Near-Field Millimetre Wave Vector Microscopy - Buried Structure Imaging

Near-field vector measurement can be used to image devices or material. From optics to microwaves, this technique uses different method and theoretical supports. Our test bench, working in the band 55 to 65 GHz and its capacity to image a buried structure on a commercial chip from GaN system are presented here. The influence of the bow-tie probe shape and the distance of measure is discussed. The capacity of our system to image a buried structure is detailed thought the information of modulus and phase of the near field reflected voltage.