Beirut Research and Innovation Center

Beirut, Lebanon

Beirut Research and Innovation Center

Beirut, Lebanon
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Takach A.A.,Beirut Research and Innovation Center | Al-Husseini M.,Beirut Research and Innovation Center | El-Hajj A.,American University of Beirut | Nassar E.,Notre Dame University - Louaize
2016 IEEE Middle East Conference on Antennas and Propagation, MECAP 2016 | Year: 2016

An antipodal Vivaldi antenna is designed for use in the ground penetrating radar (GPR) detection of landmines. Two such antennas, one transmitting and one receiving, are connected to an ultra-wideband GPR to record the responses of exact models of certain types of landmines. Later, a periodic structure converter is used to transform the antennas' linear polarization into circular polarization. The responses obtained from the same landmine models upon making the linear to circular polarization transformation show more information, and as a result are better fit for employment with signal processing algorithms aiming at detecting and classifying buried landmines. The results for the antenna design, polarization conversion, and GPR responses with both linear and circular polarization are reported. © 2016 IEEE.


Yaacoub E.,Beirut Arab University | Husseini M.,Beirut Research and Innovation Center | Ghaziri H.,Beirut Research and Innovation Center
2016 IEEE Middle East Conference on Antennas and Propagation, MECAP 2016 | Year: 2016

An overview of the main research topics for massive multiple input multiple output (MIMO) antenna arrays is presented. Massive MIMO is expected to be one of the pillars of fifth generation (5G) and beyond cellular systems. In fact, with millimeter wave (mmWave) communications, a large number of antenna elements can be used to form large arrays of reasonable sizes. This entails significant challenges that need to be overcome in practical implementations. In this paper, we present an overview of important research topics related to massive MIMIO, and discuss their associated challenges. Furthermore, we present several application areas where massive MIMO antenna arrays could lead to significant performance enhancements. © 2016 IEEE.


Safatly L.,American University of Beirut | Bkassiny M.,State University of New York at Oswego | Al-Husseini M.,Beirut Research and Innovation Center | El-Hajj A.,American University of Beirut
International Journal of Antennas and Propagation | Year: 2014

A cognitive transceiver is required to opportunistically use vacant spectrum resources licensed to primary users. Thus, it relies on a complete adaptive behavior composed of: reconfigurable radio frequency (RF) parts, enhanced spectrum sensing algorithms, and sophisticated machine learning techniques. In this paper, we present a review of the recent advances in CR transceivers hardware design and algorithms. For the RF part, three types of antennas are presented: UWB antennas, frequency-reconfigurable/tunable antennas, and UWB antennas with reconfigurable band notches. The main challenges faced by the design of the other RF blocks are also discussed. Sophisticated spectrum sensing algorithms that overcome main sensing challenges such as model uncertainty, hardware impairments, and wideband sensing are highlighted. The cognitive engine features are discussed. Moreover, we study unsupervised classification algorithms and a reinforcement learning (RL) algorithm that has been proposed to perform decision-making in CR networks. © 2014 Lise Safatly et al.


Pan X.,University of New Mexico | Al-Husseini M.,Beirut Research and Innovation Center | Atmatzakis G.,University of New Mexico | Christodoulou C.G.,University of New Mexico
2014 United States National Committee of URSI National Radio Science Meeting, USNC-URSI NRSM 2014 | Year: 2014

In this paper, a split-ring-resonator-loaded sub-wavelength waveguide with H-plane-bend (HPB) radiator structure is proposed. Improved matching is applied to minimize the reflected power at the input. This proposed waveguide is used as part of a high-power narrow-wall slotted waveguide antenna. The waveguide is loaded with an optimized split-ring resonator (SRR) array applying H-plane discontinuity. The S parameters of the SRR-loaded waveguide with HPB-radiator indicates resonance below the cutoff frequency. The transverse dimension of this waveguide is reduced significantly. An improved waveguide to waveguide transition design is proposed to be added at its input to reduce the insertion loss. The HPB-radiator [N.R. Devarapalli, Electromagnetic Compatibility, vol.53, no.2, pp.380-389, May 2011] is added to the output of the waveguide to minimize the reflected power at the input. © 2014 IEEE.


Al-Husseini M.,Beirut Research and Innovation Center | Pan X.,University of New Mexico | Atmatzakis G.,University of New Mexico | Christodoulou C.G.,University of New Mexico
2014 United States National Committee of URSI National Radio Science Meeting, USNC-URSI NRSM 2014 | Year: 2014

In this work, an S-band slotted waveguide antenna (SWA) with optimized corrugations is presented. It is based on 10 identical longitudinal elliptical slots cut in one of the broadwalls of a WR-284 waveguide (a = 2.84″, b = 1.37″). The waveguide is shorted at one end and fed from the other, leading to a resonating SWA. Elliptical slots, which have no sharp corners, are known to be more suitable for high power applications. The SWA is initially designed for operation at 3 GHz, where the guide wavelength "g = 138.5 mm. The slots are spaced at "g=2, center to center. Their length (double the ellipse's major radius) and width (two times the minor radius) are determined, and their displacements from the broadface center-line are optimized to suppress the sidelobes to below -25 dB. The total length of the waveguide is 5"g. © 2014 IEEE.


El Misilmani H.M.,American University of Beirut | Al-Husseini M.,Beirut Research and Innovation Center | Kabalan K.Y.,American University of Beirut
Progress In Electromagnetics Research C | Year: 2015

Slotted waveguide antenna (SWA) arrays offer clear advantages in terms of their design, weight, volume, power handling, directivity, and efficiency. For broadwall SWAs, the slot displacements from the wall centerline determine the antenna’s sidelobe level (SLL). This paper presents a simple inventive procedure for the design of broadwall SWAs with desired SLLs. For a specified number of identical longitudinal slots and given the required SLL and operating frequency, this procedure finds the slots length, width, locations along the length of the waveguide, and displacements from the centerline. Compared to existing methods, this procedure is much simpler as it uses a uniform length for all the slots and employs closed-form equations for the calculation of the displacements. A computer program has been developed to perform the design calculations and generate the needed slots data. Illustrative examples, based on Taylor, Chebyshev and the binomial distributions are given. In these examples, elliptical slots are considered, since their rounded corners are more robust for high power applications. A prototype SWA has been fabricated and tested, and the results are in accordance with the design Objectives © 2015 Electromagnetics Academy. All rights reserved.


El Misilmani H.M.,American University of Beirut | Kabalan K.Y.,American University of Beirut | El-Hajj A.,American University of Beirut | Al-Husseini M.,Beirut Research and Innovation Center
IEEE Antennas and Propagation Society, AP-S International Symposium (Digest) | Year: 2015

This paper presents an inventive and simple procedure for the design of a 2D slotted waveguide antenna (SWA) having a desired sidelobe level (SLL) and a pencil shape pattern. The 2D array is formed by a defined number of 1D broadwall SWAs, which are fed using an extra broadwall SWA. For specified number of identical longitudinal slots in both dimensions, the desired SLL and the required operating frequency, this procedure finds the slots length, width, locations along the length of the waveguide, and offsets from its centerline. This is done for the radiating SWAs as well as the feed SWA. An example SWA with 8×8 elliptical slots is designed using this procedure for an SLL lower than -20 dB, where the design results are also reported in this paper. © 2015 IEEE.


Rishani N.R.,American University of Beirut | El-Hajj A.,American University of Beirut | Kabalan K.Y.,American University of Beirut | Al-Husseini M.,Beirut Research and Innovation Center
Proceedings of the 2014 International Conference on High Performance Computing and Simulation, HPCS 2014 | Year: 2014

In this paper, a circularly polarized antenna operating at 1.575GHz, for GPS applications is designed. The antenna has a square patch, with cross slots to ensure Right Hand Circular Polarization (RHCP) over the operating frequency range. Electronic Band Gap (EBG) structures are incorporated between the patch and the ground plane to reduce the back lobes. The antenna has a gain of 5.37dB. The design was simulated in HFSS and a model was fabricated and tested and highly correlated results are obtained. © 2014 IEEE.


El Misilmani H.M.,American University of Beirut | Al-Husseini M.,Beirut Research and Innovation Center | Kabalan K.Y.,American University of Beirut
International Journal of Antennas and Propagation | Year: 2015

This paper presents a Vlasov antenna with curved cut shape and improved reflector position and geometry suitable for high power microwave applications. The curved shape of the proposed cut totally eliminates the sharp edges and angles present in Vlasov antennas with step and bevel cuts. Furthermore, with the proposed reflector configuration, the wave is radiated in the direction of the axis of the waveguide. A Vlasov antenna, designed for operation at 3 GHz, is used to compare the three cut types. An additional comparison is conducted to validate the concept of the enhanced reflector position, using the bevel-cut antenna and the improved cut. The proposed antenna results in increased antenna gain and in good performance in terms of sidelobe level and half-power beamwidth, with maximum radiation directed toward the axis of the waveguide center. © 2015 H. M. El Misilmani et al.


Baydoun M.,Beirut Research and Innovation Center | Dawi M.,Beirut Research and Innovation Center | Ghaziri H.,Beirut Research and Innovation Center
2016 3rd International Conference on Advances in Computational Tools for Engineering Applications, ACTEA 2016 | Year: 2016

K-Means is one of the major clustering algorithms thanks to its simplicity and performance. Also, clustering is widely used in several applications that involve image processing, machine intelligence and others. This work discusses an enhanced parallel implementation of K-Means clustering using Cilk Plus and OpenMP on the CPU and CUDA on the GPU. The results are presented for different datasets and images of varying data sizes with concentration on relatively large data. Different numbers of features and clusters are also considered. © 2016 IEEE.

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