A Compact Hybrid EBG Microstrip Bandstop Filter for Digital Clock Suppression in a Power Supply System

摘要

In this paper, a compact novel wide band microstrip bandstop filter for digital clock suppression in power supply systems is presented. Filter combines the effects of electromagnetic bandagap structure (EBG) with surface mount technology (SMT) capacitor. Parameters are optimized via numerical simulations to achieve a stopband of 12 GHz for a reject of the first nine harmonics of a 1.35 GHz digital clock frequency. A FR4 substrate of relative permittivity 4.7 is used, where mushrooms like EBG structure of rectangular patches connected to ground by vias are built. Four SMT capacitor of 1 pF to the EBG structure are added. With this is possible to obtain a rejection band at -3dB form 1 GHz to 13.1 GHz within a small circuit area of 225 mm~2.