Analysis of Artifacts on Chipless RFID Backscatter Tag Signals for Real World Implementation

Abstract

Chipless radio-frequency identification (RFID) has been studied as an alternative technique to conventional chipped RFID. However, chipless RFID tag backscatter signals are affected by motion and especially when they are attached to different objects. In this paper, we performed a comprehensive analysis of the backscattered chipless tag signal in two different stages. At the first stage, we performed an analysis of the backscattered signal in the nonanechoic environment when the frequency-coded tags were moving at different stepped positions. Then we continued to identify the response of signal where the chipless tag was attached to highly scattering objects. The results showed the variation in amplitude and shifting in the frequency of tag resonant when the tag was moving at different stepped positions. The variation was more prominent when the tag was attached to random objects. In order to address the issue, we conducted an experiment on orientation insensitive ground plane tag to solve the frequency shifting problem and proposed a robust detection method based on mother wavelet for the detection of tag IDs. The overall results show that the proposed technique reduces uncertainty in frequency-based chipless RFID tag signal response due to the variation in amplitude. The technique also helps in detecting the tag data bits with better resolution and has a good arrangement between time and frequency resolution for high-frequency signal components. The throughput of 90% is obtained even when the tag is attached to highly scattering objects. Finally, to validate the performance, a ground plane tag is implemented and the proposed algorithm is experimentally demonstrated. INDEX TERMS Chipless RFID, radar cross section (RCS), horn antennas, backscattered signal, detection algorithm, continuous wavelet transforms.

Physical Layer Detection and Security of Printed Chipless RFID Tag for Internet of Things Applications

“…7 and Fig. 8 respectively, where we choose amplitude response of the backscatter signal for further analysis due to its challenging behaviour in detecting tag IDs as discussed in [6]. Fig.…”

Chipless RFID Sensors for the Internet of Things: Challenges and Opportunities

“…Many approaches to chipless tag localization use time-resolved techniques [137][138][139] typical of widespread chipped RFID technologies, such as round-trip time of flight [140], or phase acquisition [141,142]. Frequency coded approaches are also present [143][144][145], even though detecting and localizing the chipless tags could be challenging because the indoor signal propagation environments are complex and the backscattered signal from the tag is weak [146][147][148]. To overcome these limitations, suitable radar techniques have been developed [119,149].…”

“…localizing the chipless tags could be challenging because the indoor signal propagation environments are complex and the backscattered signal from the tag is weak [146][147][148]. To overcome these limitations, suitable radar techniques have been developed [119,149].…”

Extraction of Aspect-Independent Parameters Using Spectrogram Method for Chipless Frequency-Coded RFID

“…The chipless tags are also attached to the plastic box filled in a controlled way with tape rolls. On the other hand, the mother wavelet is applied to extract the ID of tag mounted on various objects [30], where the tag motion at different stepped positions is also considered. It is important to note that all these works [25]- [30] are based on the calibrated signals (i.e., with background normalization).…”