Measurement accuracy and repeatability in near-field scanning microwave microscopy

We report on the accuracy and repeatability tests for near-field scanning microwave microscopy applications by associating a network analyzer and an evanescent microwave probe (EMP). A broadband matching network based on an interferometric technique is used to achieve a strong electromagnetic coupling between the probe tip and the material in the frequency range 1-20 GHz. The electromagnetic coupling between the probe and a planar metallic sample is investigated using numerical simulations based on finite element method (FEM). Experimental validations show that the measurement sensitivity is enhanced in the vicinity of the probe tip. Measurement accuracy and repeatability of the system are provided that are instructive and beneficial to further experiments.