Audrey Pouzin

Miniaturized patch antenna for the Radio Frequency Identification of metallic objects

The growing interest in the Radio Frequency Identification (RFID) technology is giving rise to new applications, in particular for the identification of metallic objects. This interest has initiated the development of new designs for RFID tag antenna. This paper presents a UHF miniaturized patch antenna aimed at this application. The patch antenna is fed by a balanced feed to avoid a cross-layered construction and matched with a stub. Its miniaturization is achieved by inserting a u-shaped slot in the radiating patch.

Determination of measurement uncertainties applied to the RCS and the differential RCS of UHF passive RFID tags

Measurement methodology and theoretical equations to RCS and ΔRCS determination are recalled and the measurement uncertainties are evaluated in this paper. Even if measurement uncertainties are generally not required for RFID, it is important to understand and to be able to determine the measurement uncertainty. Currently, manufacturers and testing laboratories present some results of RFID measurements but never show the associated uncertainty. Yet, seeing the values of the uncertainties, it is clear that they are not negligible.

RFID tags localization along an axis using a tunable near-field focused circular-phase array antenna

A novel concept for RFID tag localization using a tunable near-field focused circular-phase array antenna working at 5.8 GHz is presented. It serves as the reader antenna and focuses the power into a small region, in the tag vicinity. By scanning the focal spot along one axis and monitoring the differential scattered power by a tag, its position along the axis is easily computed with good accuracy. This simple localization scheme is well adapted for specific localization scheme, for example for objects placed over a conveyor belt.

Automated bench test for UHF RFID tags measurement in operational environment

This paper synthesizes protocol measurements for Ultra High Frequency (UHF) radiofrequency identification (RFID) tags’ performance. We introduce the main parameters allowing the evaluation of an inlay tag performances. We characterize all devices implemented on the test bench. We explain the different programs and all methods used for the software automation. Finally, we studied the variation of the measured parameters as a function of power, frequency, or tag orientation, both in free space and in disturbed environment through our automated test bench

Design of a Two-Channel NMR Coil Using an Impedance Transformation Approach

In the field of small-animal magnetic resonance imaging, multi-channel coils are increasingly being used. Two-channel coils based on a common conductor between the two elements are not considerably used and theoretical equations are not explicitly given. In this paper, the design of a two-channel nuclear magnetic resonance coil based on common conductor for imaging applications has been carried out using an impedance transformation approach. The equations and simulations result at an operating frequency of 300 MHz are confirmed by the characterization of the two-channel receiver coil prototype.

Measurement of RCS and reading range of UHF tags in free space and with wood support

This communication introduces measurement results of Radar Cross Section (RCS) of UHF passive tags. The RCS theory and its relationship with the reading range of tags are explained. We studied the influence of tag support, particularly those made of wood. Finally, we found that RCS is a good parameter to determine homogeneity of multiple tags of the same industrial mass production.