Dr. Issa Elfergani
Instituto de Telecomunicações Campus Universitário de Santiago 3810-193 Aveiro Portugal
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Academic Career Length
17Years (2010-Present)
(Calculated once Scilit publication data is synced: current year − year of first publication + 1)
Representative Publications
View All Publications31 January 2019 in IEEE Access
Journal Article
Naser Ojaroudi Parchin
Yasir Al-YasirAAAmmar H. Ali
Ammar H. Ali
Issa ElferganiJNJames M. Noras
James M. Noras
Raed Abd-Alhameed +1
In this paper, we propose an eight-port/four-resonator slot antenna array with a dual-polarized function for multiple-input-multiple-output (MIMO) 5G mobile terminals. The design is composed of four dual-polarized square-ring slot radiators fed by pairs of microstrip-line structures. The radiation elements are designed to operate at 3.6 GHz and are located on the corners of the smartphone PCB. The square-ring slot radiators provide good dual-polarization characteristic with similar performances in terms of fundamental radiation characteristics. In order to improve the isolation and also reduce the mutual coupling characteristic between the adjunct microstrip-line feeding ports of the dual-polarized radiators, a pair of circular-ring/open-ended parasitic structures is embedded across each square-ring slot radiator. The -10-dB impedance bandwidth of each antenna-element is 3.4-3.8 GHz. However, for -6-dB impedance bandwidth, this value is 600 MHz (3.3-3.9 GHz). The proposed MIMO antenna offers good S-parameters, high-gain radiation patterns, and sufficient total efficiencies, even though it is arranged on a high-loss FR-4 dielectric. The SAR function and the radiation characteristics of the proposed design in the vicinity of user-hand/user-head are studied. A prototype of the proposed smartphone antenna is fabricated, and good measurements are provided. The antenna provides good features with a potential application for use in the 5G mobile terminals.
8 August 2019 in IEEE Access
Journal Article
AIAmjad Iqbal
Amjad IqbalABAbdul Basir
Abdul Basir
ASAmor Smida
Amor Smida
NMNazih Khaddaj Mallat
Nazih Khaddaj MallatIssa ElferganiSKSunghwan Kim
Sunghwan Kim +1
A millimeter-wave (mm-Wave) multiple input multiple output (MIMO) antenna operating at 24 GHz (ISM band), suitable for wearable applications, is proposed in this paper. The proposed MIMO antenna consists of two elements, designed with an edge-to-edge distance of 5.14 mm, backed by a $5\times 5$ cell electromagnetic bandgap (EBG) structure. The antenna is fabricated on a flexible Rogers 6002 material ( $\epsilon _{r}=$ 2.94 , tan $\delta =$ 0.0012 , thickness = 0.254 mm ). The proposed antenna retains its performance when bent along the x-axis and y-axis. The performance of the antenna in term of s-parameters and radiation properties is studied in free space as well as on a human phantom. Good impedance matching of the antenna at the resonating frequency (24 GHz) is observed when it is bent and when worn on the body. The introduction of the EBG improves the gain by 1.9 dBi, reduces the backward radiation by 8 dB, reduces the power density on the back towards the body from > 200 W/m 2 to < 10 W/m 2 , and also enhances the 10 dB bandwidth by 100 MHz. The antenna possesses a low envelope correlation coefficient (ECC) of 0.24, high diversity gain (DG) of 9.7 dB, reasonable multiplexing efficiency of −0.684 dB and a good peak gain of 6 dBi at 24 GHz. The proposed antenna is suitable for wearable applications at mm-Wave range due to its simple geometry and good performance in bending and on-body worn scenarios.
16 May 2019 in IEEE Access
Journal Article
George OguntalaRaed Abd-AlhameedSJSteve Jones
Steve JonesYHYim-Fun Hu
Yim-Fun Hu
JNJames M. Noras
James M. Noras
JRJonathan Rodriguez
Jonathan Rodriguez
+2
Human activity recognition from sensor readings has proved to be an effective approach in pervasive computing for smart healthcare. Recent approaches in ambient assisted living (AAL) within the home or community setting offers people the prospect of independent care and improved quality of living. However, most of the available AAL systems are limited by several factors including system complexity and computational cost. In this paper, a simple, novel ambient human activity recognition framework using the multivariate Gaussian is proposed. The classification framework augments prior information from passive RFID tags to obtain more detailed activity profiling. The proposed algorithm based on multivariate Gaussian via maximum likelihood estimation is used to learn the features of the human activity model. Twelve sequential and concurrent experimental evaluations are conducted in a mock apartment environment. The sampled activities are predicted using a new dataset of the same activity and high prediction accuracy established. The proposed framework suits well for the single and multi-dwelling environment and offers pervasive sensing environment for elderly, disabled and carers.
3 May 2021 in IEEE Access
Journal Article
Mohammad Alibakhshikenari
Bal Virdee
Pancham Shukla
Yan Wang
Leyre Azpilicueta
Ernesto Limiti +9
In this paper a metamaterial-inspired T-matching network is directly imbedded inside the feedline of a microstrip antenna to realize optimum power transfer between the front-end of an RF wireless transceiver and the antenna. The proposed T-matching network, which is composed of an arrangement of series capacitor, shunt inductor, series capacitor, exhibits left-handed metamaterial characteristics. The matching network is first theoretically modelled to gain insight of its limitations. It was then implemented directly in the 50- Ω feedline to a standard circular patch antenna, which is an unconventional methodology. The antenna's performance was verified through measurements. With the proposed technique there is 2.7 dBi improvement in the antenna's radiation gain and 12% increase in the efficiency at the center frequency, and this is achieved over a significantly wider frequency range by a factor of approximately twenty. Moreover, there is good correlation between the theoretical model, method of moments simulation, and the measurement results.
Journal Article
MAMohamed Abdul-Al
Mohamed Abdul-AlASAhmed Sayed
Ahmed SayedIssa ElferganiRLRichard Littlehales
Richard LittlehalesNaser Ojaroudi ParchinRaed Abd-Alhameed +14
Employing electromagnetic fields (EMFs) in new wireless communication and sensing technologies has substantially increased the level of human exposure to EMF waves. This paper presents a useful insight into the interaction of electromagnetic fields with biological media that is defined by the heat generation due to induced currents and dielectric loss. The specific absorption rate (SAR) defines the heating amount in a biological medium that is irradiated by an electromagnetic field value. The paper reviews the radio frequency hazards due to the SAR based on various safety standards and organisations, including a detailed investigation of previously published work in terms of modelling and measurements. It also summarises the most common techniques utilised between 1978 and 2021, in terms of the operational frequency spectrum, bandwidth, and SAR values.
27 July 2021 in IEEE Transactions on Green Communications and Networking
Journal Article
Yasir Al-YasirAAAhmed M. Abdulkhaleq
Ahmed M. Abdulkhaleq
Naser Ojaroudi ParchinIssa ElferganiJRJonathan Rodriguez
Jonathan RodriguezRQRami Qahwaji
Rami Qahwaji
+3
The paper presents the general requirements and an exemplary design of the RF front-end system that in today’s handset is a key consumer of power. The design is required to minimize the carbon footprint in mobile handsets devices, whilst facilitating cooperation, and providing the energy-efficient operation of multi-standards for 5G communications. It provides the basis of hardware solutions for RF front-end integration challenges and offers design features covering energy efficiency for power amplifiers (PAs), Internet of Things (IoT) controlled tunable filters and compact highly isolated multiple-input and multiple-output (MIMO) antennas. An optimum design requires synergetic collaboration between academic institutions and industry in order to satisfy the key requirements of sub-6 GHz energy-efficient 5G transceivers, incorporating energy efficiency, good linearity and the potential for low-cost manufacturing. A highly integrated RF transceiver was designed and implemented to transmit and receive a picture using compact MIMO antennas integrated with efficient tunable filters and high linearity PAs. The proposed system has achieved a bit error rate (BER) of less than 10–10 at a data rate of 600 Mb/s with a wireless communication distance of more than 1 meter and power dissipation of 18–20 mW using hybrid beamforming technology and 64-QAM modulation.
About Me
Issa Elfergani obtained his M.Sc. and Ph.D. degrees in electrical and electronic engineering from the University of Bradford, UK, in 2008 and 2013, respectively. After his Ph.D., and since 2013, he has worked as postdoctoral researcher and then as junior investigator at Instituto de Telecomunicações Aveiro, Portugal, within the mobile systems group. In 2014, Issa received the prestigious FCT fellowship for his postdoctoral research. The evaluation of the first triennium of this scholarship was given an excellent rating by the evaluators. In 2019, Issa received a contract as a junior investigator. He has been involved in several R&D Projects, such as Agile RF Transceivers and Front-Ends for Future Smart Multi-Standard Communications Applications (ARTEMOS), where he was the task leader for the "development of tunable filters and tunable resonators" and the technical investigator responsible for designing an RF tunable bandpass filter operating over a wide continuous frequency range from 1800 MHz to 2600 MHz for use in GSM and LTE applications and for Green Terminals for Next Generation Wireless Systems (GREEN-T), where IT was the coordinator. He was also involved in a project for the best energy efficiency solutions for heterogeneous multi-core communicating systems (BENEFIC). All projects have been successfully concluded. He is currently working on Novel 5G Millimetre-Wave Array Antennas for Future Mobile Handset Applications (5GWAR) as the principal investigator.