A Miniaturized Uniplanar Metamaterial-Based EBG for Parallel-Plate Mode Suppression

The suppression of parallel-plate modes is difficult to control over electrically short lengths. The use of electromagnetic bandgap (EBG) technology allows for a large suppression with controllable bandwidth, but traditional EBGs are often too electrically large to be used in practice. Moreover, in some forms they require several metallization layers and/or interconnecting vias. We introduce a metamaterial-based EBG that is miniaturized, uniplanar, and fully printable for the suppression of signals carried by the parallel-plate mode. We also present a corresponding multiconductor transmission-line analysis for accurate modeling of the EBG's dispersive properties, which arise from the coupling of contradirected forward and backward modes. The theory is supported by full-wave finite-element-method simulations and verified by measurements of a fabricated EBG. To demonstrate the practical value of the metamaterial-based EBG, we propose an alternate implementation that extends the one-dimensional structure to a two-dimensional radial EBG suitable for the suppression of high-frequency parallel-plate noise coupled between adjacent via interconnects. The simulation and measurement results for this device were found to be in agreement with each other and with the predicted bandgap.