Novel notch modulation algorithm for enhancing the chipless RFID tags coding capacity

Abstract

The main objective of this contribution is to introduce a novel technique for increasing the coding capacity of the Frequency Coded (FC) chipless RFID system. The proposed scheme encodes 4 bits per single resonator exploiting the notch bandwidth and its corresponding frequency position. Hence, 72-bits could be achieved from 2 to 5 GHz preserving the operating frequency bandwidth. Furthermore, a Smart Singular Value Decomposition (SSVD) technique is utilized to estimate the notch bandwidth and ensure low probability of error. Consequently, high encoding efficiency and accurate detection could be achieved with simplified reader design. Likewise, a novel 4 x 5 cm 2 tag is designed to fit the requirements of the devised coding technique. Different tag configurations are manufactured and validated with measurements using Software Defined Radio (SDR) platform. The introduced coding methodology is conclusively validated using Electromagnetic (EM) simulations and real world testbed measurements.

Frequency-Coded Chipless RFID Tags: Notch Model, Detection, Angular Orientation, and Coverage Measurements

“…Therefore, the RCS frequency response could reach minimum (notches) and maximum (peaks) values based on the engineered tag structure. After that, the notch width modulation (NWM) tag, shown in Figure 2a and represented in [14], is utilized to complete the validation of the proposed notch model. The basic idea of the employed tag is to increase the coding capacity by utilizing different notch widths.…”

Adaptive spectrum scanning techniques for reducing the identification time of the frequency coded chipless RFID system

“…This allows a flexibility of identifying the tag in a backscattering mode or transmission through mode (this one is used in our measurement setup). Each slot resonator is responsible for absorbing the signal at a certain frequency (notch filter) resulting in a notch with particular resonant frequency that is decoded to represent a bit or several bits as will be described in El‐Awamry et al The used FC chipless tag has 2 advantages: The level of the backscattered power is increased by designing (2×2) array, which enhances the tag detection and identification. The detection of this tag is orientation independent since the frequency absorbing element is the circular resonator. …”

A re-transmitted chipless tag using CSRR coupled structure

“…A large number of documents have reported chipless tag based on spectral features (Ei-Awamry et al 2015;Balbin and Karmakar 2009;Nijas et al 2012;Costa et al 2013Costa et al , 2016. The encoding is achieved by changing spectral structure of resonators.…”