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Your search keyword '"Mabrouk, Ismail Ben"' showing total 40 results
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4. SIW-based frequency-adjustable antenna for IoT-based duplex wireless devices

Author

Iqbal, Amjad, Al-Hasan, Muath, Mabrouk, Ismail Ben, Andreasson, Pererik, Nilsson, Emil, Smida, Amor, Denidni, Tayeb A., Iqbal, Amjad, Al-Hasan, Muath, Mabrouk, Ismail Ben, Andreasson, Pererik, Nilsson, Emil, Smida, Amor, and Denidni, Tayeb A.

Abstract

This paper proposes a compact and frequency-adjustable/reconfigurable dielectric (DR)-loaded eighth-mode substrate integrated waveguide (EMSIW) antenna for duplex wireless communications. The miniaturization of the resonators is realized using a rectangular slot and high isolation is achieved by keeping a reasonable space between them. The proposed design is simulated using a three-dimensional (3D) full-wave simulator, then analysed with a circuit model and finally validated experimentally. Frequency-reconfigurability in the suggested antenna is achieved by placing DRs with different permittivities in the designated holes that are realized in the open-ended portion of each resonator. Consequently, the lower- and high-resonant bands can be reconfigured from 4.70 to 5.23 GHz and from 5.55 to 6.34 GHz, respectively. It is worth mentioning that both resonant band can be independently reconfigured. Moreover, the inter-resonator coupling is always lower than −23.5 dB in the bands of interest. Furthermore, the peak realized gains are always greater than 4.7 dBi in the lower frequency band and 5.5 dBi in the higher one. The suggested antenna has stable radiation properties in both bands in all frequency ranges. Hence, this design is suitable for compact reconfigurable devices due to its compactness, large frequency ranges, stable radiation patterns, and high isolation. © 2023 Elsevier GmbH, Funding: The Deanship of Scientific Research at Majmaah University for supporting this work under Project number R-2023-791.

Published
2024
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6. Simultaneous Transmit and Receive Self-Duplexing Antenna for Head Implants

Author

Amjad, Iqbal, Al-Hasan, Muath, Mabrouk, Ismail Ben, Denidni, Tayeb A., Amjad, Iqbal, Al-Hasan, Muath, Mabrouk, Ismail Ben, and Denidni, Tayeb A.

Abstract

A novel dual-port, dual-band self-duplexing implantable antenna for head implants is presented in this article. It operates at 915 MHz Industrial, Scientific, and Medical (ISM) band (when Port 1 is active) and 1420 MHz Wireless Medical Telemetry Service (WMTS) band (when Port2 is active). The proposed antenna is kept inside a flat device and simulated in a human head model. The miniaturization of the proposed antenna is achieved using a high dielectric substrate, shorted pins, and multiple capacitive slots. Consequently, it occupies a compact volume of 7.13 x 8.9 x 0.13 = 8.24 mm(3). The coupling between both radiators is enhanced by printing it on a thin substrate and placing vias between them. As a result, an isolation level better than 31.4 dB is achieved. It has peak realized gains of -18.94 and -17.06 dBi at 915 and 1420 MHz, respectively. The link budget analysis and specific absorption rate (SAR) are performed, showing promising results. The proposed concept is practically validated by measuring its performance inside the minced pork meat. Furthermore, the simultaneous transmit and receive concept is practically verified with the aid of software-defined radio (SDR). The main advantages of this antenna are its compact size, low coupling level, independently controllable bands, and simultaneous transmission and reception of signals without using a multiplexer circuit. © 2023 IEEE.

Published
2023
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7. Self-Quadruplexing Antenna for Scalp-Implantable Devices

Author

Iqbal, Amjad, Al-Hasan, Muath, Mabrouk, Ismail Ben, and Denidni, Tayeb A.

Abstract

This article presents a compact self-quadruplexing antenna for scalp-implantable devices. The proposed self-quadruplexing antenna operates at 168 MHz [industrial, scientific, and medical (ISM) band], 433 MHz (ISM band), 915 MHz (ISM band), and 1400 MHz [wireless medical telemetry service (WMTS) band] when Ports 1, 2, 3, and 4 are activated, respectively. The proposed antenna is simulated inside a rectangular device in the head of a human phantom. The suggested antenna comprises four individually excited semicircular meandered resonators with a common ground plane. The compactness of the design is achieved using a high dielectric substrate and using semicircular meandered resonators. The meandered resonators enlarge the current path, resulting in significant miniaturization. As a result, the proposed antenna consumes a small volume of $12\,\, \times 14.5 \times 0.13 = 22.62$ mm3. The coupling among all ports is also minimized using an ultrathin substrate. Consequently, the mutual coupling between any two ports is less than −21.8 dB. It provides a peak gain of −36.24, −34.78, −31.39, and −30.10 dBi at 168, 433, 915, and 1400 MHz, respectively. The link budget and specific absorption rate (SAR) analyses are performed to see the possible applications in the head implant, which show promising results. The 10-g SAR values of 0.017, 0.016, 0.014, and 0.013 W/kg are realized at 168, 433, 915, and 1400 MHz, respectively. Based on a link margin (LM) ≥10 dB, the proposed self-quadruplexing antenna can communicate up to 20, 17.5, 12, and 9 m at 168, 433, 915 and 1400 MHz, respectively (at $B_{r} = 120$ Mbps). Furthermore, the simultaneous transmit and receive (STAR) ability of this antenna is validated using software-defined radios (SDRs). To the best of the authors’ knowledge, this is the first-ever self-quadruplexing implantable antenna designed so far.

Published
2024
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11. 2D MXene Ti₃C₂Tₓ Enhanced Plasmonic Absorption in Metasurface for Terahertz Shielding

Author

Ullah, Zaka, Al Hasanl, Muath, Mabrouk, Ismail Ben, Junaid, Muhammad, Sheikh, Fawad, Al Hasan, Muath, and Ben Mabrouk, Ismail

Subjects
Elektrotechnik
Abstract

With the advancement of technology, shielding for terahertz (THz) electronic and communication equipment is increasingly important. The metamaterial absorption technique is mostly used to shield electromagnetic interference (EMI) in THz sensing technologies. The most widely used THz metamaterial absorbers suffer from their narrowband properties and the involvement of complex fabrication techniques. Materials with multifunctional properties, such as adjustable conductivity, broad bandwidth, high flexibility, and robustness, are driving future development to meet THz shielding applications. In this article, a theoretical simulation approach based on finite difference time domain (FDTD) is utilized to study the absorption and shielding characteristics of a two-dimensional (2D) MXene Ti₃C₂Tₓ metasurface absorber in the THz band. The proposed metamaterial structure is made up of a square-shaped array of MXene that is 50 nm thick and is placed on top of a silicon substrate. The bottom surface of the silicon is metalized with gold to reduce the transmission and ultimately enhance the absorption at 1–3 THz. The symmetric adjacent space between the MXene array results in a widening of bandwidth. The proposed metasurface achieves 96% absorption under normal illumination of the incident source and acquires an average of 25 dB shielding at 1 THz bandwidth, with the peak shielding reaching 65 dB. The results show that 2D MXene-based stacked metasurfaces can be proven in the realization of low-cost devices for THz shielding and sensing applications. CA extern

Published
2023

17. EM-driven size reduction and multi-criterial optimization of broadband circularly-polarized antennas using pareto front traversing and design extrapolation

Author

Ullah, Ubaid, Al-Hasan, Muath, Koziel, Slawomir, and Mabrouk, Ismail Ben

Subjects
Multidisciplinary
Abstract

Maintaining small size has become an important consideration in the design of contemporary antenna structures. In the case of broadband circularly polarized (CP) antennas, miniaturization is a challenging process due to the necessity of simultaneous handling of electrical and field properties (reflection, axial ratio, gain), as well as ensuring sufficient frequency range of operation, especially at the lower edge of the antenna bandwidth. An additional difficulty is that—for the sake of reliability—the design process has to be based on full-wave electromagnetic simulation tools. This is a computationally expensive endeavor because rendering the minimum-size design under the assumed constraints concerning the operating frequencies requires rigorous numerical optimization, which entails massive evaluations of the structure at hand. This paper describes an algorithmic framework for efficient identification of broadband CP antenna designs that realize the best possible trade-offs (Pareto set) between the antenna size and its operating bandwidth. The designs are generated sequentially by solving local optimization tasks targeting explicit reduction of the antenna footprint with implicit constraints imposed on the reflection and axial ratio characteristics. The data accumulated during the previous iterations is employed to yield good initial points for further stages by means of inverse surrogates and extrapolation. Low cost of the process is ensured by sparse sensitivity updates within the trust-region gradient-based algorithm being the main optimization engine. The proposed methodology is demonstrated using three examples of wide-slot CP structures with the trade-off designs representing broad ranges of achievable antenna sizes and operating bandwidth. The framework can be used to assess the antenna suitability for particular application areas as well to conclusively compare alternative CP geometries from the point of view of achievable miniaturization rate and capability of fulfilling given performance requirements.

Published
2021

19. UTD-Based Ray-Tracing MIMO Channel Modeling for the Next-Generation Communications Within Underground Tunnels

Author

Ghaddar, Mohamad, Molina-Garcia-Pardo, Jose-Maria, Mabrouk, Ismail Ben, Lienard, Martine, and Degauque, Pierre

Abstract

Limited work has previously been conducted into deterministic modeling of the fifth generation (5G) millimeter (mm)-wave wireless communications within geometrically nonuniform tunnels. This study predicts and analyzes broadband multiple–input multiple–output (MIMO) propagation in underground mine tunnels for 5G communications and beyond. At extremely short wavelengths, each rugged and uneven surface of the tunnel is modeled as a group of diffracting rectangular prism wedges. A deterministic ray-tracing (RT) MIMO model is developed based on the Uniform Theory of Diffraction (UTD). All predicted MIMO subchannels have been successfully fitted with the experimental measurements. MIMO multipath fading of underground tunnels is found to be lognormally distributed and strongly depends on the tunnel’s size and shape.

Published
2023
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31. Series-Slot-Fed Circularly Polarized Multiple-Input–Multiple-Output Antenna Array Enabling Circular Polarization Diversity for 5G 28 GHz Indoor Applications.

Author

Ullah, Ubaid, Al-Hasan, Muath, Koziel, Slawomir, and Mabrouk, Ismail Ben

Subjects
CIRCULAR polarization, COPLANAR waveguides, ANTENNA design, MICROSTRIP transmission lines, 5G networks, SLOT antennas
Abstract

In this article, a four-element circularly polarized series-slot-fed multiple–input-multiple-output (MIMO) antenna array with circular polarization (CP) diversity is presented. The proposed design utilizes a combination of 45° inclined slots and a straight microstrip line feeding technique. The two antennas are designed to operate with the opposite sense of CP. CP is achieved by placing a patch of just about square dimensions on the top of the V-slot with orthogonal but unequal arms. The unequal arm of the slot degenerates the fundamental mode at a slightly different frequency with a 90° phase difference occurring at the center frequency of each arm. Proper positioning of the patch on the top of the slot ensures excitation of CP. For realizing a MIMO antenna with a different sense of polarization, both the slots and the patches are flipped with respect to the feedline. Following optimization at the full-wave level of description, the antenna is prototyped and validated experimentally. The realizable antenna footprint is 20 mm $\times27.7$ mm. The simulated and measured results indicate that the proposed antenna features a wide impedance bandwidth ($\vert \text{S}_{11}\vert < -10$ dB) from 26.9 to 30.7 GHz, 3 dB axial ratio bandwidth from 27.31 to 29.65 GHz and the peak realized gain of 11.86 dBic. Moreover, it exhibits a low level of in-band isolation $\vert \text{S}_{21}\vert > -37$ dB and an almost negligible envelope correlation coefficient (ECC), less than 0.00025. The highly directional beams, high gain, and compact size of the proposed antenna permit implementation of multiple antennas for indoor applications in the 28 GHz band. [ABSTRACT FROM AUTHOR]

Published
2021
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37. Mm-waves propagation measurements in underground mine using directional MIMO antennas.

Author

Ghaddar, Mohamad, Talbi, Larbi, Nedil, Mourad, Mabrouk, Ismail Ben, and Denidni, Tayeb A.

Subjects
ANTENNAS (Electronics), MILLIMETER waves, MIMO systems, LINE-of-sight radio links, THEORY of wave motion
Abstract

This study reveals the interests towards the use of directional (D)-multiple-input and multiple-output (MIMO) setup as a potential solution to overcome the severe propagation loss of inherent line of sight (LOS) mm-waves communications in underground mine. To show the advantages of the proposed D-MIMO, two separate measurement campaigns are assessed in a comparative way; the first uses a single-input single-output (SISO), while the second uses a 2 × 2 D-MIMO system. Furthermore, due to the unavoidable blockage of direct LOS in underground mines, the miner's shadowing effects (NLOS-MSE) are investigated. Thus, using both D-SISO and D-MIMO setup, the channel propagation characteristics are extracted and investigated with and without the presence of a miner completely blocking LOS. Under LOS, results show that, besides offering a reliable mm-waves link budget, D-MIMO restrains the average path loss (PL) by more than 4.7 dB, further suppresses the root mean square delay to 1.85 ns and offers an average capacity of 23.3 bits/s/Hz. As a miner completely blocks LOS, the proposed D-MIMO system has shown a greater signal ability to overcome the effects of a miner's body; NLOS-MSE compensation of about 4.3 dB and a capacity gain of 19.6 bits/s/Hz have been achieved over the conventional SISO system. [ABSTRACT FROM AUTHOR]

Published
2016
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38. Multiple-input multiple-output beam-space for high-speed wireless communication in underground mine.

Author

Ghaddar, Mohamad, Nedil, Mourad, Mabrouk, Ismail Ben, and Talbi, Larbi

Subjects
MIMO systems, WIRELESS communications, MINES & mineral resources, MICROSTRIP transmission lines, PARAMETERIZATION
Abstract

This study presents a new low-cost multiple-input multiple-output (MIMO) beam-pace technique to increase the overall link capacity of wireless MIMO communications systems in scatter-rich underground mines. This technique is based on generating multiple orthogonal beams for data spatial multiplexing using conformal cylindrical-shape patch arrays. Hence, this study is intended to reveal interests towards the use of conformal MIMO systems for underground mine communications. Two separate 4 × 4 MIMO measurement campaigns are performed and then investigated in a comparative way; the first uses conformal microstrip patch arrays (CMPA), while the second uses conventional planar microstrip patch arrays (PMPA). Based on sweeping-frequency technique (2.35-2.55) GHz, the channel performance is characterised in terms of path loss, fading distribution, capacity and RMS time dispersion parameters. Whether under a line of sight (LOS) or a non-LOS (NLOS) condition, the extracted results confirm the performance priority of CMPA for underground mines communications as they further enhance the propagation characteristics and the capacity gain of the channel; under NLOS, a maximal capacity of 12.95 bits/s/Hz is achieved compared to 9.6 bits/s/Hz obtained using PMPA. For LOS and NLOS cases, maximal capacity boosts of up to 0.43 and 3.35 bits/s/Hz are achieved over PMPA, respectively. [ABSTRACT FROM AUTHOR]

Published
2016
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