Using spiral resonator mounted on a power plane, simultaneous switching noise and ground bouncing noise can be suppressed through very wideband from 0.22 GHz to 12.5 GHz under noise suppression margin of -25 dB. The area of diameter of 3.2 mm is necessary for the resonator, and is comparable to a clearance pad size, diameter of 3.0 mm, in a ground/power plane. Hence the small size makes discontinuity of return current path reduces, therefore the signal integrity problem of an electromagnetic bandgap structure can be improved. For the analysis of modeling, the effects of inductance and capacitance in the spiral resonator are analyzed. As a result, suppression bandwidth and resonance frequency can be easily controlled by arm length and gap of spiral. Moreover, by applying 2 different sizes of resonators on top and bottom of power via, it is identified that multi-resonance effect is also obtained. Finally, it is shown that computational time can be dramatically decreased using both transmission line method and three-dimensional electromagnetic (3D EM) simulation instead of only 3D EM simulation for analysis.