3D Microwave Imaging Using Huygens Principle: A Phantom-based Validation

The main aim of this paper is to upgrade MammoWave acquisition and appropriately extend the Huygens Principle (HP) algorithm for allowing a 3D imaging reconstruction. The MammoWave device contains a cylindrical hub and two antennas, which are positioned at the same height and connected to a 2-port vector network analyser (Cobalt C1209, Copper Mountain, Indianapolis, IN). The two antennas can rotate azimuthally all around the object to be imaged. Measurements are performed by recording the complex S21 in a multi-bistatic fashion. In this paper, we have achieved a phantom-based investigation using a multi-quote scanning procedure via MammoWave operating at a 1–6.5 GHz frequency range. Specifically, a cylindrical phantom possessing a radius of 5.5 cm and height of 13 cm is constructed and a 3D structured volumetric flask with a spherical bottom (radius 1.75 cm) is used as inclusion. The materials and mixtures used in the preparation of the phantom have a contrast of 5 in dielectric properties. Next, measurements at planes along the z-axis are performed and multi-quote data are used in a modified version of the HP-based algorithm via superimposition theorem. The complex 6 × 15 × 80 S21 is processed allowing 3D imaging reconstruction; our results clearly show the 3D visualisation of the detected inclusion at multiple planes. In more detail, we verified that the dimension of the detected inclusion varies in the different planes of visualisation, accordingly to the spherical inclusion cross-section, with an average error in dimension qualification of < 10%.