppression

With the rapid increase of the clock frequency of high-speed digital circuits, howto suppress simultaneous switching noise (SSN) has become a key technology in thehigh speed circuit design. Adding decoupling capacitors to create a low impedancepath between power and ground planes is a typical way to suppress the SSN. However,in general, these capacitors are not effective at frequencies higher than 600MHz due totheir lead inductance. According to the band gap characteristic of EBG, it provides annew way to effectively suppress SSN.This dissertation focuses on the characteristic of EBG structure. The dissertationuses the Ansoft HFSS software which is based on the finite element method tosimulate the EBG structures. Mushroom-EBG structures and the uniplanar compactEBG (UC-EBG) structures are analyzed. And then, the impact of the structurevariation of the EBG on electromagnetic interference is discussed in detail.According to simulation result of EBG structure which is mentioned above, a newkind of MS-EBG structure is presented. The numerical result shows that this structurehas a relatively wide bandwidth. The center frequency of the new structure is 3.2GHz,the stopband range is 0.4GHz ~ 6GHz, and the restrain depth is -30dB. It caneffectively inhibit the simultaneous switching noise which is mainly distributed below6GHz.