Optimum geometrical parameters for the EBG-based common mode filter design

This paper presents an efficient design procedure to obtain the physical dimensions of the electromagnetic bandgap (EBG) structure intended to filter common mode noise in high speed differential interconnects. The procedure is based on the concept of total inductance associated to the EBG geometry, and it offers wide flexibility for setting the geometrical EBG parameters. An optimum EBG design is studied investigating the relationships among the design parameters. This allows restricting the range of parameters that minimize the error between the achieved filter frequency and the nominal frequency. The study is carried out for several filtering frequency values and the results are validated by using full wave simulations. This paper also offers an example to synthesize the optimum EBG design for achieving a common mode filter at the desired frequency.