Ellie Vineyard¹, Xin-Lin Gao^2,*

CMES-Computer Modeling in Engineering & Sciences, Vol.127, No.3, pp. 819-854, 2021, DOI:10.32604/cmes.2021.015688 - 24 May 2021

Abstract 2-D and 3-D micro-architectured multiphase thermoelastic metamaterials are designed and analyzed using a parametric level set method for topology optimization and the finite element method. An asymptotic homogenization approach is employed to obtain the effective thermoelastic properties of the multiphase metamaterials. The -constraint multi-objective optimization method is adopted in the formulation. The coefficient of thermal expansion (CTE) and Poisson’s ratio (PR) are chosen as two objective functions, with the CTE optimized and the PR treated as a constraint. The optimization problems are solved by using the method of moving asymptotes. Effective isotropic and anisotropic CTEs More >

Watcharaphon Naktong¹, Amnoiy Ruengwaree^1,*, Nuchanart Fhafhiem², Piyaporn Krachodnok³

CMC-Computers, Materials & Continua, Vol.68, No.2, pp. 1731-1750, 2021, DOI:10.32604/cmc.2021.015843 - 13 April 2021

Abstract In this paper, the design of a resonator rectenna, based on metamaterials and capable of harvesting radio-frequency energy at 2.45 GHz to power any low-power devices, is presented. The proposed design uses a simple and inexpensive circuit consisting of a microstrip patch antenna with a mushroom-like electromagnetic band gap (EBG), partially reflective surface (PRS) structure, rectifier circuit, voltage multiplier circuit, and 2.45 GHz Wi-Fi module. The mushroom-like EBG sheet was fabricated on an FR4 substrate surrounding the conventional patch antenna to suppress surface waves so as to enhance the antenna performance. Furthermore, the antenna performance More >

Daniyal Ali Sehrai¹, Fazal Muhammad¹, Saad Hassan Kiani¹, Ziaul Haq Abbas², Muhammad Tufail³, Sunghwan Kim^{4, *}

CMC-Computers, Materials & Continua, Vol.64, No.3, pp. 1587-1599, 2020, DOI:10.32604/cmc.2020.011057 - 30 June 2020

Abstract Metamaterial surfaces play a vital role to achieve the surface waves suppression and in-phase reflection, in order to improve the antenna performance. In this paper, the performance comparison of a fifth generation (5G) antenna design is analyzed and compared with a metamaterial-based antenna for 5G communication system applications. Metamaterial surface is utilized as a reflector due to its in-phase reflection characteristic and high-impedance nature to improve the gain of an antenna. As conventional conducting ground plane does not give enough surface waves suppression which affects the antenna performance in terms of efficiency and gain etc.… More >

Jalal Khan¹, Daniyal Ali Sehrai¹, Mushtaq Ahmad Khan¹, Haseeb Ahmad Khan², Salman Ahmad³, Arslan Ali⁴, Arslan Arif⁵, Anwer Ahmad Memon⁶, Sahib Khan^1,4,*

CMC-Computers, Materials & Continua, Vol.60, No.2, pp. 409-420, 2019, DOI:10.32604/cmc.2019.06883

Abstract In this paper, a rotated Y-shaped antenna is designed and compared in terms of performance using a conventional and EBG ground planes for future Fifth Generation (5G) cellular communication system. The rotated Y-shaped antenna is designed to transmit at 38 GHz which is one of the most prominent candidate bands for future 5G communication systems. In the design of conventional antenna and metamaterial surfaces (mushroom, slotted), Rogers-5880 substrate having relative permittivity, thickness and loss tangent of 2.2, 0.254 mm, and 0.0009 respectively have been used. The conventional rotated Y-shaped antenna offers a satisfactory wider bandwidth… More >

Girish K.¹, Hema Singh²

CMC-Computers, Materials & Continua, Vol.52, No.3, pp. 197-212, 2016, DOI:10.3970/cmc.2016.052.196

Abstract Aerospace structures can be approximately modeled as a combination of canonical structures such as cylinder, cone and ellipsoid. Thus the RCS estimation of such canonical structures is of prime interest. Furthermore metamaterials possess peculiar electromagnetic properties which can be useful in modifying the RCS of structures. This paper is aimed at calculating the RCS of an infinitely long PEC circular cylinder coated with one or two layers of metamaterial. The incident and scattered fields of coated cylinder are expressed in terms of series summation of Bessel and Hankel functions. The unknown coefficients of summation are More >

Anju Pradeep¹, S. Mridula¹, P. Mohanan²

CMC-Computers, Materials & Continua, Vol.52, No.3, pp. 187-196, 2016, DOI:10.3970/cmc.2016.052.185

Abstract A highly compact chipless tag based on Frequency coding technique using Spiral Resonators is proposed in this paper. Spirals are well known metamaterial structures and thus capable of sharp resonance, and hence Spiral Resonators can serve as a good candidate for RF Identity Tags. The bit capacity of the proposed tag is 10 bits per sqcm. The prototype of the tag is fabricated on a low-cost substrate of dielectric constant 4.4 and loss tangent 0.02. The overall dimension of tag is 15.4 x 3 x 1.6 mm³. Two methods for reading the tags are also discussed More >

Anusha Eldo¹, Balamati Choudhury²

CMC-Computers, Materials & Continua, Vol.52, No.3, pp. 143-157, 2016, DOI:10.3970/cmc.2016.052.142

Abstract The advances in metamaterial science and technology have raised the expectations of camouflage or stealth researchers to one order higher in terms of absorption characteristics. As metamaterial inspired radar absorbing structures are proving themselves as a good candidate with near unity absorption, feasibility towards hardware realization is necessary. Hence an extensive literature survey of metamaterial inspired radar absorbing structure has been carried out and reported in this paper along with the challenges and material issues. The various types of metamaterial structures that can be used as absorber have been provided along with simulation figures. To More >

Susan Thomas¹, Dr. Balamati Choudhury²

CMC-Computers, Materials & Continua, Vol.52, No.3, pp. 133-141, 2016, DOI:10.3970/cmc.2016.052.132

Abstract A novel microwave cloak using circular split ring resonator (SRR) based metamaterial structure has been proposed in this paper. The cloak which operates at a frequency of 10.6 GHz is composed of cylindrical dielectric sheets printed with circular split ring resonators of spatially varying and anisotropic material properties. The article also focuses on the phenomenon of resonant splitting in circular SRR microwave cloak. A detailed analysis of various linear metamaterial arrays and their response has also been elucidated. More >

Sameer R. Sonkusale¹, Wangren Xu¹, Saroj Rout¹

CMC-Computers, Materials & Continua, Vol.39, No.3, pp. 301-315, 2014, DOI:10.3970/cmc.2014.039.301

Abstract This paper illustrates some new concepts in the area of hybrid metamaterials, which are metamaterials that are embedded with active circuit elements such as transistors. Such transistor/metamaterial hybrids can exhibit some exotic electromagnetic properties which can be exploited for unusual and exciting functions. Two specific examples are provided. In one application, terahertz (THz) modulator based on embedding of psuedomorphic high electron mobility transistor (pHEMT) within the metamaterial resonator, all implemented monolithically in a commercial gallium arsenide (GaAs) technology is presented. In another application, a detector array based on metamaterial perfect absorber for room-temperature detection of More >

Ligia Munteanu¹, Veturia Chiroiu¹, Viorel Şerban²

CMC-Computers, Materials & Continua, Vol.42, No.3, pp. 175-204, 2014, DOI:10.3970/cmc.2014.042.175

Abstract The paper introduces a new alternative towards fabrication of auxetic metamaterials (materials with negative Poisson’s ratio) controlled by geometric transformations. These transformations are derived from the theory of small (infinitesimal) elastic deformation superimposed on finite elastic deformations. By using this theory, a cylindrical region filled with initial deformed foam is transformed through deformation into a cylindrical shell region filled with auxetic metamaterial. As an example, the realization of the seismic cloak device becomes a practical possibility. More >