Luciano Tarricone

Introduction to GPU Computing and CUDA Programming: A Case Study on FDTD [EM Programmer's Notebook]

The recent advent of general-purpose graphics-processing units (GPGPUs) as inexpensive arithmetic-processing units brings a relevant amount of computing power to modern desktop PCs. This thus providing an interesting pathway to the acceleration of several numerical electromagnetic methods. In this paper, we explain how to exploit GPGPU features by examining how the computational time of the Finite-Difference Time-Domain Method can be reduced. The attainable efficiency is demonstrated by providing numerical results achieved on a two-dimensional study of a human-antenna interaction problem.

Electromagnetic Energy Harvesting and Wireless Power Transmission: A Unified Approach

In this paper, a rigorous procedure for the circuit-level analysis and design of entire systems, developed to provide power wirelessly, is presented. A unified theoretical approach is first introduced, based on a two-port-equivalent circuit representation, to describe the wireless power transfer link when the transmitter and the receiver are either in the near-field or in the far-field region reciprocally. This approach allows one to compute in a straightforward manner the system figure of merit, namely the power transfer efficiency. Specific guidelines for the two configurations are then intensively discussed together with the adopted software tools based on the combination of full-wave analysis and nonlinear harmonic balance techniques. Several practical examples based on this design procedure are presented, demonstrating predicted and experimental behavior of unconventional devices for both near-field and far-field power transfer usage.

Integrated models for the analysis of biological effects of EM fields used for mobile communications

The understanding of the modalities of interaction of electromagnetic (EM) fields with biological material is a key point in the identification of possible induced effects. Since the beginnings of bioelectromagnetic research studies, most of the attention has been focused on the effects on nervous systems and neuronal cells. The importance of this target has recently increased due to the wide diffusion of mobile terminals, used close to the head. In this paper, an integrated interaction model is proposed. The model, validated in each part of its components with experimental data, allows to obtain a quantitative link from the external applied field to the effects on neurons (isolated or linked to similar others). The models is firstly based on the evaluation of the EM field at cellular membrane level, then on the evaluation of the effects induced on each component of the model growing from the low biophysical level (membrane channels) to the biological one (neuron time behavior). The use of well-assessed models for the simulations of each part allows both the evaluation of the effect at different levels of complexity and the employment of this effect acting as an input on the upper level. This approach allows, for the first time, a complete quantitative evaluation of the effects on neurons due to the fields from the existing mobile systems, and can be a useful instrument for the evaluation of the possible health impact of new technologies.

UHF Wearable Rectenna on Textile Materials

A wearable rectenna for operation in the ultra high frequency (UHF) band is presented. The proposed device consists of a compact patch antenna and a full-wave bridge rectifier, both fabricated with textile materials. The patch antenna has been realized by using an adhesive conductive fabric on a bi-layer substrate made of pile and jeans. As for the rectifier, it is on a layer of jeans on the back-face of the antenna. Experimental data referring both to the patch antenna and to the rectenna are reported and discussed. From measurements performed with an incident power density of 14 μ/cm2, it is demonstrated that the rectenna here presented exhibits a conversion efficiency higher than 20% over the frequency range 860-918 MHz with a maximum of about 50% at 876 MHz.

An UHF RFID Energy-Harvesting System Enhanced by a DC-DC Charge Pump in Silicon-on-Insulator Technology

An RF-DC converter enhanced by a DC-DC voltage booster in silicon-on-insulator technology for UHF radio frequency identification (RFID) energy harvesting is presented in this letter. When the received RF power level is -14 dBm or higher, the system, fabricated on an FR4 substrate using off-the-shelf low-cost discrete components and connected to a flexible dipole antenna, is able to produce 2.4 V DC voltage to power general-purpose electronic devices. As a simple proof of concept, a device comprising microcontroller, temperature sensor, and EEPROM is considered in this work. The experimental results demonstrate the capability of the system to autonomously perform temperature data logging up to a distance of 5 m from a conventional UHF RFID reader used as an RF energy source.

RAMSES: RFID Augmented Module for Smart Environmental Sensing

This paper presents a radio frequency identification (RFID) augmented module for smart environmental sensing (RAMSES), which is a fully passive device with sensing and computation capabilities conceived to explore novel and unconventional RFID applications. RAMSES implements an RF energy-harvesting circuit enhanced by a dc-dc voltage booster in silicon-on-insulator technology, an ultralow-power microcontroller, temperature, light, and acceleration sensors, and a new-generation I2C-RFID chip to wirelessly deliver sensor data to standard RFID EPCglobal Class-1 Generation-2 readers. A preliminary RAMSES prototype, fabricated on a printed circuit board using low-cost off-the-shelf discrete components, has been extensively tested through experiments conducted both in lab and real-world application scenarios. The achieved results have demonstrated the ability of RAMSES to harvest the RF energy emitted by an interrogator placed up to 10 m of distance and autonomously perform sensing, computation, and data communication. To our knowledge, this is the longest range ever reported for fully passive RFID sensors. Furthermore, for applications requiring larger operating distances, RAMSES provides also a battery-assisted passive mode yielding up to 22-m communication range.

A Cost-Effective UHF RFID Tag for Transmission of Generic Sensor Data in Wireless Sensor Networks

The use of RF identification (RFID) technology for the automatic transmission of physical parameters in wireless sensor networks paves the way to a large class of attractive applications ranging from healthcare to automotive, diagnostic systems, robotics, and many others. Nevertheless, although some RFID tags capable to transmit sensor-like information are already on the market, only a limited number of sensors, such as those for temperature or pressure measurement, can be easily miniaturized and embedded in the RFID chip. The integration of more complex sensors, in fact, appears to be complicated and extremely expensive. In this paper, a cost-effective general-purpose multi-ID tag is proposed. It can be connected to generic sensors, regardless of the actual measured value, and it is capable to transmit, when interrogated by a standard RFID reader, a proper combination of ID codes that univocally codifies the sensor measured value. The functionalities of this device have been extensively validated under stressing conditions and the capability to transmit whatever kind of sensor data has been demonstrated.

A Battery-Assisted Sensor-Enhanced RFID Tag Enabling Heterogeneous Wireless Sensor Networks

This paper presents the design, realization, and experimental validation of a battery-assisted radio frequency identification (RFID) tag with sensing and computing capabilities conceived to explore heterogeneous RFID-based sensor network applications. The tag (hereafter called mote) features an ultra-low-power ferroelectric random-access-memory microcontroller, a LED, temperature and light sensors, three-axis accelerometer, non-volatile storage, and a new-generation I2C-RFID chip for communication with standard UHF EPCglobal Class-1 Generation-2 readers. A preliminary RFID mote prototype, fabricated on a printed circuit board using low-cost discrete components and equipped with a small 225-mAh coin battery, provides an estimated lifetime of 3 years when sensing and computing tasks are performed every 30 s. In addition, the reliable RFID communication range up to 22 m achieved in an indoor scenario represents, to the best of our knowledge, the longest distance ever reported for similar sensor-enhanced RFID tags.

A Cost-Effective SDR Platform for Performance Characterization of RFID Tags

The rigorous characterization of ultrahigh-frequency passive radio-frequency identification (RFID) tags is a challenging but mandatory task. Indeed, tags are the most critical devices in RFID systems: their performance should be adequately good, although stringent requirements in terms of compactness, used materials, and costs must be satisfied. Factors such as the goodness of the conjugate impedance matching between the chip and the antenna, the chip sensitivity, and the quality of the backscattered signal affect tag performance. Tag sensitivity and differential radar cross section (RCS) are the most significant metrics for tag characterization: they define the forward (from the reader to the tag) and the backward (from the tag to the reader) link reliability, respectively. Nevertheless, measurement of such metrics cannot be approached with conventional methods based on vector network analyzers or conventional RFID readers. Vice versa, commercially available instrumentation and solutions are very expensive and not totally flexible. In this paper, a novel approach for performance characterization of RFID tags is explored. To this end, we developed a very cheap (below

Human exposure to the near field of radiobase antennas - a full-wave solution using parallel FDTD

1000) and flexible tool based on software-defined radio, which enables measurement of tag sensitivity and differential RCS. An exhaustive experimental campaign has been carried out on ten commercial and four built-in laboratory RFID tags. Achieved results demonstrate the flexibility, accuracy, and appropriateness of the proposed approach.