A High Data Capacity Chipless RFID Sensor for Food Safety: Food Engineering Theme

Chipless RFID is an emerging technology has huge commercial applications including secured paper, item tagging and food safety. This technology has the capacity of being printed on flexible materials with very low price compared to the chipped RFID. The combination of chipless RFID tags and sensors is very beneficial for identification and sensing different physical parameters such as humidity, temperature and PH of a packaged food item at once. The low data capacity is the main bottleneck of chipless RFID. high-quality factor resonators is essential for increasing the data capacity of the tag ID. One of the significant challenges in chipless RFID tag design is the requirement of high quality-factor resonators which is suitable to be attached to smart material for sensing purposes.
In this paper, a high-quality factor resonator for a sensor with high capacity is proposed. The resonator can be used for designing a frequency domain chipless RFID tag with 50-bits content capacity in less than 4 GHz bandwidth. The high spectral efficient tag can identify and sense more 1.2 billiard different unit items. In addition to that, the resonator has the potential of being used in a multi-sensor system due to its low coupling effect between resonators in the optimised design. For instance, the frequency signature of a 15-bit tag combined by a chipless RFID sensor at different humidity conditions is shown in Fig. 1. As it can be seen the sensor resonance does not have any interference with the identification response which is promising. The simulation and measurement results of the fabricated prototype indicated the excellent performance of this chipless RFID resonator for different sensing applications.