Radio frequency (RF) energy transfer and harvesting techniques have recently become alternative methods to power the next-generation wireless networks As this emerging technology enables proactive energy replenishment of wireless devices, it is advantageous in supporting applications with quality-of-service requirements In this paper, we present a comprehensive literature review on the research progresses in wireless networks with RF energy harvesting capability, which is referred to as RF energy harvesting networks (RF-EHNs) First, we present an overview of the RF-EHNs including system architecture, RF energy harvesting techniques, and existing applications Then, we present the background in circuit design as well as the state-of-the-art circuitry implementations and review the communication protocols specially designed for RF-EHNs We also explore various key design issues in the development of RF-EHNs according to the network types, ie, single-hop networks, multiantenna networks, relay networks, and cognitive radio networks Finally, we envision some open research directions

Wireless Networks With RF Energy Harvesting: A Contemporary Survey

Introduction to Electromagnetic Compatibility

Resonance conditions for a substrate-superstrate printed antenna geometry which allow for large antenna gain are presented. Asymptotic formulas for gain, beamwidth, and bandwidth are given, and the bandwidth limitation of the method is discussed. The method is extended to produce narrow patterns about the horizon, and directive patterns at two different angles.

Gain enhancement methods for printed circuit antennas

Методы подавления шумов и помех в электронных системах. (Noise reduction techniques in electronic systems)

An efficient mutual coupling reduction method is introduced in this letter for extremely closely placed dual-element microstrip antennas positioned on a finite-sized ground plane for WLAN MIMO application at 5.8 GHz. High isolation can be achieved through a simple slot structure on the ground between the microstrip antennas. The position, length, and width of the slot have been optimized for maximizing the isolation. It is found that more than 40 dB isolation can be achieved between two parallel microstrip antennas sharing a common ground plane. The space distance of these antennas is 17.5 mm ≈ 0.33λ0 from element center to center (side by side of 1.6 mm ≈ 0.031λ0) when the ground plane size is 0.85λ0 × 0.55λ0. Along with this letter, several prototypes were fabricated, and their performances measured to validate the obtained IE3D moment method-based simulation results.

Reducing Mutual Coupling of Closely Spaced Microstrip MIMO Antennas for WLAN Application

A novel structure based on complementary split-ring resonators (SRRs) is introduced to reduce the mutual coupling between two coplanar microstrip antennas that radiate in the same frequency band. The new unit cell consists of two complementary SRR inclusions connected by an additional slot. This modification improves the rejection response in terms of bandwidth and suppression. The filtering characteristics of the band-gap structure are investigated using dispersion analysis. Using the new structure, it was possible to achieve a 10-dB reduction in the mutual coupling between two patch antennas with a separation of only 1/4 free-space wavelength between them. Since the proposed structures are broadband, they can be used to minimize coupling and co-channel interference in multiband antennas.

Mutual Coupling Reduction Between Microstrip Patch Antennas Using Slotted-Complementary Split-Ring Resonators

Single-negative magnetic metamaterials are used in order to reduce mutual coupling between high-profile antennas used in multiple-input multiple-output systems. The magnetic permeability of the developed single-negative inclusions have negative effective response over a specific frequency band. The inclusions considered here are composed of broadside coupled split-ring resonators. The single-negative magnetic inclusions are inserted between closely-spaced high-profile monopole antenna elements. It is shown that mutual coupling between the antenna elements can be reduced significantly by incorporating such magnetic inclusions. Effective response of the constitutive parameters of the developed magnetic inclusions are incorporated within the numerical models. Good agreement is obtained between the experimental and numerical results.

Electromagnetic Coupling Reduction in High-Profile Monopole Antennas Using Single-Negative Magnetic Metamaterials for MIMO Applications

This letter presents a novel engineered magnetic superstrate designed to enhance the gain and efficiency of a microstrip patch antenna without any substantial increase in the profile of the whole structure (the antenna with the superstrate). The modified split ring resonator (MSRR) inclusions are used in the design of the engineered magnetic superstrate. Numerical full-wave simulations as well as analytical models are used to analyze the entire radiating system. Considering as an example a microstrip antenna operating within the UMTS band, the broadside gain of the antenna was improved by 3.4 dB and the efficiency was improved by 17% when using the engineered superstrate. The total height of the proposed structure, antenna with superstrate, is lambda0/7, where lambda0 is the free-space wavelength at the resonance frequency of the antenna.

Enhanced-Gain Microstrip Antenna Using Engineered Magnetic Superstrates

In this paper, we present initial designs and results of a small-scale prototype of a vehicle to vehicle communication system using light fidelity (Li-Fi) technology, a new technology that was developed in the last few years, which still needs more investigations on its sustainability for outdoor vehicular networks. Vehicle to vehicle communication is the most effective solution that has been used in order to reduce vehicles' accidents. The proposed use of Li-Fi technology in this paper comprises mainly light-emitting diode (LED) bulbs as means of connectivity by sending data through light spectrum as an optical wireless medium for signal propagation. In fact, the usage of LED eliminates the need of complex wireless networks and protocols. Several case studies mimicking the vehicle to vehicle communication are explored in this work. Both numerical simulations using Proteous package and experimental results are also presented, which agree quite well.

Design and implementation of a vehicle to vehicle communication system using Li-Fi technology

A novel technique for mitigating simultaneous switching noise propagation in high-speed printed circuit boards is presented The proposed concept is based on etching complementary split-ring resonators (CSRRs) on only one metallic layer of the printed circuit board By such topology, the electric field between the power planes can be suppressed It is shown here that by concentrically cascading CSRRs, an ultrawideband suppression of switching noise from sub-GHz to 12 GHz is achieved A prototype of the proposed concept was simulated, fabricated, and tested Good agreement is observed between simulation and measurement Moreover, electromagnetic interference radiation from such perforated boards is investigated Finally, the performance of the proposed board with CSRRs is assessed through signal integrity analysis using eye diagrams and compared with a reference (solid) board

Mohammed M. Bait-Suwailam

Papers

Mutual Coupling Reduction Between Microstrip Patch Antennas Using Slotted-Complementary Split-Ring Resonators

Electromagnetic Coupling Reduction in High-Profile Monopole Antennas Using Single-Negative Magnetic Metamaterials for MIMO Applications

Enhanced-Gain Microstrip Antenna Using Engineered Magnetic Superstrates

Design and implementation of a vehicle to vehicle communication system using Li-Fi technology

Ultrawideband Mitigation of Simultaneous Switching Noise and EMI Reduction in High-Speed PCBs Using Complementary Split-Ring Resonators