1,721,419 research outputs found
Smart Solutions in Smart Spaces: Getting the Most from Far-Field Wireless Power Transfer
Full text linkIn the very near future, an almost unlimited number of monitoring applications-structural health, logistic, security, health care, and agriculture to name only a few-will require large-scale deployment of cooperative wireless microsystems with sensing capabilities, moving us closer to the effective realization of the paradigm of the Internet of Things (IoT)
A UHF Near-Field Link for Passive Sensing in Industrial Wireless Power Transfer Systems
No full textThis paper presents an innovative nonconventional exploitation of a self-resonant capacitive near-field link at UHF, for data communication, to be combined in a compact wireless power transfer (WPT) system. At UHF, an increased channel transfer efficiency is made possible by exploiting two faced auto-resonant structures, such as split-ring resonators (SRRs), one at each far-end side of the link. Their physical layouts are designed to ensure accurate prediction of both the resonant frequency and the resulting frequency-variable behavior of the two-port arrangement. This network is then used in a passive sensing system, based on a smart exploitation of the dc-power dc-load relationship of a standard RF identification (RFID) rectifier, to convert the data of a remote sensor, representing the system variable load. The reflected power variations at the transmitter side, due to the dc load variations, are successfully used to perform the sensor readout. The entire sensing system is first optimized by means of nonlinear circuit and electromagnetic (EM) simulations. Experimental data, compared to prior results, demonstrate the strength of the adopted approach
State-of-the-art of contactless energy transfer (CET) systems: design rules and applications
No full textThis paper is dedicated to the extensive review of state-of-the-art contactless energy transfer (CET) systems that are gaining increasing interest in the automatic machinery industries. We first introduce the circuit equivalent networks considered in the literature, and discuss the main operating principles. Possible circuital resonant solutions are also discussed together with the required compensating networks. Then we focus on the problem of transferring, at the maximum efficiency, high-power levels (of the order of 1 kW or higher), showing that highly coupled inductive links are needed, requiring to refrain from the resonance condition. These systems are usually referred to as CET systems, since the link distances are negligible with respect to the coils dimensions. The operating frequencies are of the order of tens to hundreds of kilohertz. The fundamental figures of merit are analytically defined and used to measure the actual limitations involved in this class of systems, including aspects related to realization feasibility with respect to voltages and currents limitations. Finally, state-of-the-art CET works are surveyed, and realistic applications for different operating frequencies are considered and critically compared
Co-Location of PV Panel With Meshed Antenna Array for Inter-Satellite Energy Transmission
No full textThis paper investigates the design and fabrication, by additive manufacturing, of optically transparent meshed patch antenna arrays atop photovoltaic (PV) panels. This integration is foreseen to be exploited in space by small satellites to enable wireless power transfer among them, while maintaining optimal solar power production, with no need for extra areas for the antenna subsystems. The proposed antenna arrays utilize a novel approach, where horizontal conductive strips of a meshed metallization are removed, to enhance transparency without compromising antenna performance. Two arrays are designed at 2.45 GHz and 5.8 GHz, and the associated design choices and issues are discussed. The antenna metallizations make use of vertical strips only with a line spacing of 0.04 lambda, found to be the best compromise to ensure maximal transparency and antenna performance, using low-cost printing technique on 110 mm X 110 mm borosilicate glass. Simulations and experiments show that the underlying PV metallization patterns have a significant impact on the antenna radiation properties at the highest operating frequency of 5.8 GHz. In this case, a degradation of the antenna gain compared to the predictions is observed. Through a reverse-engineering method, this effect is modeled by the effective electromagnetic characteristics of the glass substrate, rather than by accounting for the pattern layout-wise. It is demonstrated that this choice enables an efficient yet accurate full-wave simulation of the entire system, suggesting the necessity for a co-design of the PV panel and the antenna to facilitate an accurate representation of the entire system and its current radiating characteristics
Coupling-Independent Wireless Power Transfer
No full textIt is well known that mid-range wireless power transfer can be realized by a link consisting of mutually coupled series resonant circuits operating at the common resonant frequency. However, in such conditions, the link load which maximizes the output power or the transfer efficiency is coupling dependent. This letter provides an analytical solution to this problem by exploiting the frequency bifurcation phenomenon, which occurs after a certain threshold value of the coupling. When the system is operated at one of the secondary resonances, it behaves as an ideal transformer; thus, it is able to deliver to a prescribed load constant output power with constant efficiency. This is true for variable coil distances or coil misalignment, that is, for variable coupling coefficient
Preliminary Study of an In-Space Wireless Power Transmission for CubeSats
No full textAdvances in technology allows CubeSats to provide
more powerful and cost-effective services in a variety of contexts:
from providing reliable internet access in remote areas to
utilizing them for deep space missions. Unfortunately, their
current power generation capacity relies on solar cells only
and remains insufficient for numerous high level applications.
This article highlights an additional power supply method to
fulfill the energy requirements for advanced, power-intensive
applications, also in challenging or extreme conditions. The
concept of harnessing wireless power from larger satellites in
close orbit, excess power availability, along with adjacent small
satellites in swarm formation, is introduced. The idea is to
integrate transparent antenna technology onto the existing solar
panels, creating a substantial antenna array without requiring
any extra space. This integration aims to combine wireless power
transfer with solar power generation efficiently. The full-wave
simulation of antenna arrays realized on top of solar panels are
carried out to provide an accurate estimation of inter-satellite
link budget. The predictions suggest that wirelessly powering a
CubeSat from a larger satellite, located a few kilometers away
is a possible operation
Integration of Solar Power and Microwave WPT Exploiting Transparent Antennas
Full text linkThis paper presents an integrated system for concurrent wireless power transfer and solar powering by means of a unique transparent antenna array which is obtained by an additive printing process on borosilicate glass. The optical transparency of the proposed 2-element microstrip patch antenna array, operating at 2.4 GHz, is achieved by the meshing technique. To ensure sufficient radiation property and optical transmittance, the design with 68.6% theoretical transparency and 6.9 dB simulated antenna gain is chosen. Moreover, the exploitation of the conductive layer as a ground plane of the antenna inside the solar cell has been validated by the measurements while resulting further compactness into the system. The subsequent solar power readings demonstrate that the printed meshed antenna arrays are suitable for integration with solar panels especially in energy cooperative in-space applications
Modular Artificial Neural Networks for Wireless Power Transfer Optimization in Sensor-Driven Industrial IoT
Full text linkThis work presents a novel approach, utilizing modular Artificial Neural Networks (ANNs), to model complex and confined electromagnetic (EM) environments, when the far-field approximation is inadequate. The main objective is to optimize energy harvesting and sensor placement within Wireless Power Transfer (WPT) systems, which are crucial for the autonomous functioning of Wireless Sensor Networks (WSNs) in harsh EM environments. To enhance computational efficiency, the Integral Solver method is adopted to create parameterized EM simulation scenarios, for the generation of the training data. Additionally, an active learning algorithm is employed to identify an optimal, minimal dataset for training and testing the modular ANN architecture. This architecture comprises distinct sub-networks aimed at predicting both optimal sensors spatial coordinates and maximum power density levels. The evaluation of these sub-networks demonstrates the effectiveness of ANN-based methods in tackling the challenges associated with WPT optimization for WSN applications in demanding EM environments
Wireless sensing and power transfer in a rotary tool
No full textAn innovative system, which pairs an RFID-based passive sensor link with a ferrite-based power CET unit, is designed for a temperature-controlled heating system remotely located in a rotary machine tool. Capacitive and inductive coupling are integrated in a unique platform to implement the wireless data and power links, respectively. This ensures at the same time compactness and absence of cross coupling between data and power transfer. The rectifying part of a passive RFID tag is exploited to simultaneously power and read a Pt1000 temperature probe located in a inaccessible part of the rotary tool. The procedure to design layout-wise the system is described and an extensive experimental validation is discussed
- …
