Chipless RFID Tag Using Hybrid Coding Technique

TLDR

Chipless RFID tags require increased coding capacity to support miniaturization. The study proposes a hybrid coding technique that combines phase deviation and frequency position encoding. The tag uses five C‑shaped metallic strip resonators operating between 2.5 and 7.5 GHz, with various configurations designed and validated in a bi‑static measurement setup. The tag achieves 22.9 bits of coding capacity in a 2 cm × 4 cm area, is low‑cost due to a single conductive layer, and shows strong agreement between measurement and simulation.

Abstract

Increasing the coding capacity of chipless RFID tags is a key factor while considering the development of miniaturized tags. A novel hybrid coding technique by combining phase deviation and frequency position encoding is proposed here. A coding capacity of 22.9 bits is obtained simply with five resonators within a reduced dimension of 2 cm × 4 cm. The proposed tag is based on 5 `C' like metallic strip resonators having resonance frequency within the band of 2.5 GHz to 7.5 GHz. The tag is potentially low-cost since only one conductive layer is needed for the fabrication. Different tag configurations are designed and validated with measurement results in bi-static configuration. A good agreement between measurement and simulation validates the theoretical predictions.