Magdy F. Iskander

Bio: Magdy F. Iskander is an academic researcher from University of Hawaii at Manoa. The author has contributed to research in topics: Dipole antenna & Antenna measurement. The author has an hindex of 32, co-authored 238 publications receiving 3134 citations. Previous affiliations of Magdy F. Iskander include University of Hawaii.

Ray Tracing for Radio Propagation Modeling: Principles and Applications

Abstract: This paper reviews the basic concepts of rays, ray tracing algorithms, and radio propagation modeling using ray tracing methods We focus on the fundamental concepts and the development of practical ray tracing algorithms The most recent progress and a future perspective of ray tracing are also discussed We envision propagation modeling in the near future as an intelligent, accurate, and real-time system in which ray tracing plays an important role This review is especially useful for experts who are developing new ray tracing algorithms to enhance modeling accuracy and improve computational speed

A Dual-Polarization Slot Antenna Using a Compact CPW Feeding Structure

Abstract: A dual-polarization coplanar waveguide (CPW)-fed slot antenna is proposed in this letter. By exploiting the even and odd modes of a CPW structure, two orthogonal polarizations can be excited in a slot aperture by the same feeding CPW, which results in a compact dual-polarization antenna design with very good isolation between the ports. The -10-dB reflection coefficient bandwidths of two polarizations are 670 MHz (27.9%) for one polarization and 850 MHz (35.4%) for the other, and the isolation between the two ports in the WLAN band is better than -32.6 dB. The radiation pattern and efficiency of the proposed antenna are also measured, and radiation pattern data are compared with simulation results.

A Compact Hepta-Band Loop-Inverted F Reconfigurable Antenna for Mobile Phone

Abstract: A folded loop-inverted F reconfigurable antenna for mobile phone applications is designed and the obtained results are discussed in this communication. It is shown that loop antenna mode and an inverted F antenna (IFA) mode are controlled by only one p-i-n diodes with simple bias circuit. The impedance can be matched by adopting a matching bridge for both the loop and IFA modes. In a compact volume of 60 × 5 × 5 mm3, the proposed antenna operates in hepta-band, including GSM850, GSM900, GPS, DCS, PCS, UMTS and WLAN, with the return loss lower than 6 dB. A prototype of the proposed antenna is fabricated, measured, and obtained results including return loss, efficiency and gain, are presented.

A ray-tracing method based on the triangular grid approach and application to propagation prediction in urban environments

Abstract: This paper presents a fast ray-tracing procedure based on triangular division of the propagation environments. Unlike other accelerating methods that are mostly based on pre-establishment of visibility, this method does not require knowledge of the position information of the base station and/or receiving antennas and is thus more general. Although the triangulation is done in a two-dimensional (2-D) plane, this method is suitable for three-dimensional (3-D) simulations when a proper data structure for buildings is constructed. Validation results show good agreement between calculated and measured data from the European COST 231 project. The improvement in the computational efficiency is clearly demonstrated in examples.

A MNG-TL Loop Antenna Array With Horizontally Polarized Omnidirectional Patterns

Abstract: A horizontally polarized omnidirectional planar loop antenna that employs an artificial mu-negative transmission line (MNG-TL) is proposed. The MNG-TL is designed using periodically loaded parallel-plate lines. The reactive loading is inspired by the zeroth-order resonator (ZOR), which has a propagation constant of zero. Due to the unique property of an infinite wavelength, the MNG-TL loop antenna presented in this paper allows current along the loop to remain in phase so that a horizontal polarized omnidirectional pattern is generated. A series-fed array, which is composed of four MNG-TL loop antennas and operates at 2.4 GHz band, is designed, fabrication, and measured. The MNG-TL loop antenna array offers a horizontally polarized omnidirectional radiation pattern with enhanced gain of 6.5 ~ 7.9 dBi and measured radiation efficiency exceeding 85% for covering bands. The concept extends the degrees of design freedom for horizontally polarized omnidirectional antenna array.

Principles Of Optics Electromagnetic Theory Of Propagation Interference And Diffraction Of Light

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A Tutorial on UAVs for Wireless Networks: Applications, Challenges, and Open Problems

Abstract: The use of flying platforms such as unmanned aerial vehicles (UAVs), popularly known as drones, is rapidly growing. In particular, with their inherent attributes such as mobility, flexibility, and adaptive altitude, UAVs admit several key potential applications in wireless systems. On the one hand, UAVs can be used as aerial base stations to enhance coverage, capacity, reliability, and energy efficiency of wireless networks. On the other hand, UAVs can operate as flying mobile terminals within a cellular network. Such cellular-connected UAVs can enable several applications ranging from real-time video streaming to item delivery. In this paper, a comprehensive tutorial on the potential benefits and applications of UAVs in wireless communications is presented. Moreover, the important challenges and the fundamental tradeoffs in UAV-enabled wireless networks are thoroughly investigated. In particular, the key UAV challenges such as 3D deployment, performance analysis, channel modeling, and energy efficiency are explored along with representative results. Then, open problems and potential research directions pertaining to UAV communications are introduced. Finally, various analytical frameworks and mathematical tools, such as optimization theory, machine learning, stochastic geometry, transport theory, and game theory are described. The use of such tools for addressing unique UAV problems is also presented. In a nutshell, this tutorial provides key guidelines on how to analyze, optimize, and design UAV-based wireless communication systems.

A Tutorial on UAVs for Wireless Networks: Applications, Challenges, and Open Problems

Abstract: The use of flying platforms such as unmanned aerial vehicles (UAVs), popularly known as drones, is rapidly growing. In particular, with their inherent attributes such as mobility, flexibility, and adaptive altitude, UAVs admit several key potential applications in wireless systems. On the one hand, UAVs can be used as aerial base stations to enhance coverage, capacity, reliability, and energy efficiency of wireless networks. On the other hand, UAVs can operate as flying mobile terminals within a cellular network. Such cellular-connected UAVs can enable several applications ranging from real-time video streaming to item delivery. In this paper, a comprehensive tutorial on the potential benefits and applications of UAVs in wireless communications is presented. Moreover, the important challenges and the fundamental tradeoffs in UAV-enabled wireless networks are thoroughly investigated. In particular, the key UAV challenges such as three-dimensional deployment, performance analysis, channel modeling, and energy efficiency are explored along with representative results. Then, open problems and potential research directions pertaining to UAV communications are introduced. Finally, various analytical frameworks and mathematical tools such as optimization theory, machine learning, stochastic geometry, transport theory, and game theory are described. The use of such tools for addressing unique UAV problems is also presented. In a nutshell, this tutorial provides key guidelines on how to analyze, optimize, and design UAV-based wireless communication systems.

A review of antennas and propagation for MIMO wireless communications

Abstract: Multiple-input-multiple-output (MIMO) wireless systems use multiple antenna elements at transmit and receive to offer improved capacity over single antenna topologies in multipath channels In such systems, the antenna properties as well as the multipath channel characteristics play a key role in determining communication performance This paper reviews recent research findings concerning antennas and propagation in MIMO systems Issues considered include channel capacity computation, channel measurement and modeling approaches, and the impact of antenna element properties and array configuration on system performance Throughout the discussion, outstanding research questions in these areas are highlighted