35,493 research outputs found

    Harvesting Energy of Radio Frequency

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    Renewable Energy sources are the center of attraction for research and development all over the world nowadays. Oil and Gas are no more the main source of Energy, consequently the demand of a lasting cheap source of energy that is environmental friendly, is the main challenge recently. During the last decade, power consumption has decreased opening the field for energy harvesting to become a real time solution for providing different sources of electrical power. Energy Harvesting is a new technology that is going to make a revolution in the coming decade. Energy Harvesting is a technique to provide alternative sources of energy that are environmental friendly and low in cost. Radio Frequency Energy Harvesting is one of the methods to provide electrical energy from the ambient Radio Frequency Energy that already exists in the environment. For example Hand phones can be directly charged from Radio frequencies in the environment like 915 MHz. Laptops can be charged by frequencies like 2.45 GHz. RFID passive tags can be powered by these radio frequencies without the supply of any batteries increasing the range of passive RFID tags to longer distances with lower cost. Radio Frequency Energy Harvesting can provide a world with batteryless devices. With RF Energy Harvesting, the true mobility can be achieved where mobile devices do not depend on centralized power sources for charging. Instead they make use of the existing energy in the environment

    Radio Frequency Energy Harvesting - Sources and Techniques

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    Energy harvesting technology is attracting huge attention and holds a promising future for generating electrical power. This process offers various environmentally friendly alternative energy sources. Especially, radio frequency (RF) energy has interesting key attributes that make it very attractive for low-power consumer electronics and wireless sensor networks (WSNs). Ambient RF energy could be provided by commercial RF broadcasting stations such as TV, GSM, Wi-Fi, or radar. In this study, particular attention is given to radio frequency energy harvesting (RFEH) as a green technology, which is very suitable for overcoming problems related to wireless sensor nodes located in harsh environments or inaccessible places. The aim of this paper is to review the progress achievements, the current approaches, and the future directions in the field of RF harvesting energy. Therefore, our aim is to provide RF energy harvesting techniques that open the possibility to power directly electronics or recharge secondary batteries. As a result, this overview is expected to lead to relevant techniques for developing an efficient RF energy harvesting system

    Resource Allocation in Wireless Networks with RF Energy Harvesting and Transfer

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    Radio frequency (RF) energy harvesting and transfer techniques have recently become alternative methods to power the next generation of wireless networks. As this emerging technology enables proactive replenishment of wireless devices, it is advantageous in supporting applications with quality-of-service (QoS) requirement. This article focuses on the resource allocation issues in wireless networks with RF energy harvesting capability, referred to as RF energy harvesting networks (RF-EHNs). First, we present an overview of the RF-EHNs, followed by a review of a variety of issues regarding resource allocation. Then, we present a case study of designing in the receiver operation policy, which is of paramount importance in the RF-EHNs. We focus on QoS support and service differentiation, which have not been addressed by previous literatures. Furthermore, we outline some open research directions.Comment: To appear in IEEE Networ

    RF-Powered Cognitive Radio Networks: Technical Challenges and Limitations

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    The increasing demand for spectral and energy efficient communication networks has spurred a great interest in energy harvesting (EH) cognitive radio networks (CRNs). Such a revolutionary technology represents a paradigm shift in the development of wireless networks, as it can simultaneously enable the efficient use of the available spectrum and the exploitation of radio frequency (RF) energy in order to reduce the reliance on traditional energy sources. This is mainly triggered by the recent advancements in microelectronics that puts forward RF energy harvesting as a plausible technique in the near future. On the other hand, it is suggested that the operation of a network relying on harvested energy needs to be redesigned to allow the network to reliably function in the long term. To this end, the aim of this survey paper is to provide a comprehensive overview of the recent development and the challenges regarding the operation of CRNs powered by RF energy. In addition, the potential open issues that might be considered for the future research are also discussed in this paper.Comment: 8 pages, 2 figures, 1 table, Accepted in IEEE Communications Magazin

    Message Conveyor by Motion for Paralyze People Powered Using RF Energy Harvesting

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    This paper developed message conveyor for paralyze people is designed to help communicate because some of the paralyze people cannot talk. This project is introducing the latest and current technology update in the world, RF energy harvesting. RF energy harvesting is an option to powering the circuit by converting RF energy to DC power. RF energy is generated from the ambient environment transmitted by millions of radio transmitters and telecommunications media around the globe, such as wireless internet, mobile phones, base station, broadcasting station, Wi-Fi and a Radio Frequency transmitter. RF energy is a long-lasting replacement of power if the Radio Frequency signal is present in the surrounding area. Arduino Mega is used in this project as it is easier to program the coding and a low power sensor. The project serves the needs of the community as it can paralyses people to communicate and can enhance the reduction of electricity bills as the RF signal controls the motion sensor

    Design of a ferrite rod antenna for harvesting energy from medium wave broadcast signals

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    Radio frequency (RF) energy harvesting is an emerging technology that has the potential to eliminate the need for batteries and reduce maintenance costs of sensing applications. The antenna is one of the critical components that determines its performance and while antenna design has been well researched for the purpose of communication, the design for RF energy harvesting applications has not been widely addressed. The authors present an optimised design for such an antenna for harvesting energy from medium wave broadcast transmissions. They derive and use a model for computing the optimal antenna configuration given application requirements on output voltage and power, material costs and physical dimensions. Design requirements for powering autonomous smart meters have been considered. The proposed approach was used to obtain the antenna configuration that is able to deliver 1 mW of power to 1 kΩ load at a distance of up to 9 km, sufficient to replace batteries on low-power sensing applications. Measurements using a prototype device have been used to verify the authors simulations

    Radio frequency energy harvesting for autonomous systems

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    A thesis submitted to the University of Bedfordshire in partial fulfilment of the requirements for the degree of Doctor of PhilosophyRadio Frequency Energy Harvesting (RFEH) is a technology which enables wireless power delivery to multiple devices from a single energy source. The main components of this technology are the antenna and the rectifying circuitry that converts the RF signal into DC power. The devices which are using Radio Frequency (RF) power may be integrated into Wireless Sensor Networks (WSN), Radio Frequency Identification (RFID), biomedical implants, Internet of Things (IoT), Unmanned Aerial Vehicles (UAVs), smart meters, telemetry systems and may even be used to charge mobile phones. Aside from autonomous systems such as WSNs and RFID, the multi-billion portable electronics market – from GSM phones to MP3 players – would be an attractive application for RF energy harvesting if the power requirements are met. To investigate the potential for ambient RFEH, several RF site surveys were conducted around London. Using the results from these surveys, various harvesters were designed and tested for different frequency bands from the RF sources with the highest power density within the Medium Wave (MW), ultra- and super-high (UHF and SHF) frequency spectrum. Prototypes were fabricated and tested for each of the bands and proved that a large urban area around Brookmans park radio centre is suitable location for harvesting ambient RF energy. Although the RFEH offers very good efficiency performance, if a single antenna is considered, the maximum power delivered is generally not enough to power all the elements of an autonomous system. In this thesis we present techniques for optimising the power efficiency of the RFEH device under demanding conditions such as ultra-low power densities, arbitrary polarisation and diverse load impedances. Subsequently, an energy harvesting ferrite rod rectenna is designed to power up a wireless sensor and its transmitter, generating dedicated Medium Wave (MW) signals in an indoor environment. Harvested power management, application scenarios and practical results are also presented

    Radio-Frequency Identification (RFID) Item Finder Using Radio Frequency Energy Harvesting

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    This paper investigates Radio Frequency Identification (RFID) finder powered by Radio Frequency Energy Harvesting. Misplaced and losing item is a normal situation that happens almost anytime and anywhere. When this problem occurs in situation during the emergency time or in hurry, panic will come and start searching around for that lost item from where it was last seen it or place it. RFID is a technology that is used for item identification. A RFID Item Finder is developed with the Radio Frequency (RF) Energy Harvesting technology. The Output of RF Energy Harvesting is used as the input source for the RFID Item Finder by converting RF signal source to DC source that needed by the Item Finder. A RFID tag is attached over the item so that it can be searched by using RFID reader which if the tag in a read zone of the reader, user can know whether the misplaced item is in that certain area by the communication between RFID tag and reader

    RF Energy Harvesting in WSNs

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    As a vital factor affecting system cost and lifetime, energy consumption in wireless sensor networks (WSNs) has been paid much attention to. This article reviews existing energy harvesting technology applied in WSNs, and analyzes advantages of harvesting radio frequency (RF) energy in WSNs
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