Localized Planar EBG Structure of CSRR for Ultrawideband SSN Mitigation and Signal Integrity Improvement in Mixed-Signal Systems

In this paper, a power plane with localized planar electromagnetic bandgap (EBG) structure is designed for suppressing simultaneous switching noise (SSN) in mixed-signal systems. Nonbianisotropic complementary split ring resonator with a bandgap behavior is used to constitute the EBG cells, which are partially located on the power plane to prohibit the noise propagation within the board. An equivalent circuit model is proposed to predict the lower cutoff frequency of the transmission behavior. From the measured results, an ultrawideband mitigation of SSN from 0.26 to 25 GHz is achieved with a high suppression level of -50 dB. Furthermore, signal integrity problem is investigated, and it is found that partial discontinuities of the proposed design can reduce the influence on signal quality compared with the traditional global EBG structure. In addition, the proposed design can lower the electromagnetic interference radiation from edges of the board.