Enabling Self-Powered Autonomous Wireless Sensors with New-Generation I2C-RFID Chips

A self-powered autonomous RFID device with sensing and computing capabilities is presented in this paper. Powered by an RF energy-harvesting circuit enhanced by a DC-DC voltage booster in silicon-on-insulator (SOI) technology, the device relies on a microcontroller and a new generation I2C-RFID chip to wirelessly deliver sensor data to standard RFID EPC Class-1 Generation-2 (Gen2) readers. When the RF power received from the interrogating reader is -14 dBm or higher, the device, fabricated on an FR4 substrate using low-cost discrete components, is able to produce 2.4-V DC voltage to power its circuitry. The experimental results demonstrate the effectiveness of the device to perform reliable sensor data transmissions up to 5 meters in fully-passive mode. To the best of our knowledge, this represents the longest read range ever reported for passive UHF RFID sensors compliant with the EPC Gen2 standard

Dielectric resonators antennas potential unleashed by 3D printing technology: A practical application in the IoT framework

One of the most promising and exciting research fields of the last decade is that of 3D-printed antennas, as proven by the increasing number of related scientific papers. More specifically, the most common and cost-effective 3D printing technologies, which have become more and more widespread in recent years, are particularly suitable for the development of dielectric resonator antennas (DRAs), which are very interesting types of antennas exhibiting good gain, excellent efficiency, and potentially very small size. After a brief survey on how additive manufacturing (AM) can be used in 3D printing of antennas and how much the manufacturing process of DRAs can benefit from those technologies, a specific example, consisting of a wideband antenna operating at 2.4 GHz and 3.8 GHz, was deeply analyzed, realized, and tested. The obtained prototype exhibited compact size (60 × 60 × 16 mm3, considering the whole antenna) and a good agreement between measured and simulated S11, with a fractional bandwidth of 46%. Simulated gain and efficiency were also quite good, with values of 5.45 dBi and 6.38 dBi for the gain and 91% and 90% for the efficiency, respectively, at 2.45 GHz and 3.6 GHz

04/15/1985 - Weekly Preview Review

Conventional RFID readers combine transmission (to the tag) and reception (from the tag) functions in a single physical device. In this paper we discuss the design and potential applications of a receive-only device, called "RFID listener", that decodes the signals from both the tag and the reader. This enables augmented RFID systems where one transmitter coexists with multiple listeners offering reception redundancy and diversity. We present a Software-Defined Radio (SDR) implementation of an RFID listener compliant with Gen2 standard, which can serve as a research tool for experimenting "on air" novel augmented RFID systems. Moreover, our listener can be used as a flexible and cheap protocol analyzer for conventional reader/tag systems. We present a test-bed setting where our listener and a conventional SDR reader are used in conjunction to measure separately the maximum downlink and uplink range. © 2011 IEEE

Proof of Presence: Novel Vehicle Detection System

The detection of vehicle presence in parking slots is a fundamental part of smart parking systems. The problem is commonly approached with devices composed of specific sensors, which usually are either magnetic or infrared. The sensor is continuously sampled by an onboard microcontroller capable of determining the slot status (available or occupied) and sending the information to a central collection and gathering system by means of a wireless technology. Nevertheless, cost and power consumption are still an issue. Based on the consideration that the vehicle slot status is only a single bit of information, in this article an alternative low-power and cost-effective approach is proposed. Specifically, two novel vehicle presence detectors, one battery-powered and based on 868 MHz LoRa technology and one solar-cell-powered and adopting BAP 866 MHz UHF RFID technology, are presented, designed, realized, and tested. The obtained results demonstrate the appropriateness of the proposed approach since the same functionalities of conventional devices at lower cost and lower consumption are reached

Electromagnetic analysis and performance comparison of fully 3D-printed antennas

In this work, the possibility of directly prototyping antennas by exploiting additive manufacturing 3D-printing technology is investigated. In particular, the availability of printable filaments with interesting conductive properties allows for printing of even the antenna conductive elements. Three samples of a 2.45 GHz microstrip patch antenna have been 3D-printed by using different approaches and materials, and their performance evaluated and compared. In particular, the same dielectric substrate printed in polylactic acid (PLA) has been adopted in all cases, whilst copper tape and two different conductive filaments have been used to realize the conductive parts of the three antenna samples, respectively. Even if an expected radiation efficiency reduction has been observed for the conductive filament case, the comparative analysis clearly demonstrates that 3D-printing technology can be exploited to design working fully-printed antennas, including the conductive parts

Evaluating the Effectiveness of Planar and Waveguide 3D-Printed Antennas Manufactured Using Dielectric and Conductive Filaments

3D printing is a technology suitable for creating electronics and electromagnetic devices. However, the manufacturing of both dielectric and conductive parts in the same process still remain a challenging task. This study explores the combination of 3D printing with traditional manufacturing techniques for antenna design and fabrication, giving the designer the advantage of using the additive manufacturing technology only to implement the most critical parts of a certain structure, ensuring a satisfying electromagnetic performance, but limiting the production cost and complexity. In the former part of the study, the focus is on three proximity-coupled patch antennas. It demonstrates how hybrid devices made of metal, dielectric, and 3D-printed (using Fused Filament Fabrication) conductive polymers can be successfully simulated and created for different operating frequency bands. In the latter part, the study compares three prototypes of a 5G-NR, high gain, and wideband waveguide antenna: respectively a fully 3D printed one made of electrifi (which is the most conductive commercial 3D-printable filament), an all-metal one, and a hybrid (3D-printed electrifi & metal) one. The results show a 15% reduction in efficiency when using the all-Electrifi configuration compared to all-metal one, and a 4-5% reduction when using the hybrid version

Electromagnetic characterisation of conductive 3D-Printable filaments for designing fully 3D-Printed antennas

Additive manufacturing (AM) 3D-printing technology is increasingly bringing benefits even in electromagnetics, with interesting prospects of application. Apart from the use of additive manufacturing for realising dielectric components of suitably shaped antennas, the ambitious target is, undoubtedly, the fully 3D realisation of radiofrequency and microwave circuits as well as radiating structures, including, therefore, conductive parts. In this regard, 3D-printable filaments with interesting conductive properties are being produced. However, their rigorous conductivity characterisation is still missing, making it difficult to estimate the real behaviour of the final 3D printed electromagnetic device. To fill this gap, the conductivity of one of the most interesting conductive filaments, named Electrifi, is first experimentally evaluated in a frequency range as large as 0.72–6 GHz, accounting also for its roughness. Then it has been validated by designing, realising, and testing three fully 3D-printed antennas. Specifically, two bow-tie antennas, operating at 2.8 and 4 GHz, respectively, and an ultrawideband antenna, borrowed from the existing literature, operating between 1 and 7 GHz. The good agreement between simulated and measured results demonstrates the reliability of the performed electrical conductivity characterisation, even in the design of efficient radiating structures entirely realised with thermoplastic materials with copper nanoparticle additives

Electromagnetic characterisation of conductive 3D-Printable filaments for designing fully 3D-Printed antennas

Additive manufacturing (AM) 3D-printing technology is increasingly bringing benefits even in electromagnetics, with interesting prospects of application. Apart from the use of additive manufacturing for realising dielectric components of suitably shaped antennas, the ambitious target is, undoubtedly, the fully 3D realisation of radiofrequency and microwave circuits as well as radiating structures, including, therefore, conductive parts. In this regard, 3D-printable filaments with interesting conductive properties are being produced. However, their rigorous conductivity characterisation is still missing, making it difficult to estimate the real behaviour of the final 3D printed electromagnetic device. To fill this gap, the conductivity of one of the most interesting conductive filaments, named Electrifi, is first experimentally evaluated in a frequency range as large as 0.72-6 GHz, accounting also for its roughness. Then it has been validated by designing, realising, and testing three fully 3D-printed antennas. Specifically, two bow-tie antennas, operating at 2.8 and 4 GHz, respectively, and an ultrawideband antenna, borrowed from the existing literature, operating between 1 and 7 GHz. The good agreement between simulated and measured results demonstrates the reliability of the performed electrical conductivity characterisation, even in the design of efficient radiating structures entirely realised with thermoplastic materials with copper nanoparticle additives

Designing UHF RFID tag antennas with Barcode shape for dual-technology identification

In this paper, a novel methodology to design Ultra High Frequency Radio-Frequency IDentification (UHF RFID) tag antennas with Barcode layout is proposed with the challenging goal of "fusing" both technologies in a single device. Specifically, after a brief recall of the well-known barcode standard, a procedure to design meandered barcode-shaped UHF RFID tags is introduced and discussed leveraging on electromagnetic evidence. The main steps of the proposed method are described by highlighting the constraints inherited by both the adopted technologies, as well as the useful opportunities to automatise the entire antenna design process after a preliminary simulation campaign through a full-wave simulator. Different RFID-Barcode tag antennas are designed, manufactured, and characterised in terms of maximum reading range and tag sensitivity. Obtained results demonstrate the validity of the proposed approach

An IoT-Aware Smart System Exploiting the Electromagnetic Behavior of UHF-RFID Tags to Improve Worker Safety in Outdoor Environments

Recently, different solutions leveraging Internet of Things (IoT) technologies have been adopted to avoid accidents in agricultural working environments. As an example, heavy vehicles, e.g., tractors or excavators, have been upgraded with remote controls. Nonetheless, the community continues to encourage discussions on safety issues. In this framework, a localization system installed on remote-controlled farm machines (RCFM) can help in preventing fatal accidents and reduce collision risks. This paper presents an innovative system that exploits passive UHF-RFID technology supported by commercial BLE Beacons for monitoring and preventing accidents that may occur when ground-workers in RCFM collaborate in outdoor agricultural working areas. To this aim, a modular architecture is proposed to locate workers, obstacles and machines and guarantees the security of RCFM movements by using specific notifications for ground-workers prompt interventions. Its main characteristics are presented with its main positioning features based on passive UHF-RFID technology. An experimental campaign discusses its performance and determines the best configuration of the UHF-RFID tags installed on workers and obstacles. Finally, system validation demonstrates the reliability of the main components and the usefulness of the proposed architecture for worker safety