Open stub electromagnetic bandgap structure for 2.4/5.2 GHz dual-band suppression of power plane noise

A conventional open stub electromagnetic bandgap (EBG) structure has a compact unit cell size. However, each bandgap of this structure may not be controlled independently of the others, making the structure impossible to be used for several predetermined frequency ranges required in wireless communication. In this paper we upgrade the EBG structure by using two open stubs and realize dual-band operation. In present case, unit cell size is 2.3 mm × 2.7 mm almost same as the previously described open stub EBG structure. Through equivalent-circuit analytic calculation and finite element method (FEM) simulation, we estimated bandgaps of the proposed structure. According to obtained data, they cover 2.4- and 5.2-GHz bands used in wireless LAN. Then we confirmed these results by measuring insertion loss of corresponding patterns disposed in a fabricated evaluation board.