Woochan Lee¹, Woobin Park¹, Jaeyoung Park², Young-Joon Kim³, Moonseong Kim^4,*

Intelligent Automation & Soft Computing, Vol.36, No.2, pp. 1585-1602, 2023, DOI:10.32604/iasc.2023.033112

Abstract The finite element method is a key player in computational electromagnetics for designing RF (Radio Frequency) components such as waveguides. The frequency-domain analysis is fundamental to identify the characteristics of the components. For the conventional frequency-domain electromagnetic analysis using FEM (Finite Element Method), the system matrix is complex-numbered as well as indefinite. The iterative solvers can be faster than the direct solver when the solver convergence is guaranteed and done in a few steps. However, such complex-numbered and indefinite systems are hard to exploit the merit of the iterative solver. It is also hard to benefit from matrix factorization techniques… More >

Omar A. Saraereh^*

Computer Systems Science and Engineering, Vol.43, No.1, pp. 413-422, 2022, DOI:10.32604/csse.2022.024202

Abstract At present, the microwave frequency band bandwidth used for mobile communication is only 600 MHz. In 2020, the 5G mobile Communication required about 1 GHz of bandwidth, so people need to tap new spectrum resources to meet the development needs of mobile Internet traffic that will increase by 1,000 times in the next 10 years. Utilize the potentially large bandwidth (30∼300 GHz) of the millimeter wave frequency band to provide higher data rates is regarded as the potential development trend of the future wireless communication technology. A microstrip patch implementation approach based on electromagnetic coupling feeding is presented to increase the… More >

Kabir Hossain^1,2, Thennarasan Sabapathy^1,2,*, Muzammil Jusoh^1,2, Ping Jack Soh^1,3, Samir Salem Al-Bawri⁴, Mohamed Nasrun Osman^1,2, Hasliza A. Rahim^1,2, Danai Torrungrueng⁵, Prayoot Akkaraekthalin⁶

CMC-Computers, Materials & Continua, Vol.71, No.1, pp. 1677-1693, 2022, DOI:10.32604/cmc.2022.022227

Abstract This paper introduces a decagonal C-shaped complementary split-ring resonator (CSRR) textile-based metamaterial (MTM). The overall size of the proposed sub-wavelength MTM unit cell is 0.28λ₀ × 0.255λ₀ at 3 GHz. Its stopband behaviour was first studied prior analysing the negative index properties of the proposed MTM. It is worth noting that in this work a unique way the experiments were completed. For both simulations and measurements, the proposed MTM exhibited negative-permittivity and negative-refractive index characteristics with an average bandwidth of more than 3 GHz (considering 1.7 to 8.2 GHz as the measurements were carried out within this range). In simulations, the MTM… More >

M. Premkumar¹, Pradeep Jangir², B. Santhosh Kumar³, Mohammad A. Alqudah⁴, Kottakkaran Sooppy Nisar^5,*

CMC-Computers, Materials & Continua, Vol.70, No.2, pp. 2435-2452, 2022, DOI:10.32604/cmc.2022.016488

Abstract The first step in the design phase of the Brushless Direct Current (BLDC) motor is the formulation of the mathematical framework and is often used due to its analytical structure. Therefore, the BLDC motor design problem is considered to be an optimization problem. In this paper, the analytical model of the BLDC motor is presented, and it is considered to be a basis for emphasizing the optimization methods. The analytical model used for the experimentation has 78 non-linear equations, two objective functions, five design variables, and six non-linear constraints, so the BLDC motor design problem is considered as highly non-linear… More >

C. J. Reddy¹

CMES-Computer Modeling in Engineering & Sciences, Vol.5, No.5, pp. 455-462, 2004, DOI:10.3970/cmes.2004.005.455

Abstract This paper presents an efficient algorithm to evaluate multi-spectral and multi-angular monostatic radar cross section (RCS) of large objects with very fine increments. The technique is based on the combination of Model Based Parameter Estimation (MBPE) method with hybrid frequency domain formulations. A general approach to formulation of MBPE is presented along with a similar approach called the Asymptotic Waveform Evaluation (AWE). Various numerical examples are presented for multi-spectral response calculations using method of moments (MoM) and the hybrid Finite Element-MoM technique in conjunction with MBPE. Example application of MBPE for hybrid MoM-Physical Optics approach for multi-angular calculations is also… More >

Raju R. Namburu¹, Eric R. Mark, Jerry A. Clarke

CMES-Computer Modeling in Engineering & Sciences, Vol.5, No.5, pp. 443-454, 2004, DOI:10.3970/cmes.2004.005.443

Abstract Computational electromagnetic (CEM) simulations of full-range military vehicles play a critical role in enhancing the survivability and target recognition of combat systems. Modeling of full-range military systems subjected to high frequencies may involve generating large-scale meshes, solving equations, visualization, and analysis of results in the range of billions of unknowns or grid points. Hence, the overall objective of this research is to develop and demonstrate a scalable CEM software environment to address accurate prediction of radar cross sections (RCS) for full- range armored vehicles with realistic material treatments and complex geometric configurations. A software environment consisting of scalable preprocessing, postprocessing,… More >

J. S. Hesthaven¹, T. Warburton²

CMES-Computer Modeling in Engineering & Sciences, Vol.5, No.5, pp. 395-408, 2004, DOI:10.3970/cmes.2004.005.395

Abstract We discuss the formulation, validation, and parallel performance of a high-order accurate method for the time-domain solution of the three-dimensional Maxwell's equations on general unstructured grids. Attention is paid to the development of a general discontinuous element/penalty approximation to Maxwell's equations and a locally divergence free form of this. We further discuss the motivation for using a nodal Lagrangian basis for the accurate and efficient representation of solutions and operators. The performance of the scheme is illustrated by solving benchmark problems as well as large scale scattering applications. More >

Meng Fan¹, Lesong Wang², John Steinhoff³

CMES-Computer Modeling in Engineering & Sciences, Vol.5, No.4, pp. 373-382, 2004, DOI:10.3970/cmes.2004.005.373

Abstract A new method is described that has the potential to greatly extend the range of application of current Eulerian time domain electromagnetic or acoustic computational methods for certain problems. More >

W.C. Chew¹, J.M. Song¹, T.J. Cui¹, S. Velamparambil¹, M.L. Hastriter¹, B. Hu¹

CMES-Computer Modeling in Engineering & Sciences, Vol.5, No.4, pp. 361-372, 2004, DOI:10.3970/cmes.2004.005.361

Abstract This paper reviews recent advances in large-scale computational electromagnetics using frequency domain integral equations. It gives a brief history of methods to solve Maxwell's equations, followed by a description of various historical ages in solution technique developments. Then it describes computational electromagnetics followed by a brief description of how fast integral equation solvers such as the multilevel fast multipole algorithm (MLFMA) is constructed using the tree network. Some examples of large scale computing using MLFMA are given. Ray physics used to further accelerate the speed of MLFMA. The parallel implementation of MLFMA in a code called ScaleME is reviewed, and… More >

E. Bleszynski¹, M. Bleszynski¹, T. Jaroszewicz¹

CMES-Computer Modeling in Engineering & Sciences, Vol.5, No.4, pp. 295-318, 2004, DOI:10.3970/cmes.2004.005.295

Abstract We describe elements of our current work on the development of new methods for high frequency electromagnetic scattering, based on the wavefront (WF) representation of propagating fields and on the asymptotic but rigorous solution of integral equations for surface currents. In the wavefront evolution technique, surfaces of constant phase are constructed and treated not merely as collections of independent rays, but as well defined geometrical objects endowed with the full connectivity information. Hence, a precise determination of shadow and reflection boundaries, a construction of (multiply) diffracted wavefronts, a dynamic adjustment of the number of rays, an approximately constant ray-ray distance,… More >