Design of a Microwave Sensing System for the Detection of Food Contaminants in Near-Field

In this paper, a novel microwave sensing (MWS) system for the detection of food contaminants in the near-field region is designed. The MWS system is composed of a pair of radiating and receiving horns and a pair of transmissive metasurface arrays with electrically reconfigurable unit cells. By manipulating the phases of the unit cells, the radiating electromagnetic beam can be focused at different target parts of the food package to be inspected. Experiment results show that, the electric field at the detection position in near-field is enhanced by almost 20% and the detection area is larger for the proposed MWS system compared with that for the traditional system without the arrays.