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.
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 an original passive microwave substrate integrated cavity resonator substrate integrated waveguides (SIWs) as an environment sensor for humidity detection. The proposed structures ...are based on a high quality factor (Q ~ 300) substrate integrated cavity resonator operating at 3.6 and 4.15 GHz. The detection principle is based on a frequency shift due to the permittivity variation of the humid air. This variation can be detected and used as the sensor indication. The frequency shift has been estimated analytically using the dielectric perturbation method for the resonator prototypes. The structure of the presented SIW resonators has been tested in the presence of humidity and shows sensitive characteristics in the range of 0%-80% relative humidity in accordance with the proposed model. A comparison of sensitivity performance between the new structure and other reported microwave components for environmental sensing is also presented. Measurements of repeatability and reliability for the proposed structure are discussed as well. As a new microwave component type, the proposed substrate integrated environmental sensor has the advantage of providing a new fabrication solution for radio frequency environmental sensing and greatly simplifies the sensor's manufacturing processes and cost.
A new multiband Ultra High Frequency (UHF) Radiofrequency Identification (RFID) sensor tag for industrial applications is proposed. The principle relies on a very simple operation: the effect of ...flipping the tag itself on a metallic surface for operation either in the European Telecommunications Standards Institute (ETSI) or the Federal Communication Commission (FCC) UHF RFID frequency bands. Moreover, the tag design aims an optimization for operation on metallic objects and maintains a small form factor. An analysis based on the equivalent circuit of the antenna impedance considering the two positions explains the physical concept and shows the impact of the metallic surface on the resonance frequency of the RFID sensor tag. Measurement results demonstrate a read range up to 3 m for ETSI and FCC UHF RFID frequency bands when the sensor tag is operating on metallic surface.
Radio frequency identification (RFID) sensors are increasingly recognized as the way for achieving smart environment monitoring. Real world industrial applications, such as multiobjects orientation ...detection, motion sensing as well as monitoring in harsh environment require real-time operation and fast responses for control decisions. This paper examines the timing analysis of UHF networked RFID sensors tag system and the factors influencing time latency. Time constrains in RFID communication channel, such as the minimum detection time of the reader in the vicinity of the RFID tag and the effect of protocol requirements are examined experimentally for commercial tags in compliance with the European Telecommunications Standards Institute (ETSI) regulations. This assessment has the objective to analyze the RFID tag for instance as a motion sensor. In order to illustrate the interest of the presented delay analysis, a method to measure the response time due to rotation speed is introduced. A case study using two commercial RFID tags under rotation is presented and analyzed in terms of delays.
The aim of this paper is to develop a framework of a chipless wireless system for sensing in compliance with the standard international regulations. The proposed approach offers a solution to solve ...the main difficulty met for the deployment of chipless systems that require specific readers (based on non-standardized large frequency bands and specific signal waveforms). The possibility of interrogating chipless sensors in the regulated bands is demonstrated. The concept is introduced from several chipless sensor solutions, including specific sensors (here sensors for detecting temperature then motion), and the associated reader architecture built as a prototyping platform based on universal software radio peripheral (USRP).
This paper presents a novel compact scatterer structure for a passive chipless wireless temperature threshold sensor. The structure is based on a single C-scatterer with multiple embedded slots; each ...slot forms a sub-scatterer dedicated to resonating in one regulated band. This structure has the advantage of increasing the data capacity without increasing the number of scatterers, which results in a more compact sensor size. The sensing principle is based on the detuning of the resonance frequency peaks of the backscattered signal from the slotted scatterer due to temperature variations. For the first time, this work demonstrates the design of a passive chipless sensor while at the same time respecting the conventional radio frequency (RF) emission regulations. The sensor only exploits the allowed bands: European Telecommunications Standards Institute (ETSI) and Industrial, Scientific and Medical (ISM). Sensitivity measurement results show sensitive characteristics in the order of 10−4 GHz/°C in accordance with the theoretical predictions.
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.
This paper presents a textile-based stretchable microstrip patch antenna with intrinsic strain for e-textiles with seamlessly integrated multifunctional devices. Several microstrip antennas have been ...developed with the patch alone (stretchable up to 40%) or both the patch and the ground plane (stretchable up to 100%) meshed by using rectangular serpentine units. The changes in the resonant frequency of the meshed antennas, as a result of stretching, have been exploited to demonstrate the intrinsic uniaxial strain sensing. The obtained results indicate that resonant frequency decreases linearly with increasing applied strain, suggesting that the designed antennas can also be used as strain sensors with stretchability up to 100% and a sensitivity of 0.25. The results were validated through full-wave electromagnetic simulations and a two-dimensional digital image correlation (DIC) technique to model the antenna deformations during the tensile tests. In terms of stretchability, the meshed textile patch antenna on a solid ground plane showed more than a 2-fold improvement compared to a meshed gold patch antenna, showing a linear frequency shift. As potential applications, we demonstrate the use of a highly deformable fully meshed textile antenna as a strain sensor capable of measuring joint angles of a human limb. To do that, a microwave readout circuit based on RF to DC rectifier was realized. The rectifier obtained a peak conversion efficiency of 71% at 10 dBm input power overload resistor of 3 kΩ.
•Microwave Substrate Integrated Waveguides (SIW) sensors used for gas detection.•Electromagnetic model of sensitivity of SIW sensors based on dielectric perturbation technique.•Evolution of ...sensitivity depending on influent parameters such as dimensions, relative permittivity and the topology of the structure.
This paper presents a theoretical and experimental study of a substrate integrated resonator (SIW) structure for gas sensing applications. The goal of the presented work is to evaluate, via an analytical model of sensitivity based on the resonant perturbation method, the evolution of the sensitivity of SIW sensors, which essentially depends on the properties of the functionalized region. The effect of the SIW resonator parameters, such as the size, the relative permittivity and the topology of the functionalized areas, are studied. In order to validate the theoretical study and propose the best design to maximize the sensitivity, different topologies of SIW sensors are fabricated and tested experimentally. The operation frequency of the SIW resonator is comprised between 4 and 6GHz, and hydrogen is used as the detection gas. The SIW resonators are functionalized with tin oxide (SnO2) micro powder, which is a dielectric material sensitive to hydrogen gas. Thus, the experimental results of the sensor, whose detection principle is based on the variation of the effective dielectric permittivity caused by the presence of hydrogen, exhibit sensitivities ranging from 8.1 to 33.9%, depending on the size, the relative permittivity or the topology of the functionalized region of the gas sensor. This new concept provides a low-cost solution for passive sensors that can be easily integrated in a PCB fabrication process.
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