Object reconstruction in non-destructive microwave defectoscopy

Abstract:
Current contribution presents a new signal processing method providing an enhanced spatial image resolution and a more accurate defect classification by using low-cost microwave defectoscopy only. In order to reduce the diffraction effects, two approaches have been followed. First, several antenna configurations have been tested experimentally and optimized numerically with respect to the main emission characteristics. These include, among others, the antenna footprint, return loss, polarization and focusing characteristics of the radiated waves to detect defects in different depths in plastic materials. Secondly, the data analysis techniques are employed in the post-processing stage to suppress the diffraction effects. Within the approach, we determine the transfer function of the antenna, or so-called point spread function (PSF), which allows overcoming the diffraction limit in object reconstruction, and substantially increases sharpness and accuracy of the final image.