1,721,249 research outputs found
A novel time-based beamforming strategy for enhanced localization capability
No full textThe paper describes an original time-based driving strategy of a compact antenna array suitable for future 5G IoT applications. Subsets of array elements are selectively activated in real-time for agile and precise localization of tagged objects, randomly distributed in harsh electromagnetic environments. A new layout, starting from a standard time-modulated array (TMA) solution, is implemented, which allows to fruitfully exploit the sideband radiation capability, typical of this array family. One radiating element of the array is replaced by a multi-antenna architecture, thus enabling the designer to have a total control of the maximum radiation direction of the array not only at the sideband harmonics, as for standard TMAs, but also at the fundamental. In this way, an extremely accurate localization capability is obtained by properly driving the nonlinear switches at each antenna port, without resorting to complex feeding networks or phase shifters. The antenna system design must be carried out through an accurate circuit/electromagnetic co-simulation approach, thus accounting for the electromagnetic couplings among the radiating elements and the nonlinear behavior of the switches. This is demonstrated with a compact-size planar patch array operating at 5.8 GHz. compatible with portable device equipments for concurrent future wireless operations
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)
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
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
Wirelessly powering: An enabling technology for zero-power sensors, IoT and D2D communication
No full textWireless power transfer (WPT) is foreseen as a key enabling technology for energy-autonomous wireless sensors, Internet of Things and Device to Device communication. RF energy, either scavenged from the ambient or intentionally provided to a wireless device, can be successfully exploited for autonomously sustaining its operations. In this paper we overview the main aspects to be addressed for a successful design of a far-field WPT system. The end-to-end circuit level co-design of the WPT link is described as the procedure to effectively address the system optimum efficiency. Specific selection of antenna elements and active sub-circuits are analyzed, depending on the power levels involved and on the specific application environment. The base-band design of the power management unit used to dynamically provide the receiver with optimum loading conditions is also analyzed
Energizing 5G: near- and far-field wireless energy and data trantransfer as an enabling technology for the 5G IoT
Full text linkWe are surrounded in our daily lives by a multitude of small, relatively inexpensive computing devices, many equipped with communication and sensing features. From these has evolved the concept of "pervasive intelligence" [1], [2], a basis from we can envision our future world as an Internet of Things/Internet of Everything (IoT/IoE), in terms of both a consumer IoT/IoE (interconnected devices within an individual's environment) and the Industrial IoT (interconnectedness to improve business-to-business services, mainly through machineto-machine interactions) [3]
Energy-Harvesting Fabric Antenna
No full textIn this chapter the exploitation of novel fabrics, in place of standard substrates and metallizations, in the realization of radio-frequency energy harvesting systems, commonly referred as rectennas, rectifying antennas, for Body Area Network applications is deeply discussed. The use of these unconventional materials makes the design approach a delicate issue: firstly, the electromagnetic characterization of fabrics is needed; furthermore, the effects of bending of the whole system, as well as the proximity to human tissue must be considered in the optimization procedure. The consequences of an approximate approach in the design of wearable rectennas could lead to significant deviations from the final prototypes performance. For these reasons we consider a computer-aided platform, which relies on the combination of full-wave solvers and nonlinear circuit-level tools, through the rigorous application of the electromagnetic theory: this way the unavoidable electromagnetic couplings between different system sections, the dispersive/nonlinear behavior of the entire rectenna. In this way the actual available power at the rectifier input port are accurately taken into account. The procedure is deeply described in this chapter through the step-wise analysis of the project of a fully wearable, fully autonomous tri-band rectenna. The experimental characterization of the prototype is used to provide a validation of the design procedure. The two-step procedure consists in the design of the rectenna with a fixed-load in radio-frequency (RF) stationary conditions, followed by the transient baseband design of the power management unit which acts as a dynamically variable load, depending on the actual incident RF power
Time-based RF showers for energy-aware power transmission
No full textThis paper proposes a review of the use of time-based arrays as RF energy providers in those wireless applications where an energy-aware transmission is of key importance. The higher simplicity and versatility of time-modulated arrays (TMAs) with respect to other modern radiating systems is deeply discussed: in particular, the multi-harmonic radiation capability of TMA is efficiently deployed in the smart wireless power transfer procedure. This two-step procedure is demonstrated through a 2.45 GHz 8-monopole planar array, by resorting to a rigorous co-simulation approach: it combines the Harmonic Balance technique, for the accurate description of the nonlinear switches, with the full-wave analysis of the array and its feeding network
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