Characterization of Material Properties by Using an Auto-Tuned RFID Chip

This article introduces a UHF RFID tag incorporating a self-adjustable Magnus S3 chip to effectively compensate variations in antenna impedance. The auto-tuning capability is harnessed for enhanced precision in wireless sensing applications. An existing tag is examined to understand the distinct roles of the antenna and the RFID chip under changing boundary conditions. The study employs a range of solid and liquid materials to investigate the tag's behavior and identification mechanisms. Experimental validation is conducted using commercially available liquids emphasizing the tag response to fluctuating antenna impedance, while accounting for external factors such as solids and liquids.