scholarly journals UWB-Printed Rectangular-Based Monopole Antenna for Biological Tissue Analysis

Electronics ◽  
2021 ◽  
Vol 10 (3) ◽  
pp. 304
Author(s):  
Andrea Martínez-Lozano ◽  
Carolina Blanco-Angulo ◽  
Héctor García-Martínez ◽  
Roberto Gutiérrez-Mazón ◽  
Germán Torregrosa-Penalva ◽  
...  
Keyword(s):  
Medical Imaging ◽  
Biological Tissue ◽  
Low Cost ◽  
Microwave Frequency ◽  
Monopole Antenna ◽  
Tissue Analysis ◽  
The Finite Element Method ◽  
Frequency Range ◽  
Step Type ◽  
Made In

This paper presents the design of a printed step-type monopole antenna for biological tissue analysis and medical imaging applications in the microwave frequency range. The design starts from a very simple and widely known rectangular monopole antenna, and different modifications to the antenna geometry are made in order to increase the bandwidth. The antenna dimensions are optimized by means of a parametric analysis of each dimension using a 3-D electromagnetic simulator based on the finite element method. The optimized antenna, with final dimensions of 40 × 36 mm2, is manufactured onto a low-cost FR4 (fiber glass epoxy) substrate. The characteristics of the antenna have been measured inside an anechoic chamber, obtaining an omnidirectional radiation pattern and a working frequency range between 2.7 GHz and 11.4 GHz, which covers the UWB frequencies and enables the use of the antenna in medical imaging applications. Finally, the behaviour of four of these antennas located around a realistic breast model, made with biocompatible materials, has been analysed with the electromagnetic simulator, obtaining good results and demonstrating the usefulness of the designed antenna in the proposed application.

A Compact CPW-Fed Curved Meander Line Monopole Antenna (MLMA) for GSM Application

2017 ◽  
Vol 6 (1) ◽  
pp. 207
Author(s):  
Nor Afifah Borhan ◽  
Noor Asniza Murad
Keyword(s):  
Communication Systems ◽  
Return Loss ◽  
Low Cost ◽  
Low Frequency ◽  
Monopole Antenna ◽  
Conventional Design ◽  
Meander Line ◽  
Made In

<p>Monopole antenna is widely used in many communication systems especially in broadcasting where omnidirectional pattern allow the 360-degree coverage. However, at low frequency the conventional design may require miniaturization to fit in versatile spaces. Thus, this paper discusses a low cost, compact CPW-fed curved meander line monopole antenna (MLMA) designed to operate at 0.9 GHz GSM band. The overall dimension is 25mm x 80mm. The antenna is well matched at required GSM band with the bandwidth from 0.88 GHz to 0.93 GHz. Comparison between the conventional MLMA and curved (MLMA) is made in term of return loss and gain. It was found that the curved MLMA has a better gain compared to the conventional MLMA which is 1.472 dB.</p>

scholarly journals Synthesis and characterization of Mg–Zn ferrite based flexible microwave composites and its application as SNG metamaterial

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Md Atiqur Rahman ◽  
Mohammad Tariqul Islam ◽  
Mandeep Singh Jit Singh ◽  
Md Samsuzzaman ◽  
Muhammad E. H. Chowdhury
Keyword(s):  
Low Cost ◽  
Sol Gel ◽  
Microwave Frequency ◽  
Dielectric Substrate ◽  
Dielectric Constants ◽  
Potential Candidate ◽  
Flexible Composites ◽  
Average Grain Size ◽  
Zn Ferrite ◽  
High Flexibility

AbstractIn this article, we propose SNG (single negative) metamaterial fabricated on Mg–Zn ferrite-based flexible microwave composites. Firstly, the flexible composites are synthesized by the sol-gel method having four different molecular compositions of MgxZn(1−x)Fe2O4, which are denoted as Mg20, Mg40, Mg60, and Mg80. The structural, morphological, and microwave properties of the synthesized flexible composites are analyzed using X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), and conventional dielectric assessment kit (DAK) to justify their possible application as dielectric substrate at microwave frequency regime. Thus the average grain size is found from 20 to 24 nm, and the dielectric constants are 6.01, 5.10, 4.19, and 3.28, as well as loss tangents, are 0.002, 0.004, 0.006, and 0.008 for the prepared Mg–Zn ferrites, i.e., Mg20, Mg40, Mg60, and Mg80 respectively. Besides, the prepared low-cost Mg–Zn ferrite composites exhibit high flexibility and lightweight, which makes them a potential candidate as a metamaterial substrate. Furthermore, a single negative (SNG) metamaterial unit cell is fabricated on the prepared, flexible microwave composites, and their essential electromagnetic behaviors are observed. Very good effective medium ratios (EMR) vales are obtained from 14.65 to 18.47, which ensure the compactness of the fabricated prototypes with a physical dimension of 8 × 6.5 mm2. Also, the proposed materials have shown better performances comparing with conventional FR4 and RO4533 materials, and they have covered S-, C-, X-, Ku-, and K-band of microwave frequency region. Thus, the prepared, flexible SNG metamaterials on MgxZn(1−x)Fe2O4 composites are suitable for microwave and flexible technologies.

scholarly journals Bimetallic Ni-Based Catalysts for CO2 Methanation: A Review

Nanomaterials ◽  
2020 ◽  
Vol 11 (1) ◽  
pp. 28
Author(s):  
Anastasios I. Tsiotsias ◽  
Nikolaos D. Charisiou ◽  
Ioannis V. Yentekakis ◽  
Maria A. Goula
Keyword(s):  
Low Temperature ◽  
Noble Metals ◽  
Recent Progress ◽  
Low Cost ◽  
Alloy Formation ◽  
Co2 Methanation ◽  
High Performing ◽  
Mobile Sources ◽  
Low Dispersion ◽  
Made In

CO2 methanation has recently emerged as a process that targets the reduction in anthropogenic CO2 emissions, via the conversion of CO2 captured from point and mobile sources, as well as H2 produced from renewables into CH4. Ni, among the early transition metals, as well as Ru and Rh, among the noble metals, have been known to be among the most active methanation catalysts, with Ni being favoured due to its low cost and high natural abundance. However, insufficient low-temperature activity, low dispersion and reducibility, as well as nanoparticle sintering are some of the main drawbacks when using Ni-based catalysts. Such problems can be partly overcome via the introduction of a second transition metal (e.g., Fe, Co) or a noble metal (e.g., Ru, Rh, Pt, Pd and Re) in Ni-based catalysts. Through Ni-M alloy formation, or the intricate synergy between two adjacent metallic phases, new high-performing and low-cost methanation catalysts can be obtained. This review summarizes and critically discusses recent progress made in the field of bimetallic Ni-M (M = Fe, Co, Cu, Ru, Rh, Pt, Pd, Re)-based catalyst development for the CO2 methanation reaction.

scholarly journals A Comparison of Time-Domain Implementation Methods for Fractional-Order Battery Impedance Models

Energies ◽  
2021 ◽  
Vol 14 (15) ◽  
pp. 4415
Author(s):  
Brian Ospina Agudelo ◽  
Walter Zamboni ◽  
Eric Monmasson
Keyword(s):  
Fractional Order ◽  
Time Domain ◽  
Li Ion Batteries ◽  
Simulation Framework ◽  
Frequency Range ◽  
Interesting Approach ◽  
Li Ion ◽  
Impedance Parameters ◽  
Impedance Models ◽  
Made In

This paper is a comparative study of the multiple RC, Oustaloup and Grünwald–Letnikov approaches for time domain implementations of fractional-order battery models. The comparisons are made in terms of accuracy, computational burden and suitability for the identification of impedance parameters from time-domain measurements. The study was performed in a simulation framework and focused on a set of ZARC elements, representing the middle frequency range of Li-ion batteries’ impedance. It was found that the multiple RC approach offers the best accuracy–complexity compromise, making it the most interesting approach for real-time battery simulation applications. As for applications requiring the identification of impedance parameters, the Oustaloup approach offers the best compromise between the goodness of the obtained frequency response and the accuracy–complexity requirements.

EBG at microwave frequency range: Bragg and/or resonant effect?

2004 ◽  
Vol 42 (5) ◽  
pp. 383-385 ◽  
Author(s):  
Asier Ibáñez Loinaz ◽  
Carlos del Río Bocio
Keyword(s):  
Microwave Frequency ◽  
Frequency Range ◽  
Resonant Effect

InSb Czochralski Growth Single Crystals for InGaSb Substrates

2014 ◽  
Vol 1616 ◽  
Author(s):  
J. E. Flores Mena ◽  
R. Castillo Ojeda ◽  
J. Díaz Reyes
Keyword(s):  
Low Cost ◽  
Electronic Devices ◽  
Czochralski Method ◽  
Liquid Nitrogen Temperature ◽  
Longitudinal Optical ◽  
Czochralski Growth ◽  
Etch Pit ◽  
Growth System ◽  
Radiation Sensors ◽  
Made In

ABSTRACTThe massive crystal growth of single crystal semiconductors materials has been of fundamental importance for the actual electronic devices industry. As a consequence of this one, we can obtain easily a large variety of low cost devices almost as made ones of silicon. Nowadays, the III-V semiconductors compounds and their alloys have been proved to be very important because of their optical properties and applications. It is the case of the elements In, Ga, As, Sb, which can be utilized for the fabrication of radiation sensors. In this work we present the results obtained from the ingots grown by the Czochralski method, using a growth system made in home. These results include anisotropic chemical attacks in order to reveal the crystallographic orientation and the possible polycrystallinity. Isotropic chemical attacks were made to evaluate the etch pit density. Metallographic pictures of the chemical attacks are presented in this work. Among the results of these measurements, the best samples presented in this work showed mobilities of 62.000 cm2/V*s at room temperature and 99.000 cm2/V*s at liquid nitrogen temperature. Typical pit density was 10,000/cm2. The Raman spectra present two dominant peaks associated at Transversal Optical (TO)- and Longitudinal Optical (LO)-InSb, the first vibrational mode is dominant due to the crystalline direction of the ingots and second one is associated to high defects density.

Compact Triple/Quadruple-Band Reconfigurable Monopole Antenna for Wireless Applications

2021 ◽  
pp. 2150277
Author(s):  
Asmaa Zugari ◽  
Wael Abd Ellatif Ali ◽  
Mohammad Ahmad Salamin ◽  
El Mokhtar Hamham
Keyword(s):  
Simple Structure ◽  
Low Cost ◽  
Ground Plane ◽  
Monopole Antenna ◽  
Pin Diode ◽  
Wireless Applications ◽  
Rectangular Patch ◽  
Antenna Performance ◽  
Compact Size ◽  
Multi Band

In this paper, a compact reconfigurable tri-band/quad-band monopole antenna is presented. To achieve the multi-band behavior, two right-angled triangles were etched in a conventional rectangular patch, and a partial ground plane is used. Moreover, the proposed multi-band antenna is printed on a low cost FR4 epoxy with compact dimensions of 0.23[Formula: see text], where [Formula: see text] is calculated at the lowest resonance frequency. To provide frequency agility, a metal strip which acts as PIN diode was embedded in the frame of the modified patch. The tri-band/quad-band antenna performance in terms of reflection coefficient, radiation patterns, peak gain and efficiency was studied. The measured results are consistent with the simulated results for both cases. The simple structure and the compact size of the proposed antenna could make it a good candidate for multi-band wireless applications.

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