Millimeter-wave near-field imaging with bow-tie antennas

A near-field reflectometry experiment operating at 60 GHz is built in view of material and circuit inspection. Experiments are always obtained in constant height mode of operation. The bow-tie near-field probe acts mostly as a linearly-polarized electric dipole and allows strongly subwavelength resolution of ≈ λ/130. Its interaction with sample is shown polarization dependent and sensitive to both the local topography and the local dielectric constant or metal conductivity. Resonant and non-resonant probes are both evaluated.