Study On The Chipless RFID Tag Structureand Detection

Chipless RFID tag, a crucial role in radio frequency identification, has the potential to replace the bar code in the future. This paper studies about the design and detection of chipless RFID tags.According to the associate between the scatter’s complex nature resonance and the natural structure, a novel chipless RFID polygon tag is proposed, the main advantage of this polygon tag compared with others is insensitive to the polarization angles. By opening eight slots on two trapezoidal structures, the RCS curve will appear 8 peaks. The tag is capable of representing 8 bits by increasing/decreasing slots.Then other three kinds of chipless RFID tags are proposed: Cross-shaped array tags, slit-slotted tags and U-shape-slotted tags. These tags are sensitive to polarization of the incident wave. The presence or absence of the resonant frequency is used to encode bits by the cross-shaped array tag, but also a principle similar to frequency hopping. Slit-slotted tag achieves a frequency shift with a small slider to adjust the slot length, whose data is encoded in the frequency shift. U-shape-slotted tag is essentially an array of tags, whose data encoding is similar to the slit-slotted tag.At last, this paper discusses the detection and identification program of the chipless RFID tags. It’s demonstrated that poles and residues can be used to achieve this work. Subsequently, quality factor which is suitable for chipless RFID tag is defined by modeling RLC parallel resonant circuit, it’s recommended as an auxiliary parameter to detect/identify tags.