On the way to design Substrate Integrated Waveguide Bandpass Filter (SIW-BPF) for wideband applications a parametric study of the slot geometry etched on a SIW structure is the preliminary step to design such filter. Three different structures, namely, H-Slotted, T-Slotted, and U-Slotted SIW is investigated in order to examine the effect of altering different geometrical parameter of the unit on its response. H-Slotted Electromagnetic Band Gap (EBG) shows the highest Fractional Band Width (FBW), which is about 90% compared to the others, consequently it could be used to design a wideband SIW-BPF.