A NOVEL COMPACT ELECTROMAGNETIC BAND GAP STRUCTURE TO REDUCE THE MUTUAL COUPLING IN MULTILAYER MIMO ANTENNA

This paper presents a novel compact multilayer meander strip line step-via electromagnetic band-gap (MLSV-EBG) structure with the application of mutual coupling reduction in a multilayer multiple input multiple output (MIMO) antenna. The proposed EBG-cell has been developed by using multilayer, novel meander strip line, and step-via concept. To analyse the proposed EBG a parallel LC model method is used. In the proposed MLSV-EBG structure, due to step-via concept, current path length increases, and compactness is achieved per unit cell. Parametric study is also presented. MLSV-EBG structure unit cell is simulated using ANSYS high frequency structure simulator (HFSS), and 5 × 5 cells are printed on an FR4 substrate for band-gap measurements. Simulated and measured results prove that compared with three-layer central located via EBG (CLV-EBG) and edge located via EBG (ELV-EBG), size reductions of 47.01% and 43.01% have been achieved, respectively, which shows that step via concept gives the significant size reduction per unit multilayer EBG cell. The application of proposed MLSV-EBG for the reduction of mutual coupling between two multilayer MIMO antennas is also demonstrated. The key contribution of the presented work is that the proposed compact multi-layer EBG structure is useful in a multi-layer environment at a lower frequency.