Numerical characterization of a TEM-t cell as evaluation case of field solvers

By measuring the transmission loss in a TEM-t cell the conductivity of thin materials used in shielding can be determined over a large frequency range. The behavior of the empty and loaded cell is simulated numerically by using 2D and 3D field solvers. Static solvers are used to establish an equivalent circuit model of the cell: the line parameters of the straight section with static 2D solvers, the equivalent circuit of the interrupted inner conductor with a static 3D solver. Dynamic 3D solvers accurately simulate the electromagnetic behavior of a complete cell, including coax to taper transition, tapered section, interrupted inner conductor, Teflon supports and thin conductive material. The numerical results are confirmed by measurements.