Smart Prototyping Techniques for Uhf Rfid Tags: Electromagnetic Characterization and Comparison With Traditional Approaches

Abstract

Abstract-Over the last few years, the active and growing interest in Radiofrequency Identification (RFID) technology has stimulated a conspicuous research activity involving design and realization of passive label-type UHF RFID tags customized for specific applications. In most of the literature, presented and discussed tags are prototyped by using either rough-and-ready procedures or photolithography techniques on rigid Printed Circuit Boards. However, for several reasons, such approaches are not the most recommended, in particular they are rather time-consuming and, moreover, they give rise to low quality devices in one case, and to cumbersome and rigid tags in the other. In this work, two alternative prototyping techniques suitable for cost-effective, time-saving and high-performance built-in-lab tags are introduced and discussed. The former is based on the joint use of flexible PCBs and solid ink printers. The latter makes use of a cutting plotter to precisely shape the tag antenna on thin copper sheets. Afterwards, a selection of tags, designed and manufactured by using both traditional and alternative techniques, is rigorously characterized from the electromagnetic point of view in terms of input impedance and whole tag sensitivity by means of appropriate measurement setups. Results are then compared, thus guiding the tag designer towards the most appropriate technique on the basis of specific needs.

Switched-Beam Antenna for WSN Nodes Enabling Hardware-driven Power Saving

“…Several tests and measures have been performed in order to obtain an accurate characterization of the electromagnetic properties of the proposed antenna; for this purpose, a very cost-effective prototype of the switched-beam antenna with an overall size of 10 x 10 cm 2 has been fabricated through a technique described in [17]- [18], using an FR-4 substrate with thickness Mt = 0,8 mm and dielectric constant εr = 4,7 @ 2,45 GHz (see Fig. 4).…”

Wearable Antennas for Remote Health Care Monitoring Systems

“…A low-cost antenna manufacturing technique exploiting a cutting plotter was originally proposed in [32] for fabricating UHF RFID tags made out of adhesive copper tape. The use of NWCFs in combination with a cutting plotter for fabricating wearable antennas was demonstrated for the first time in [33].…”

“…In practical applications, however, it is recommended to avoid fabricating an antenna containing elements with dimensions comparable to the resolution of the used plotter [32]. Also, geometries with excessively small dimensions could make it much harder to accurately carry out the aforementioned step number 5.…”

Novel fully-passive multifunction RFID-enabled devices

“…A low-cost general-purpose alternative to the WISP is the sensor-tag (STag) presented in the authors' earlier works [5], [6]. Fabricated on a flexible substrate [7] and based on a multi-ID approach [8], the S-Tag can be connected to generic sensors and, when interrogated by a standard Gen2 reader, it is capable to transmit a proper combination of EPCs that univocally encodes the sensor value. In [9] and [10], the electronic components of an augmented UHF RFID tag, including antenna, microcontroller unit (MCU), and sensors, are integrated in flexible organic substrates using inkjet-printing technology.…”