This paper studies the detection of chipless frequency-coded tags. The detection exploits a temporal separation that allows obtaining the identification (ID) with only one measurement. In this way, ...the flexibility of reading of this type of chipless tags is clearly improved, which is highly expected for future real implementation. This temporal separation is possible when the tag presents a long-time signature, longer than the backscattering wave corresponding to the surrounding objects. A technique based on the short-time Fourier transform (STFT) is used to differentiate the useful parts of the signal, which contain the tag ID. Up to now, this was done by using a calibration process based on two measurements at least to remove coupling and clutter contribution. With the proposed approach the acquisition of the tag ID is direct, and it is not necessary to have further information such as the measurement of the environment without the tag. A study on the time duration of several frequency-coded tags is performed based on simulations and measurements. The study shows that this approach can be used with classical depolarizing chipless tags already proposed in the literature. It is proven that the proposed approach is useful to detect the tag response with a single measurement.
Designing a reader for chipless RFID is a hard task since both the polarization and operating frequency agility have to be implemented. The new tag design proposed in this paper is polarization ...independent, making the design of the reader easier since only linear polarization is needed to detect the tag. The proposed chipless tag is based on multiple circular ring patch resonators. The coding capacity of this tag reaches 19 bits within a compact surface of cm . Further, the frequency band is within 3.1 to 10.6 GHz to be compliant with FCC and ECC regulations for UWB. This new design is experimentally validated in the frequency domain using bi-static measurement set-up. Both amplitude and group delay responses of the tag are investigated and carried out.
This paper aims to present a further exploration on a new concept regarding the operation of an ultrahigh frequency (UHF) radio frequency identification (RFID) sensor tag. Exploiting the antenna of a ...UHF RFID tag as a temperature transducer and a UHF RFID chip with self-tuning capabilities as the means of communication, a UHF RFID tag can operate as a very low-power sensor with high read range and small size. The antenna of the tag is taking advantage of the intrinsic characteristics of the used substrate to vary its overall complex impedance according to temperature. These changes of the impedance of the antenna are leading the self-tuning circuit of the used RFID chip to self-tune and based on the value it acquires an estimation of the sensed temperature can be made. This paper also reports a design and a set of measurements of a UHF RFID tag transformed to act as a temperature sensor. This concept is further explored for the assessment of the contribution of each of the constituents of the UHF RFID tag, i.e., antenna and UHF RFID chip, to the sensing procedure. This paper is accompanied by the simulation of a designed 3-D model of the UHF RFID sensor tag and by sets of measurement of the impedances of the UHF RFID chip and of the antenna.
This paper presents a new radio frequency identification (RFID) chipless tag that is highly compact and potentially low-cost. This tag has a lot of advantages, such as being fully printable on ...products since no ground plane is needed for fabrication. The actual issue of the chipless tag family having a single layer, that is, their detuning effect, is compensated for the first time by a correction technique based on the use of a sensing resonator. The design is based on multiple λ/4 coplanar strip-line resonators where resonant frequencies can be shifted by setting an additional short circuit at particular locations. An accurate model is proposed to easily link the footprint of the structure to the resonant frequency. Considering a frequency resolution of 50 MHz for the reading system and a tag dimension of 15 × 20 mm 2 , 9 b can be encoded in the frequency band 2.0-5.5 GHz. Several experimental results validate the proposed design as well as its implementation in a realistic application and environment.
This letter demonstrates the possibility of combining advantages of barcode and radio-frequency identification (RFID) technologies on the same smart label. In this letter, several UHF RFID tag ...designs based on barcodes of different standards and sizes are realized and measured using a professional RFID measurement system. Measurements of all realized prototypes are in good agreement with simulations. Interesting results are obtained with a maximum RFID read range reaching around 12 m while keeping the prototypes readability as a standard barcode. Another tag configuration which avoids soldering the IC to the structure and based on the coupling of a near-field RFID tag to the barcode is also presented, showing a read range of more than 7 m.
A novel dual-band ultrahigh-frequency (UHF) radio frequency identification (RFID) sensor tag, designed to operate on metallic surfaces, is proposed. This particular UHF RFID sensor tag is capable of ...operating in both the main RFID frequency bands of the European Telecommunications Standards Institute (ETSI) and the Federal Communication Commission (FCC). The dual-band operation of the UHF RFID sensor tag is based on a very simple concept; by flipping the UHF RFID sensor tag on a metallic surface, it can operate either in the ETSI or FCC RFID frequency bands. The impedance and radiation characteristics of the UHF RFID sensor tag are presented with an extensive analysis of the effects of the metallic surface on the UHF RFID sensor tag. In addition, an equivalent model of the UHF RFID sensor tag, which includes the effects of the metallic surface on the sensor tag, is proposed. The UHF RFID sensor tag has a small form factor and presents a satisfying read range of around 3 m for both the operating frequency bands in a metallic environment as well as a read range of 1.4 m when operating in free space.
In this paper, a novel artificial magnetic conductor (AMC) reflector is proposed for gain stability enhancement of a low‐profile wideband bowtie antenna (operates at C‐band). Two AMC reflectors are ...investigated: the first one is based on a standard square patch cell while the second one is based on a novel cell geometry called modified cross shape (MCS). The two units' cell geometries are studied and optimized to achieve the desirable performances, namely; low‐profile, wide impedance bandwidth, and gain stability. The proposed antenna structure with 5 × 8 MCS unit cells is fabricated and measured. The results show a significant steady gain compared to similar work in the literature. The fabricated structure presents a low thickness of 0.084 λL (λL is the guided wavelength at the lowest frequency, i.e., 3.94 GHz) with 0.85 dB of gain variation over a wide impedance bandwidth of about 50% (3.94–6.61 GHz).
Tag collision is one of the most significant limitations of the RFID systems. Current anti-collision algorithms process the problem in medium access control layer as an estimation of the collided ...tags number. This process requires retransmission of the RN16 sequence, and hence the discarding of signals in the PHY layer. This letter shows how to use the physical signal in order to decode collided tags. The contributions of this letter are as follows: 1) a simulation model of the Ultra High Frequency RFID system using a Nexxim circuit in conjunction with a system designer using Ansoft Designer simulator platform; 2) a proposed edge transition scheme to recover collision and decode tag signals. This scheme permits us to decode collision signal of three tags, which increases the system throughput from 0.37 (slotted Aloha) to 1.37; 3) an experimental setup that was able to collect and decode the real collision tag signal thanks to our proposed edge transition scheme.
The aim of this paper is to create an autonomous reconfigurable radio communication system that can produce an adequate transmission rate according to propagation medium fluctuation while maintaining ...a higher quality of service (QoS). In this work, we have achieved an experimental implementation of adaptive modulation technique using SDR platforms as USRP B210, RTL-SDR and HackRF One. The implemented system provides a real time data communication equipped by an adaptive modulation techniques. The system autonomously chooses the most suitable modulation among BPSK, QPSK and 8-PSK based on the estimation of link quality measured by the signal to noise ratio (SNR).
Harmonic Power Harvesting System for Passive RFID Sensor Tags Allane, Dahmane; Andia Vera, Gianfranco; Duroc, Yvan ...
IEEE transactions on microwave theory and techniques,
2016-July, 2016-7-00, 20160701, 2016-07-01, Letnik:
64, Številka:
7
Journal Article
Recenzirano
This paper introduces a relevant concept of energy harvesting for passive UHF radio frequency identification (RFID) relying on the exploitation of the power carried by the third harmonic signal ...generated by the RFID chip. The idea consists on the use of the sole third harmonic energy to power up an associated sensor to the RFID tag. The proposed concept is first demonstrated in simulation thanks to an equivalent model for the RF front-end of a passive UHF RFID chip. Although the proposed model is simplified, it considers the generated nonlinear signals, allowing an efficient design of the rectifier circuit, which is responsible of harvesting the third harmonic power besides ensuring the activation of the RFID chip in order to communicate with the reader. The power driving between the RFID chip, third harmonic harvester, and antenna at the fundamental and third harmonic frequencies is achieved by designing a low-loss distributed three-port impedance matching network. Simulation results confirm the operation of the matching network and the exploitation of the third harmonic signal by analyzing the power at different nodes in the circuit. Measurement results validate the proposed nonlinear chip model. A prototype of the RFID tag harmonic-harvester produces 39 μW of dc power harvested from the harmonic signal, showing good agreement with the simulation results. Finally, a sensor application exploiting the harmonic harvested power to energize a commercial temperature sensor at a distance of 80 cm from the reader is demonstrated.
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