A passive harmonic tag for buried assets localization is presented for utility localization. The tag design is based on a dual-polarized patch antenna at Ultra High Frequency (UHF) band. One of its feeders is connected to a frequency doubler based on a Schottky diode that generates the second harmonic, which is transmitted using a linear-polarized patch tuned at this frequency. The power received at the other feeder of the dual-polarized antenna is harvested by an RF to DC converter based on a five-stage voltage multiplier whose energy is used to bias a low-power quartz oscillator that modulates the output of the doubler. The different parts of the system are presented, and the theoretical read range is estimated as a function of the soil composition and the water content. A low-cost reader based on a software defined radio is also presented. Finally, experiments with a prototype of the tag are performed for different soil conditions.

A simple solution to efficient pressure measurement in sports balls using a force sensitive resistance sensor connected to an ultra high frequencies (UHF) radio frequency identification (RFID) tag is presented. The proposed solution has the advantage of increasing the pressure range measurement without changing the configuration of the employed RFID chip. It also offers a small and compact sensor structure due to miniaturised antenna design. The designed antenna is placed between the ball inner and outer layers. Prototypes were fabricated on a flexible substrate to make their integration easy into a sport ball. This smart tag concept was fully validated through measurements on different types of sports balls, and the results successfully compared to data from electronic ball pressure gauge.

The industrial sector of cheese production with particular quality protection occupies an important position in the industrial context of the European Union. Compared to conventional casein labels, UHF RFID tags can be read at greater distances and can store more information about the product which represents a more reliable solution for traceability. This paper discusses the main challenges of designing UHF RFID tags for the identification of dairy products such as cheese wheels in an industrial environment. Two different realization techniques are presented in this paper, and the performances of the realized prototypes were measured and compared using a professional RFID measurement system and a commercial handheld RFID reader in a real industrial 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.

In this paper, a novel passive UHF RFID sensor configuration is presented. Configurations based on strain gauges are tested. The first configuration uses a flexible substrate to be suitable to measure the bending of a given surface and the second one uses a specific designed structure for measuring absolute force in a limited range. An energy harvesting block that can collect the RF power received from UHF RFID Reader is integrated in order to cover the extra energy supply demand. Realized measurements show a high level of accuracy and reliability of fabricated prototypes.

This paper presents a passive proximity sensor using UHF radio-frequency identification (RFID) technology. The sensing operation allows detecting and counting goods or persons with no RFID tags attached. The system comprises a customized double-antenna sensor tag and a commercial reader. The design is performed at two layers. In the physical layer, a distribution network prioritizes power towards one antenna to detect presence, while allows the other antenna communicating with the reader. In the communication layer, the RFID chip (EM4325) is programmed to set an alarm when triggered by an RF event, and hence changing the tag identifier. Design directives are given and experimental sensing tests consisting of an access gate demonstrates the proposal.