Microwave Reconstruction of Fabrication Defects in Known Objects Using Scattering Parameter Sensitivities

This paper investigates the detection of permittivity defects in a fabricated, known object, motivated by a desire to detect errors in additively manufactured objects that may affect their electromagnetic performance. We use scattering parameter sensitivities to reconstruct the relative permittivity of a generic 2D object from microwave scattering measurements and a known reference model. To find guidelines for the implementation of a future measurement system, this reconstruction was done using different parameters such as number of antennas used, frequencies, and bandwidth. The effect of bandwidth on the limits of the reconstruction's spatial resolution was investigated, showing a resolution of approximately one tenth of a wavelength, which improves with increased bandwidth.