Multi-Frequency Microwave Imaging Inspection for Industrial Food Quality Assessment

Progressive automation and throughput scaling are essential for the economic development and robustness of a productive food manufacturing company. Reliable scanning verification technologies must be put in place to ensure products quality and conformity. Due to the impressive yield of high-speed production lines, possible and undesirable malfunctionings may irreversibly alter the compliance of some of the fabricated samples, by contaminating them with foreign intrusions. In this paper, we propose the use of microwave imaging as a novel exploitable strategy, complementary to other well-established technologies (such as X-rays and metal detectors), to sense foreign intrusions inside food products. The examined setup is made of a set of printed monopole antennas mounted on a 3D printed arch, which suits the placement on production chain conveyor belts. Foreign body reconstructions for an oil-filled jar, scanned in a fixed position, have been obtained in the frequency range 9 - 10 GHz. The impact of mathematical multi-frequency approaches is explored, combining available information from different spectral perspectives. © 2025 European Association on Antennas and Propagation.