Precise investigation of field homogeneity inside a GTEM cell

In order to investigate the field distribution and therefore also the quality of the homogeneity of the field inside a GTEM cell, a high resolution scan has been accomplished. This is done over a frequency range of 30 MHz to 4.2 GHz with 305 frequency points. Further the SWR of the cell is been measured and the voltage amplitude ripple is calculated. From the obtained data a plot is provided that shows at which frequencies the homogeneity according to the norm is violated and at which frequencies the homogeneity of the measurement plane complies with the standard.