Causes of discrepancies between measurements and em simulations of millimeter-wave antennas [Measurements Corner]

This article describes the possible factors that can introduce discrepancies between measurements and three-dimensional EM simulations of millimeter-wave (mm-wave) antennas. The effects of the choice of the simulation solver, the relative permittivity and the homogeneity of the substrate material, the manufacturing tolerance, and the measurement errors are discussed. It is concluded that a fair comparison between measurements and simulations of mm-wave antennas can only be made if all these possible causes of discrepancies are taken into account.