Research on Spatial Resolution Performance of Microwave Near-field Testing

Based on the principle of near-field microwave testing, a simulation analysis of the equivalent model of the probe sample was carried out, and the spatial resolution of a probe with a needle tip radius of $20\mu \mathrm{m}$ was calculated. Subsequently, a near-field scanning microwave microscope system was constructed, and a group of Cu thin films with decreasing widths and a group of Cu thin films with increasing thicknesses were tested. The profile curves obtained from scanning were analyzed to obtain the probe's different resolutions in the lateral and depth directions. Combined with the basic theory in the field of near-field microwave, a method for measuring the spatial resolution of the probe was proposed, laying the foundation for further research on near-field scanning microwave microscopes.