Osama M. Haraz

Bio: Osama M. Haraz is an academic researcher from Assiut University. The author has contributed to research in topics: Antenna (radio) & Antenna measurement. The author has an hindex of 14, co-authored 75 publications receiving 782 citations. Previous affiliations of Osama M. Haraz include King Saud University & King Abdulaziz City for Science and Technology.

Dense Dielectric Patch Array Antenna With Improved Radiation Characteristics Using EBG Ground Structure and Dielectric Superstrate for Future 5G Cellular Networks

Abstract: In this paper, a new dense dielectric (DD) patch array antenna prototype operating at 28 GHz for future fifth generation (5G) cellular networks is presented. This array antenna is proposed and designed with a standard printed circuit board process to be suitable for integration with radio frequency/microwave circuitry. The proposed structure employs four circular-shaped DD patch radiator antenna elements fed by a 1-to-4 Wilkinson power divider. To improve the array radiation characteristics, a ground structure based on a compact uniplanar electromagnetic bandgap unit cell has been used. The DD patch shows better radiation and total efficiencies compared with the metallic patch radiator. For further gain improvement, a dielectric layer of a superstrate is applied above the array antenna. The measured impedance bandwidth of the proposed array antenna ranges from 27 to beyond 32 GHz for a reflection coefficient (S11) of less than -10 dB. The proposed design exhibits stable radiation patterns over the whole frequency band of interest, with a total realized gain more than 16 dBi. Due to the remarkable performance of the proposed array, it can be considered as a good candidate for 5G communication applications.

28/38-GHz dual-band millimeter wave SIW array antenna with EBG structures for 5G applications

Abstract: The design of linearly polarized dual-band substrate integrated waveguide (SIW) antenna/array operating at Ka-band is proposed. The single antenna element consists of a SIW cavity with two longitudinal slots engraved in one of the conducting planes. The longer and shorter slots are resonating at 28 GHz and 38 GHz, respectively. Only the simulated results are presented. All simulations have been carried out using industry-standard software, CST Microwave Studio. For single antenna element, an impedance bandwidth (S11< −10 dB) of 0.45 GHz (1.60 %) and 2.20 GHz (5.8 %) is achieved with the maximum gain of 5.2 dBi and 5.9 dBi at 28 GHz and 38 GHz, respectively. To achieve high gain, a horizontally polarized linear array of four elements (1 × 4) is designed. For the antenna array, a microstrip lines feed network is designed using 3-dB wilkinson power divider. At 28 GHz and 38 GHz, the impedance bandwidth is 0.32 GHz (1.14 %) and 1.9 GHz (5%) having maximum gain of 11.9 dBi and 11.2 dBi, respectively. A low loss/cost substrate, RT/Duroid 5880 is used in the proposed designs.

Design of a 28/38 GHz dual-band printed slot antenna for the future 5G mobile communication Networks

Abstract: In this article, a dual-band printed slot antenna for the future fifth generation (5G) mobile networks are proposed. The antenna is compact with size of 0.8 λ 0 × 0.75 λ 0 at 28 GHz. Matching between a sector-disk shaped radiating patch and the 50-Ω microstrip line is manipulated through aproximity-feed technique. An elliptically shaped aperture is etched in the ground plane to enhance the antenna bandwidth. A shunt stub is used to get more enhancement of the impedance bandwidth of the antenna. To reduce the interference between the 5G system and other systems, π-shaped slot is etched off in the feed line to create a notched band of 30–34 GHz. The simulated results show that the designed antenna has a dual band function at 28/38 GHz that covers future 5G applications. The proposed antenna provides almost omni-directional patterns, relatively flat gain, and high radiation efficiency through the frequency band excluding the rejected band.

Four-element dual-band printed slot antenna array for the future 5G mobile communication networks

Abstract: In this article, a four-element dual-band printed slot antenna array for the future fifth generation (5G) mobile networks is proposed. The antenna element has a compact with size of 0.8 λ 0 × 0.75 λ 0 at 28 GHz. The simulated results show that the designed antenna has a dual-band function at 28/38 GHz that covers future 5G applications. The designed 1-to-4 modified Wilkinson power divider is used to feed the proposed array. For further enhancement of the designed power divider, an electromagnetic bandgap (EBG) structures are used. The proposed antenna array provides directional patterns, relatively flat gain, and high radiation efficiency through the frequency band excluding the rejected band.

UWB Antennas for Wireless Applications

Abstract: Currently, there is an increased interest in ultra-wideband (UWB) technology for use in sev‐ eral present and future applications. UWB technology received a major boost especially in 2002 since the US Federal Communication Commission (FCC) permitted the authorization of using the unlicensed frequency band starting from 3.1 to 10.6 GHz for commercial com‐ munication applications [1]. Although existing third-generation (3G) communication tech‐ nology can provide us with many wide services such as fast internet access, video telephony, enhanced video/music download as well as digital voice services, UWB –as a new technology– is very promising for many reasons. The FCC allocated an absolute band‐ width up to 7.5 GHz which is about 110% fractional bandwidth of the center frequency. This large bandwidth spectrum is available for high data rate communi-cations as well as radar and safety applications to operate in. The UWB technology has another advantage from the power consumption point of view. Due to spreading the ener-gy of the UWB signals over a large frequency band, the maximum power available to the antenna –as part of UWB sys‐ tem– will be as small as in order of 0.5mW according to the FCC spectral mask. This power is considered to be a small value and it is actually very close to the noise floor compared to what is currently used in different radio communica-tion systems [2].

International Journal of Business Data Communications and Networking

Abstract: Welcome to the second installment of IJBDCN. This issue contains three research papers and a comprehensive survey article on mobile ad hoc networks. We would like to publish a couple of survey or tutorial articles per year as we believe this to be of value to our readers. Many research papers are necessarily focused and do not allow for a " panoramic " view of a particular subject. This is the gap that well-written survey or tutorial papers can fill. We are also planning a guest-edited special issue for the last quarter of this year and welcome your suggestions for future special issues of the journal. This second issue starts with a paper entitled " An Approach to Solving the Surviv-able Capacitated Network Design Problem " where Sridhar and Park studied the problem of selecting links of a network to construct primary and secondary routes for transfer of commodity traffic between nodes of the network. Their technique allows the design of survivable and cost-effective networks. In the second paper, " Query Processing Strategies for Location-Dependent Information Services " , Jayaputera and Taniar propose a new approach to generate a query result for location-dependent information services (LDIS). They argue that choosing a square as the scope of a query and dividing it into four equal regions, where a user is a center point of the scope, results in a faster searching time to find targets queried and brings a bigger chance to get rare targets. In addition, by avoiding resubmitting the same queries when the query results missed, the approach reduced bandwidth use at both the server and client sides. The third paper, " Addressing SPAM E-Mail Using Hashcash " by Curran and Honan tackles a problem experienced by most of us. The authors present the Hashcash proof-of-work approach and investigate the feasibility of implementing a solution based on that mechanism along with what they called a " cocktail " of antispam measures designed to keep junk mail under control. Finally , in the last paper, entitled " MANET: Applications, Issues, and Challenges for the Future " , Dhar presents an informative survey of mobile ad hoc networks, describing the main characteristics of those networks and how they are being used, and discussing the most pressing issues and challenges associated with these temporary wireless networks. We hope that you enjoy this and the upcoming issues of IJBDCN. Our goal is to …

Solving the 5G Mobile Antenna Puzzle: Assessing Future Directions for the 5G Mobile Antenna Paradigm Shift

Abstract: Advances in antenna technologies for cellular hand-held devices have been synchronous with the evolution of mobile phones over nearly 40 years. Having gone through four major wireless evolutions [1], [2], starting with the analog-based first generation to the current fourth-generation (4G) mobile broadband, technologies from manufacturers and their wireless network capacities today are advancing at unprecedented rates to meet our unrelenting service demands. These ever-growing demands, driven by exponential growth in wireless data usage around the globe [3], have gone hand in hand with major technological milestones achieved by the antenna design community. For instance, realizing the theory regarding the physical limitation of antennas [4]-[6] was paramount to the elimination of external antennas for mobile phones in the 1990s. This achievement triggered a variety of revolutionary mobile phone designs and the creation of new wireless services, establishing the current cycle of cellular advances and advances in mobile antenna technologies.

Broadband mm-Wave Microstrip Array Antenna With Improved Radiation Characteristics for Different 5G Applications

Abstract: A Ka-band inset-fed microstrip patches linear antenna array is presented for the fifth generation (5G) applications in different countries. The bandwidth is enhanced by stacking parasitic patches on top of each inset-fed patch. The array employs 16 elements in an H-plane new configuration. The radiating patches and their feed lines are arranged in an alternating out-of-phase 180° rotating sequence to decrease the mutual coupling and improve the radiation pattern symmetry. A (24.4%) measured bandwidth (24.35–31.13 GHz) is achieved with −15 dB reflection coefficients and 20 dB mutual coupling between the elements. With uniform amplitude distribution, a maximum broadside gain of 19.88 dBi is achieved. Scanning the main beam to 49.5° from the broadside achieved 18.7 dBi gain with −12.1 dB sidelobe level. These characteristics are in good agreement with the simulations, rendering the antenna to be a good candidate for 5G applications.

Towards 5G: A Photonic Based Millimeter Wave Signal Generation for Applying in 5G Access Fronthaul.

Abstract: 5G communications require a multi Gb/s data transmission in its small cells. For this purpose millimeter wave (mm-wave) RF signals are the best solutions to be utilized for high speed data transmission. Generation of these high frequency RF signals is challenging in electrical domain therefore photonic generation of these signals is more studied. In this work, a photonic based simple and robust method for generating millimeter waves applicable in 5G access fronthaul is presented. Besides generating of the mm-wave signal in the 60 GHz frequency band the radio over fiber (RoF) system for transmission of orthogonal frequency division multiplexing (OFDM) with 5 GHz bandwidth is presented. For the purpose of wireless transmission for 5G application the required antenna is designed and developed. The total system performance in one small cell was studied and the error vector magnitude (EVM) of the system was evaluated.