Radar Cross Section of Chipless RFID Tags and BER Performance

Abstract

The performance of different chipless RFID tag topologies are analysed in terms of Radar Cross Section (RCS) and Bit Error Rate (BER). It is shown that the BER is mainly determined by the tag Radar Cross Section (RCS) once that a standard reading scenario is considered and a fixed size of the tag is chosen. It is shown that the arrangement of the resonators in the chipless tag plays a crucial role in determining the cross-polar RCS of the tag. The RCS of the tag is computed theoretically by using array theory where each resonator is treated as a separate scatterer completely characterized by a specific reflection coefficient. Several resonators arrangements (periodic and non-periodic) are compared, keeping the physical area of the tag fixed. Theoretical and experimental analysis demonstrate that the periodic configuration guarantees the maximum achievable RCS thus providing a global lower BER of the chipless RFID communication system. We believe that the BER is the more meaningful and fair figure of merit for comparing the performance of different tags than bit/cm 2 or bit/Hz since the increase of encoded information of the tag is useful only if it can be correctly decoded.

A Review of RFID Sensors, the New Frontier of Internet of Things

“…The possibility of correctly reading the information encoded within the tag (detection probability) is strictly related to the RCS of the tag. The RCS of the tag is proportional to the square of the footprint of the label if all the particles radiate in phase [ 61 ]. In the case of periodic tags, the average value of RCS can be controlled by increasing or decreasing the number of unit cells, and thus the footprint of the tag [ 61 ].…”

“…The RCS of the tag is proportional to the square of the footprint of the label if all the particles radiate in phase [ 61 ]. In the case of periodic tags, the average value of RCS can be controlled by increasing or decreasing the number of unit cells, and thus the footprint of the tag [ 61 ]. Finally, it has to be mentioned that readers for chipless RFID require complex and specialized architectures based on their mode of operation, and competitive commercial products are currently available.…”

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

“…According to Figure 4 , an eligible coding capacity of 60 bits can be then obtained, leading to theoretical spatial coding density of about 300 bits/cm 2 . Such a performance is several orders of magnitude better than coding density obtained with a chipless RFID system [ 4 , 5 , 6 , 7 , 8 ], mainly since THz wavelengths are a hundred times smaller than in the RF .…”

“…Chipless RFID is mainly based on resonator technology and the tag’s performance of course depends on the resonators design, number, the selected frequency range, and on the coding technique. Moreover, in the RF domain mainly, the design of chipless structures, and more generally the research for efficient performance, remains a hot topic subject with very rapid development [ 4 , 5 , 6 , 7 , 8 ]. The best performances published in the last two years reach about 30 bits but remains for the majority around 20 bits, corresponding to spatial density in the range of 1 bit/cm 2 , very exceptionally around 10 bits/cm 2 or higher.…”

Antenna characterization based on backscattered electromagnetic waves

“…Diversity of polarization and resonance frequencies are performed to achieve wireless communication to passive RFID tags. 3,4 The Radar technique as a noninvasive characterization technique was initiated in the 1960s, 5,6 then it was revived for the characterization of small antennas in the 1990s, [7][8][9][10][11] and 2000s. [12][13][14][15][16][17][18][19] It aims to determine the radiation, diffraction and matching characteristics of the antenna.…”