Ayman Hindi

Bio: Ayman Hindi is an academic researcher from Najran University. The author has contributed to research in topics: Materials science & Surface plasmon resonance. The author has an hindex of 2, co-authored 6 publications receiving 9 citations.

Metamaterial-based wearable flexible elliptical UWB antenna for WBAN and breast imaging applications

Abstract: This paper presents a metamaterial-based flexible wearable ultra-wideband (UWB) antenna for breast imaging and wireless body area network (WBAN) applications. The wearable antenna is required to be a planar and low-profile structure using flexible materials. The proposed antenna comprises two layers of denim (10 × 10 mm2) and felt (10 × 15 mm2). The antenna was integrated with six metamaterial unit cells using a modified grain rice shape within a split ring resonator to enhance the bandwidth, gain, and directivity and reduce the specific absorption rate value to less than 2 W/kg. The proposed antenna operates within a broad bandwidth range (6.5 GHz–35 GHz) with the maximum gain and directivity of 8.85 dBi and 10 dBi, respectively, and a radiation efficiency of more than 70% over its operating frequency band. The results verified good agreement between the simulation and measurement of the proposed technique in detecting an existing tumor with a diameter of 4 mm from any location inside the breast. The results convincingly proved the capability of the proposed wearable UWB antenna system for both WBAN and breast imaging applications.

Compact Elliptical UWB Antenna for Underwater Wireless Communications

Abstract: The increasing needs of free licensed frequency bands like Industrial, Scientific, and Medical (ISM), Wireless Local Area Network (WLAN), and 5G for underwater communications required more bandwidth (BW) with higher data transferring rate. Microwaves produce a higher transferring rate of data, and their associated devices are smaller in comparison with sonar and ultrasonic. Thus, transceivers should have broad BW to cover more of a frequency band, especially from ultra-wideband (UWB) systems, which show potential outcomes. However, previous designs of similar work for underwater communications were very complicated, uneasy to fabricate, and large. Therefore, to overcome these shortcomings, a novel compact elliptical UWB antenna is designed to resonate from 1.3 to 7.2 GHz. It is invented from a polytetrafluoroethylene (PTFE) layer with a dielectric constant of 2.55 mm and a thickness of 0.8 mm. The proposed antenna shows higher gain and radiation efficiency and stability throughout the working band when compared to recent similarly reported designs, even at a smaller size. The characteristics of the functioning antenna are investigated through fluid mediums of fresh-water, seawater, distilled water, and Debye model water. Later, its channel capacity, bit rate error, and data rate are evaluated. The results demonstrated that the antenna offers compact, easier fabrication with better UWB characteristics for underwater 5G communications.

The impact of integration of solar farms on the power losses, voltage profile and short circuit level in the distribution system

Abstract: This paper introduces a study of utilizing solar energy farm that is integrated with the national grid based on intensive data availability of solar energy in Jordan. The study discusses the impact and the ability of integrating solar farms into the national grid of Jordan. The study considerd different cases and, various power system studies for connection points of solar farms to medium voltage networks. Among these studies are short circuit level, voltage profile and power losses. The main objective of the study is to analyze impacts of integration of solar farms on distribution systems of the chosen areas. Photovoltaic (PV) system with varying penetration levels are integrated at different locations (connection points) into the distribution network. Calculations are performed and models are built using actual data obtained from the Jordanian power grid with PV interconnection. The effect of the short circuit level, voltage profile and power losses in the distribution system are also analyzed. Finally, the most suitable method of connecting the solar farm to the national power network is recommended.

Full Ground Ultra-Wideband Wearable Textile Antenna for Breast Cancer and Wireless Body Area Network Applications

Abstract: Wireless body area network (WBAN) applications have broad utility in monitoring patient health and transmitting the data wirelessly. WBAN can greatly benefit from wearable antennas. Wearable antennas provide comfort and continuity of the monitoring of the patient. Therefore, they must be comfortable, flexible, and operate without excessive degradation near the body. Most wearable antennas use a truncated ground, which increases specific absorption rate (SAR) undesirably. A full ground ultra-wideband (UWB) antenna is proposed and utilized here to attain a broad bandwidth while keeping SAR in the acceptable range based on both 1 g and 10 g standards. It is designed on a denim substrate with a dielectric constant of 1.4 and thickness of 0.7 mm alongside the ShieldIt conductive textile. The antenna is fed using a ground coplanar waveguide (GCPW) through a substrate-integrated waveguide (SIW) transition. This transition creates a perfect match while reducing SAR. In addition, the proposed antenna has a bandwidth (BW) of 7-28 GHz, maximum directive gain of 10.5 dBi and maximum radiation efficiency of 96%, with small dimensions of 60 × 50 × 0.7 mm3. The good antenna's performance while it is placed on the breast shows that it is a good candidate for both breast cancer imaging and WBAN.

A Jug-Shaped CPW-Fed Ultra-Wideband Printed Monopole Antenna for Wireless Communications Networks

Abstract: A type of telecommunication technology called an ultra-wideband (UWB) is used to provide a typical solution for short-range wireless communication due to large bandwidth and low power consumption in transmission and reception. Printed monopole antennas are considered as a preferred platform for implementing this technology because of its alluring characteristics such as light weight, low cost, ease of fabrication, integration capability with other systems, etc. Therefore, a compact-sized ultra-wideband (UWB) printed monopole antenna with improved gain and efficiency is presented in this article. Computer simulation technology microwave studio (CSTMWS) software is used to build and analyze the proposed antenna design technique. This broadband printed monopole antenna contains a jug-shaped radiator fed by a coplanar waveguide (CPW) technique. The designed UWB antenna is fabricated on a low-cost FR-4 substrate with relative permittivity of 4.3, loss tangent of 0.025, and a standard height of 1.6 mm, sized at 25 mm × 22 mm × 1.6 mm, suitable for wireless communication system. The designed UWB antenna works with maximum gain (peak gain of 4.1 dB) across the whole UWB spectrum of 3–11 GHz. The results are simulated, measured, and debated in detail. Different parametric studies based on numerical simulations are involved to arrive at the optimal design through monitoring the effects of adding cuts on the performance of the proposed antennas. Therefore, these parametric studies are optimized to achieve maximum antenna bandwidth with relatively best gain. The proposed patch antenna shape is like a jug with a handle that offers greater bandwidth, good gain, higher efficiency, and compact size.

Using Y-source network as a connector between turbine and network in the structure of variable speed wind turbine

Abstract: Environmental factors such as air pollution and increase in global warming by using polluting fuels are the most important reasons of using renewable and clean energy that runs in global community. Wind energy is one of the most suitable and widely used kind of renewable energy which had been in consideration so well. This paper introduces an electric power generation system of wind based on Y-source and improved Y-source inverter to deliver optimal electrical power to the network. This new converter is from impedance source converters family. This presented converter has more degrees of freedom to adjust voltage gain and modulation. Also, by limiting the range of simultaneous control (shooting through) while it maintains the highest power of maximizer, it can operate in higher modulation range. This causes the reduce of stress in switching and thus it will improve the quality of output. Recommended system had been simulated in MATLAB/Simulink and shown results indicate accurate functionality.

Flexible Substrate based Printed Wearable Antennas for Wireless Body Area Networks Medical Applications (Review)

Abstract: The wireless body area networks (WBAN) enable to communicate with the on-body wireless devices and systems. For on-body applications, the key requirement for the antennas is the antennas flexibility to mount the antennas on the body. Wearable antennas are fabricated on a flexible substrate to make these antennas suitable for mounting on the human body. Due to the wearable feature of these antennas, they are used in many on-body applications. The wearable characteristic also makes these antennas suitable for many on-body medical applications. This paper presents the technical review of the WBAN, WBAN frequency bands, wearable antenna fundamentals, flexible substrate characteristics, design and development of wearable antennas for medical applications. The wearable antennas are fabricated using the fabrics. The review of the material properties of various flexible substrates is given in detail. Due to the presence of the air in the gaps of fabrics, the dielectric constants of these materials are very low. Detailed analysis of antenna performance due to flexible substrate material characteristics is also discussed. The developments of wearable antennas for WBAN medical applications are presented. The paper also focuses on the design considerations, fabrication methods, challenges, and proposed solutions for the wearable printed antennas.