An ultra compact electromagnetic band gap filter for GHz power noise suppression using LTCC technology

A new structure to suppress simultaneous switching noise using an electromagnetic band gap filter is proposed. Based on periodic structure concept, this structure is one dimensional periodic structure with three unit cells. The size is comparable with noise suppression component such as capacitors, ferrite beads and pi filters. But unlike these components, the proposed structure would not suffer from noise problems at higher frequencies. The special characteristic is its flexible operation frequency. The band gap can be designed by using proper geometrical structure parameter. To make use of the parameter in this work, the noise beyond limitation of the pi filter could be suppressed by this structure. In this work, the size of proposed structure is 1.2 mmtimes3.8 mmtimes0.728 mm. The stop band is from 2 GHz to 5.5 GHz and is validated both by simulation and experiment. Over 25 dB noise reduction in the stop band could be achieved by this structure.