Compact hybrid open stub EBG structure for power noise suppression in WLAN band

A compact hybrid open stub EBG structure for broadband power noise suppression is proposed. With an additional lumped component on proper locations of open stub, the proposed EBG structure could offer a wider bandgap to cover the whole associated WLAN bands or an aggregated bandgap ranging from WLAN band to above 10 GHz. A 1-D equivalent circuit model is also developed with validation by full-wave simulation and adopted to investigate design concepts. Test board is fabricated with 0402 capacitor and measured for verifying simulation results. The proposed EBG structure with single broadband design offers bandgap from 2.4 GHz to 6.1 GHz with 89.7% fractional bandwidth, and the one with bandgap aggregation design provides bandgap from 2.4 GHz to 10.8 GHz with 127.3% fractional bandwidth. The unit-cell area of proposed EBG is about 6.6 times smaller than traditional mushroom with the same lower bound cutoff frequency for WLAN band.