Bio-Inspired Circular-Polarized UHF RFID Tag Design Using Characteristic Mode Analysis

This article presents a bio-inspired circularly polarized ultrahigh-frequency (UHF) radio frequency identification (RFID) tag antenna for metallic and low-permittivity substances. design is based on leaf-shaped radiator, two shorting stubs, slots etched F4B substrate. Initially, the designed using characteristics mode analysis (CMA) by analyzing first six characteristic modes (CM) angles. The width of orthogonal varied to get resonance CM in required US RFID band. Moreover, edges are blended current distribution, which necessary circular polarization. In addition, proposed optimized further CST Microwave studio an chip exploited as capacitive coupling element (CCE) run with pattern. can also be tunable European (EU) band (866–868 MHz) changing length shorter diagonal slot. offers read range 7–4.5 m $100\times100$ mm2 metals plate substrates (for 902–928-MHz band). EU band, corresponding ranges 5.7 3.5 above metal objects, respectively. advantageous terms cost, polarization feature, ease fabrication due absence vias, pins, matching circuits. Therefore, this suitable labeling various industrial conveyer belt applications, baggage handling systems, Internet Things (IoT) applications.