Meander And Koch Hybrid Fractal Curve Based Dual Hexagonal Radiating Patch Antenna For Quad Band Wireless Applications

A unique dual hexagonal-shaped radiating patch design with hybrid fractal curves (Meander and Koch) is presented for quad-band wireless applications. Initially, the antenna from 0th to 2nd iteration of hybrid fractal curves with PGP (Partial Ground Plane) is designed and investigated. Further, to get better results of the designed antenna in respect of Bandwidth (BW) and coefficient of reflection these hybrid curves are superimposed on the limited ground plane of 1st and 2nd iteration of the antenna, and the generated antennas are designated as Antenna – 1 and Antenna – 2. A comparison between both the antennas has been made and it is observed that antenna -2 shows better results in respect of improved BW and coefficient of reflection. The proposed antenna exhibits four resonant frequency bands 1.6, 4.8, 6.9, and 8.8GHz with improved corresponding impedance BW of 2.09, 1.36, 0.86, and 1.51GHz. The designed antenna is simulated and made on FR4 glass epoxy substrate with an overall size of 20×40×1.6 mm3. The fabricated proposed antenna is tested experimentally for the authentication of simulated results with experimental results and these are compatible with each other. The other performance indicators like radiation pattern, peak realized gain, and radiation efficiency are also determined for the proposed Hybrid Fractal Antenna (HFA) and all are found satisfactory. Due to the improved operational parameters, the designed HFA can be considered as a suitable applicant for distinct wireless applications in anticipated operational frequency ranges.

Use of Extended Cover Factor Theory in UV Protection of Woven Fabric

The paper presents an extension of existed cover factor theory more suitable for the evaluation of light penetration through a net woven fabrics structure. It also introduces a new simplified model of predicting the ultraviolet (UV) protective properties of woven fabrics assuming that the coefficient of reflection (KR), transmission (KT), and absorption (KA) of constitutive yarns are known. Since usually they are not, the procedure of preparation of simulation of proper woven fabric samples without interlacing and with known constructional parameters is also presented. The procedure finishes with a fast and cheap detection of missed coefficient for any type of yarns. There are differences between theoretical and measured results, which are not particularly significant in regard to the purpose and demands of investigation.

Coulsonite FeV2O4—A Rare Vanadium Spinel Group Mineral in Metamorphosed Massive Sulfide Ores of the Kola Region, Russia

This work presents new data on a rare vanadium spinel group mineral, i.e., coulsonite FeV2O4 established in massive sulfide ores of the Bragino occurrence in the Kola region, Russia. Coulsonite in massive sulfide ores of the Bragino occurrence is one of the most common vanadium minerals. Three varieties of coulsonite were established based on its chemical composition, some physical properties, and mineral association: coulsonite-I, coulsonite-II, and coulsonite-III. Coulsonite-I forms octahedral crystal clusters of up to 500 µm, and has a uniformly high content of Cr2O3 (20–30 wt.%), ZnO (up to 4.5 wt.%), and MnO (2.8 wt.%), high microhardness (743 kg/mm2) and coefficient of reflection. Coulsonite-II was found in relics of quartz–albite veins in association with other vanadium minerals. Its features are a thin tabular shape and enrichment in TiO2 of up to 18 wt.%. Coulsonite-III is the most common variety in massive sulfide ores of the Bragino occurrence. Coulsonite-III forms octahedral crystals of up to 150 µm, crystal clusters, and intergrowths with V-bearing ilmenite, W-V-bearing rutile, Sc-V-bearing senaite, etc. Chemical composition of coulsonite-III is characterized by wide variation of the major compounds—Fe, V, Cr. In some crystals of coulsonite-III, relics of chromite are observed. The microhardness of coulsonite-III is 577 kg/mm2, the reflection coefficient changes in relation to iron, vanadium, and chromium content.

ADE-FDTD method for study of two-dimensional electromagnetic wave propagation in lossy lorentz medium

In order to study the reflection of electromagnetic wave in Lorentz medium layer, the finite difference time domain method of auxiliary differential equation (ADE-FDTD) is used to derive the difference formula of two-dimensional TM wave propagating in lossy Lorentz medium, and the reflection coefficient of reflection field is calculated in one-dimensional case. The calculated reflection coefficients coincide very well, which shows that the derived propagation formula of two-dimensional TM wave in lossy Lorentz medium is correct. In addition, the reflection of plane electromagnetic wave by infinite high Lorentz medium layer is also simulated. The results show that the reflection of plane electromagnetic wave by Lorentz dispersive medium layer is correct.

Field Optimization using Segmented Patch Antennas at High Frequencies

in recent day’s communication technology has increased in every field where in antenna propagation transmission of signals to the other end is dependent on antennas. This propagation should be appropriate in both the fields as near and far fields for effectively covering which RFIDs are used which abbreviate as radio frequency identification which are considered as reader antenna developed for operating in near and far fields with high frequency band range. Here in this paper segmented loop designed of patch antenna is developed and the fabrication of antenna is done where the frequency range will be 900 MHz approximately with coefficient of reflection as less than 8dB which covers major UHB frequency range of band. It has linearly polarized pattern of radiation which provides gain of 6dBi and the capacity of reading of antenna is from 12-15m for both the applications of near and far field.

A Metallic WBAN Dielectric Resonator Antenna for ISM Band Applications

A compact cylindrical dielectric resonator antenna (CDRA) for Industrial, Scientific and Medical (ISM) applications is proposed in this article. The simple microstrip feeding system can be used to stimulate a certain CDRA. An implemented dielectric resonator delivers the functionalities for an efficient radiator with the feeding specifications. The permitted band can be accumulated by varying the design specifications. The standardized design comprises the resonator to attain frequency of 2.4 GHz. The ISM band is used in wireless body area networks (WBAN) technology for transmission of real time traffic such as video and information to monitor the health conditions. A U-shaped metal strip is located over the dielectric resonator material in order to miniaturize the size and enhance the resonator appearance. The consequences on antenna appearance for various radio wire specifications are explored. The intended model has competitive prices, lower volumes, and adequate containment. The evaluation of antenna illustrates the optimal bandwidth, coefficient of reflection (< -10 dB) as well as substantial gain across the specified bands. Coefficients of reflection, voltage standing wave ratio (VSWR) and radiation structure were discovered in each scenario. Architecture content and simulated results of Ansoft's HFSS are demonstrated. For ISM band implementations, the constructed antenna is sensible.

Novel fractal antenna for UWB applications using the coplanar waveguide feed line

In this study an original Coplanar Waveguide (CPW) antenna has been achieved into simulation and manufacturing in order to be an important candidate for the Ultra-wideband applications. The area of the proposed structure is 34mm x 43mm operating in the frequency range 3.1 GHz – 10.6 GHz released as UWB by the Federal Communications Commission (FCC). To perform the design of the proposed CPW antenna two electromagnetic solvers has been adopted which are CST of Microwave Studio and ADS of Agilent. The radiating patch has been chosen circular with fractal geometry based on circular slots with different sizes. The dielectric substrate is an Epoxy FR4 with a Relative permittivity 4.4, a thickness 1.6 and a loss tangent 0.025. To valid the functionality of the antenna two parameters has been computed which are the coefficient of reflection and the radiation pattern and confirmed into measurement by using the Network Analyser and the anechoic chamber.

Analisis Faktor yang Mempengaruhi Turnover Intention di Panca Sumber Diesel Group Pekanbaru

Managing a company is not something that is easy, there are many obstacles that might be faced in creating a quality and competent company, especially managing people within the company. This study aims to determine the effect of leadership and motivation on turnover intention at the Panca Source Diesel Group. Analysis was carried out on 32 respondents, this study was taken by census method and data was collected through questionnaires. The data analysis technique used is multiple linear regression through T test statistics and test models (F and Coefficient of reflection). The results showed that the overall leadership and motivation variables partially or simultaneously had an effect on turnover intention. Keywords: Leadership, Motivation, Turnover Intention