RFID (radio frequency identification) technology appeared nearly 70 years ago. Deployed more widely only from the early 2000s, it is now booming and its development is still accelerating. As its name indicates, its original function was the identification (of objects, animals, people) and its applications were then essentially aimed at traceability, access control and logistics. If this type of use is still relevant today with more and more new application contexts and more and more efficient RFID tags, RFID has also evolved by integrating new capabilities. These new tags, known as augmented tags, include an information capture function. With the explosion of connected objects and the emergence of the Internet of Things (IoT), this old technology that is RFID still has a promising future and will probably be more and more present in our private and professional environments in all fields: logistics, industry, agriculture, building, health and even space.

This paper presents a complete radio frequency identification (RFID) test platform to characterize the nonlinear effects produced by passive ultra-high frequency (UHF) RFID chips. In full operation mode, automated measurements of activation power, harmonic response level, and impedances are performed in a wide frequency range up to the fourth harmonic. The characterization method, platform composition, and operation are explained through real measurements on UHF Class-1 Generation-2 chips. A harmonic treatment is presented thanks to the joint use of an RFID tester and impedance tuners, and the effect of the antenna-chip impedance matching on the harmonic responses is compared before and after treatment. To the best of our knowledge, no similar platform has been presented in the literature.

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).

A novel dual-band Ultra High 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 European Telecommunications Standards Institute (ETSI) and 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 meters for both the operating frequency bands in a metallic environment as well as a read range of 1.4 meters when operating in free space.

This paper presents the design of an ultra high-frequency (UHF) radio frequency identification (RFID) sensor tag integrated into a textile yarn and manufactured using the E-Thread^® technology. The temperature detection concept is based on the modification of the impedance matching between RFID tag’s antenna and the chip. This modification is created by the change in the resistance of a thermistor integrated within the tag system due to a temperature variation. Moreover, in order to obtain an environment independent detection, a differential approach is proposed that avoids the use of a pre-calibration phase by the use of a reference tag. Experimental characterization demonstrates the RFID sensor’s potential of detecting a temperature variation or a temperature threshold between $25$ and 70 °C through the variation of the transmitted differential activation power.