Hussain M. Al-Rizzo

Bio: Hussain M. Al-Rizzo is an academic researcher from University of Arkansas at Little Rock. The author has contributed to research in topics: Microstrip antenna & Dipole antenna. The author has an hindex of 22, co-authored 128 publications receiving 1947 citations. Previous affiliations of Hussain M. Al-Rizzo include ASTRON & University of New Brunswick.

Flexible and Compact AMC Based Antenna for Telemedicine Applications

Abstract: We present a flexible, compact antenna system intended for telemedicine applications. The design is based on an M-shaped printed monopole antenna operating in the Industrial, Scientific, and Medical (ISM) 2.45 GHz band integrated with a miniaturized slotted Jerusalem Cross (JC) Artificial Magnetic Conductor (AMC) ground plane. The AMC ground plane is utilized to isolate the user's body from undesired electromagnetic radiation in addition to minimizing the antenna's impedance mismatch caused by the proximity to human tissues. Specific Absorption Rate (SAR) is analyzed using a numerical human body model (HUGO) to assess the feasibility of the proposed design. The antenna expresses 18% impedance bandwidth; moreover, the inclusion of the AMC ground plane increases the front to back ratio by 8 dB, provides 3.7 dB increase in gain, in addition to 64% reduction in SAR. Experimental and numerical results show that the radiation characteristics, impedance matching, and SAR values of the proposed design are significantly improved compared to conventional monopole and dipole antennas. Furthermore, it offers a compact and flexible solution which makes it a good candidate for the wearable telemedicine application.

A Survey on Multipath Routing Protocols for QoS Assurances in Real-Time Wireless Multimedia Sensor Networks

Abstract: The vision of wireless multimedia sensor networks (WMSNs) is to provide real-time multimedia applications using wireless sensors deployed for long-term usage. Quality of service assurances for both best effort data and real-time multimedia applications introduced new challenges in prioritizing multipath routing protocols in WMSNs. Multipath routing approaches with multiple constraints have received considerable research interest. In this paper, a comprehensive survey of both best effort data and real-time multipath routing protocols for WMSNs is presented. Results of a preliminary investigation into design issues affecting the development of strategic multipath routing protocols that support multimedia data in WMSNs are also presented and discussed from the network application perspective.

A Compact Polyimide-Based UWB Antenna for Flexible Electronics

Abstract: In this letter, we present a compact ultrawideband (UWB) antenna printed on a 50.8-μm Kapton polyimide substrate. The antenna is fed by a linearly tapered coplanar waveguide (CPW) that provides smooth transitional impedance for improved matching. The proposed design is tuned to cover the 2.2-14.3-GHz frequency range that encompasses both the 2.45-GHz Industrial, Scientific, Medical (ISM) band and the standard 3.1-10.6-GHz UWB band. Furthermore, the antenna is compared to a conventional CPW-fed antenna to demonstrate the significance of the proposed design. A parametric study is first performed on the feed of the proposed design to achieve the desired impedance matching. Next, a prototype is fabricated; measurement results show good agreement with the simulated model. Moreover, the antenna demonstrates a very low susceptibility to performance degradation due to bending effects in terms of impedance matching and far-field radiation patterns, which makes it suitable for integration within modern flexible electronic devices.

Analysis of a choke ring groundplane for multipath control in Global Positioning System (GPS) applications

Abstract: In this paper a computational scheme is presented for accurately predicting the farfield amplitude and phase characteristics of Global Positioning System (GPS) antennas flush-mounted to a corrugated groundplane. The algorithm developed is particularly well-suited in beamshaping of (GPS) antennas in order to provide a high level of multipath rejection. The usefulness of the analytical model has been verified by the excellent agreement achieved between experimental data and predicted amplitude and phase patterns. >

Compact Polyimide-Based Antennas for Flexible Displays

Abstract: In this paper, we present two compact ultra thin and flexible printed monopole antennas intended for integration with flexible displays, such as flexible organic light-emission displays (FOLEDs) and active matrix electro-phoretic displays (AM-EPDs). The proposed antennas are designed to provide Wireless local area network (WLAN) and Bluetooth connectivity for flexible displays. The first design is a dual band antenna operating at 2.45 GHz and 5.2 GHz while the second is a single band antenna operating at 2.4 GHz. Both antennas were printed on a Kapton polyimide-based substrate with dimensions (35 mmt25 mm) and (26.5 mmt25 mm) for the dual and single band respectively. Antenna properties, such as gain, far-field radiation patterns, scattering parameter S11 are provided. Moreover, the effect of folding/bending was performed experimentally on both designs to study its influence on the antennas performance. The proposed compact, thin and flexible designs along with antennas characteristics are perfectly suitable for integration into flexible displays for WLAN and Bluetooth connectivity.

Light passing through subwavelength apertures

Abstract: This review provides a perspective on the recent developments in the transmission of light through subwavelength apertures in metal films. The main focus is on the phenomenon of extraordinary optical transmission in periodic hole arrays, discovered over a decade ago. It is shown that surface electromagnetic modes play a key role in the emergence of the resonant transmission. These modes are also shown to be at the root of both the enhanced transmission and beaming of light found in single apertures surrounded by periodic corrugations. This review describes both the theoretical and experimental aspects of the subject. For clarity, the physical mechanisms operating in the different structures considered are analyzed within a common theoretical framework. Several applications based on the transmission properties of subwavelength apertures are also addressed.

Introduction to RF Propagation

Abstract: Preface. 1. Introduction. 1.1 Frequency Designations. 1.2 Modes of Propagation. 1.3 Why Model Propagation? 1.4 Model Selection and Application. 1.4.1 Model Sources. 1.5 Summary. 2. Electromagnetics and RF Propagation. 2.1 Introduction. 2.2 The Electric Field. 2.3 The Magnetic Field. 2.4 Electromagnetic Waves. 2.5 Wave Polarization. 2.6 Propagation of Electromagnetic Waves at Material Boundaries. 2.7 Propagation Impairment. 2.8 Ground Effects on Circular Polarization. 2.9 Summary. 3. Antenna Fundamentals. 3.1 Introduction. 3.2 Antenna Parameters. 3.3 Antenna Radiation Regions. 3.4 Some Common Antennas. 3.5 Antenna Polarization. 3.6 Antenna Pointing loss. 3.7 Summary. 4. Communication Systems and the Link Budget. 4.1 Introduction. 4.2 Path Loss. 4.3 Noise. 4.4 Interference. 4.5 Detailed Link Budget. 4.6 Summary. 5. Radar Systems. 5.1 Introduction. 5.2 The Radar Range Equation. 5.3 Radar Measurements. 5.4 Clutter. 5.5 Atmospheric Impairments. 5.6 Summary. 6. Atmospheric Effects. 6.1 Introduction. 6.2 Atmospheric Refraction. 6.3 Atmospheric Attenuation. 6.4 Loss From Moisture and Precipitation. 6.5 Summary. 7. Near-Earth Propagation Models. 7.1 Introduction. 7.2 Foliage Models. 7.3 Terrain Modeling. 7.4 Propagation in Built-Up Areas. 7.5 Summary. 8. Fading and Multipath Characterization. 8.1 Introduction. 8.2 Ground-Bounce Multipath. 8.3 Large-Scale or Log-Normal Fading. 8.4 Small-Scale Fading. 8.5 Summary. 9. Indoor Propagation Modeling. 9.1 Introduction. 9.2 Interference. 9.3 The Indoor Environment. 9.4 Summary. 10. Rain Attenuation of Microwave and Millimeter Wave Signals. 10.1 Introduction. 10.2 Link Budget. 10.3 Rain Fades. 10.4 The Link Distance Chart. 10.5 Availability Curves. 10.6 Other Precipitation. 10.7 Cross-Polarization Effects. 10.8 Summary. 11. Satellite Communications. 11.1 Introduction. 11.2 Satellite Orbits. 11.3 Satellite Operating Frequency. 11.4 Satellite Path Free-Space Loss. 11.5 Atmospheric Attenuation. 11.6 Ionospheric Effects. 11.7 Rain Fades. 11.8 Antenna Considerations. 11.10 Summary. 12. RF Safety. 12.1 Introduction. 12.2 Biological Effects of RF Exposure. 12.3 CC Guidelines. 12.4 Antenna Considerations. 12.5 FCC Computations. 12.6 Station Evaluations. 12.7 Summary. Appendix A: Review of Probability for Propagation Modeling. Index.

Light scattering by particles: Computational methods

Abstract: This book presents the separation-of-variables and T-matrix methods of calculating the scattering of electromagnetic waves by particles. Analytical details and computer programs are provided for determining the scattering and absorption characteristics of the finite-thickness slab, infinite circular cylinder (normal incidence), general axisymmetric particle, and sphere.The computer programs are designed to generate data that is easy to graph and visualize, and test cases in the book illustrate the capabilities of the programs. The connection between the theory and the computer programs is reinforced by references in the computer programs to equations in the text. This cross-referencing will help the reader understand the computer programs, and, if necessary, modify them for other purposes.

Numerical methods in electromagnetic scattering theory

Abstract: An overview is given over some of the most widely used numerical techniques for solving the electromagnetic scattering problem that start from rigorous electromagnetic theory. In particular, the theoretical foundations of the separation of variables method, the finite-difference time-domain method, the finite-element method, the method of lines, the point matching method, the method of moments, the discrete dipole approximation, and the null-field method (or extended boundary condition method) are reviewed, and the advantages and disadvantages of the different methods are discussed. Aspects concerning the T matrix formulation and the surface Green's function formulation of the electromagnetic scattering problem are addressed.

A Survey on the Internet of Things (IoT) Forensics: Challenges, Approaches, and Open Issues

Abstract: Today is the era of the Internet of Things (IoT). The recent advances in hardware and information technology have accelerated the deployment of billions of interconnected, smart and adaptive devices in critical infrastructures like health, transportation, environmental control, and home automation. Transferring data over a network without requiring any kind of human-to-computer or human-to-human interaction, brings reliability and convenience to consumers, but also opens a new world of opportunity for intruders, and introduces a whole set of unique and complicated questions to the field of Digital Forensics. Although IoT data could be a rich source of evidence, forensics professionals cope with diverse problems, starting from the huge variety of IoT devices and non-standard formats, to the multi-tenant cloud infrastructure and the resulting multi-jurisdictional litigations. A further challenge is the end-to-end encryption which represents a trade-off between users’ right to privacy and the success of the forensics investigation. Due to its volatile nature, digital evidence has to be acquired and analyzed using validated tools and techniques that ensure the maintenance of the Chain of Custody. Therefore, the purpose of this paper is to identify and discuss the main issues involved in the complex process of IoT-based investigations, particularly all legal, privacy and cloud security challenges. Furthermore, this work provides an overview of the past and current theoretical models in the digital forensics science. Special attention is paid to frameworks that aim to extract data in a privacy-preserving manner or secure the evidence integrity using decentralized blockchain-based solutions. In addition, the present paper addresses the ongoing Forensics-as-a-Service (FaaS) paradigm, as well as some promising cross-cutting data reduction and forensics intelligence techniques. Finally, several other research trends and open issues are presented, with emphasis on the need for proactive Forensics Readiness strategies and generally agreed-upon standards.