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Publisher: Elsevier   (Total: 3183 journals)

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Showing 1 - 200 of 3183 Journals sorted alphabetically
Academic Pediatrics     Hybrid Journal   (Followers: 38, SJR: 1.655, CiteScore: 2)
Academic Radiology     Hybrid Journal   (Followers: 26, SJR: 1.015, CiteScore: 2)
Accident Analysis & Prevention     Partially Free   (Followers: 102, SJR: 1.462, CiteScore: 3)
Accounting Forum     Hybrid Journal   (Followers: 28, SJR: 0.932, CiteScore: 2)
Accounting, Organizations and Society     Hybrid Journal   (Followers: 40, SJR: 1.771, CiteScore: 3)
Achievements in the Life Sciences     Open Access   (Followers: 7)
Acta Anaesthesiologica Taiwanica     Open Access   (Followers: 6)
Acta Astronautica     Hybrid Journal   (Followers: 436, SJR: 0.758, CiteScore: 2)
Acta Automatica Sinica     Full-text available via subscription   (Followers: 2)
Acta Biomaterialia     Hybrid Journal   (Followers: 28, SJR: 1.967, CiteScore: 7)
Acta Colombiana de Cuidado Intensivo     Full-text available via subscription   (Followers: 3)
Acta de Investigación Psicológica     Open Access   (Followers: 3)
Acta Ecologica Sinica     Open Access   (Followers: 11, SJR: 0.18, CiteScore: 1)
Acta Histochemica     Hybrid Journal   (Followers: 6, SJR: 0.661, CiteScore: 2)
Acta Materialia     Hybrid Journal   (Followers: 311, SJR: 3.263, CiteScore: 6)
Acta Mathematica Scientia     Full-text available via subscription   (Followers: 5, SJR: 0.504, CiteScore: 1)
Acta Mechanica Solida Sinica     Full-text available via subscription   (Followers: 9, SJR: 0.542, CiteScore: 1)
Acta Oecologica     Hybrid Journal   (Followers: 12, SJR: 0.834, CiteScore: 2)
Acta Otorrinolaringologica (English Edition)     Full-text available via subscription  
Acta Otorrinolaringológica Española     Full-text available via subscription   (Followers: 2, SJR: 0.307, CiteScore: 0)
Acta Pharmaceutica Sinica B     Open Access   (Followers: 1, SJR: 1.793, CiteScore: 6)
Acta Poética     Open Access   (Followers: 4, SJR: 0.101, CiteScore: 0)
Acta Psychologica     Hybrid Journal   (Followers: 26, SJR: 1.331, CiteScore: 2)
Acta Sociológica     Open Access   (Followers: 1)
Acta Tropica     Hybrid Journal   (Followers: 6, SJR: 1.052, CiteScore: 2)
Acta Urológica Portuguesa     Open Access  
Actas Dermo-Sifiliograficas     Full-text available via subscription   (Followers: 3, SJR: 0.374, CiteScore: 1)
Actas Dermo-Sifiliográficas (English Edition)     Full-text available via subscription   (Followers: 2)
Actas Urológicas Españolas     Full-text available via subscription   (Followers: 3, SJR: 0.344, CiteScore: 1)
Actas Urológicas Españolas (English Edition)     Full-text available via subscription   (Followers: 1)
Actualites Pharmaceutiques     Full-text available via subscription   (Followers: 7, SJR: 0.19, CiteScore: 0)
Actualites Pharmaceutiques Hospitalieres     Full-text available via subscription   (Followers: 3)
Acupuncture and Related Therapies     Hybrid Journal   (Followers: 8)
Acute Pain     Full-text available via subscription   (Followers: 15, SJR: 2.671, CiteScore: 5)
Ad Hoc Networks     Hybrid Journal   (Followers: 11, SJR: 0.53, CiteScore: 4)
Addictive Behaviors     Hybrid Journal   (Followers: 18, SJR: 1.29, CiteScore: 3)
Addictive Behaviors Reports     Open Access   (Followers: 9, SJR: 0.755, CiteScore: 2)
Additive Manufacturing     Hybrid Journal   (Followers: 11, SJR: 2.611, CiteScore: 8)
Additives for Polymers     Full-text available via subscription   (Followers: 23)
Advanced Drug Delivery Reviews     Hybrid Journal   (Followers: 184, SJR: 4.09, CiteScore: 13)
Advanced Engineering Informatics     Hybrid Journal   (Followers: 12, SJR: 1.167, CiteScore: 4)
Advanced Powder Technology     Hybrid Journal   (Followers: 17, SJR: 0.694, CiteScore: 3)
Advances in Accounting     Hybrid Journal   (Followers: 9, SJR: 0.277, CiteScore: 1)
Advances in Agronomy     Full-text available via subscription   (Followers: 17, SJR: 2.384, CiteScore: 5)
Advances in Anesthesia     Full-text available via subscription   (Followers: 29, SJR: 0.126, CiteScore: 0)
Advances in Antiviral Drug Design     Full-text available via subscription   (Followers: 2)
Advances in Applied Mathematics     Full-text available via subscription   (Followers: 12, SJR: 0.992, CiteScore: 1)
Advances in Applied Mechanics     Full-text available via subscription   (Followers: 12, SJR: 1.551, CiteScore: 4)
Advances in Applied Microbiology     Full-text available via subscription   (Followers: 24, SJR: 2.089, CiteScore: 5)
Advances In Atomic, Molecular, and Optical Physics     Full-text available via subscription   (Followers: 15, SJR: 0.572, CiteScore: 2)
Advances in Biological Regulation     Hybrid Journal   (Followers: 4, SJR: 2.61, CiteScore: 7)
Advances in Botanical Research     Full-text available via subscription   (Followers: 2, SJR: 0.686, CiteScore: 2)
Advances in Cancer Research     Full-text available via subscription   (Followers: 34, SJR: 3.043, CiteScore: 6)
Advances in Carbohydrate Chemistry and Biochemistry     Full-text available via subscription   (Followers: 9, SJR: 1.453, CiteScore: 2)
Advances in Catalysis     Full-text available via subscription   (Followers: 5, SJR: 1.992, CiteScore: 5)
Advances in Cell Aging and Gerontology     Full-text available via subscription   (Followers: 5)
Advances in Cellular and Molecular Biology of Membranes and Organelles     Full-text available via subscription   (Followers: 14)
Advances in Chemical Engineering     Full-text available via subscription   (Followers: 29, SJR: 0.156, CiteScore: 1)
Advances in Child Development and Behavior     Full-text available via subscription   (Followers: 11, SJR: 0.713, CiteScore: 1)
Advances in Chronic Kidney Disease     Full-text available via subscription   (Followers: 10, SJR: 1.316, CiteScore: 2)
Advances in Clinical Chemistry     Full-text available via subscription   (Followers: 26, SJR: 1.562, CiteScore: 3)
Advances in Colloid and Interface Science     Full-text available via subscription   (Followers: 20, SJR: 1.977, CiteScore: 8)
Advances in Computers     Full-text available via subscription   (Followers: 14, SJR: 0.205, CiteScore: 1)
Advances in Dermatology     Full-text available via subscription   (Followers: 15)
Advances in Developmental Biology     Full-text available via subscription   (Followers: 13)
Advances in Digestive Medicine     Open Access   (Followers: 12)
Advances in DNA Sequence-Specific Agents     Full-text available via subscription   (Followers: 7)
Advances in Drug Research     Full-text available via subscription   (Followers: 26)
Advances in Ecological Research     Full-text available via subscription   (Followers: 43, SJR: 2.524, CiteScore: 4)
Advances in Engineering Software     Hybrid Journal   (Followers: 29, SJR: 1.159, CiteScore: 4)
Advances in Experimental Biology     Full-text available via subscription   (Followers: 8)
Advances in Experimental Social Psychology     Full-text available via subscription   (Followers: 51, SJR: 5.39, CiteScore: 8)
Advances in Exploration Geophysics     Full-text available via subscription   (Followers: 1)
Advances in Fluorine Science     Full-text available via subscription   (Followers: 9)
Advances in Food and Nutrition Research     Full-text available via subscription   (Followers: 66, SJR: 0.591, CiteScore: 2)
Advances in Fuel Cells     Full-text available via subscription   (Followers: 17)
Advances in Genetics     Full-text available via subscription   (Followers: 21, SJR: 1.354, CiteScore: 4)
Advances in Genome Biology     Full-text available via subscription   (Followers: 10, SJR: 12.74, CiteScore: 13)
Advances in Geophysics     Full-text available via subscription   (Followers: 7, SJR: 1.193, CiteScore: 3)
Advances in Heat Transfer     Full-text available via subscription   (Followers: 26, SJR: 0.368, CiteScore: 1)
Advances in Heterocyclic Chemistry     Full-text available via subscription   (Followers: 11, SJR: 0.749, CiteScore: 3)
Advances in Human Factors/Ergonomics     Full-text available via subscription   (Followers: 25)
Advances in Imaging and Electron Physics     Full-text available via subscription   (Followers: 3, SJR: 0.193, CiteScore: 0)
Advances in Immunology     Full-text available via subscription   (Followers: 37, SJR: 4.433, CiteScore: 6)
Advances in Inorganic Chemistry     Full-text available via subscription   (Followers: 10, SJR: 1.163, CiteScore: 2)
Advances in Insect Physiology     Full-text available via subscription   (Followers: 2, SJR: 1.938, CiteScore: 3)
Advances in Integrative Medicine     Hybrid Journal   (Followers: 6, SJR: 0.176, CiteScore: 0)
Advances in Intl. Accounting     Full-text available via subscription   (Followers: 3)
Advances in Life Course Research     Hybrid Journal   (Followers: 9, SJR: 0.682, CiteScore: 2)
Advances in Lipobiology     Full-text available via subscription   (Followers: 1)
Advances in Magnetic and Optical Resonance     Full-text available via subscription   (Followers: 8)
Advances in Marine Biology     Full-text available via subscription   (Followers: 21, SJR: 0.88, CiteScore: 2)
Advances in Mathematics     Full-text available via subscription   (Followers: 14, SJR: 3.027, CiteScore: 2)
Advances in Medical Sciences     Hybrid Journal   (Followers: 8, SJR: 0.694, CiteScore: 2)
Advances in Medicinal Chemistry     Full-text available via subscription   (Followers: 6)
Advances in Microbial Physiology     Full-text available via subscription   (Followers: 5, SJR: 1.158, CiteScore: 3)
Advances in Molecular and Cell Biology     Full-text available via subscription   (Followers: 24)
Advances in Molecular and Cellular Endocrinology     Full-text available via subscription   (Followers: 8)
Advances in Molecular Toxicology     Full-text available via subscription   (Followers: 7, SJR: 0.182, CiteScore: 0)
Advances in Nanoporous Materials     Full-text available via subscription   (Followers: 5)
Advances in Oncobiology     Full-text available via subscription   (Followers: 2)
Advances in Organ Biology     Full-text available via subscription   (Followers: 2)
Advances in Organometallic Chemistry     Full-text available via subscription   (Followers: 18, SJR: 1.875, CiteScore: 4)
Advances in Parallel Computing     Full-text available via subscription   (Followers: 7, SJR: 0.174, CiteScore: 0)
Advances in Parasitology     Full-text available via subscription   (Followers: 5, SJR: 1.579, CiteScore: 4)
Advances in Pediatrics     Full-text available via subscription   (Followers: 27, SJR: 0.461, CiteScore: 1)
Advances in Pharmaceutical Sciences     Full-text available via subscription   (Followers: 19)
Advances in Pharmacology     Full-text available via subscription   (Followers: 17, SJR: 1.536, CiteScore: 3)
Advances in Physical Organic Chemistry     Full-text available via subscription   (Followers: 9, SJR: 0.574, CiteScore: 1)
Advances in Phytomedicine     Full-text available via subscription  
Advances in Planar Lipid Bilayers and Liposomes     Full-text available via subscription   (Followers: 3, SJR: 0.109, CiteScore: 1)
Advances in Plant Biochemistry and Molecular Biology     Full-text available via subscription   (Followers: 10)
Advances in Plant Pathology     Full-text available via subscription   (Followers: 6)
Advances in Porous Media     Full-text available via subscription   (Followers: 5)
Advances in Protein Chemistry     Full-text available via subscription   (Followers: 19)
Advances in Protein Chemistry and Structural Biology     Full-text available via subscription   (Followers: 20, SJR: 0.791, CiteScore: 2)
Advances in Psychology     Full-text available via subscription   (Followers: 67)
Advances in Quantum Chemistry     Full-text available via subscription   (Followers: 6, SJR: 0.371, CiteScore: 1)
Advances in Radiation Oncology     Open Access   (Followers: 1, SJR: 0.263, CiteScore: 1)
Advances in Small Animal Medicine and Surgery     Hybrid Journal   (Followers: 3, SJR: 0.101, CiteScore: 0)
Advances in Space Biology and Medicine     Full-text available via subscription   (Followers: 6)
Advances in Space Research     Full-text available via subscription   (Followers: 421, SJR: 0.569, CiteScore: 2)
Advances in Structural Biology     Full-text available via subscription   (Followers: 5)
Advances in Surgery     Full-text available via subscription   (Followers: 13, SJR: 0.555, CiteScore: 2)
Advances in the Study of Behavior     Full-text available via subscription   (Followers: 37, SJR: 2.208, CiteScore: 4)
Advances in Veterinary Medicine     Full-text available via subscription   (Followers: 20)
Advances in Veterinary Science and Comparative Medicine     Full-text available via subscription   (Followers: 15)
Advances in Virus Research     Full-text available via subscription   (Followers: 6, SJR: 2.262, CiteScore: 5)
Advances in Water Resources     Hybrid Journal   (Followers: 53, SJR: 1.551, CiteScore: 3)
Aeolian Research     Hybrid Journal   (Followers: 6, SJR: 1.117, CiteScore: 3)
Aerospace Science and Technology     Hybrid Journal   (Followers: 383, SJR: 0.796, CiteScore: 3)
AEU - Intl. J. of Electronics and Communications     Hybrid Journal   (Followers: 8, SJR: 0.42, CiteScore: 2)
African J. of Emergency Medicine     Open Access   (Followers: 6, SJR: 0.296, CiteScore: 0)
Ageing Research Reviews     Hybrid Journal   (Followers: 12, SJR: 3.671, CiteScore: 9)
Aggression and Violent Behavior     Hybrid Journal   (Followers: 475, SJR: 1.238, CiteScore: 3)
Agri Gene     Hybrid Journal   (Followers: 1, SJR: 0.13, CiteScore: 0)
Agricultural and Forest Meteorology     Hybrid Journal   (Followers: 18, SJR: 1.818, CiteScore: 5)
Agricultural Systems     Hybrid Journal   (Followers: 31, SJR: 1.156, CiteScore: 4)
Agricultural Water Management     Hybrid Journal   (Followers: 44, SJR: 1.272, CiteScore: 3)
Agriculture and Agricultural Science Procedia     Open Access   (Followers: 4)
Agriculture and Natural Resources     Open Access   (Followers: 3)
Agriculture, Ecosystems & Environment     Hybrid Journal   (Followers: 58, SJR: 1.747, CiteScore: 4)
Ain Shams Engineering J.     Open Access   (Followers: 5, SJR: 0.589, CiteScore: 3)
Air Medical J.     Hybrid Journal   (Followers: 8, SJR: 0.26, CiteScore: 0)
AKCE Intl. J. of Graphs and Combinatorics     Open Access   (SJR: 0.19, CiteScore: 0)
Alcohol     Hybrid Journal   (Followers: 12, SJR: 1.153, CiteScore: 3)
Alcoholism and Drug Addiction     Open Access   (Followers: 12)
Alergologia Polska : Polish J. of Allergology     Full-text available via subscription   (Followers: 1)
Alexandria Engineering J.     Open Access   (Followers: 2, SJR: 0.604, CiteScore: 3)
Alexandria J. of Medicine     Open Access   (Followers: 1, SJR: 0.191, CiteScore: 1)
Algal Research     Partially Free   (Followers: 11, SJR: 1.142, CiteScore: 4)
Alkaloids: Chemical and Biological Perspectives     Full-text available via subscription   (Followers: 2)
Allergologia et Immunopathologia     Full-text available via subscription   (Followers: 1, SJR: 0.504, CiteScore: 1)
Allergology Intl.     Open Access   (Followers: 5, SJR: 1.148, CiteScore: 2)
Alpha Omegan     Full-text available via subscription   (SJR: 3.521, CiteScore: 6)
ALTER - European J. of Disability Research / Revue Européenne de Recherche sur le Handicap     Full-text available via subscription   (Followers: 10, SJR: 0.201, CiteScore: 1)
Alzheimer's & Dementia     Hybrid Journal   (Followers: 53, SJR: 4.66, CiteScore: 10)
Alzheimer's & Dementia: Diagnosis, Assessment & Disease Monitoring     Open Access   (Followers: 6, SJR: 1.796, CiteScore: 4)
Alzheimer's & Dementia: Translational Research & Clinical Interventions     Open Access   (Followers: 6, SJR: 1.108, CiteScore: 3)
Ambulatory Pediatrics     Hybrid Journal   (Followers: 5)
American Heart J.     Hybrid Journal   (Followers: 58, SJR: 3.267, CiteScore: 4)
American J. of Cardiology     Hybrid Journal   (Followers: 63, SJR: 1.93, CiteScore: 3)
American J. of Emergency Medicine     Hybrid Journal   (Followers: 46, SJR: 0.604, CiteScore: 1)
American J. of Geriatric Pharmacotherapy     Full-text available via subscription   (Followers: 12)
American J. of Geriatric Psychiatry     Hybrid Journal   (Followers: 14, SJR: 1.524, CiteScore: 3)
American J. of Human Genetics     Hybrid Journal   (Followers: 37, SJR: 7.45, CiteScore: 8)
American J. of Infection Control     Hybrid Journal   (Followers: 29, SJR: 1.062, CiteScore: 2)
American J. of Kidney Diseases     Hybrid Journal   (Followers: 36, SJR: 2.973, CiteScore: 4)
American J. of Medicine     Hybrid Journal   (Followers: 50)
American J. of Medicine Supplements     Full-text available via subscription   (Followers: 3, SJR: 1.967, CiteScore: 2)
American J. of Obstetrics and Gynecology     Hybrid Journal   (Followers: 254, SJR: 2.7, CiteScore: 4)
American J. of Ophthalmology     Hybrid Journal   (Followers: 66, SJR: 3.184, CiteScore: 4)
American J. of Ophthalmology Case Reports     Open Access   (Followers: 5, SJR: 0.265, CiteScore: 0)
American J. of Orthodontics and Dentofacial Orthopedics     Full-text available via subscription   (Followers: 6, SJR: 1.289, CiteScore: 1)
American J. of Otolaryngology     Hybrid Journal   (Followers: 25, SJR: 0.59, CiteScore: 1)
American J. of Pathology     Hybrid Journal   (Followers: 33, SJR: 2.139, CiteScore: 4)
American J. of Preventive Medicine     Hybrid Journal   (Followers: 28, SJR: 2.164, CiteScore: 4)
American J. of Surgery     Hybrid Journal   (Followers: 39, SJR: 1.141, CiteScore: 2)
American J. of the Medical Sciences     Hybrid Journal   (Followers: 12, SJR: 0.767, CiteScore: 1)
Ampersand : An Intl. J. of General and Applied Linguistics     Open Access   (Followers: 7)
Anaerobe     Hybrid Journal   (Followers: 4, SJR: 1.144, CiteScore: 3)
Anaesthesia & Intensive Care Medicine     Full-text available via subscription   (Followers: 66, SJR: 0.138, CiteScore: 0)
Anaesthesia Critical Care & Pain Medicine     Full-text available via subscription   (Followers: 24, SJR: 0.411, CiteScore: 1)
Anales de Cirugia Vascular     Full-text available via subscription   (Followers: 1)
Anales de Pediatría     Full-text available via subscription   (Followers: 3, SJR: 0.277, CiteScore: 0)
Anales de Pediatría (English Edition)     Full-text available via subscription  
Anales de Pediatría Continuada     Full-text available via subscription  
Analytic Methods in Accident Research     Hybrid Journal   (Followers: 5, SJR: 4.849, CiteScore: 10)
Analytica Chimica Acta     Hybrid Journal   (Followers: 44, SJR: 1.512, CiteScore: 5)
Analytica Chimica Acta : X     Open Access  
Analytical Biochemistry     Hybrid Journal   (Followers: 210, SJR: 0.633, CiteScore: 2)
Analytical Chemistry Research     Open Access   (Followers: 13, SJR: 0.411, CiteScore: 2)
Analytical Spectroscopy Library     Full-text available via subscription   (Followers: 14)
Anesthésie & Réanimation     Full-text available via subscription   (Followers: 2)
Anesthesiology Clinics     Full-text available via subscription   (Followers: 25, SJR: 0.683, CiteScore: 2)
Angiología     Full-text available via subscription   (SJR: 0.121, CiteScore: 0)
Angiologia e Cirurgia Vascular     Open Access   (Followers: 1, SJR: 0.111, CiteScore: 0)
Animal Behaviour     Hybrid Journal   (Followers: 223, SJR: 1.58, CiteScore: 3)
Animal Feed Science and Technology     Hybrid Journal   (Followers: 6, SJR: 0.937, CiteScore: 2)
Animal Reproduction Science     Hybrid Journal   (Followers: 7, SJR: 0.704, CiteScore: 2)

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Similar Journals
Journal Cover
AEU - International Journal of Electronics and Communications
Journal Prestige (SJR): 0.42
Citation Impact (citeScore): 2
Number of Followers: 8  
 
  Hybrid Journal Hybrid journal (It can contain Open Access articles)
ISSN (Print) 1434-8411
Published by Elsevier Homepage  [3183 journals]
  • Multiplierless Chaotic Pseudo Random Number Generators
    • Abstract: Publication date: Available online 17 October 2019Source: AEU - International Journal of Electronics and CommunicationsAuthor(s): Ahmed A. Rezk, Ahmed H. Madian, Ahmed G. Radwan, Ahmed M. Soliman This paper presents a multiplierless based FPGA implementation for six different chaotic Pseudo Random Number Generators (PRNGs) that are based on: Chua, modified Lorenz, modified Rössler, Frequency Dependent Negative Resistor (FDNR) oscillator, and other two systems that are modelled using the simple jerk equation. These chosen systems can be employed in high speed applications because they don’t utilize any hardware multiplier. The proposed PRNGs have been implemented using VHDL, synthesized on Xilinx, using the FPGA: XC5VLX50T, and tested using the NIST statistical suite. Furthermore, a comparison has been established between the performance of all the PRNGs, regarding the implementation area, speed, and the statistical randomness quality. It has been found that the modified Lorenz PRNG has the best randomness quality and the best hardware performance as it can pass all the NIST tests while operating at 298.597 MHz and utilizing only 0.23% and 0.62% from the FPGA’s slice registers and Look-Up-Tables (LUTs) respectively.
       
  • Design of a Tapered CPW-fed Wideband Antenna and its Application to
           Multi-Channel Transmission Using a Hybrid Wireless Communication System
    • Abstract: Publication date: Available online 16 October 2019Source: AEU - International Journal of Electronics and CommunicationsAuthor(s): J.H. Abril-García, R.E. Tapia-Rodríguez, A. García-Juárez, J.R. Noriega, L.A. García-Delgado, A.L. Leal-Cruz, A.G. Correa-Mena, I.E. Zaldívar-Huerta, R. Gómez-Colín A tapered Coplanar Waveguide (CPW)-fed wideband antenna with a nearly omnidirectional radiation pattern in the H-plane and a stable dipole-like radiation pattern for the E-plane is presented. The proposed antenna operates in two wide bands centered at 3.3 and 5 GHz. Furthermore, the antenna structure consists of a tapered feed line, which provides an impedance transformation from the quarter-wave monopole impedance to the 50 Ω input characteristic impedance. Also, two trapezoidal ground planes are added between the monopole and the CPW to achieve impedance matching. Variations in the antenna dimensions are included to monitor the bandwidth and to evaluate the efficiency of impedance matching. Moreover, in order to evaluate the performance of the proposed antenna, a hybrid wireless communication system is used to simultaneously transmit two analog TV signals. These TV signals modulate two microwave subcarriers located at 3.3 and 5 GHz. The resulting multiplexed signal is propagated between two antennas that are separated by a distance of 1m. The modulated subcarriers are transmitted over an optical link of 30 km by using an optical communication system based on external modulation. The signal at the end of the optical link is successfully recovered by using a conventional demodulation scheme.
       
  • Outage Probability of NOMA System with Wireless Power Transfer at Source
           and Full-Duplex Relay
    • Abstract: Publication date: Available online 16 October 2019Source: AEU - International Journal of Electronics and CommunicationsAuthor(s): Ba Cao Nguyen, Tran Manh Hoang, Phuong T. Tran, Tan N. Nguyen In this paper, we analyze the performance of a novel communication scheme that combines three new techniques, namely energy harvesting (EH), full-duplex (FD) relay and cooperative non-orthogonal multiple access (NOMA). In this scheme, both the source and the relay harvest energy from the power beacon (PB) at the first phase of the transmission block and then use the harvested energy to transmit messages during the remaining phase. In this proposed EH-FD-NOMA system, the FD relay employs the amplify-and-forward scheme. We consider two destinations, one of them is far from the FD relay and the other is near the FD relay. Based on the mathematical calculation, we derive the closed-form expressions for the outage probability (OP) of the two users of interest. The numerical results show that the performance at two destinations can be maintained at the same level with proper power allocation. Furthermore, for each value of the PB transmit power, there exists an optimal value for the EH time duration to improve the performance of both users. In addition, the impact of the residual self-interference (RSI) due to imperfect self-interference cancellation (SIC) at the FD relay is also considered. Finally, numerical results are demonstrated through Monte-Carlo simulations.
       
  • Band-pass filters based on periodic structures in SIW technology
    • Abstract: Publication date: Available online 15 October 2019Source: AEU - International Journal of Electronics and CommunicationsAuthor(s): J. Martínez, Á. Coves, E. Bronchalo, Á.A. San Blas, M. Bozzi In this work, the study of two different topologies of S-band band-pass filters based on periodic structures in substrate integrated waveguide (SIW) technology is theoretical and experimentally addressed. The first topology consists of periodic rectangular perforations of the SIW substrate. In this filter topology, the lower cutoff frequency is determined by the cutoff frequency of the first Floquet mode of the periodic structure, while the upper cutoff frequency and the rejection band are conditioned by its first band-gap. The second topology consists of a periodic array of square complementary split-ring resonators (CSRRs) etched on the waveguide surface. In this case, the use of subwavelength resonators with evanescent-wave transmission leads to a much smaller filter, given that the pass-band is below the cutoff frequency of the waveguide. The effect of the different dimensions of the unit cell in the filters characteristics (lower cutoff frequency, pass-band, and rejection-band associated to the first band-gap of the periodic structure) is analyzed through the dispersion diagram of the periodic cell. Finally, two band-pass filters based on each topology have been designed and built, showing in both cases good matching and low insertion loss in the pass-band, and a deep rejection band.
       
  • Design and Packaging of Multi-Polarized Triple-Band Antenna for Automotive
           Applications
    • Abstract: Publication date: Available online 15 October 2019Source: AEU - International Journal of Electronics and CommunicationsAuthor(s): Niraj Agrawal, Anil Kumar Gautam, Karumudi Rambabu This paper proposes a novel design and packaging of single-fed asymmetric slot loaded triple band antenna with left-hand circular polarization (LHCP) at SDARS, right-hand circular polarization (RHCP) at GPS L5 band, and linear polarization at GSM-1900 that be able to deploy at hand-held device for geo-informatics and surveying applications. Triple-band operation and multi-polarization are obtained by inculcation of asymmetric slots in the patch. The all-inclusive dimensions of the designed antenna is only 51×52×1.6 mm3, rendering it attractive for the user market. A archetype of the proposed model is fabricated, and its performance is substantiate through measurement. Measured results shows that the antenna exhibits multiple independent polarized radiations, i.e. RHCP and LHCP radiation at two distinct bands namely Global Positioning System (GPS) L5 (1.17645 GHz) and Satellite Digital Audio Radio Service (SDARS) (2.320-2.345 GHz) bands, respectively and linear Polarized radiation at GSM-1900 band. The proposed antenna display good radiation performance when installed on car housing and various other type of housing.
       
  • On the Physical Layer Security over Beaulieu-Xie Fading Channel
    • Abstract: Publication date: Available online 15 October 2019Source: AEU - International Journal of Electronics and CommunicationsAuthor(s): Puspraj Singh Chauhan, Sandeep Kumar, Sanjay Kumar Soni With the expansion of IoT and device-to-device communication applications, the security and privacy of the information have been kept at the forefront. The existence of a secondary eavesdropper, which attempts to access the confidential information of the legitimate partners, makes the data communication insecure. In this regard, we study the effect of randomness caused by the Beaulieu-Xie fading channel on the performance of physical layer security. To this end, the analysis for the secrecy outage probability (SOP) and average secrecy capacity (ASC) is carried out. Further, we derived the closed-form expressions for lower-bound of secrecy outage probability and strictly positive secrecy capacity (SPSC) for the said channel. To get more insight into the system, the high-power and low-power analysis of the ASC are also provided. Besides, the impact of different fading parameters on the system matrices is also investigated. Finally, the theoretical results are verified via extensive Monte Carlo simulations.
       
  • Crosstalk Analysis at Near-End and Far-End of the Coupled Transmission
           Lines Based on Eigenvector Decomposition
    • Abstract: Publication date: Available online 14 October 2019Source: AEU - International Journal of Electronics and CommunicationsAuthor(s): Nastaran Soleimani, Mohammad G.H. Alijani, Mohammad H. Neshati In this paper, a new analytical method is proposed to accurately estimate the near-end and far-end crosstalk of a coupled Transmission Lines (TLs) based on eigenvector decomposition. For a non-homogenous two coupled lines, the related linear differential equations system (LDES) is derived for distributed voltage and current and then using matrix analysis, its four distinct eigenvalues and their associated eigenvectors are determined. It is shown that the two eigenvalues represent the self-propagation constant, while the other ones are linked to the mutual propagation constant of the coupled lines. In addition to, for these lines a closed form expression for near-end and far-end crosstalk is presented. In special case of homogenous coupled lines, the LDES is also determined and it is shown that they provide two couples of eigenvalues. Using the concept of generalized eigenvalues, the solution of these systems is derived and a closed form formula is derived for crosstalk. In order to verify the accuracy of the proposed method a few types of coupled lines, including homogeneous or non-homogeneous are investigated and the amount of crosstalk is estimated. The calculated crosstalk is presented and compared with those obtained by numerical investigation. It is shown that a good agreement is obtained between the calculated and measured results.
       
  • Design and analysis of floating inductance simulators using VDDDAs and
           their applications
    • Abstract: Publication date: December 2019Source: AEU - International Journal of Electronics and Communications, Volume 112Author(s): Winai Jaikla, Roman Sotner, Fabian Khateb This contribution introduces the design of new electronically controllable floating inductance simulators including lossless inductor, parallel resistor-inductor and series resistor-inductor circuits. The proposed simulators consist of two voltage differencing differential difference amplifiers (VDDDAs) as active function block with one resistor and one grounded capacitor. For real practical test and cheap cost, the VDDDA employed in this paper is constructed from commercially available ICs. The proposed active inductors don’t require any critical matching condition of passive element. If second port of the proposed inductors is assigned as output voltage, it can be simply adapted to achieve low impedance output voltage node with unity or double gain amplifier which is beneficial feature. Moreover, the third order low-pass and fourth order band-pass ladder filters are designed using proposed simulators. Low impedance output voltage node and double output voltage gain of ladder filters with electronic controllability of pass-band frequency are obtained. The performances of the presented simulator circuits and ladder filters are tested by Pspice simulation and experiment using VDDDA constructed from ICs, AD830 and LM13700. The simulation and experimental results confirm with theoretical behavior. Moreover, the recommended design for chip implementation to reduce number of VDDDA is included. The recommended lossless inductor, parallel resistor-inductor and series resistor-inductor circuits consist of single VDDDA which contains plus and minus z terminals along with single resistor and single grounded capacitor.
       
  • Fast and accurate synthesis of frequency reconfigurable slot antenna using
           back propagation network
    • Abstract: Publication date: Available online 14 October 2019Source: AEU - International Journal of Electronics and CommunicationsAuthor(s): Rajeev Kumar, Pawan Kumar, Surjit Singh, Ritu Vijay In this work, the synthesis of a hexagonal shaped frequency reconfigurable antenna based on the back-propagation network (BPN) is presented. Initially, two dimensions of the antenna are selected as the input of BPN and the best solution is considered as the optimal parameters of antenna design. The proposed antenna resonates at eight different bands of frequency, one at a time, using four p-i-n diodes for the variation between 2.36 GHz to 3.92 GHz. In this work, the Ansoft HFSS software is used for antenna design and simulation whereas BPN algorithms are implemented in Scilab software. The Proposed design is fabricated and validated. The frequency tuning ratio is found to be 1.66:1. In this design, the biasing circuit is incorporated into the ground plane of the antenna which reduces the parasitic effects and this design can be used for cognitive radio system applications. Moreover, the simulated and measured results are found to be in fine concurrence with each other.
       
  • A Performance Study on Diversity Receivers over κ-μ Shadowed Fading
           Channels
    • Abstract: Publication date: Available online 11 October 2019Source: AEU - International Journal of Electronics and CommunicationsAuthor(s): Mehmet Bilim In this study, N-branch selection combining (SC), dual-branch SC and dual-branch maximal ratio combining (MRC) receivers over κ-μ shadowed fading channels are investigated in terms of average bit error probability (BEP), outage probability (OP) and channel capacity (CC). Firstly, a cumulative distribution function (CDF) expression for instantaneous signal-to-noise ratio (SNR) at the output of the N-branch SC system over a κ-μ shadowed fading channel is derived. Based on the proposed CDF expression of output SNR for N-branch SC receiver, OP and approximate average BEP expressions are obtained. Secondly, the probability density function (PDF) expression for a dual-branch SC system over κ-μ shadowed channels is derived. Then, two different CC expressions of a dual-branch SC receiver are obtained by using the proposed PDF expression. Thirdly, a PDF expression for a dual-branch MRC system under κ-μ shadowed conditions is proposed and its CC expression with channel inversion with fixed rate for is derived. Effects of the fading parameters and the total number of branches on the system performance are examined with different scenarios. Finally, the obtained results from OP, average BEP and CC expressions are verified with numerical simulations.
       
  • Novel Strained Superjunction Vertical Single Diffused MOSFET
    • Abstract: Publication date: Available online 11 October 2019Source: AEU - International Journal of Electronics and CommunicationsAuthor(s): Onika Parmar, Prateek Baghel, Alok Naugarhiya In this article, a novel strained superjunction vertical single diffused MOSFET is proposed with enhanced current driving capability. In this design strain is induced by using SiGe layer in a superjunction vertical single diffused MOSFET (SJ-VSDMOS) and it improves the device performance. The structure is simulated in Silvaco 2-D device simulator. Proposed device exhibits 30% increase in current driving capability, 6.8% less gate charge is required by the device with improved peak transconductance on comparing with conventional device. Area specific on resistance of the proposed device is reduced by 24%. Hence, proposed device exhibits enhanced electrical behavior compared to conventional device.
       
  • Design of High Gain, Wideband Microstrip Resonant Cavity Antenna Using FSS
           Superstrate with Equivalent Circuit Model
    • Abstract: Publication date: Available online 1 October 2019Source: AEU - International Journal of Electronics and CommunicationsAuthor(s): Mojtaba Simruni, Shahrokh Jam A high directivity wideband resonant cavity antenna (RCA) is proposed in which a compact wideband microstrip patch antenna (MPA) is utilized as radiator. Through introducing an interdigital capacitor (IDC) in the patch, a planar metamaterial (MTM) unit cell in the ground plane and cutting two vertical slits from the slot, size reduction of the radiator is realized. To improve the directivity of the proposed MPA, a wideband FSS superstrate is designed and placed above the MPA making the whole antenna to operate as RCA. By using image theory, even and odd modes in RCA are analysed and the distance between FSS and the radiator is adjusted leading to optimum directivity and bandwidth in the proposed RCA. Maximum directivity enhancement in the designed RCA compared to the single element radiator is 4.2 dBi in the impedance matching bandwidth. The measured bandwidth and maximum gain of the proposed RCA are 24.9% and 11.2 dBi, respectively. Additionally, an equivalent circuit model for MPA and designed RCA is developed. The proposed antenna exhibits high gain and low cross polarization level making it a good candidate for radar applications. The final designed antenna is fabricated and the measurement results agree well with the simulation results.
       
  • Magnitude-Only Modeling for Sigma-Delta Modulator Characterization
    • Abstract: Publication date: Available online 30 September 2019Source: AEU - International Journal of Electronics and CommunicationsAuthor(s): Konstantinos Touloupas, Paul Peter Sotiriadis Sigma-Delta modulators (SDM) are unambiguous blocks in many applications. Since they are inherently non-linear systems, they are often approximately linearized to allow for the derivation of their theoretical Noise-Transfer-Function (NTF). SDM NTF is used for both analyzing and synthesizing them. Although linearization is the standard approach for its derivation, there do exist SDM architectures to which it cannot be applied. The aim of this paper is twofold: To provide a general framework for deriving the NTF for all SDM architectures, and, to use it to evaluate the accuracy of the standard theoretical NTF approximation for those SDM architectures accepting linearization. To this end, we introduce a new magnitude-only transfer-function modeling framework for SDM architectures, which is based on output noise spectrum and produces a stable LTI NTF approximation model. This framework is based on a phase reconstruction and a rational transfer-function fitting step, using the Vector Fitting algorithm. To show its viability, we used it to derive NTF models for SDMs at system level and RTL. Finally, the generality of our approach is demonstrated by deriving experimental NTF for a class of SDMs without standard linearized models.
       
  • Realization of Green Fractional Order Devices by using Bacterial Cellulose
    • Abstract: Publication date: Available online 30 September 2019Source: AEU - International Journal of Electronics and CommunicationsAuthor(s): R. Caponetto, G. Di Pasquale, S. Graziani, E. Murgano, A. Pollicino In this paper, we propose and demonstrate the possibility of using Bacterial Cellulose (BC), a bio-derived polymer, for the realization of fractional order electronic devices. BC, unlike plant-derived cellulose, is produced by some genera of bacteria, if a suitable culture is maintained. Compared to plant-derived cellulose, BC can be obtained with a green and low-energy production process, which does not produce pollutants nor carbon composites. BC is used as the bulk in a capacitor-like structure. The device impedance has been investigated and experimental evidence of its fractional nature is given. A model is proposed and a possible explanation of the involved phenomena is provided.
       
  • Interference-aware Channel Assignment and Power Allocation for
           Device-to-Device Communication Underlaying Cellular Network
    • Abstract: Publication date: Available online 27 September 2019Source: AEU - International Journal of Electronics and CommunicationsAuthor(s): Praveen Pawar, Aditya Trivedi Device-to-device (D2D) communication is a promising technology in 5G new radio (NR) interface to improve the system performance in terms of high data rate, low latency, coverage extension, traffic offloading, and higher spectrum and energy efficiency. In this study, channel assignment and power allocation techniques for D2D communication underlaying cellular network are proposed, those in turn, lead to a spectrum-efficient system. Firstly, the channel assignment problem is solved by employing channel-characteristics of target link and interference links. Then the power allocation problem is solved by allocating the optimal power to the D2D transmitters with allowable interference. This optimal power allocation approach allows multiple D2D communications to reuse the available cellular uplink resources. Numerical results demonstrate significant throughput gains for D2D communication for different transmission and interference power settings. Network throughput comparison with other existing approaches is provided to confirm the efficacy of the proposed approach. In addition, energy efficiency analysis is carried out by considering D2D transmission power, circuit power consumption, D2D link distance, and D2D user density.
       
  • General Performance of Detect-and-Forward Cooperative Relaying in the
           Presence of Multiple Interferers for Optimum Combining Receivers
    • Abstract: Publication date: Available online 24 September 2019Source: AEU - International Journal of Electronics and CommunicationsAuthor(s): Henry W. Merino, Carlos E. Câmara, Celso Almeida Detect-and-Forward (DF) is a cooperative technique based on the retransmission of a detected version of the transmit signal. It improves performance, throughput and cellular coverage. However, in cellular scenarios, it coexists with co-channel interference (CCI), which is the principal factor that affects the performance of cellular networks. On the other hand, Optimum Combining (OC) is a low complexity combining technique that maximizes the signal-to-interference-plus-noise ratio (SINR), achieving in this case diversity gain by eliminating the CCI. In the present paper, the performance of cooperative DF network in the presence of multiple CCI at relay and destination is analysed, where relay and destination are equipped with multiple antennas and OC. Furthermore, scenarios by considering multiple antenna transmission (MAT) and transmit antenna selection (TAS) technique at relay are supposed. For both MAT and TAS techniques, a tight approximation of the end-to-end instantaneous SINR is proposed. Subsequently, its moment-generating function is derived in closed-form in order to evaluate the average bit-error rate of the system. Analytical results are validated using Monte-Carlo simulations for several scenarios, showing that OC eliminates fully the CCI, even in the case of high-power CCI. The diversity gain depends on the number of destination antennas, relay antennas and interferers.
       
  • Special Type of Current Conveyor-Based Schmitt Trigger in Novel Design of
           Triangular Waveform Generator
    • Abstract: Publication date: Available online 23 September 2019Source: AEU - International Journal of Electronics and CommunicationsAuthor(s): Roman Sotner, Jan Jerabek, Vilem Kledrowetz This paper introduces novel solution of triangular and square wave generator employing circuitry of interesting and unusual Schmitt trigger and specially prepared modification of lossless integrator connected in low-impedance input terminal of the comparator that allows linear charging of capacity and therefore also triangular wave generation that is not available in standard cases of applications (only relaxation generator available – exponential and square wave). Design and supposed operation of the circuit was verified not only theoretically but also experimentally with CMOS implementation of employed active elements available in form of IC device fabricated in 0.35 μm I3T ON Semiconductor process. Achieved result confirmed studied features of triangular wave generation and linear electronic tunability of its frequency between 23 and 151 kHz.
       
  • System-Level Study on Impulse-Radio Integration-and-Fire (IRIF)
           Transceiver
    • Abstract: Publication date: Available online 9 September 2019Source: AEU - International Journal of Electronics and CommunicationsAuthor(s): Iman Kianpour, Bilal Hussain, Hélio S. Mendonça, Vítor G. Tavares Integrate-and-fire (IFN) model of a biological neuron is an amplitude-to-time conversion technique that encodes information in the time-spacing between action potentials (spikes). In principle, this encoding scheme can be used to modulate signals in an impulse radio ultra wide-band (IR-UWB) transmitter, making it suitable for low-power applications, such as in wireless sensor networks (WSN) and biomedical monitoring.This paper then proposes an architecture based on IFN encoding method applied to a UWB transceiver scenario, referred to herein as impulse-radio integrate-and-fire (IRIF) transceiver, followed by a system-level study to attest its effectiveness. The transmitter is composed of an integrate-and-fire modulator, a digital controller and memory block, followed by a UWB pulse generator and filter. At the receiver side, a low-noise amplifier, a squarer, a low-pass filter and a comparator form an energy-detection receiver. A processor reconstructs the original signal at the receiver, and the quality of the synthesized signal is then verified in terms of effective number of bits (ENOB). Finally, a link budget is performed.
       
  • Spatial-polarization diversity HAP-MIMO transmission system for emergency
           high-capacity mobile communications
    • Abstract: Publication date: Available online 28 August 2019Source: AEU - International Journal of Electronics and CommunicationsAuthor(s): Lei Shi, Lei Zhao, Yanming Liu, Qi Li The deployment of high-altitude platforms (HAPs) as an emergency communication system is a cost-effective method to deal with the decrease in channel capacity caused by shadows or multipath fading at low elevation angles. This study proposes a 4 × 4 multiple-input multiple-output (MIMO) scheme that employs spatial and polarization diversity to improve the channel capacity for HAP communication systems. This scheme utilizes the advantages of HAP size to install two pairs of dual-polarized antennas between HAP and mobile terminals to form a 4 × 4 spatial-polarized diversity MIMO system to counteract shadows and multipath fading. The polarization and spatial correlation matrices are obtained through the reasonable expansion of a 2 × 2 polarized parametric or spatial geometry MIMO channel model. Simulation results show that the proposed 4 × 4 MIMO transmission scheme can effectively improve the channel capacity by 1.5 times compared with the existing satellite 2 × 2 dual-polarization MIMO system at low elevation angles under typical scenarios.
       
  • Center pulse width modulation implementation based on memristor
    • Abstract: Publication date: November 2019Source: AEU - International Journal of Electronics and Communications, Volume 111Author(s): Ahmed M. Hassanein, Abdulaziz H. Elsafty, Ahmed H. Madian, Lobna A. Said, Ahmed G. Radwan This paper introduces two new versions for memristor-based center pulse-width modulator (PWM) circuits. The proposed circuits use only one comparator which reduces the circuit complexity and power dissipation compared to a former work. The first design is based on two memristors and two resistors while the second design is based on four memristors. Theoretical analysis is provided, and the numerical solution is handled on MATLAB. Simulation is carried out on Cadence software, and the results follow the theoretical analysis. The experiment is implemented using commercial off-the-shelf components and, the results match both theoretical analysis and simulation results.
       
  • Quad-band bandpass filter based on sextuple-mode and dual-mode stub-loaded
           resonators
    • Abstract: Publication date: November 2019Source: AEU - International Journal of Electronics and Communications, Volume 111Author(s): Sugchai Tantiviwat, Siti Zuraidah Ibrahim, Mohammad Shahrazel Razalli, Soh Ping Jack A quad-band bandpass filter (BPF) employing a sextuple-mode and a dual-mode stub loaded resonator are presented in this paper. The proposed sextuple-mode resonator generates the first, second and the fourth passband while the third passband is achieved by the dual-mode open stub-loaded resonator. The proposed sextuple-mode resonator modified from quintuple-mode resonator produces five resonant modes while the sixth-mode is generated by the coupling of the open ends of two stub resonators. Based on the odd- and even-mode analysis of the sextuple-mode resonator, the odd- and even-mode resonant frequencies can be flexibly controlled by tuning the corresponding resonator dimensions. Subsequently, the proposed sextuple resonator is combined with dual-mode open stub loaded resonator to achieve the quad-band BPF, centered at 1.75/2.45/3.50/5.25 GHz. The size of filter is about 0.13λg×0.22λg, where λg is guided wavelength on the substrate at 1.75 GHz. The measured results agree well with the simulated results.
       
  • Highly sensitive Al/Al2O3/Ag MIM diode for energy
           harvesting applications
    • Abstract: Publication date: November 2019Source: AEU - International Journal of Electronics and Communications, Volume 111Author(s): Kapil Bhatt, Sandeep Kumar, Chandra Charu Tripathi The requirement of energy has always been one of the major concerns in developing as well as developed countries. In quest of present energy demands, advancement in rectenna technology has resulted in intensive research on Metal/Insulator/Metal (MIM) diodes as a high-frequency rectifier. Due to extremely small amplitudes at very high frequencies, MIM diode must have high nonlinearity and zero bias sensitivity to rectify the input signal. In this article, a highly sensitive Al/Al2O3/Ag MIM diode is presented to be used as a rectifier in rectenna for energy harvesting applications. Fabricated diodes exhibit significant sensitivity of 18 V−1 and nonlinearity of 12.5 with the assymetry of as large as 1.2. Low-frequency measurements were also performed to validate the rectification characteristics of MIM diodes.Graphical abstractGraphical abstract for this article
       
  • Design of an Optical Attocells Configuration for an Indoor Visible Light
           Communications System
    • Abstract: Publication date: Available online 9 October 2019Source: AEU - International Journal of Electronics and CommunicationsAuthor(s): M.S.M. Gismalla, M.F.L. Abdullah, B. Das, Wafi A. Mabrouk, Nouran E. Mahfouz Visible light communications (VLC) is deemed as a promising technology for future indoor cellular communications due to its unique features, namely unlicensed free spectrum, high bandwidth, high security, and low power consumption. A small base stations (BS) called optical attocells are mounted on the ceiling of the room to provide communication and illumination simultaneously. In this paper, an optical attocells configuration model is proposed with the aim of providing a uniform illumination distribution while the field of view (FOV) is optimized to increase the receiver gain, furthermore, improving the received power and SNR distribution. The average illumination level of 635.6113 Lx is obtained, besides that, the minimum received power is improved from −2.17 to -1.286 dBm as compared with the previous studies. The proposed optical attocells model has used small number of LEDs chips, and hence, a reduction in link power consumption by 30.6% is achieved. Also, it was resolved the blind area at the centre of the room, and the total received power at the centre is improved from 3.2 to 5.967 dBm.
       
  • A low-profile holographic antenna with dual-metasurface and printed Yagi
           feed
    • Abstract: Publication date: November 2019Source: AEU - International Journal of Electronics and Communications, Volume 111Author(s): Eqab Almajali, Derek McNamara, Saqer S. Alja'afreh, Mohammad S. Sharawi, Ismail Mabrouk A low-profile microwave holographic antenna comprised of a dual-metasurface and an integrated printed Yagi feed is presented. The proposed design utilizes two metasurfaces with an aperture size of 0.0134 m2, with no ground plane, to produce a single pencil beam normal to the plane of the Yagi feed. The holographic antenna is designed at a centre frequency of 20 GHz and shown to have an excellent performance in the frequency range 19.75–21.25 GHz. The aperture efficiency and 1 dB gain bandwidth achieved are 28% and 7.5%, respectively. This is an improved aperture efficiency/bandwidth combination over that of comparable low-profile holographic antennas. Simulated and measured results demonstrate the advantages of the proposed design.
       
  • A high efficient dual-output rectifier for piezoelectric energy harvesting
    • Abstract: Publication date: November 2019Source: AEU - International Journal of Electronics and Communications, Volume 111Author(s): Peng Wah Yuen, Gabriel Chong, Harikrishnan Ramiah In this paper, a high efficient active NMOS dual-output rectifier for piezoelectric energy harvesting (PEH) in CMOS technology is proposed. The rectifier adopts a cross-coupled active NMOS topology producing two output DC voltages. A DC-DC combiner at the rectifier’s output is employed to sum the output DC voltages which improves the effective Voltage Conversion Efficiency (VCE) and Power Conversion Efficiency (PCE). Simulated on a standard 65-nm CMOS technology, the proposed rectifier achieves a VCE > 98% across a connected output load of Rrec > 9 kΩ and a peak PCE of ∼84% for Rrec = 12 kΩ. Compared to conventional piezoelectric rectifiers, the PCE of the proposed rectifier is significantly improved with comparative VCE performance.
       
  • A Miniaturized Quad-band Antenna with Slotted Patch for WiMAX/WLAN/GSM
           Applications
    • Abstract: Publication date: Available online 4 October 2019Source: AEU - International Journal of Electronics and CommunicationsAuthor(s): Ajay Kumar Gangwar, Muhmmad Shah Alam A miniaturized quad-band patch antenna for WiMAX/WLAN/GSM applications is presented in this paper. The proposed antenna structure consists two L-slots and a slit in the patch. The longer between two slots, resonates at 1.74 GHz (1.8 GHz band), whereas the shorter at 2.58 GHz (2.4/2.5 GHz band). The third and fourth resonances at 3.6 GHz (3.5 GHz band) and 5.6 GHz (5.2/5.5/5.8 bands) are due to the slit and length of the patch, respectively. A detail parametric analysis is carried out by varying the length of the slots (i.e. L-slots and slit) to achieve the desired frequency bands. An equivalent circuit model of the antenna is developed and the various antenna performances are analyzed. The antenna simulated results for return loss and 2D radiation patterns are experimentally verified.
       
  • Hyperjerk multiscroll oscillators with megastability: Analysis, FPGA
           implementation and A Novel ANN-Ring-based True Random Number Generator
    • Abstract: Publication date: Available online 4 October 2019Source: AEU - International Journal of Electronics and CommunicationsAuthor(s): Murat Tuna, Anitha Karthikeyan, Karthikeyan Rajagopal, Murat Alçın, İsmail Koyuncu Metastable oscillators are a special case of chaotic attractors with infinite coexisting attractors. In this paper we propose a class of hyperjerk chaotic oscillators which exhibits megastability with and without forcing term. As the systems have infinite equilibrium points, all these coexisting attractors falls in the special category of hidden attractors. We have considered the unforced hyperjerk system to show the multiscrolls and also to investigate the system bifurcations. Then, the proposed hyperjerk multiscroll chaotic system has been designed as ANN-based on FPGA. TanSig activation function, used in the design of ANN-based chaotic oscillator, has been modeled using CORDIC-LUT approximation. To improve the chaos-based engineering applications, this paper presents a new dual entropy core hybrid TRNG having high speed by using the structures of ANN-based chaotic system and ring oscillator. The designs have been coded in VHDL with respect to IEEE-754 1985 number standard. The implemented new proposed TRNG unit has been synthesized for Virtex-6 FPGA chip. After the Place-Route process, FPGA chip statistics and maximum operating frequency have been given as 167.4 MHz. 1million bit stream generated by the proposed TRNG has been subjected to NIST-800-22 randomness tests and it has successfully passed all of the randomness tests.
       
  • Development of a Wide Band TEM-based Bethe Hole Coupler Using Ridge Gap
           Waveguide Technology
    • Abstract: Publication date: Available online 24 September 2019Source: AEU - International Journal of Electronics and CommunicationsAuthor(s): Efat Nematpour, Mohamad Hossein Ostovarzadeh, Seyed Ali Razavi A 20 dB Bethe Hole coupler is designed and fabricated using ridge gap waveguide technology for operation at the Ku band. The use of ridge gap waveguide concept makes an opportunity to develop a lowloss and wideband directional coupler because of supporting TEM wave propagation in air region.The simulation results show a very flat -20dB coupling coefficient response, higher than 20dB isolationand proper impedance matching over a wide frequency rangewhich are in agreement with the measurement results.
       
  • 0.5V Sixth-order Chebyshev band-pass filter based on multiple-input
           bulk-driven OTA
    • Abstract: Publication date: Available online 23 September 2019Source: AEU - International Journal of Electronics and CommunicationsAuthor(s): Montree Kumngern, Tomasz Kulej, Viera Stopjakova, Fabian Khateb This paper presents a low-voltage sixth-order Chebyshev band-pass filter based on multiple-input operational transconductance amplifier (MI-OTA). The used voltage supply is 0.5 V and the filter employs six MI-OTAs and six capacitors. The third intermodulation distortion (3rd IMD) is below 1 % for input sine wave signal with peak-to-peak up to rail-to-rail while the dynamic range (DR) is 66.8 dB. In order to insure low-voltage operation capability, extended linear range, increased voltage gain of the MI-OTA, the multiple-input bulk-driven transistor (MIBD) along with self-cascode techniques have been used. As a result, the proposed MI-OTA based on MIBD is capable to work with 0.5 V supply voltage and consumes power in the range of (2.5 to 1.2E3) nW for tunable bias current in the range from 1 nA to 500 nA. The MI-OTA and the filter circuits were designed and simulated in Cadence/Spectre environment using 0.18 µm CMOS process from TSMC. The simulation results agree well with theory and confirm the filter functionality.
       
  • A concurrent dual-band continuous Class-F power amplifier with
           intermodulation impedance tuning: Analysis and design technique
    • Abstract: Publication date: November 2019Source: AEU - International Journal of Electronics and Communications, Volume 111Author(s): Milad Shariatifar, Mohsen Jalali, Abdolali Abdipour In this paper, first the behaviour of dual-band continuous class-F (Class-CF) power amplifiers under concurrent input drive at both bands are studied. Then, a novel structure including second and third harmonic control networks as well as intermodulation tuning network intended for higher concurrent-mode efficiency is proposed accompanied by a detailed design methodology. The study has revealed that the performance of concurrent Class-CF dual-band power amplifiers (DB-PAs) under overdrive condition strongly depends on the design space factor. The impact of the device nonlinear output capacitance on the concurrent mode efficiency is also evaluated. To authenticate the validity of the proposed methodology, a Class-CF concurrent dual-band PA operating at 1.842 and 2.655 GHz bands is implemented. Experimental results exhibit output powers of 41.7 and 40.5 dBm and efficiencies of 75% and 72% at the lower and upper bands, respectively, while 62% concurrent-mode efficiency is obtained.
       
  • Evaluation of an Optical Energy Harvester for SHM Application
    • Abstract: Publication date: Available online 20 September 2019Source: AEU - International Journal of Electronics and CommunicationsAuthor(s): Rocco Citroni, Franco Di Paolo, Patrizia Livreri In this paper a preliminary study on an array configuration of rectified optical nanoantennas for energy harvesting application is proposed. Currently, the major impediments for the use of the rectified optical nanoantenna known as rectenna are the relatively low conversion efficiency and low power transfer to the load, both of them caused mainly by the mismatch between the impedance of the rectifier (several kilo ohms) and that of the antenna (hundreds of ohm). For this reason, the design of the array represents a crucial point to obtain the maximum energy transfer from the rectenna to the load, represented as a typical DC/DC boost power converter, and modeled by an equivalent input impedance. The novelty of this study confirms that it is possible to obtain dynamically an impedance matching between the array of optical rectennas and the load. According to this method, in the proposed rectenna array, N elements can be serially connected so to allow to the open circuit voltage to be increased and M elements can be parallel connected to give the degree of freedom needed to achieve the impedance matching with the load. Finally, a case study for Structural Health Monitoring (SHM) application is presented.
       
  • Dual input buck-boost converter for hybrid Piezoelectric Energy Harvester-
           Supercapacitor sources
    • Abstract: Publication date: Available online 20 September 2019Source: AEU - International Journal of Electronics and CommunicationsAuthor(s): Raghavendran Srinivasan, Umapathy Mangalanathan, Uma Gandhi Integration of energy sources provides superior flexibility and reliability in low power electronic system. A dual input positive buck-boost converter is proposed for integrating piezoelectric energy harvester (PEH) and supercapacitor sources. The converter circuit consists of three active power switches, a common inductor, and an output filter capacitor. The active switch connected with the PEH is operated at the optimum duty cycle for maximum power extraction through impedance matching. The voltage at the output can be regulated by adjusting the duty ratio of the active switch connected with the supercapacitor. The charging mechanism of supercapacitor from a piezoelectric energy harvester is also presented. The operational performance of the proposed system is verified through simulation and validated by experimental investigation. The output power is measured for the range of load resistance, and a maximum power of 4.48 mW with the efficiency of 59% is obtained for the load resistance of 22 k□.
       
  • On the Mechanism of Creating Pinched Hysteresis Loops using a Commercial
           Memristor Device
    • Abstract: Publication date: Available online 19 September 2019Source: AEU - International Journal of Electronics and CommunicationsAuthor(s): S. Majzoub, A.S. Elwakil, C. Psychalinos, B.J. Maundy In this short communication we analyze the impact of signal harmonics on the formation of the pinched hysteresis loop using a commercial memristor device. We show that by using only the fundamental frequency and the second harmonic components, extracted from the measured electrical current signal, a distortion-less pinched hysteresis loop is re-created. This loop is then used to simulate memristor-based AND/OR gates without any loss in digital functionality. This verifies that the generation of a pinched hysteresis loop requires a nonlinear frequency doubling mechanism to create a second harmonic in the current signal from an applied single frequency voltage excitation. Obtaining a pinched loop with three pinch points from the experimentally measured data is also demonstrated.
       
  • Shallow Extension Engineered Dual Material Surrounding Gate (SEE-DM-SG)
           MOSFET for Improved Gate Leakages, Analysis of Circuit and Noise
           Performance
    • Abstract: Publication date: Available online 18 September 2019Source: AEU - International Journal of Electronics and CommunicationsAuthor(s): Anubha Goel, Sonam Rewari, Seema Verma, R.S. Gupta The leakages in off state, particularly Gate Induced Drain Leakage (GIDL) has been addressed and reduced by proposing a Shallow Extension Engineered Dual Material Surrounding Gate (SEE-DM-SG) MOSFET. The shallow extensions create an insulating layer, which acts as a diffusion stopper and thereby suppresses the off state leakages. It is done by comparing the off-state performance of SEE-DM-SG MOSFET with Dual Metal Surrounding Gate (DM-SG) MOSFET and Surrounding Gate (SG) MOSFET. GIDL current is being reduced to an order of 10-12 A. Drain Induced Barrier Lowering (DIBL) has been curtailed to a greater extent in SEE-DM-SG MOSFET when compared with DM-SG MOSFET and SG MOSFET. GIDL has been extensively investigated for different drain voltages and temperatures; in order to study their impact on it. It was so found that GIDL was minimal for SEE-DM-SG MOSFET under different bias and temperature conditions. Arrhenius plot has also been plotted and deeply investigated as it instigates the GIDL activation energy (EA). It has been so found that SEE-DM-SG MOSFET poses higher EA and thereby suggests minimal BTBT (Band To Band Tunneling). So as to enhance the device applicability for low noise amplifier, the noise performance of SEE-DM-SG MOSFET has also been deeply investigated. Noise conductance (NC) and Noise Figure (NF) have been significantly curtailed in SEE-DM-SG MOSFET over DM-SG and SG MOSFET. A CMOS inverter has also been designed using SEE-DM-SG MOSFET and the output characteristics have also been compared for the aforesaid device architectures and higher Noise Margin has been observed in SEE-DM-SG MOSFET, making it more immune to noise.
       
  • A CMOS Power Amplifier with Reconfigurable Power Cells and Matching
           Network for 2.4 GHz Wireless Communications
    • Abstract: Publication date: Available online 17 September 2019Source: AEU - International Journal of Electronics and CommunicationsAuthor(s): A.A. Modesto, F. Santos, J.H. Pereira, B. Leite, A.A. Mariano This paper presents a twelve-mode 130 nm CMOS power amplifier with reconfigurable output matching network (OMN) and supply voltage selection. To select operation modes, nine inputs enable or disable individually a set of power cells in the power stage and capacitors in the OMN. The gain stage is a cascode structure while the power stage is composed of three differently sized parallel cascode power cells with a voltage supply ranging from 1.1 V to 1.8 V. The OMN is composed of two reconfigurable capacitor banks and a fixed inductor. Each bank is composed of three capacitance cells. When a different combination of power cells is enabled, the OMN is altered to match impedances and so improve efficiency. The low-power mode achieves an output 1 dB compression point (OCP1dB) of 10.1 dBm, a DC power (PDC) consumption of 94.7 mW, and 10.6% power added efficiency (PAE) at OCP1dB. The high-power mode achieves an OCP1dB of 18.22 dBm, 341.4 mW PDC and 19.4% PAE at OCP1dB. Employing IEEE 802.11n, IEEE 802.11ax and LTE signals for each mode, digital channel simulations were performed to determine the maximum output power in compliance with the respective Error Vector Magnitude and Adjacent Channel Power Ratio.
       
  • Wideband and High Gain Tuning Fork Shaped Monopole Antenna using High
           Impedance Surface
    • Abstract: Publication date: Available online 16 September 2019Source: AEU - International Journal of Electronics and CommunicationsAuthor(s): Prakash Kumar Panda, Debalina Ghosh This paper formulates a design methodology for a low profile monopole antenna backed by a high impedance surface (HIS). The formulated design achieves high gain and high directivity while maintaining the low-profile nature. It is demonstrated that the choice of the monopole antenna does not hamper the enhancement of gain due to HIS backing. The designed HIS is a uniplanar structure designed to have the advantage of suppressing surface waves while image current and antenna current are in phase with each other at each frequency. The fabricated design exhibits a wide bandwidth ranging between 2.68 GHz and 3.65 GHz with a relative impedance bandwidth of 32.3% and a gain increase of 4.5 dBi as compared to the unbacked antenna. A comprehensive simulation study has been carried out which helps in verification of the proposed methodology for strategizing the fabrication process.
       
  • Permutation Index-Quadrature Spatial Modulation: A Spectral Efficient
           Spatial Modulation for Next Generation Networks
    • Abstract: Publication date: Available online 13 September 2019Source: AEU - International Journal of Electronics and CommunicationsAuthor(s): Vishnu Vardhan Gudla, Vinoth Babu Kumaravelu Spatial Modulation techniques (SMTs) offer an exceptional trade-off between spectral and energy efficiencies. In this work, we propose a new SMT termed as permutation index-quadrature spatial modulation (PI-QSM), aiming for enhanced spectral efficiency and better average bit error rate (ABER) performance compared to rival SMTs. To enhance spectral efficiency, PI-QSM exploits permutations of active transmit antennas by conveying additional information bits innovatively through indices of active antenna permutations. PI-QSM also alleviates the major constraint in some of the SMTs, where the total number of transmit antennas need to be a power of two. At any time instance, PI-QSM transmits real and imaginary parts of two complex modulated symbols separately using four different active antennas. To avoid any ambiguities at the receiver and to improve the error performance of the overall system, a rotation angle is introduced between the two modulated symbols before transmission. The rotation angle is optimized for different M-quadrature amplitude modulation (QAM) constellations using extensive Monte Carlo simulations. Performance of PI-QSM scheme is analyzed by deriving closed-form expressions for upper bound and asymptotic average bit error probability (ABEP) over Rayleigh fading channels. The Simulation results substantiate the accuracy of analytical analysis and also indicate that the proposed PI-QSM scheme offers better ABER performance than rival SMTs such as QSM and generalized QSM (GQSM).
       
  • Compact Asymmetric Fractal Frequency and Pattern Reconfigurable Monopole
           Antenna
    • Abstract: Publication date: Available online 12 September 2019Source: AEU - International Journal of Electronics and CommunicationsAuthor(s): Anuradha A. Palsokar, S.L. Lahudkar A compact frequency and pattern reconfigurable monopole for LTE and WLAN applications is presented. The antenna consists of an asymmetric fractal patch which is derived from a bow-tie antenna and optimized using Pattern search algorithm. The antenna operates at 1.8GHz and 5.2GHz frequency with a different radiation pattern for each case. A single PIN diode is used to achieve frequency and pattern reconfigurability. The antenna is simulated using Ansoft High Frequency Structural Simulator (HFSS) software and fabricated on FR4 substrate with the relative permittivity of 4.4; having size of 30mm * 24mm and thickness of 1.6mm.Graphical abstractGraphical abstract for this article
       
  • A compact quad-band ring string-shaped antenna
    • Abstract: Publication date: Available online 11 September 2019Source: AEU - International Journal of Electronics and CommunicationsAuthor(s): Xia Cao, Yingqing Xia, Ling Wu, Lei Lang In this article, a novel microstrip antenna offering four operation bands to WiMAX (3.3 GHz-3.7 GHz), INST (4.5 GHz-4.8 GHz), downlink of X-band satellite communication (7.25 GHz-7.75 GHz) and X-band (8 GHz-12 GHz) is studied. The ring string-shaped radiator in the antenna consists of a circular ring patch and three elliptical rings of different sizes contributing to quad-band characteristics. The proposed antenna is fabricated on a FR-4 substrate with volume of 16 × 24 × 0.8 mm3. The measured reflection coefficient is lower than -20 dB and the peak gains are higher than 1.58 dBi at the center frequency of each operating bands. There is a high consistency between the measured results and the simulation results. It indicates that the idea of this antenna is correct and the proposed antenna can suit for the four desired operating bands.
       
  • Design and Implementation of Low Loss and Compact Microstrip Triplexer
           Using CSRR Loaded Coupled Lines
    • Abstract: Publication date: Available online 10 September 2019Source: AEU - International Journal of Electronics and CommunicationsAuthor(s): S. Keshavarz, A. Abdipour, A. Mohammadi, R. Keshavarz In this paper, a passive S-band triplexer using complementary split ring resonators (CSRRs) etched on the ground plane and interdigital capacitor in the upper metal is presented. The proposed structure is designed with three output ports operating at three distinct center frequencies of 1.4 GHz, 1.8 GHz and 3.2 GHz, which are suitable for multiband receivers working at LTE bands. The proposed triplexer is simulated, fabricated and measured. Simulation and experimental results of scattering parameters are in good agreement. This structure comprises these specifications: insertion loss less than 2 dB, isolation between channels approximately 20 dB and about 5% fractional bandwidth regarding VSWR
       
  • A Dual-Wideband Bi-Layered Chiral Metamaterial to Develop
           Cross-Polarization Conversion and Asymmetric Transmission Functionalities
           for the Linearly Polarized Electromagnetic Waves
    • Abstract: Publication date: Available online 10 September 2019Source: AEU - International Journal of Electronics and CommunicationsAuthor(s): Farnaz Mirzamohammadi, Javad Nourinia, Changiz Ghobadi, Rahim Naderali A novel modified bi-layered chiral metamaterial (CMM) with dual-wideband cross-polarization conversion and asymmetric transmission (AT) operations is introduced for the transmission of the linearly polarized electromagnetic (EM) waves. To this end, any unit cell of the presented CMM includes a pair of twisted meander-shaped metallic layers arranged on two opposite sides of a thin dielectric slab. The proposed CMM can cover two frequency bands from 8GHz to 12GHz and 14GHz to 15GHz, which makes it appropriate to be used in X-band and Ku–band applications. The simulated and measured results with acceptable coincidence indicate that the suggested CMM has a significant potential to transform an incident linearly x- (y-) polarized wave into the orthogonal polarization by transmission across the sample along –z (+z) propagation. Parametric studies of the applied structural modifications are investigated to achieve desirable asymmetric transmission. The realized polarization conversion ratio (PCR) has values above 86% at both operating frequency bands. Also, the obtained polarization rotation azimuth angleθ confirms that the plane of the polarization for the transmitted linearly polarized wave rotates relative to the incident one. Furthermore, the procedures of the cross-polarization conversions are investigated by the surface current distributions at two resonant frequencies.
       
  • Accelerating Microwave Tomography Based on Generalized Analytical Singular
           Value Decomposition
    • Abstract: Publication date: Available online 10 September 2019Source: AEU - International Journal of Electronics and CommunicationsAuthor(s): Sirous Bahrami In this paper, a 2-D microwave tomography system with circular observation domain is proposed. By means of Analytical Singular Value Decomposition (ASVD) object reconstruction process significantly accelerated. The spectral expansion of the Green’s function is employed to derive generalized SVD of scattering integral operator. The analytical formulation of singular values and vectors is straightforward without considerable computation cost. Influence of medium properties and configuration on singular values are studied numerically. Also, the performance of the proposed method is validated against experimental data. Thanks to the spectral representation, truncation parameter for singular values can be determined in a closed form. As a result, small singular values can be filtered out to ensure stability.
       
  • Design of a compact quad-radiating element MIMO antenna for LTE/Wi-Fi
           application
    • Abstract: Publication date: Available online 10 September 2019Source: AEU - International Journal of Electronics and CommunicationsAuthor(s): Abubeker A. Yussuf, Selcuk Paker In this paper, a compact quad-element multiple-input-multiple-output (MIMO) antenna for LTE/Wi-Fi application is proposed. The four dual-elliptically tapered antenna elements are an orthogonal orientation to one another. The MIMO antenna comprises a cross-shaped stub between the quad-radiating elements and ring-shaped stripes between the partially ground planes that act as a decoupling element to suppress mutual coupling. The dimension of the designed MIMO antenna is (66×66×1.6)mm3. A prototype MIMO antenna was fabricated and S-parameters were measured in order to characterize the performance parameters of the MIMO antenna. The designed MIMO antenna operates at 2.3 to 2.7 GHz frequency band with high isolation exceeding 17 dB. Thus, the measured results give an envelope correlation coefficient below 0.04 and a channel capacity loss is lower than 0.6 b/s/Hz, which reasonably agrees with the simulated results.
       
  • Hetero-Dielectric Oxide Engineering on Dopingless Gate All Around Nanowire
           MOSFET with Schottky Contact Source/Drain
    • Abstract: Publication date: Available online 7 September 2019Source: AEU - International Journal of Electronics and CommunicationsAuthor(s): Agamreet Kaur, Rajesh Mehra, Amit Saini In proposed work, gate oxide engineered Schottky Barrier (SB) Hetero-Dielectric (HD) Single Metal (SM) Gate All around Nanowire MOSFET is purposed for low power digital circuitry. Proposed device has an asymmetric oxide geometry having high-k (HfxTi1-xO2) on source side and SiO2 on drain side with Schottky Source/Drain regions. Leakage currents are reduced to an order of 10−15 over 10−9 A as compared to conventional GAA MOSFET. Device is simpler in fabrication in contrast to Junctionless (JL) NWFETs due to its dopingless design. Also, it has almost negligible gate induced drain leakage (GIDL) current value. An extensive comparison is outlined between the subthreshold performance of Single metal, Dual metal hetero-Dielectric (HD) and Gate Stack (GS) SB-SM-GAA NWFET configurations. An improvement is observed in ON to OFF-state current ratio by 68.05% and an impressive decline in drain induced barrier lowering (DIBL) by 48.15% in HD-SB-SM-GAA NWFET as compared to Gate stack structure at same physical dimensions. Further, SM device has been found to have better ION/IOFF ratio, higher transconductance, lowered DIBL and an optimum subthreshold slope as compared to DM device.
       
  • Application of wireless sensor networks for Rhino protection against
           poachers in Kaziranga National Park
    • Abstract: Publication date: Available online 6 September 2019Source: AEU - International Journal of Electronics and CommunicationsAuthor(s): Tathagata Nath, Md Azharuddin Last few decades many animals, birds, reptile and fish species were wiped out from the planet due to human activity. Many more species are likely to lose their existence because of lost their natural habitat, increased human land use and poaching. Rhino is one of them which can be found now only in few protected areas such as Assam, West Bengal etc. of India because of poaching. In this paper, we propose a model of wireless sensor network’s application to protect the Rhino against poachers in Kaziranga National Park, Assam, India. In the model, we place the sensor nodes in the boundary region of the Rhino inhabited area to take necessary action upon detection of human movement. Then, we propose a routing algorithm for the model where a sensor node selects a next hop sensor node based on a fitness function. We also propose a linear programming formulation for the proposed algorithm. Finally, we simulate the proposed algorithm for varying number of sensor nodes and BSs and compare different results in terms of various performance metrics.
       
  • Reduction of the chromatic dispersion and chirping effects by using an
           injection-locked and directly intensity-modulated Fabry–Pérot laser in
           point-to-point optical access networks
    • Abstract: Publication date: Available online 6 September 2019Source: AEU - International Journal of Electronics and CommunicationsAuthor(s): Jakup Ratkoceri, Andrej Lavrič, Boštjan Batagelj We present recent improvements achieved for two important transmission parameters—dispersion, induced by the optical fiber, and the chirp parameter of the laser source—in a directly modulated system based on an injection-locked and directly modulated Fabry–Pérot laser diode for high-speed optical access networks with a point-to-point topology. Measurements in the 20-GHz range of the frequency response for distances up to 35 km are conducted by carefully adjusting the optical power and frequency detuning of the distributed master laser in the central office, thereby overcoming the problem of chromatic dispersion in high-speed optical access. Moreover, the enhancements make it possible to increase the transmission distance when a 1550-nm Fabry–Pérot laser is used as the light source in the central office of a point-to-point optical access network by distributing the seed light into numerous downstream lasers. This improvement to the injection-locked Fabry–Pérot laser is expected to extend the length of already-built, fiber-to-the-home, point-to-point networks with a simple upgrade in the central office without prejudicing the terminal equipment.
       
  • Design and investigation of a multi-functional antenna with variable
           wideband/notched UWB behavior for WLAN/X-band/UWB and Ku-band applications
           
    • Abstract: Publication date: Available online 6 September 2019Source: AEU - International Journal of Electronics and CommunicationsAuthor(s): Mohammad Ahmad Salamin, Wael A.E. Ali, Sudipta Das, Asmaa Zugari In this article, a novel wideband/band-notched UWB antenna with multi-functional behavior is presented. The proposed antenna consists of a rectangular metallic part which formed the patch and a partial ground plane. A novel open loop resonator is loaded at the top side of the patch for the purpose of bandwidth improvement and to create band notched mechanism. The antenna occupies a tiny size of just 0.25 λo* 0.24 λo. The proposed antenna provides dual modes of operation. The first mode represents a wideband antenna with a usable impedance bandwidth (S11
       
  • Performance Analysis of MIMO-RDWT-OFDM System with Optimal Genetic
           Algorithm
    • Abstract: Publication date: Available online 6 September 2019Source: AEU - International Journal of Electronics and CommunicationsAuthor(s): Abdul Hussain Sharief, M SatyaSai Ram Multiple input multiple output orthogonal frequency division multiplexing (MIMO-OFDM) is required to achieve ultra-high data rate (UHDR) due to the increasing demand of 5th generation wireless networks with reduced inter symbol interference (ISI) and inter carrier interference (ICI) for the efficient transmission of data. Discrete wavelet transform-based OFDM (DWT-OFDM) presents itself as a key solution since it provides good orthogonality by employing orthogonal wavelets, which enclose further possibilities of ISI and ICI impacts mitigation because of multipath attenuation environs and extends the efficacy of further bandwidth which equate to the traditional OFDM systems. However, DWT-OFDM systems suffer from down sampling, which mitigates the actual size of input bit streams and thereby degrading the system efficiency. To resolve this, redundant discrete wavelet transform (R-DWT) is utilized in place of DWT for enhanced spectral efficiency. Further, mitigation of jitter noise with enhancement in the performance of CIR results in reduction of inter carrier interference (ICI) in MIMO-RDWT-OFDM system and is presented in this article. Proposed methodology utilizes optimal genetic algorithm (OGA) to find the optimized weights of proposed ICI cancellation scheme. This algorithm reduces complexity and processing delay, improves bit error rate (BER) performance and enhances the performance of CIR in MIMO-RDWT-OFDM system.
       
  • Demonstration of a Self-Polarizing Dual-band Single-feed Circularly
           Polarized Fabry-Perot Cavity Antenna with a Broadband Axial Ratio
    • Abstract: Publication date: Available online 5 September 2019Source: AEU - International Journal of Electronics and CommunicationsAuthor(s): Yousef. Azizi, Nader. Komjani, Majid. Karimipour, Iman. Aryanian A cost-efficient low profile dual-band circularly polarized (CP) fabry-perot cavity antenna (FPCA) with large axial ratio (AR) bandwidth is experimentally demonstrated in this paper. The utilized partially reflective surface (PRS) which comprises an array of square loops in one side and asymmetric meander-lines in another side of dielectric layer, is designed so as to realize a roughly linear phase of transmittance in a wide frequency band for both LP components with nearly 90° phase difference between them. A single-layer high impedance surface (HIS) is employed to compensate the phase difference between the two LP components of the reflected waves from the PRS. The cavity is excited by a linearly polarized (LP) primary source with embedded two parasitic patches, which are all aligned along an optimal slant angle equal to 55o to not only generate two notches within the band 14-15.5 GHz, but also compensate the difference between magnitudes of two orthogonal components of transmitted waves through the PRS. A prototype with the dimensions of 1.7λmin×1.7λmin×.41λmin is fabricated and the measurement results show that the peak gain of antenna is 10 dBi and 9.2 dBi at 14.125 GHz and 15.375 GHz, respectively and the AR is below 3 dB from 13.5 GHz to 15.7 GHz (15 %).
       
  • Augmented Lagrange geolocation algorithm using TDOA measurements and
           calibration sources in the presence of satellite position errors
    • Abstract: Publication date: Available online 4 September 2019Source: AEU - International Journal of Electronics and CommunicationsAuthor(s): Xin Chen, Ding Wang, Jiexin Yin, Changgui Jia Satellite position errors are known to deteriorate geolocation accuracy significantly. Based on a time difference of arrival (TDOA) satellite localization system, this paper investigates the use of calibration sources to reduce the loss of localization accuracy due to satellite position errors. First, we deduce pseudo-linear equations according to the available TDOA measurements from the target and calibration sources. Based on these equations, a total least squares optimization model with an equality constraint is formulated. To solve this constrained optimization problem, we propose an augmented Lagrange geolocation algorithm by which the target position and refined satellite positions can be obtained. Subsequently, the theoretical performance of the augmented Lagrange geolocation algorithm is derived, and it is proved that the mean square error of the proposed algorithm coincides with the corresponding Cramér–Rao lower bound under first-order perturbation analysis. Finally, simulation results corroborate the theoretical developments and demonstrate the superior performance of the proposed algorithm compared with existing algorithms.
       
  • Wideband Out-of-Phase Power Divider Using Klopfenstein Tapered Line
           Transformers
    • Abstract: Publication date: Available online 3 September 2019Source: AEU - International Journal of Electronics and CommunicationsAuthor(s): Weijuan Chen, Yongle Wu, Weimin Wang, Shulan Li A novel wideband out-of-phase power divider based on Klopfenstein tapered line is proposed for the first time. By using double-sided parallel-strip line (DSPSL) with inserted conductor plane as virtual ground, frequency-impendent phase difference can be achieved with antisymmetric output structures. Odd-/even-mode analysis shows that the introduced Klopfenstein tapered line can expand bandwidth greatly, and additional eight pairs of isolation resistors are added to realize high output matching and isolation. For verification, this presented power divider is fabricated and measured. The simulation and measurements shown that this structure can achieve a wide frequency range from 0.5 GHz to 7.3 GHz, in which the S-parameters (S11, S22, S32) are all better than 10 dB, and the phase imbalance is less than 7°.
       
  • Performance Analysis of Low Power LNA using Particle Swarm Optimization
           for Wide Band Application
    • Abstract: Publication date: Available online 3 September 2019Source: AEU - International Journal of Electronics and CommunicationsAuthor(s): Manish Kumar, Vinay Kumar Deolia This paper characterizes a design analysis of low power (LP) and low voltage (LV) optimized low noise amplifier (LNA) for wide band applications. With review discussion on design challenges of LP and LV, a new biasing metric has been introduced for radio frequency analog circuit. The proposed LNA consists of two stages, the first stage is a current reuse topology, in which a combination of PMOS transistor stack on top of NMOS transistor has been used with series inductive peaking in the feed-back loop. It helps a lot to achieve the target of LP and LV, while the second stage is a mutually coupled CS stage, used for wideband matching to enhance the bandwidth and noise figure (NF). For optimization of passive component parameters of proposed LNA, particle swarm optimization (PSO) algorithm has been used. All the simulations have been done for a range of frequency 0-35 GHz in Cadence Virtuoso software 45-nm CMOS technology. The results quoted 18.57 dB maximum voltage gain, 2.4 dB NF, 17.1dB S11, 16.6dB S21, at frequency 25.4 GHz with 0.8V, 1.6mW broad band LNA.
       
  • Different Transitions of Bursting and Mixed-Mode Oscillations in
           Liénard System
    • Abstract: Publication date: Available online 3 September 2019Source: AEU - International Journal of Electronics and CommunicationsAuthor(s): S. Dinesh Vijay, S. Leo Kingston, K. Thamilmaran In this paper, we present the emergence of bursting oscillations, mixed-mode oscillations and transient chaos in the forced Liénard system. The system exhibits intriguing dynamical transitions such as from chaotic bursting oscillations to spiking trains via periodic bursting oscillations, period doubling mixed-mode oscillations route to chaos, and intermittent mixed-mode oscillations on variation of the nonlinear damping coefficient as the control parameter. In addition, the system transits from spiking trains to chaotic bursting oscillations through successive period adding sequences of bursting oscillations upon variation of the strength of nonlinearity. Besides the system exhibits transient chaos also. We believe that it is for the first time that these multiplicity of dynamical behaviors and transitions are reported in a single model. We validate our numerical investigations with the help of experimental observations using a simple nonlinear electronic circuit implementation of the model.
       
  • A Power Efficient Active Inductor-based Receiver Front End for 20 Gb/s
           High Speed Serial Link
    • Abstract: Publication date: Available online 3 September 2019Source: AEU - International Journal of Electronics and CommunicationsAuthor(s): Javed S Gaggatur, Deepanraj Thulasiraman A low-power receiver front end (RFE) with 2-tap continuous time linear equalization (CTLE) was designed in 28nm CMOS technology. The CTLE uses a transconductance-based active inductor for high frequency operation and for area reduction. The active inductor can be tuned around 10 GHz while consuming 7.57 mW from 0.9 V power supply. The CTLE compensates about 7 dB of attenuation due to the channel at a data rate of 20 Gb/s per link, with a power efficiency of 12.6 fJ/bit/dB, nearly 4X better power efficiency than the previous works reported in the literature. It shows prominence in the receivers used for wireline I/O interfaces like USB 3.2 and PCI Express 4.0.
       
  • Non-ideal memristor synapse-coupled bi-neuron Hopfield neural network:
           Numerical simulations and breadboard experiments
    • Abstract: Publication date: Available online 31 August 2019Source: AEU - International Journal of Electronics and CommunicationsAuthor(s): Chengjie Chen, Han Bao, Mo Chen, Quan Xu, Bocheng Bao This paper presents a third-order non-ideal memristor synapse-coupled bi-neuron Hopfield neural network (HNN), in which a non-ideal memristor synapse is employed to generate an electromagnetic induction current caused by the potential difference between two neurons. The memristive HNN model possesses an odd number of equilibrium points including one (or three, dependent on the memristor coupling strength) unstable saddle point, two unstable index-2 saddle-foci, and two (or four) stable node-foci. Bifurcation plots, local attraction basins, and phase plane plots show that the memristive HNN model behaves bi-stability of coexisting chaotic and stable point attractors, which is perfectly validated by breadboard experiments based on discrete components.
       
  • A Decentralized Beam Selection for mmWave Beamspace Multi-User MIMO System
    • Abstract: Publication date: Available online 30 August 2019Source: AEU - International Journal of Electronics and CommunicationsAuthor(s): Rahul Pal, K.P. Sarawadekar, K.V. Srinivas A millimeter beamspace multi-user multi-input-multi-output system is a key enabling technology of 5G to fulfil the demand for high data rate. But, it suffers from high RF complexity. However, RF Complexity can be reduced by the beam selection algorithm. Hence, few beam selection algorithms were proposed with a centralized approach. In this paper, a decentralized beam selection algorithm for millimeter wave beamspace multi-user MIMO is discussed. Unlike the centralized beam selection algorithm, the decentralized beam selection algorithm doesn’t require a central unit or access point to select beams. The users themselves play an active role to select beams by sharing the local information with the neighbour users. This is also the requirement of a dynamic network. The performance thoroughly confides on the network cooperation to select beams in an efficient manner. The proposed decentralized beam selection algorithm enables the access point to be free from handling of a large channel matrix. Therefore, this low complexity beam selection algorithm is a better alternative. The performance and complexity of the proposed beam selection algorithm are examined in the following section.
       
  • Multifrequency Rectangular Microstrip Antenna with array of L-slots
    • Abstract: Publication date: Available online 29 August 2019Source: AEU - International Journal of Electronics and CommunicationsAuthor(s): Antara Ghosal, Sisir Kumar Das, Annapurna Das A rectangular microstrip antenna containing an array of narrow L-slots and inverted L-slots is described for multifrequency operation. The patch was designed for TM010 mode of excitation at 2.1 GHz and is fed with a coaxial probe from the ground plane. The slots are cut on the patch at two opposite corners. The widths and lengths of these slots are varied to obtain the optimum performance at multiple frequencies. The performance parameters of this antenna are reflection coefficient (S11), radiation pattern, gain, and efficiency. A simple slotted structure without any additional electronic circuit was designed for multifrequency operation. The Ansoft HFSS software tool was used for the simulation and optimum design of the antenna on a FR-4 dielectric substrate above a ground plane. It is observed that the final configuration produces very good performance at penta frequencies: 1.25, 1.48, 1.8, 2.25, and 2.9 GHz with reasonable gain. The simulation results are verified with the experimental results and are found to be in good agreement.
       
  • Optimum Time/Power Fraction of Energy Harvesting in TSR/PSR SWIPT-based
           Cooperative Communications with Effective Capacity Maximization Approach
    • Abstract: Publication date: Available online 28 August 2019Source: AEU - International Journal of Electronics and CommunicationsAuthor(s): Abdulhamid Zahedi, Mustafa Ergen, Ibraheem Shayea In relay-based cooperative communications (RBCC) system, the energy problem of relays is a significant issue needs to be addressed. In the last few years, the simultaneous wireless information and power transfer (SWIPT) technique has been introduced to solve that matter. SWIPT technique aims to carry data and power over the wireless signals from the source node to the destination for the relays system. The SWIPT technique can be implemented utilizing two protocols. The first one has been introduced as time switch relay (TSR) protocol, which is time division between energy harvesting and data transmission. The second one has been introduced as power switch relay (PSR) protocol based on power division between two mentioned processes. The time or power fraction directly affects the quality of service (QoS) parameters in SWIPT-based cooperative communication systems. This paper aims to maximize effective capacity by implementing an optimization to find the optimum time or power fraction of energy harvesting in relays system utilizing TSR or PSR protocols. The optimization is applied using Lagrange multipliers while simulation results are used to verify the theoretical results obtained from the optimization process. In addition, outage probability of the source-relay-destination link is analyzed in both TSR and PSR protocols.
       
  • A Robust Calibration Method for R-2R Ladder-Based Current-Steering DAC
    • Abstract: Publication date: Available online 27 August 2019Source: AEU - International Journal of Electronics and CommunicationsAuthor(s): Arash Esmaili, Hadiseh Babazadeh A foreground calibration technique for high-resolution, high-speed R-2R ladder-based current-steering digital-to-analog converter (DAC) is proposed. This kind of converter suffers from both current source mismatch and resistor mismatch. It is proved mathematically that the mismatch effect of the network resistors can be mapped to auxiliary current sources in parallel to the main current sources. Then this current sources can be calibrated in such a way that the output seems to be near ideal. A 125MHz, 14-bit current-steering DAC is designed in 0.18μm CMOS with the proposed calibration scheme. Assuming a variance of ±10Ω for 1kΩ network resistors and ±2% mismatch among current sources, the INL and DNL are improved from 13b and 26b respectively to 0.5b and 0.8b utilizing the calibration. The spurious-free-dynamic-range (SFDR) raises from 63.7dB to 93.1dB while SNDR improves from 60.7dB to 84.2dB. This occurs for a small power penalty, and this process is resettable for PVT changes.
       
  • Tunable Dual-Band Bandpass Filter for Multi-Standard Applications
    • Abstract: Publication date: Available online 26 August 2019Source: AEU - International Journal of Electronics and CommunicationsAuthor(s): Samaneh Sedighi Maragheh, Massoud Dousti, Mehdi Dolatshahi, Behbod Ghalamkari A new tunable dual-mode dual bandpass filter (DBPF) is presented based on coupled-line resonators structure. The center frequency and bandwidth can be individually tuned in each band with varactors, which are loaded at the end and middle of the coupled resonators. Varactor diodes can adjust the lower band from GPS to GSM standards (from 1.57 to 1.85 GHz), and the higher band for GSM, UMTS, WiFi and WiMAX applications (from 1.85 to 2.5 GHz). The LC equivalent model of the proposed filter is presented to analyze the resonator at odd- and even-mode frequencies to prove the favorable role of each varactor in tuning the center frequency and bandwidth. To validate the simulation results, the proposed filter is fabricated and measured. Measurement results are in good agreement with LC equivalent model and simulation results.
       
  • Design and Analysis of Loran Transmitter Based on PWM Switching and OMOE
           Indicator
    • Abstract: Publication date: Available online 23 August 2019Source: AEU - International Journal of Electronics and CommunicationsAuthor(s): Abazar Khorrami, Ahmad Afifi, Mohamad Hossein Ghezelayagh Successful implementation of amplitude modulated Loran signal transmitter using switching amplifiers has been reported, but its implementation using Pulse Width Modulation (PWM) technique has not yet been addressed. Here, a Loran transmitter topology using PWM switching amplifiers and its basic building blocks, which can be implemented easily by conventional hardware, is proposed. In this work, performance of both direct amplitude modulation and PWM-based transmitters has been evaluated using Overall Measure Of Effectiveness (OMOE) indicator. The work also consists of mathematical expression of the shape and timing of provided signal in comparison to desired Loran signal. Simulation results indicate that the proposed three-level PWM structure meets the specifications of desired Loran signal closer than the amplitude modulation. The OMOE indicator for three-level PWM yields 0.488 and for conventional amplitude based switching is 0.429.Graphical abstractGraphical abstract for this article
       
  • Threshold Optimization of Collaborative Spectrum Sensing by Maximizing the
           Sensing Reliability Index Under Nakagami-M Fading
    • Abstract: Publication date: Available online 23 August 2019Source: AEU - International Journal of Electronics and CommunicationsAuthor(s): Elahe Gholami Matikolaei, Hamid Meghdadi, Ali Shahzadi, Mohammad Akhondi Darzikolaei Secondary users in a cognitive radio system use the frequency bands allocated for the primary user when these bands are unoccupied. In this paper, spectrum sensing in cognitive radio is investigated. The secondary users are uniformly distributed and can move in the area. The probability distribution function of the distance between primary and secondary users is theoretically calculated and used to obtain Sensing Reliability Index (SRI) as a measure of the system performance. The optimal threshold of energy detection is computed by maximizing SRI.
       
  • Compact and Wideband Planar Loop Antenna with Microstrip to Parallel Strip
           Balun Feed Using Metamaterials
    • Abstract: Publication date: Available online 23 August 2019Source: AEU - International Journal of Electronics and CommunicationsAuthor(s): Shima Poorgholam Khanjari, Saughar Jarchi, Mahmoud Mohammad-Taheri In this paper, a small size, wideband and high gain planar loop antenna with a new feed is presented. The antenna consists of a printed rectangular loop with two gaps, a corrugated reflector in order to reduce the antenna size and a dipole. In addition, a parasitic strip and metamaterials are also used in the antenna structure. Corrugating the reflector will extend the current path, it means the effective electrical length increases and resonance frequency decreases and therefore, the current on the reflector flows over a longer path which results in a size reduction. Compared to the originally printed loop antennas, the size of the proposed antenna is reduced by 50.1%. The parasitic strip and metamaterials act as a director for a quasi-Yagi-Uda in high frequency, and also improve the main directivity. In addition, using the metamaterials improve the antenna gain and impedance matching. To demonstrate the capability of the proposed design method, the antenna has been fabricated and its parameters measured. Measured results show that the fabricated antenna has a wide fractional bandwidth of 53% from 2.01 to 3.478 GHz with return loss of better than 10 dB and a measured peak gain of 5.4 dBi.
       
  • Dual Polarized Antennas with Reduced User Effects for LTE-U MIMO Mobile
           Terminals
    • Abstract: Publication date: Available online 23 August 2019Source: AEU - International Journal of Electronics and CommunicationsAuthor(s): Rizwan Khan, Azremi Abdullah Al-Hadi, Ping Jack Soh, Che Muhammad Nor Che Isa, Mohd Tarmizi Ali, Owais, Shahid Khan A concept of using dual-polarized, three dimensional antenna elements with minimized current distribution on ground plane to reduce the effects of user’s hand on a mobile terminal operating in LTE-U 5G band is proposed. This method which also minimizes mutual coupling (MC) is studied using a structure consisting of two non-identical antenna elements based on folded monopole topology, fed using distinct feeding mechanisms and consequently resulting in dual-polarization. For validation, the performance of this proposed MIMO antenna (MA1) is compared with a pair of dual-polarized conventional PIFA (MA2) placed orthogonally on an identical mobile terminal chassis. Both structures are assessed in terms of radiation efficiency (ƞrad), envelop correlation coefficient (ECC) and multiplexing efficiency (ME). Moreover, due to large radiation coverage, a multitude of hand phantoms and types of grips are used in simulations and experimental evaluations to validate users’ effect. Despite the presence of human hand in various modes and grips, the proposed antenna indicated decreased ƞrad and ME of about 27 % and 25 %, respectively. This is due to the near negligible difference in current distributions on ground plane. In comparison, conventional PIFA which exhibited ƞrad and ME decrease of up to 71 % and 70 %, respectively.
       
  • On Harvesting Residual Thermal Energy from Photovoltaic Module Back
           Surface
    • Abstract: Publication date: Available online 22 August 2019Source: AEU - International Journal of Electronics and CommunicationsAuthor(s): Renata I.S. Pereira, Marcelo M. Camboim, Andrea W.R. Villarim, Cleonilson P. Souza, Sandro C.S. Jucá, Paulo C.M. Carvalho In Brazil, photovoltaic (PV) plants have been increasing their importance in the country’s electricity matrix mainly because its annual irradiation can achieve up to 2,400 kWh/m2. On the other hand, the high temperature levels along the PV modules impose a negative effect on the electrical efficiency. For instance, in a PV plant in the Brazilian Northeast region, the PV modules temperature can reach 70°C in a sunny day while the ambient temperature is around 30°C. This difference can be used to generate heat as a residual thermal energy, but, in general, it is wasted to the surrounding environment. In other context, currently, there is an increasing development of Renewable Energy Monitoring Systems (REMS) for monitoring PV plants. In this paper, we present an experimental study on the potential of harvesting PV-module residual thermal energy using thermoelectric generators (TEGs) for powering low-power wireless sensor for REMS to monitor the whole PV plant itself. From the experimental results, 3.3 V is achieved from stepping up about 220 mV harvested from monthly average temperature difference of 15 °C. In addition, it is shown that 528 mW can be harvested every burst of 30 ms, which is enough to power low-power devices.Graphical abstractGraphical abstract for this article
       
  • Atom search optimization algorithm based hybrid antenna array receive
           beamforming to control sidelobe level and steering the null
    • Abstract: Publication date: Available online 2 August 2019Source: AEU - International Journal of Electronics and CommunicationsAuthor(s): Mohammed A. Almagboul, Feng Shu, Yuwen Qian, Xiaobo Zhou, Jin Wang, Jinsong Hu Modern and upcoming 5G cellular communication networks require large-scale antenna systems to improve gain in order to face the weaknesses in the suggested millimeter-wave (mmWave) signals and to meet the higher capacity demand. These systems implement digital beamforming which requires radio frequency (RF) chain connected to each antenna. Hybrid analog-digital (HAD) beamforming has been proposed as a solution to many of the challenges facing the implementation of fully-digital beamforming, namely, energy consumption, hardware cost, and complexity. The main goals of this paper are to reduce the peak sidelobe level (SLL) of the beam pattern and steering the nulls in the desired directions along with reducing the power consumption, hardware cost, and complexity. To achieve these goals, a novel partial-connected hybrid analog-digital receive beamformer based on an atom search optimization (ASO) algorithm is proposed. ASO is a recently invented metaheuristic optimization algorithm imitating the physical movements of atoms as described in molecular dynamics simulation with the advantage of having few parameters to tune. The desired optimization weights are accomplished by controlling the amplitudes-only of the digital beamformer’s vector along with the phase shifts of the analog beamformer’s vectors. Finally, to demonstrate the effectiveness of the proposed beamformer, a comparison with other state-of-the-art metaheuristic algorithms through several scenarios is conducted, in terms of peak SLL reduction, null depth, and convergence rates. Simulation results show that the proposed algorithm has always been outperforming other types of beamformers.
       
  • A Power-Switch Thermal Limiting Technique for Current-Mode Monolithic
           DC-DC Converters
    • Abstract: Publication date: Available online 13 July 2019Source: AEU - International Journal of Electronics and CommunicationsAuthor(s): Zhiming Xiao, Yu Wang, Guangshu Zhao, Yitao Xu, Chao Lu, Weibo Hu This paper presents a power-switch thermal limiting technique for peak current-mode DC-DC converters to achieve maximized load current deliverability under a fixed thermal constraint. The inductor current limit of the converter is adaptively set based on the sensed switching duty-cycle to maintain a fixed power consumption limit across a wide input voltage range. The proposed current limiting circuit exhibits a fast-transient response and the chances of power-switch overheating is minimized. Since the temperature rise of the converter chip is also a function of the heat-conduction conditions such as the package type, the PCB layout, and the ambient temperature, the proposed architecture allows the power limit to be adjustable through a single off-chip resistor. Compared with a conventional switching converter which sets the inductor current limit to be constant across the entire input voltage range, the proposed approach achieves a higher available load current, especially with a higher input voltage under the same thermal constraint. In the proposed boost converter with an allowable temperature rise of 40°C, the proposed converter achieved 46% more available load current compared with the conventional one at the highest input voltage.
       
 
 
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