Video-Rate Identification of High-Capacity Low-Cost Tags in the Terahertz Domain.

Florent Bonnefoy,Nicolas Barbot,Eiji Kato,David Hely,Etienne Perret,Maxime Bernier,Romain Siragusa,Frederic Garet

doi:10.3390/s21113692

Abstract

In this article, we report on video-rate identification of very low-cost tags in the terahertz (THz) domain. Contrary to barcodes, Radio Frequency Identification (RFID) tags, or even chipless RFID tags, operate in the Ultra-Wide Band (UWB). These THz labels are not based on a planar surface pattern but are instead embedded, thus hidden, in the volume of the product to identify. The tag is entirely made of dielectric materials and is based on a 1D photonic bandgap structure, made of a quasi-periodic stack of two different polyethylene-based materials presenting different refractive indices. The thickness of each layer is of the order of the THz wavelength, leading to an overall tag thickness in the millimetre range. More particularly, we show in this article that the binary information coded within these tags can be rapidly and reliably identified using a commercial terahertz Time Domain Spectroscopy (THz-TDS) system as a reader. More precisely, a bit error rate smaller than 1% is experimentally reached for a reading duration as short as a few tens of milliseconds on an 8 bits (~40 bits/cm2) THID tag. The performance limits of such a tag structure are explored in terms of both dielectric material properties (losses) and angular acceptance. Finally, realistic coding capacities of about 60 bits (~300 bits/cm2) can be envisaged with such tags.

Highlights

Published: 26 May 2021The idea to extend the concept of chipless Radio Frequency Identification (RFID) to the THz domain is mainly motivated by the necessity of fighting against counterfeiting, and thereby to reach higher security level for identification systems
The idea to extend the concept of chipless RFID to the THz domain is mainly motivated by the necessity of fighting against counterfeiting, and thereby to reach higher security level for identification systems
Chipless RFID is mainly based on resonator technology and the tag’s performance depends on the resonators design, number, the selected frequency range, and on the coding technique

Summary

Introduction

The idea to extend the concept of chipless RFID to the THz domain is mainly motivated by the necessity of fighting against counterfeiting, and thereby to reach higher security level for identification systems. Some ongoing developments are very encouraging to continue to reduce their cost and size, for example, by using multimode laser integrated on glass to be used for THz generation by frequency mixing [23] In this context, we show that the prospect to operationally read and reliably identify a low-cost and easy to manufacture tag, is made possible using commercially available THz spectrometers. Terahertz Time Domain Spectrometer (THz-TDS), while keeping a bit error rate smaller than 1% We deduced from these results a criterion to ensure minimum reading reliability, that takes into account the reader performances, such as, for example, its signal to noise ratio. Let’s noticed that such angular acceptance remains sufficient for application using, for example, smart cards type objects

Description of the THID Tag and of the Measurement Setup

Frequency

Principle and Theory of Coding

THz with a resolution spectral resolution several

Findings

Conclusions