Study and Suppression of Ripples in Passbands of Series/Parallel Loaded EBG Filters

摘要

This paper presents a method to suppress the ripples in passbands of series/parallel loaded finite period electromagnetic-bandgap (EBG) filters. Based on the study of equivalent circuits, the ripples in passbands of EBG filters with different resonant loads are compared. A four-section resonant slot loaded microstrip EBG filter is exemplified to validate the proposed design method experimentally. Both simulation and measurement show 50-dB attenuation at the center of the first stopband and less than 0.29-dB ripples in the adjacent passbands.