Yu.E. Nikolaenko^a , D.V. Pekur^b,*, V.Yu. Кravets^a, V.M. Sorokin^b, D.V. Kozaka , R.S. Melnyk^a, L.V. Lipnitskyi^a, A.S. Solomakha^a

Frontiers in Heat and Mass Transfer, Vol.18, pp. 1-13, 2022, DOI:10.5098/hmt.18.23

Abstract This study compares thermal characteristics of two design versions of a new low-cost air-cooling system with a standard heat sink profile and built-in flat heat pipes of a simple design with a similar cooling system design without the heat pipes. The aim of the work is to determining the thermal characteristics and choosing the most effective option in a practical context. Using computer simulation in the Solidworks Flow Simulation standard software package allowed determining how the temperature of 8 transistors with a total power of 224 W was affected by changes in air velocity from 1 to 30 m/s, effective… More >

Awais Khan^1,2,*, Shahid Bashir¹, Salman Ghafoor³, Hatem Rmili^4,5, Jawad Mirza⁶, Ammar Ahmad¹

CMC-Computers, Materials & Continua, Vol.75, No.1, pp. 911-925, 2023, DOI:10.32604/cmc.2023.033866

Abstract Mutual coupling reduction or isolation enhancement in antenna arrays is an important area of research as it severely affects the performance of an antenna. In this paper, a new type of compact and highly isolated Multiple-Input-Multiple-Output (MIMO) antenna for ultra-wideband (UWB) applications is presented. The design consists of four radiators that are orthogonally positioned and confined to a compact 40 × 40 × 0.8 mm³ space. The final antenna design uses an inverted L shape partial ground to produce an acceptable reflection coefficient (S11 < −10 dB) in an entire UWB band (3.1–10.6) giga hertz (GHz). Moreover, the inter-element isolation… More >

Saqer S. Alja’Afreh^1,*, Mallak H. Alshamaileh¹, Eqab Almajali², Jawad Yousaf³, Amir Altaf⁴

CMC-Computers, Materials & Continua, Vol.73, No.2, pp. 3181-3198, 2022, DOI:10.32604/cmc.2022.029863

Abstract Due to the limited space and large mutual coupling levels, the design of sub-6 GHz massive Multi-Input Multi-Output (m-MIMO) smartphone antenna system attracts antennas’ designers and engineers worldwide. Therefore, this paper presents 18-element m-MIMO antenna system that covers the long-term evolution 42 (LTE42) frequency band (3.4–3.6 GHz) for the fifth generation (5G) applications in metallic frame smartphones. The proposed array system is etched on the long sides of a metal rim of the mobile chassis symmetrically, which is electrically connected to the system ground plane with zero ground clearance. A low-profile frame of height 7 mm (λ/12.3) is symmetrically placed… More >

Shalermchon Tangwachirapan, Wanwisa Thaiwirot^*, Prayoot Akkaraekthalin

CMC-Computers, Materials & Continua, Vol.73, No.1, pp. 411-431, 2022, DOI:10.32604/cmc.2022.028294

Abstract This paper presents the design and analysis of antipodal Vivaldi antennas (AVAs) for breast cancer detection. In order to enhance the antenna gain, different techniques such as using the uniform and non-uniform corrugation, expanding the dielectric substrate and adding the parasitic patch are applied to original AVA. The design procedure of two developed AVA structures i.e., AVA with non-uniform corrugation and AVA with parasitic patch are presented. The proposed AVAs are designed on inexpensive FR4 substrate. The AVA with non-uniform corrugation has compact dimension of mm² or , where is wavelength of the lowest operating frequency. The antenna can operate… More >

Chafaa Hamrouni^1,*

CMC-Computers, Materials & Continua, Vol.72, No.3, pp. 4233-4248, 2022, DOI:10.32604/cmc.2022.023453

Abstract This research contributes to small satellite system development based on electromagnetic modeling and an integrated meta-materials antenna networks design for multimedia transmission contents. It includes an adaptive nonsingular mode tracking control design for small satellites systems using fuzzy waveless antenna networks. By analyzing and modeling based on electromagnetic methods, propagation properties of guided waves from metallic structures with simple or complex forms charge partially or entirely by anisotropic materials such as metamaterials. We propose a system control rule to omit uncertainties, including the inevitable approximation errors resulting from the finite number of fuzzy signal power value basis functions in antenna… More >

N. A. Koma'rudin¹, Z. Zakaria^1,*, A. A. Althuwayb², H. Lago³, H. Alsariera¹, H. Nornikman¹, A. J. A. Al-Gburi¹, P. J. Soh^4,5

CMC-Computers, Materials & Continua, Vol.72, No.1, pp. 983-998, 2022, DOI:10.32604/cmc.2022.024782

Abstract This work proposes a wideband and unidirectional antenna consisting of dual layer of coplanar waveguide based on the circular parasitic element technique. The design procedure is implemented in three stages: Design A, which operates at 3.94 GHz with a bandwidth of 3.83 GHz and a fractional bandwidth (FBW) of 97.2%; Design B, which operates at 3.98 GHz with a bandwidth of 0.66 GHz (FBW of 56.53%); and Design C as the final antenna. The final Design C is designed to resonate at several frequencies between 2.89 and 7.0 GHz for microwave imaging applications with a bandwidth of 4.11 GHz (79.8%)… More >

Muhannad Y. Muhsin^1,*, Ali J. Salim², Jawad K. Ali²

Computer Systems Science and Engineering, Vol.42, No.3, pp. 919-934, 2022, DOI:10.32604/csse.2022.023102

Abstract A compact self-isolated Multi Input Multi Output (MIMO) antenna array is presented for 5G mobile phone devices. The proposed antenna system is operating at the 3.5 GHz band (3400–3600 MHz) and consists of eight antenna elements placed along two side edges of a mobile device, which meets the current trend requirements of full-screen smartphone devices. Each antenna element is divided into two parts, a front part and back part. The front part consists of an I-shaped feeding line and a modified Hilbert fractal monopole antenna, whereas the back part is an L-shaped element shorted to the system ground by a… More >

Amor Smida^1,2,*

CMC-Computers, Materials & Continua, Vol.71, No.1, pp. 1613-1623, 2022, DOI:10.32604/cmc.2022.022289

Abstract High gain antennas are highly desirable for long-range wireless communication systems. In this paper, a compact, low profile, and high gain dielectric resonator antenna is proposed, fabricated, experimentally tested, and verified. The proposed antenna system has a cylindrical dielectric resonator antenna with a height of 9 mm and a radius of 6.35 mm as a radiating element. The proposed dielectric resonator antenna is sourced with a slot while the slot is excited with a rectangular microstrip transmission line. The microstrip transmission line is designed for a 50 Ω impedance to provide maximum power to the slot. As a result, 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 >

Samir Salem Al-Bawri¹, Mohammad Tariqul Islam^2,*, Kabir Hossain^3,4, Thennarasan Sabapathy^3,4, Muzammil Jusoh^3,4

CMC-Computers, Materials & Continua, Vol.71, No.1, pp. 611-628, 2022, DOI:10.32604/cmc.2022.021244

Abstract This paper presents a textile-based C-shaped split-ring resonators (SRR) metamaterial (MTM) unit cells with an electrical tunability function. The proposed MTM was composed of two symmetrical C-shaped SRR combined with a central diagonal metal bar, whereas the RF varactor diode is placed on the backside of the splitted ground plane. Stopband behavior of single and array MTM unit cells were analyzed while the achieved negative index physical characteristics were widely studies. Though four different MTM arrays (i.e., 1 × 1, 1 × 2, 2 × 1, and 2 × 2) were analyzed in simulation, a 2 × 2-unit cell array… More >