The optimization design of septum in TEM cells for IC EMC Measurement

TEM cell can be used to test radiated emission and immunity of integrated circuits (ICs).The impedance mismatch of septum will cause voltage standing wave ratio (VSWR) improved and transmission performance deteriorated. This paper investigates several methods for locating the connection point between main part and transition part of septum in TEM cell to get perfect electric and magnetic fields distribution. The three-dimensional model of TEM cell with different connection point location has been established in order to analysis the mode of electromagnetic wave and transmission characteristics. The field distribution of optimized TEM cell will become more uniform and the maximum VSWR can reduce from 1.38 to 1.20 in whole working bandwidth.