Wire Medium Research Articles

Anisotropy in a wire medium resulting from the rectangularity of a unit cell

Anisotropy in a wire medium resulting from the rectangularity of a unit cell

Sub-GHz Broadband Multi-channel Waveguiding Based on Subwavelength Wire Media

The paper involves the development of a new type of image transfer. With this aim the multi-channel waveguide was considered in a novel representation – it was based on a wire media structure where each space between each four the closest wires is a single subchannel. The utilized wire media (WM) structure has 10-by-10 wires dimensions and 150 mm of the length, thus the first Fabry-Perot resonance appears around 0.9-1 GHz. The goal is to show the broadband multi-channel imaging at frequencies lower than the first Fabry-Perot resonance that means the considered structure tends to electrically short size that has not been studied previously. Taking into account the multi-channel principle of the wire media, the imaging can be performed as a binary one. For this reason, each single channel is fed by individual electromagnetic (EM) source that is a dipole antenna in the non-resonant mode. The reason is to use a weak source and match it with a single channel because in the other case the dipole is perfectly matched at the defined resonance frequency. It was found in the paper that the broadband transfer is possible in the frequency range-under-study and impossible at the region of the first Fabry-Perot resonance due to the perfect complex interaction between all wires of structure. As evidence, a simultaneous transfer of EM power from several independent EM sources shaped as R-letter was performed in the frequency range from 0.3 to 0.75 GHz by simulations and experimental investigations. The clear recovery of the transferred letter is possible in the case when it performs not at the frequency of Fabry-Perot and for the enough value of signal-to-noise ratio (SNR). The binary recovery of the transferred image became possible in the paper with an additional post-image processing with a threshold method involvement.

INFRASTRUKTUR JARINGAN KOMPUTER BERBASIS CISCO PACKET TRACER DI LABKOM E-18 UNIVERSITAS MUHAMMADIYAH SUKABUMI

Computer network technology plays a crucial role in supporting teaching and learning activities. A Local Area Network (LAN) is a type of computer network that connects devices within a specific area. The application of network technology supports the learning process, including in the Computer Laboratory of the Information Technology Education Program. This research aims to design and configure the computer network infrastructure in the laboratory using wired media. The method used is the Network Development Life Cycle (NDLC), which relies on previous development processes. The research methodology involves simulation with Cisco Packet Tracer to design network topology and configure devices. The research results include the design of computer network infrastructure using wired media and optimal IP configuration. Findings indicate that the devices within the designed network topology are interconnected and can access the internet effectively.

Performance improvement of slot antenna with metamaterial for modern wireless communication

A slot antenna has been widely used for multifunction in modern wireless communication technologies such as WLAN, WiMAX, IoT, and GSM. Generally, slot antennas can operate in wideband. Nevertheless, this antenna type was limited in terms of lower gain because of wideband operation. Therefore, this paper presents a slot antenna designed for operation frequencies between 1.8 GHz and 6.5 GHz and a study of the performance improvement of slot antennas with metamaterials to increase antenna quality. The utilization of metamaterials can improve the performance of slot antennas by increasing gain levels, reducing sidelobe levels, and optimizing reflection coefficients (S11). As a result, determine the metallic hole structure and wire medium structure put behind the slot antenna for comparing performance. All of them act like reflectors for reflected radiation from the back to the front, which improved the average gain of all operating frequencies from 3.41 dBi to 7.33 dBi for metallic hole structure and 7.42 dBi for wire medium structure. Moreover, the simulation and measurement gave great results. These proposed metamaterials provided enhanced gain and reduced sidelobe level.

EQS-Band Human Body Communication through frequency hopping and MCU-Based transmitter

Human Body Communication (HBC) is an emerging technology that uses the human body as a communication channel. It offers significant advantages over traditional RF techniques in terms of power consumption and security. In recent developments, Electro-quasistatic HBC (EQS-HBC) in the frequency band below 1 MHz has been employed to enable communication without signal radiation beyond the body, effectively turning the body into a wired communication medium. This paper delves into the application of the EQS band for HBC. Experimental results show the determinantal effect of intermittent noise that sporadically disrupts communications across the band of interest. To address this challenge, we introduce an innovative frequency-hopping transceiver system, which allows the transmitter to seamlessly adapt to different frequencies. In addition, we present a miniature transmitter design, incorporating a simplified micro-controller unit (MCU) to facilitate the implementation of HBC. Furthermore, to validate this proposed design, we present a fully functional prototype of an HBC system that effectively employs frequency hopping techniques for practical applications.

Localized source above a time-modulated dielectric half-space: Green's function theory

In this paper, we explore the two-dimensional Green's function problem above an instantaneous time-modulated dielectric half-space. In particular, we focus on studying the excitation dynamic with modulation that is carried out near the critical angle and the total internal reflection regime, where an impinging spectrum of waves expects the so-called lateral wave excitation on the interface. We start by analyzing the reflection of a plane wave, with detailed attention given to the difference between two cases: a slow quasistatic modulation versus a relatively fast modulation that leads to substantial excitation of intermodulation frequencies. Next, we provide a space-time representation to the space-domain Green's function, and later, we move to evaluate the spectral integral both in a brute-force numerically exact manner and using integration along the steepest descent path and the branch cuts, which unravel the distinction between different wave phenomena associated with the excitation problem. Thus, we identify different wave species that can be associated with reflected rays and waves that resemble the known head wave in the classical problem of stationary stratified media. We examine the unique time-dependent behavior of each wave species that arises as a consequence of the interface between the time-harmonics of the reflected space-time plane wave spectrum. Lastly, we demonstrate the broader validity of our analytical predictions, also in the case of a dispersive and finite time-modulated medium. To that end, we use a full-wave simulation of a source above a finite time-modulated thick layer that is implemented using a time-varying wire medium. These full-wave results are compared with our current analytical model with effective (homogenized) parameters of the time-modulated wire medium taken from . Published by the American Physical Society 2024

Enhancing the directional violation of Kirchhoff's law of thermal radiation with a nonreciprocal wire medium

Enhancing the directional violation of Kirchhoff's law of thermal radiation with a nonreciprocal wire medium

Experimental verification of magnetic near-field channeling using a helical-shaped wire medium lens

We experimentally verify that a magnetic uniaxial wire medium lens consisting of a racemic array of helical-shaped metallic wires may enable channeling the normal component of the magnetic field of near-field sources with resolution well below the diffraction limit over a broad bandwidth. It is experimentally demonstrated that the helical-shaped wire medium lens can be regarded as the magnetic counterpart of the usual wire medium lenses formed by straight metallic wires. The experimental results are validated with full-wave numerical simulations. We envision that the proposed metamaterial lens may have potential applications in magnetic resonance imaging, near-field wireless power transfer, and sensing.

Controlling the dispersion of longitudinal waves via the affine deformation of the interlaced wire medium

We studied the dispersion properties of double interlaced wire metamaterials with geometry modified by affine transformation. That metamaterials were found to support eigenmodes with longitudinal polarization at low frequencies for all deformations. Due to spatial dispersion, the metamaterials’ isofrequency surfaces are centered at the Brillouin zone edges (rather than at Γ-point) and have the shape of ellipsoids. Their refractive indices corresponding to the ellipsoids were analyzed both analytically and numerically.

Electrostatic screening in a wire medium

We extensively study screening in anisotropic artificial media formed by arrays of parallel metal wires both analytically and experimentally. Our findings show that the electrostatic potential distribution produced by probe charge is spherically symmetrical in the vicinity of the source. We also derive a boundary condition for the wire medium and confirm its validity experimentally. Despite the finite dimensions of the wire arrays, the field symmetry near the charge remains unaffected, but a local maximum potential is produced at the boundary. The screening depth of the wire medium is determined by its geometrical parameters and is proportional to the plasma frequency, which leads us to propose an experimental method for defining plasma frequency through static E-field measurement.

Efficient Centralized Cooperative Spectrum Sensing Techniques for Cognitive Networks

Wireless Communication is a system for communicating information from one point to other, without utilizing any connections like wire, cable, or other physical medium. Cognitive Radio (CR) based systems and networks are a revolutionary new perception in wireless communications. Spectrum sensing is a vital task of CR to avert destructive intrusion with licensed primary or main users and discover the accessible spectrum for the efficient utilization of the spectrum. Centralized Cooperative Spectrum Sensing (CSS) is a kind of spectrum sensing. Most of the test metrics designed till now for sensing the spectrum is produced by using the Sample Covariance Matrix (SCM) of the received signal. Some of the methods that use the SCM for the process of detection are Pietra-Ricci Index Detector (PRIDe), Hadamard Ratio (HR) detector, Gini Index Detector (GID), etc. This paper presents the simulation and comparative performance analysis of PRIDe with various other detectors like GID, HR, Arithmetic to Geometric Mean (AGM), Volume-based Detector number 1 (VD1), Maximum-to-Minimum Eigenvalue Detection (MMED), and Generalized Likelihood Ratio Test (GLRT) using the MATLAB software. The PRIDe provides better performance in the presence of variations in the power of the signal and the noise power with less computational complexity.

Quadraxial metamaterial.

We study the dispersion of electromagnetic waves in a spatially dispersive metamaterial with Lorentz-like dependence of principal permittivity tensor components on the respective components of the wave vector performing the analysis of isofrequency contours. The considered permittivity tensor describes a triple non-connected wire medium. It is demonstrated that the metamaterial has four optic axes in the frequency range below the artificial plasma frequency. The directions of the optical axes do not depend on frequency and coincide with the diagonals of quadrants. The conical refraction effect is observed for all four optic axes.

Wire metamaterial filled metallic resonators

In this work we study electromagnetic properties of a resonator recently suggested for the search of axions - a hypothetical candidate to explain dark matter. A wire medium loaded resonator (called a plasma haloscope when used to search for dark matter) consists of a box filled with a dense array of parallel wires electrically connected to top and bottom walls. We show that the homogenization model of wire medium works for this resonator without mesoscopic corrections, and that the resonator quality $Q$ at the frequency of our interest drops versus the growth of the resonator volume $V$ until it is dominated by resistive losses in the wires. We find that even at room temperature metals like copper can give quality factors in the thousands, an order of magnitude higher than originally assumed. Our theoretical results for both loaded and unloaded resonator quality factors were confirmed by building an experimental prototype. We discuss ways to further improve WM loaded resonators.

An IoT based Smart Energy Meter Monitoring System using Android Application

The headway of the Internet of Things has been arising step by step. The Internet of Things (IoT) spins association that implanted with gadgets, programming, sensors, actuators that help clients in observing and controlling gadgets from a distance and proficiently. In the IoT based framework article and living being are given extraordinary identifiers with the capacity to move information. The area of IoT has intensified from the intermingling of remote advances, microelectromechanical frameworks and the Internet. These days IoT innovation is being applied in numerous areas like power, gas, water and so forth to make our life computerized. These days because of the inordinate utilization of the web, these regions become modernized and online installment framework makes conceivable. However, getting to meter perusing is a manual interaction and has the chance of blunder which causes high income cost .This innovation works with the evaluation of energy utilization and investigation of information for charging and installment. This innovation expects to bring the gadget on the web and associating gadget with the web which is in other term Internet of Things. This innovation utilizing remote correspondence is less expensive than wired medium. Thus, WiFi is more reasonable for the proposed framework as it is extremely considered normal in each home.

PEMBUKTIAN LASER DIODA SPEKTRUM BIRU 1500 miliWatt DIGUNAKAN SEBAGAI KOMPONEN PEMANCAR CAHAYA PADA OPTICAL WIRELESS TRANSFER ENERGY

So far, the transfer of electric power is done by wire or cable. Recent discoveries use electromagnetic waves or magnetic induction. In this study, we tried the latest innovations, namely trials to prove with light as a substitute for wire media. The light (beam) used is a laser beam. The use of a diode type laser optical component with a blue color in the technology for wireless transfer of electrical energy. Laser tested 1500 milliWatt power. The working voltage is 6 Volts, 1 ampere. While the measurement of voltage, current and light strength with a multimeter fluxmeter. The electrical load used for this experiment is a red LED (Light Emiting Diode), with an additional 220 ohm resistor, 0.5 watts.This research method uses the type of experiment (experiment).The variables tested and measured are voltage in volts, current in amperes and light intensity in lux. The power supply can be varied from 0 volts to 15 volts, the current is 1.5 amperes of direct current. Light measuring instrument (fluxmeter or lightmeter) is expressed in lux.The results of the tests and measurements are expressed in the form of a graph of the current voltage and light intensity in the form of a graph. At a distance of 3 meters with a source voltage of 6 volts and 1 ampere on the laser, the electrical energy generated is transferred is an electric voltage of 3.9 volts, an electric current of 8.75 milli-Amperes.From this experiment, it can be proven that light can be used as a medium to distribute or transfer electrical energy, from one place to another, which is called optical wireless energy transfer. The transfer of electric power can be done with light.Keywords: Optical Wireless Energy Transfer, Blue Laser-Diode, Lux.

Analysis of Video Transmission Capabilities in a Simulated OFDM-Based Supplementary BPL-PLC System

The design and maintenance of a reliable communication system, especially in harsh working conditions for the oil and mining industry, brings many challenges. With the use of a video transmission system, one can monitor the crew and their working environment. Broadband over power line–power line communication (BPL-PLC) seems an ideal medium for such a service, since it enables the use of the existing wired infrastructure for supplementary applications. In this paper, we perform a set of simulations for a dedicated wired medium as well as analyses of a visual data transmission system, designed to deliver video content with quadrature amplitude modulation (QAM) and orthogonal frequency division multiplexing (OFDM). We investigate a set of video sequences at 480 × 270 resolution under varying network conditions, including signal-to-noise ratio (SNR) and bit error rate (BER). We perform a subjective evaluation study of video content transmitted over our simulated communication link. The results of this study may aid parties involved in designing additional services for portable devices and user terminals, including reliable means of contact, surveillance and monitoring. The obtained results may be of particular interest to researchers and professionals related to the Industry 4.0 and Internet of things (IoT) concepts.

Analisis Noise Floor Threshold Terhadap Signal Strength Pada Wireless Local Area Network Protokol Nv2

Data transmission media using wireless is currently an alternative to using wired transmission media. Wireless Local Area Network (WLAN) used so far uses 2.4 GHz and 5 GHz frequencies. The use of frequency in the IEEE 802.11 standard protocol is increasingly dense and prone to interference. So that various protocols began to be developed according to needs. In this study using a frequency of 5 GHz and the Nv2 protocol. One of the protocol features in the Mikrotik Wireless device. Signal strength is affected by the Noise Floor Threshold. Noise Floor Threshold value -128 to -110. The higher the Noise Floor Threshold value, the weaker the signal strength will be. The lower the Noise Floor Threshold value, the stronger the signal strength. The Noise Floor Threshold value will also affect the Signal To Noise (dB). When the Noise Floor Threshold value is low, the Signal To Noise (dB) strength is getting stronger, and vice versa

Interlaced wire medium with quasicrystal lattice

We propose a design of an interlaced wire medium with a quasicrystalline lattice based on fivefold rotation symmetry Penrose tiling. The transport properties of this structure are studied. We distinguish two transport regimes, namely, a propagation regime related to the low-frequency interval and localization regime in the high-frequency interval. While the former is observed in structures both with and without the translation symmetry property, the latter is exclusive for aperiodic structures only. We show that the localization regime is promising for many applications, including the engineering of effective multichannel devices for telecommunication and imaging systems.

Wave Analysis and Homogenization of a Spatiotemporally Modulated Wire Medium

In this paper we develop homogenization theory for spatiotemporally modulated wire medium. We first solve for the modal waves that are supported by this composite medium, we show peculiar properties such as extraordinary waves that propagate at frequencies below the cut-off frequency of the corresponding stationary medium. We explain how these unique solutions give rise to an extreme Fresnel drag that exists already with weak and slow spatiotemporal modulation. Next, we turn to derive the effective material permittivity that corresponds to each of the first few supported modes, and write the average fields and Poynting's vector. Nonlocality, nonreciprocity, and anisotropy due to the spatiotemporal modulation direction, are three inherent properties of this medium, and are clearly seen in the effective material parameters. As a figure of merit, we also derive the effective permittivity of a plasma medium with spatiotemporally modulated plasma frequency. This comparison is interesting since the plasma medium can be considered as the effective medium that is obtained by a stationary wire medium. We validate that homogenization and spatiotemporal variation are not necessarily interchangeable operations. And indeed, in certain parameter regimes the homogenization should be performed directly on spatiotemporally modulated composite medium, rather than first homogenize the stationary medium and then phenomenologically introduce the effect of the space-time modulation.

Tetra-axial metamaterial

In this work we theoretically and numerically demonstrate that triple non-connected wire medium has four optical axes. The axes coinside with diagonals of the unit cell.