A compact meander flexible UHF tag for industrial applications

The objective of this paper is to introduce a novel design for a flexible Ultra-High Frequency tag (UHF tag) through the utilization of the meander line technique (MLA) and loop antenna method. The primary goal is to achieve a compact UHF tag operating at 868 MHz. The physical dimensions of the UHF tag are 110×12×0.1mm3. The proposed UHF tag is manufactured using the inkjet printing method on a polyamide substrate featuring a relative dielectric constant of 3.5, a tangent loss of 0.0027, and a height of 0.0508 mm. Through electromagnetic simulation and validation, the functionality of the proposed UHF tag covers the UHF band ranging from 854.57 to 883.89 MHz, with a bandwidth of 29.32 MHz. The reflection coefficient at 868 MHz is approximately -22.46 dB. The simulated gain measures 1.79 dBi, while the theoretical read range is estimated at 5 m. The UHF tag is produced using silver ink with a thickness of 0.05 mm and assembled using an anisotropic conductive paste (ACP). Subsequent to electromagnetic simulation, the UHF tag’s performance is confirmed through a reading test conducted with a radio frequency identification (RFID) base station. The results are consistent with the theoretical expectations, showcasing a commendable read range of 5 m. To safeguard the UHF tag from challenging environmental conditions, it is enclosed within a polyethylene film (PE). Following encapsulation, the read range decreases to 3 m, making it suitable for RFID applications requiring mid-range capabilities.