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Sound health is considered a prerequisite for performing any action, whether it is participation in sports or performing any other activity of life. From the perspective of Islam, health and fitness are imperative for the appropriate performance of various religious obligations. Sports and other physical activities are considered very effective means to achieve good health. In this paper, the researchers analyzed diverse Islamic standards and rules with reference to participation in games. Moreover, researchers also analyzed the preservation and maintenance of health in the light of the teachings of Islam. After a brief discussion, it was concluded that the Islamic approach is very clear and Islam endorses the upkeep and maintenance of health, fitness and physical power. It was also concluded that sports and other physical activities of today are variations of such activities performed in the past. The study also claims that Islam promotes involvement in leisure sports and other physical activities carried out to strengthen the body and to retain fitness, while observing Islamic teachings, formulated rules and regulations. It can be inferred that the Holy Prophet (SAW) not only took part in different games but also convinced and encouraged his disciples to take part in sporting activities.

We're living in a world where information processing isn't confined to desktop computers-it's being integrated into everyday objects and activities. Pervasive computation is human centered: it permeates our physical world, helping us achieve goals and fulfill our needs with minimum effort by exploiting natural interaction styles. Remote interaction with screen displays requires a sensor-based, multimodal, touchless approach. For example, by processing user hand gestures, this paradigm removes constraints requiring physical contact and permits natural interaction with tangible digital information. Such touchless interaction can be multimodal, exploiting the visual, auditory, and olfactory senses. ; Acknowledgments This study received funding from Universidad Carlos III de Madrid and the European Union's Horizon 2020 Research and Innovation Programme under Marie Sklodowska-Curie grant 801538. *is study was also partially supported by Ministerio de Ciencia, Innovación y Universidades, Gobierno de España (MCIU/AEI/FEDER, UE) (RTI2018- 095499-B-C31). Additionally, the authors sincerely appreciate funding from Researchers Supporting Project (RSP- 2021/58), King Saud University, Riyadh, Saudi Arabia.

This article belongs to the Special Issue Prospective Multiple Antenna Technologies for 5G and Beyond. ; In this paper, an umbrella-shaped patch antenna for future millimeter-wave applications for the 5G frequency band is presented. The proposed antenna resonates at multiple frequency bands, i.e., 28 GHz, 38 GHz, and 55 GHz (V-band) that have been globally allocated for 5G communications systems. The proposed antenna is designed using Rogers RT/duroid 5870, with a relative permittivity, loss tangent and thickness of 2.33 mm, 0.0012 mm and 0.79 mm, respectively. The antenna has an overall size of 8 mm × 8 mm which correspond to 0.7 λ × 0.7 λ, where λ is free space wavelength at the lowest resonance. Moreover, the wide bandwidth, high gain and tri band operational mode is achieved by introducing two stubs to the initial design. The antenna prototype was fabricated and validated experimentally. The comparison of the simulated and measured results demonstrates a good correlation. Additionally, the comparative analysis with state of the art work demonstrates that the proposed antenna offers compact size, simple geometrical configuration, wide bandwidth, high gain, and radiation efficiency which makes the proposed antenna a potential candidate for compact smart 5G devices. ; The authors appreciate financial support from Universidad Carlos III de Madrid and the European Union's Horizon 2020 research and innovation program under the Marie Sklodowska-Curie Grant 801538. Moreover, this work was partially supported by the Antenna and Wireless Propagation Group (https://sites.google.com/view/awpgrp/home, assessed on 15 August 2021) and from the Researchers Supporting Project number (RSP-2021/58), King Saud University, Riyadh, Saudi Arabia.

The design of a 4 x 4 MIMO antenna for UWB communication systems is presented in this study. The single antenna element is comprised of a fractal circular ring structure backed by a modified partial ground plane having dimensions of 30 x 30 mm2. The single antenna element has a wide impedance bandwidth of 9.33 GHz and operates from 2.67 GHz to 12 GHz. Furthermore, the gain of a single antenna element increases as the frequency increases, with a peak realized gain and antenna efficiency of 5 dBi and >75%, respectively. For MIMO applications, a 4 x 4 array is designed and analyzed. The antenna elements are positioned in a plus-shaped configuration to provide pattern as well as polarization diversity. It is worth mentioning that good isolation characteristics are achieved without the utilization of any isolation enhancement network. The proposed MIMO antenna was fabricated and tested, and the results show that it provides UWB response from 2.77 GHz to over 12 GHz. The isolation between the antenna elements is more than 15 dB. Based on performance attributes, it can be said that the proposed design is suitable for UWB MIMO applications. ; The authors would like to appreciate Universidad Carlos III de Madrid and the European Union's Horizon 2020 research and innovation programme for the funding of this research work under the Marie Sklodowska-Curie Grant 801538.

This article presents the design and realization of compact, geometrically simple, wideband and high gain antenna for V-band communication systems. The antenna is designed by using a conventional circular patch, which is further modified by using another fractal circular patch. Furthermore, the addition of three elliptical shaped patches significantly increases the bandwidth of the antenna. Afterwards, a circular slot is etched from the radiator to improve the radiation pattern of the antenna. The proposed structure comprises of an overall substrate size of 13 × 12 × 0.508 mm3 and designed using Duroid 5880 having very low loss tangent of 0.0009. To verify the presented results, the antenna prototype is fabricated and tested. The comparison among simulated and measured results shows a strong performance. Moreover, the comparison with state of the artwork shows that the antenna offers compact size, wide bandwidth, high gain, and good radiation efficiency. Thus, it makes the proposed antenna a potential candidate for the V-band communication systems. ; The authors sincerely appreciate the funding from Universidad Carlos III de Madrid and the European Union's Horizon 2020 research and innovation program under the Marie Sklodowska-Curie Grant 801538. Also, this work is partially supported by Antenna and Wireless Propagation Group (AWPG); https://sites.google.com/view/awpgrp, and from the Researchers Supporting Project number (RSP-2021/58), King Saud University, Riyadh, Saudi Arabia.

The authors appreciate financial support from Universidad Carlos III de Madrid and the European Union's Horizon 2020 research and innovation program under the Marie Sklodowska-Curie grant Agreement No 801538. As well as, this work was partially supported by the Antenna and Wireless Propagation Group (https://sites.google.com/view/awpgrp/home accessed on 16 June 2021) and from the Researchers Supporting Project number (RSP-2021/58), King Saud University, Riyadh, Saudi Arabia.

This paper presents a unique concentric hexagonal-shaped ring antenna for radio frequency identification (RFID) tags. The rings are excited with a common microstrip feedline. The radiation characteristics of the antenna is improved by locating a horizontal a parasitic element in the vicinity of the hexagonal-shaped rings. The proposed antenna was used in the implementation of a 3×1 antenna array. The impedance match of the 3×1 RFID tag was enhanced by incorporating a T-shaped stub. The antenna is designed to operate at the UHF band from 800 MHz to 960 MHz. It was implemented on FR-4 substrate with dielectric constant and thickness of 4.3 and 1.6 mm, respectively. The size of the RFID tag antenna is 36×10 mm 2 . Its impedance was matched to Alien Higgs RFIC chip of impedance 10 – j 82.5 Ω at 895 MHz. Measured results show the proposed RFID tag antenna provides an impedance bandwidth, maximum gain and radiation efficiency of 160 MHz, 2 dBi, and 66.5%, respectively. With effective isotropic radiated power (EIRP) limited to 36 dBm to comply with FCC regulations for UHF band RFIDs it radiates in the broadside direction over a range of 9 m making it desirable for various applications including supply chain management, logistic control, and vehicle identification. ; This project has received funding from Universidad Carlos III de Madrid and the European Union's Horizon 2020 research and innovation program under the Marie Sklodowska-Curie Grant 801538. Also, this work is partially supported by RTI2018-095499-B-C31, Funded by Ministerio de Ciencia,Innovación y Universidades, Gobierno de España (MCIU/AEI/FEDER,UE). Additionally, it received funding from the Researchers Supporting Project number (RSP-2021/58), King Saud University, Riyadh, Saudi Arabia.

In this article, a compact printed monopole dual-band antenna using artificial magnetic conductor (AMC)-plane with improved gain and broader bandwidth, applicable for off-body internet of things (IoT) devices is presented. The monopole antenna consists of two C-shaped resonators connected through a U-shaped monopole, parasitic elements, discrete ground circular rings and a co-planar waveguide (CPW) feedline. Each artificial magnetic conductor (AMC) unit cell consists of a slotted circular and a square stubs, designed with two zero-crossing phases for improving the radiation characteristics and to achieve the high gain. The overall size of the proposed AMC-backed antenna is 44.4 mm ×44.4 mm ×1.6 mm with electrical dimensions of 0.75lambdag×0.75lambdag×0.027lambdag . This AMC-backed antenna featured measured bandwidths of 9.6% and 12.4% with improved measured gain values of 4.88 dB and 4.73 dB at 2.45 GHz and 5.8 GHz, respectively. The specific absorption rate (SAR) values are analysed and found to be 1.58 W/kg at 2.45 GHz and 0.9 W/kg at 5.8 GHz. Therefore, the proposed AMC-backed antenna is useful for off-body IoT devices operating at 2.45 and 5.8 GHz industrial, scientific, and medical (ISM) band applications. ; This work was supported in part by the Universidad Carlos III de Madrid; in part by the European Union's Horizon 2020 Research and Innovation Programme under Marie Sklodowska-Curie Grant 801538; in part by the Ministerio de Ciencia, Innovación y Universidades, Gobierno de España (MCIU/AEI/FEDER and UE) under Grant RTI2018-095499-B-C31; and in part by the Researchers Supporting Project, King Saud University, Riyadh, Saudi Arabia, under Project number RSP-2021/58.

Circular polarized (CP) antennas are well suited for long-distance transmission attainment. In order to be adaptable for beyond 5G communication, a detailed and systematic investigation of their important conventional features is required for expected enhancements. The existing designs employing millimeter wave, microwave, and ultra-wideband (UWB) frequencies form the elementary platform for future studies. The 3.4–3.8 GHz frequency band has been identified as a worthy candidate for 5G communications because of spectrum availability. This band comes under UWB frequencies (3.1–10.6 GHz). In this survey, a review of CP antennas in the selected areas to improve the understanding of early-stage researchers specially experienced antenna designers has presented for the first time as best of our knowledge. Design implementations involving size, axial ratio, efficiency, and gain improvements are covered in detail. Besides that, various design approaches to realize CP antennas including (a) printed CP antennas based on parasitic or slotted elements, (b) dielectric resonator CP antennas, (c) reconfigurable CP antennas, (d) substrate integrated waveguide CP antennas, (e) fractal CP antennas, (f) hybrid techniques CP antennas, and (g) 3D printing CP antennas with single and multiple feeding structures have investigated and analyzed. The aim of this work is to provide necessary guidance for the selection of CP antenna geometries in terms of the required dimensions, available bandwidth, gain, and useful materials for the integration and realization in future communication systems. ; This project has received funding from Universidad Carlos III de Madrid and the European Union's Horizon 2020 research and innovation program under the Marie Sklodowska-Curie Grant 801538. Also, this work was partially supported by RTI2018-095499-B-C31, Funded by Ministerio de Ciencia,Innovación y Universidades, Gobierno de España (MCIU/AEI/FEDER,UE).