for Journals by Title or ISSN
for Articles by Keywords
help

Publisher: Elsevier   (Total: 3160 journals)

 A  B  C  D  E  F  G  H  I  J  K  L  M  N  O  P  Q  R  S  T  U  V  W  X  Y  Z  

        1 2 3 4 5 6 7 8 | Last   [Sort by number of followers]   [Restore default list]

Showing 1 - 200 of 3160 Journals sorted alphabetically
Academic Pediatrics     Hybrid Journal   (Followers: 37, SJR: 1.655, CiteScore: 2)
Academic Radiology     Hybrid Journal   (Followers: 25, SJR: 1.015, CiteScore: 2)
Accident Analysis & Prevention     Partially Free   (Followers: 97, SJR: 1.462, CiteScore: 3)
Accounting Forum     Hybrid Journal   (Followers: 28, SJR: 0.932, CiteScore: 2)
Accounting, Organizations and Society     Hybrid Journal   (Followers: 37, SJR: 1.771, CiteScore: 3)
Achievements in the Life Sciences     Open Access   (Followers: 5)
Acta Anaesthesiologica Taiwanica     Open Access   (Followers: 7)
Acta Astronautica     Hybrid Journal   (Followers: 427, 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: 2)
Acta de Investigación Psicológica     Open Access   (Followers: 3)
Acta Ecologica Sinica     Open Access   (Followers: 10, SJR: 0.18, CiteScore: 1)
Acta Haematologica Polonica     Free   (Followers: 1, SJR: 0.128, CiteScore: 0)
Acta Histochemica     Hybrid Journal   (Followers: 3, SJR: 0.661, CiteScore: 2)
Acta Materialia     Hybrid Journal   (Followers: 288, SJR: 3.263, CiteScore: 6)
Acta Mathematica Scientia     Full-text available via subscription   (Followers: 6, 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: 27, 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: 17, 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: 176, 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: 16, SJR: 2.384, CiteScore: 5)
Advances in Anesthesia     Full-text available via subscription   (Followers: 28, 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: 10, SJR: 0.992, CiteScore: 1)
Advances in Applied Mechanics     Full-text available via subscription   (Followers: 11, 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: 14, 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: 32, 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: 4)
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: 28, SJR: 0.156, CiteScore: 1)
Advances in Child Development and Behavior     Full-text available via subscription   (Followers: 10, 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: 11)
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: 49, 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: 61, 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: 20, 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: 6, SJR: 1.193, CiteScore: 3)
Advances in Heat Transfer     Full-text available via subscription   (Followers: 24, SJR: 0.368, CiteScore: 1)
Advances in Heterocyclic Chemistry     Full-text available via subscription   (Followers: 12, SJR: 0.749, CiteScore: 3)
Advances in Human Factors/Ergonomics     Full-text available via subscription   (Followers: 23)
Advances in Imaging and Electron Physics     Full-text available via subscription   (Followers: 2, SJR: 0.193, CiteScore: 0)
Advances in Immunology     Full-text available via subscription   (Followers: 36, 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: 8, 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: 18, SJR: 0.88, CiteScore: 2)
Advances in Mathematics     Full-text available via subscription   (Followers: 11, SJR: 3.027, CiteScore: 2)
Advances in Medical Sciences     Hybrid Journal   (Followers: 7, SJR: 0.694, CiteScore: 2)
Advances in Medicinal Chemistry     Full-text available via subscription   (Followers: 5)
Advances in Microbial Physiology     Full-text available via subscription   (Followers: 4, SJR: 1.158, CiteScore: 3)
Advances in Molecular and Cell Biology     Full-text available via subscription   (Followers: 23)
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: 4)
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: 17, 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: 25, SJR: 0.461, CiteScore: 1)
Advances in Pharmaceutical Sciences     Full-text available via subscription   (Followers: 12)
Advances in Pharmacology     Full-text available via subscription   (Followers: 16, SJR: 1.536, CiteScore: 3)
Advances in Physical Organic Chemistry     Full-text available via subscription   (Followers: 8, 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: 5)
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: 66)
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: 413, 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: 12, SJR: 0.555, CiteScore: 2)
Advances in the Study of Behavior     Full-text available via subscription   (Followers: 35, SJR: 2.208, CiteScore: 4)
Advances in Veterinary Medicine     Full-text available via subscription   (Followers: 19)
Advances in Veterinary Science and Comparative Medicine     Full-text available via subscription   (Followers: 15)
Advances in Virus Research     Full-text available via subscription   (Followers: 5, SJR: 2.262, CiteScore: 5)
Advances in Water Resources     Hybrid Journal   (Followers: 49, SJR: 1.551, CiteScore: 3)
Aeolian Research     Hybrid Journal   (Followers: 6, SJR: 1.117, CiteScore: 3)
Aerospace Science and Technology     Hybrid Journal   (Followers: 362, 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: 11, SJR: 3.671, CiteScore: 9)
Aggression and Violent Behavior     Hybrid Journal   (Followers: 470, SJR: 1.238, CiteScore: 3)
Agri Gene     Hybrid Journal   (Followers: 1, SJR: 0.13, CiteScore: 0)
Agricultural and Forest Meteorology     Hybrid Journal   (Followers: 17, SJR: 1.818, CiteScore: 5)
Agricultural Systems     Hybrid Journal   (Followers: 31, SJR: 1.156, CiteScore: 4)
Agricultural Water Management     Hybrid Journal   (Followers: 43, 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: 6, 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: 11)
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: 52, SJR: 4.66, CiteScore: 10)
Alzheimer's & Dementia: Diagnosis, Assessment & Disease Monitoring     Open Access   (Followers: 4, SJR: 1.796, CiteScore: 4)
Alzheimer's & Dementia: Translational Research & Clinical Interventions     Open Access   (Followers: 4, SJR: 1.108, CiteScore: 3)
Ambulatory Pediatrics     Hybrid Journal   (Followers: 6)
American Heart J.     Hybrid Journal   (Followers: 57, SJR: 3.267, CiteScore: 4)
American J. of Cardiology     Hybrid Journal   (Followers: 62, SJR: 1.93, CiteScore: 3)
American J. of Emergency Medicine     Hybrid Journal   (Followers: 44, SJR: 0.604, CiteScore: 1)
American J. of Geriatric Pharmacotherapy     Full-text available via subscription   (Followers: 11)
American J. of Geriatric Psychiatry     Hybrid Journal   (Followers: 13, SJR: 1.524, CiteScore: 3)
American J. of Human Genetics     Hybrid Journal   (Followers: 34, 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: 35, SJR: 2.973, CiteScore: 4)
American J. of Medicine     Hybrid Journal   (Followers: 48)
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: 231, 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: 29, 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: 63, SJR: 0.138, CiteScore: 0)
Anaesthesia Critical Care & Pain Medicine     Full-text available via subscription   (Followers: 20, 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: 200, SJR: 0.633, CiteScore: 2)
Analytical Chemistry Research     Open Access   (Followers: 12, 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: 23, 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: 206, SJR: 1.58, CiteScore: 3)
Animal Feed Science and Technology     Hybrid Journal   (Followers: 6, SJR: 0.937, CiteScore: 2)

        1 2 3 4 5 6 7 8 | Last   [Sort by number of followers]   [Restore default list]

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  [3160 journals]
  • A Charge Amplifier with Noise Peaking Suppression and Gain Drop
           Compensation utilizing a Quasi-Miller RC Network
    • Abstract: Publication date: Available online 21 May 2019Source: AEU - International Journal of Electronics and CommunicationsAuthor(s): Zhen Gu, Xiaojun Bi A charge amplifier with noise peaking suppression and gain drop compensation is proposed. By utilizing the proposed Quasi-Miller RC network, the noise peaking is suppressed and gain drop is compensated, which alleviates the design trade-off between charge gain and output root-mean-square (RMS) noise, therefore obtains an improved sensitivity. Meanwhile, the Quasi-Miller RC network permits the charge amplifier to support ultra-low frequency operation without using a huge resistor, which is normally required by the charge amplifier. The fabricated charge amplifier demonstrates an input-referred RMS noise charge of 909 aC, a charge gain of 10.2 V/pC and a 3-dB bandwidth from 80 Hz to 38 MHz. Low noise and high charge gain are obtained simultaneously. Meanwhile, extremely low cut-off frequency is also obtained, which is beneficial to maintain the signal integrity.
       
  • Impact of Ferroelectric on the Electrical Characteristics of
           Silicon–Germanium based heterojunction Schottky Barrier FET
    • Abstract: Publication date: Available online 21 May 2019Source: AEU - International Journal of Electronics and CommunicationsAuthor(s): Adla Vinod, Prashanth Kumar, Brinda Bhowmick This work investigates the impact of ferroelectric gate oxide on high-k gate dielectric with low band gap Silicon Germanium ferroelectric Schottky barrier FET (SiGe Fe-SBFET), has been qualitatively simulated. The present research focuses on major improvement over the conventional device in terms of drain current and reduced subthreshold swing and analog performances. The proposed device has been analyzed in terms of numerous device electrostatic parameters such as electric field and energy band diagram using a ferroelectric material. A novel approach of SiGe-Fe-SBFET provides an effective technique helps to increase the performance in terms of on-current and off-state current of the device. The SiGe-Fe-SBFET also provides high Ion/Ioff ratio of 4.188x1012 and low Subthreshold swing of 67mV/dec in comparison with germanium (Ge) and silicon (Si) material based ferroelectric SBFET. Apart from this, the increasing of tunneling width for the drive of carriers in the drain-channel junction, which results in a reduction of ambipolar conduction in off-state with gate drain underlap. Further, the analog performances of proposed and conventional device are evaluated such as transconductance, intrinsic gate delay, output conductance and cut-frequency which is dependent of parasitic gate capacitances are also investigated through a 2D Silvaco Atlas simulator.
       
  • Performance Analysis of QAM Schemes for Non-regenerative Cooperative MIMO
           Network with Transmit Antenna Selection
    • Abstract: Publication date: Available online 20 May 2019Source: AEU - International Journal of Electronics and CommunicationsAuthor(s): Parvez Shaik, Praveen K. Singya, Vimal Bhatia In this paper, performance of a dual-hop cooperative multiple-input and multiple-output (MIMO) system for various futuristic QAM schemes is analyzed. A non-regenerative MIMO scheme with transmit antenna selection strategy is considered where a single transmit antenna maximizing the total received signal power is selected for transmission. In the considered system model, it is assumed that the source, relay and the destination are equipped with multiple antennas. As a performance measure, generalized expressions for average symbol error rate for hexagonal quadrature amplitude modulation, rectangular quadrature amplitude modulation, square quadrature amplitude modulation and 32-cross quadrature amplitude modulation are derived. the impact of pathloss is highlighted for the considered system model and finally, the derived analytical expressions are validated through Monte-Carlo simulations.
       
  • Design and Analysis of Multiplier Using Approximate 4-2 Compressor
    • Abstract: Publication date: Available online 18 May 2019Source: AEU - International Journal of Electronics and CommunicationsAuthor(s): Karri Manikantta Reddy, M.H. Vasantha, Y.B. Nithin Kumar, Devesh Dwivedi Approximate computing has received significant attention as an attractive paradigm for error-tolerant applications to reduce the power consumption, delay and area with some trade-off in accuracy. This paper proposes the design of a novel approximate 4-2 compressor. A modified architecture of Dadda Multiplier is presented for the effective utilization of the proposed compressor and to reduce the error at the output. Through extensive experimental evaluation, the efficiency of the proposed compressor and multiplier are evaluated in a 45nm standard CMOS technology and their parameters are compared with those of the state-of-the-art approximate multipliers. The results show that the proposed compressor accomplish a significant reduction in error rate compared to other approximate compressors available in the literature. In addition, the proposed multiplier shows 35%, 36% and 17% reduction in power consumption, delay and area respectively compared to those of exact multiplier. The effectiveness of multiplier is assessed by some of the image processing applications. On an average, the proposed multiplier processes images with 85% structural similarity compared to the exact output image.
       
  • Compact Ultra-Wideband Circularly Polarized CPW-Fed Monopole Antenna
    • Abstract: Publication date: Available online 18 May 2019Source: AEU - International Journal of Electronics and CommunicationsAuthor(s): Prashant Chaudhary, Ashwani Kumar This paper presents a coplanar waveguide (CPW) -fed quadrilateral-shaped compact planar monopole antenna for ultra-wideband (UWB) application. The fractional axial ratio bandwidth (ARBW) of the antenna for circular polarization (CP) is 56.64% (5.91-10.58GHz) and its fractional impedance matching bandwidth (IMBW) is 137.1% (3.1-17.5GHz), which are realized by designing a quadrilateral-shaped monopole with an asymmetric ground plane. The proposed antenna structure is simple and compact; hence its design is efficient, and it has an impedance matching (S11) in UWB band with embedded wideband circular polarization. The gain of the antenna varies between 3.33 to 8.9dBi. Furthermore, its application for designing the linear array and planar array of 1×2 and 2×2 antenna elements are presented. The gain improves to 5.1dBi ∼ 9 dBi for 1×2 array elements and to 9dBi ∼ 11.2dBi for 2×2 array with UWB IMBW. Simulated and experimental results are presented to validate the antenna design and are shown to be in good agreement.
       
  • A Utilization of Multiple Antenna Elements for Matched Filter Based
           Spectrum Sensing Performance Enhancement in Cognitive Radio System
    • Abstract: Publication date: Available online 18 May 2019Source: AEU - International Journal of Electronics and CommunicationsAuthor(s): Ahmed A. Kabeel, Amr H. Hussein, Ashraf A.M. Khalaf, Hesham F.A. Hamed Cognitive radio (CR) has been classified as a promising technology which can significantly mitigate the impact of spectrum underutilization and spectrum scarceness arising from massive expansion of wireless applications. That is as a result of the CR capability to improve both the spectral and energy management efficiently. Spectrum sensing is the most important technological requirement for accomplishment of cognitive radio systems. For a known primary user (PU) signal, matched filtering is the common technique used for signal detection over a specific band of spectrum, therefore, detection performance enhancement of the matched filter detector has gained great attention. In this paper, a new multiple antenna elements (MAE) and matched filtering (MF) based spectrum sensing technique named as MAE/MF is proposed for detection capability enhancement. Multiple antenna elements utilization improves the received signal to noise ratio (SNR) in proportional to the achieved antenna array gain. The likelihood ratio test is used to decide the presence/ absence of PU signal. Simulation results showed that the proposed MAE/MF technique outperforms the single antenna element based matched filter (SAE/MF) and other existing techniques in the state-of-the-art, especially at extremely low signal to noise ratios and limited number of received signal samples.
       
  • Design and validation of an adaptive cubesat transmitter system
    • Abstract: Publication date: Available online 17 May 2019Source: AEU - International Journal of Electronics and CommunicationsAuthor(s): Fitri Jaswar, Ahmed M. Al-Samman, Tharek Abdul Rahman, Yasser Asrul Ahmad CubeSat in low earth orbit (LEO) primarily uses an amateur radio-band transmitter with a fixed specification. Nevertheless, the LEO satellite does not have an orbital velocity that equates to one sidereal day. Therefore, the ground station antenna views the satellite at different elevation angles which result in varied propagation path lengths. In this paper, an adaptive transmitter is designed to optimise the LEO satellite communication link and overcome the variability of the propagation path length issue due to different ground station elevation angles. A satellite communication link and operation analyses are performed to identify the relationship between the variation of the elevation angle so as to determine the optimum signal-to-noise ratio (SNR), improve data rate and increase the power efficiency of an adaptive link. Based on the results, a model is developed to control the adaptive configuration. The SNR and power consumption performance of the developed transmitter is compared with commercial transmitters. The results indicate that the transmitter output power is adjustable from 0.5W to 1W, and the data rate is selectable between 9,600bps and 19,200bps. Compared to other CubeSat transmitters, the developed adaptive transmitter demonstrates more than 20% improvement in terms of SNR optimisation, additional throughput and power reduction.
       
  • High power T-ray generation using a new array of photoconductive antennas
    • Abstract: Publication date: Available online 17 May 2019Source: AEU - International Journal of Electronics and CommunicationsAuthor(s): Hamid Reza Zangeneh, Farzad Moradiannejad In this work, a new array of photoconductive antennas is proposed as a high power T-ray source. The array was modeled and simulated by the finite difference time domain method. The structure and characteristics of the T-ray source were studied. The potential advantages of the proposed array include enhanced efficiency of the broadband THz radiation and confined radiated THz pulse. Also, an asymmetry in the design of the array allows optimizing high optical-to-terahertz conversion efficiencies. These potential advantages of the proposed array can be exploited in satellite telecommunications such as geostationary terahertz satellite links. Moreover, the array is capable of employing radiation-band shaping technique for generation of tunable and narrow-band THz radiation.
       
  • Analysis of MEMS electrostatic energy harvesters electrically configured
           as voltage multipliers
    • Abstract: Publication date: Available online 15 May 2019Source: AEU - International Journal of Electronics and CommunicationsAuthor(s): Binh Duc Truong, Cuong Phu Le, Einar Halvorsen This paper presents the analysis of an efficient alternative interface circuit for MEMS electrostatic energy harvesters. It is entirely composed of diodes and capacitors. Based on modeling and simulation, an anti-phase gap-closing structure is investigated. We find that when configured as a voltage multiplier, it can operate at very low acceleration amplitudes. In addition, the allowed maximum voltage between electrodes is barely limited by the pull-in effect. The parasitic capacitance of the harvester and non-ideal characteristics of electronic components are taken into account. A lumped-model of the harvesting system has been implemented in a circuit simulator. Simulation results show that an output voltage of 22 V is obtained with 0.15 g input acceleration. The minimum necessary ratio between the maximum and minimum capacitances of the generators, which allows operation of the circuit, can be lower than 2. This overcomes a crucial obstacle in low-power energy harvesting devices. A comparison between the voltage multiplier against other current topologies is highlighted. An advantage of the former over the latter is to generate much higher saturation voltage, while the minimum required initial bias and the minimum capacitance ratio in both cases are at similar levels.
       
  • Compact and ultra-wideband CPW-fed square slot antenna for wearable
           applications
    • Abstract: Publication date: July 2019Source: AEU - International Journal of Electronics and Communications, Volume 106Author(s): Seyed Mohsen Hosseini Varkiani, Majid Afsahi This paper is devoted to a compact and ultra-wideband (UWB) CPW (Co-Planar Waveguide)-fed square slot Antenna for wearable applications. In our design, the antenna fabricated on the cotton layer with dielectric constant of 1.65 with compact size of 0.76λ × 0.72λ in which the antenna has a silver based fabric radiating element. The UWB operation of this compact antenna varies from 3.2 GHz to 16.3 GHz considering the fractional band width (FWB) to be 135. To clarify for wearable applications, this compact antenna were compared with different dielectric constant such as non-woven (εr = 1.15, thickness (h) = 5 mm) and FR4 (εr = 4.4, h = 1.6 mm). This antenna, then, were examined both in air, and on a suit shirt situations. The Antenna which is located on body compared to antenna in air has a lower efficiency. Furthermore; it decreases the radiation toward body approximately 10 dB. It also causes frequency shifts and reduces the bandwidth. In both cases, the examinations indicated the compact antenna in the UWB is very desirable.
       
  • High inter-port isolation dual circularly polarized slot antenna with
           split-ring resonator based novel metasurface
    • Abstract: Publication date: Available online 13 May 2019Source: AEU - International Journal of Electronics and CommunicationsAuthor(s): Sumantra Chaudhuri, Rakhesh Singh Kshetrimayum, Ramesh Kumar Sonkar In this paper, a Dual Circularly Polarized (DCP) full-duplex planar slot antenna suitable for C-band applications is presented. The antenna has a single slot with a T-shaped stub that is shared by both the transmitting (TX) and receiving (RX) ports which operate at two mutually orthogonal circular polarizations. A metasurface made up of 4 pairs of face-to-face Split Ring Resonators (SRRs) acts as a decoupling network to enhance the isolation between TX and RX ports. The designed antenna has an impedance bandwidth of 1340 MHz which is 28.52% of centre frequency f0=4.71 GHz. The 3 dB axial ratio (AR) bandwidth is 8.97% centred at fAR=4.44 GHz whereas inter-port isolation is better than 27 dB and reaches up to 36 dB within the usable band. The proposed design also exhibits characteristics suitable for MIMO applications.
       
  • A Balanced energy efficient virtual backbone construction algorithm in
           wireless sensor networks
    • Abstract: Publication date: Available online 11 May 2019Source: AEU - International Journal of Electronics and CommunicationsAuthor(s): G.V. ShaamiliVarsa, D. Sridharan A steady increase in the number Wireless Sensor Networks(WSN) applications in day-to-day life lead to the design of new algorithms and protocols to solve their various issues such as energy efficiency, topology control and data gathering. Energy efficiency can be achieved by focusing on the communication part, since the communication cost is higher than that of the computation. The use of Connected Dominating Set (CDS) as the virtual backbone for data transmission towards the Base Station improvesthe network lifetime. Therefore, a Balanced Energy Efficient Virtual Backbone Construction (BEE-VBC) algorithm in WSN is proposed in this paper using the well-known heuristic Genetic Algorithm (GA). This work emphasizes on the design of fitness function using multiple factors such as energy, coverage of neighbors, reliability, data rate, and traffic deviation. The CDS construction using the maximum fitness nodes, provides network longevity. This ensures a steady connectivity among the dominator nodes and path towards the BS, thus improving the quality of the solution. The simulation experiments have been carried out and compared with a few CDS-based and clustering-based algorithms to show the performance improvement achieved in the proposed work.
       
  • Single-stage multipath class-AB bulk-driven OTA with enhanced power
           efficiency
    • Abstract: Publication date: Available online 11 May 2019Source: AEU - International Journal of Electronics and CommunicationsAuthor(s): Qisheng Zhang, Yongqing Wang, Xiao Zhao, Liyuan Dong A single-stage multipath class-AB bulk-driven operational transconductance amplifier working in weak inversion region with enhanced power efficiency is presented in this paper. The proposed bulk-driven amplifier makes use of four signal path to conduct small signal current, which leads to significant enhancement of transconductance when compared to conventional recycling structure. In addition, two of the signal paths build output stage operating at class-AB, resulting in a boost of slew rate. Most of all, the power efficiency of the proposed amplifier is improved over that of traditional recycling counterpart, enabling it more suitable for low-power applications. Simulated on SMIC 180nm process, results demonstrate that the proposed bulk-driven amplifier achieves a 256% slew rate improvement and 100% unity-gain bandwidth enhancement when compared to the conventional recycling structure.
       
  • Performance Enhancement of Shorted Polygonal Archimedean Spiral Antenna
           Using Hybrid Reflector
    • Abstract: Publication date: Available online 11 May 2019Source: AEU - International Journal of Electronics and CommunicationsAuthor(s): R. Udaiyakumar, R. Maheswar, T. Janani, R. Vigneshram, Iraj S Amiri, P Yupapin In this paper, performance enhancement in a shorted polygonal archimedean spiral antenna has been proposed by backing it with a hybrid reflector. In the proposed work, two arms of the polygonal spiral antenna are shorted at an outer octagonal conductive ring aiding in size reduction of the polygonal spiral. The shorted polygonal spiral antenna with the advantages of low profile and the good axial ratio at lowest frequencies of operation is backed by a hybrid reflector that utilizes combination ferrite layer which tapers towards the center to a PEC layer. The hybrid reflector helps to improve the gain of the antenna significantly at low frequencies without compromising the gain of the antenna at high frequencies. The antenna operates from 0.6 GHz to 6.5 GHz with a minimum boresight gain of 0.2 dBic at 0.6 GHz and an average gain of 6 dBic from 2.2 GHz. The antenna also demonstrates a good axial ratio of ≤ 3 dB over the VSWR bandwidth in a low-profile dimension of 0.13 λ0 x 0.13 λ0 x 0.04 λ0. The proposed work thus presents a novel idea to develop a compact high-performance spiral by shorting the arms of a polygonal spiral with a conductive ring and backing the same by a hybrid reflector and cavity.
       
  • A low-cost energy-harvesting sensory headwear useful for tetraplegic
           people to drive home automation
    • Abstract: Publication date: Available online 11 May 2019Source: AEU - International Journal of Electronics and CommunicationsAuthor(s): Giuseppe Piscitelli, Vito Errico, Mariachiara Ricci, Franco Giannini, Giovanni Saggio, Alfiero Leoni, Vincenzo Stornelli, Giuseppe Ferri, Leonardo Pantoli, Iolanda Ulisse Tetraplegic people need continuous assistance in every daily activity. Assistive technologies can improve, to a certain degree, their quality of life allowing partial autonomy with powering their residual capability of movements. In this work, we propose a novel wire-free low-cost user-friendly battery-operated sensory headwear, which allows home automation controlled by head movements. The headwear is equipped with an inertial measurement unit (IMU), a low power microcontroller and a transmission module to measure, condition and wireless transmit data related to head movements. Such a sensory headwear allows the subject, simply by head movements, either to select one computer icon among an ensemble or to select one actuator, among a number of others. Each icon and each actuator drive a specific physical action in a home or work environment. We devoted particular efforts to increase the battery autonomy, by means of radio frequency energy harvesting solutions, for lasting operational mode. The harvester, based on commercial chipsets, was optimized in the 2.4-2.5GHz range to exploit headwear itself radiated energy and environmental energy, in particular from Wi-Fi and Bluetooth surrounding devices. An average efficiency, calculated as output to input power ratio, of around 60% at -5dBm input power level has been obtained.
       
  • Miniaturized Dual-Band CPW Wilkinson Power Divider Using T-Network
           Adopting Series Stubs with a High Frequency Ratio
    • Abstract: Publication date: Available online 10 May 2019Source: AEU - International Journal of Electronics and CommunicationsAuthor(s): Heba Jaradat, Nihad Dib, Khair Al Shamaileh In this paper, a compact dual-band coplanar waveguide (CPW) Wilkinson power divider (WPD) is presented. Two arbitrary frequency bands are obtained by replacing the quarter-wavelength transmission lines in the conventional design by two compact ones separated by a series stub. The proposed methodology facilitates a maximum frequency ratio around 7 without incorporating reactive components, making it attractive for high frequency applications. To validate the design procedure, a dual-band CPW-based WPD that operates at 0.5 and 2.5 GHz is simulated and measured. Results show input/output ports matching better than –20 dB along with 30 dB isolation between the output ports. Furthermore, transmission parameters of –3.56 dB and –5.6 dB are obtained at the first and the second design frequencies, respectively. Simulated results agree very well with the measured ones.
       
  • Perfect Isolation Performance Among Two-Element MIMO Antennas
    • Abstract: Publication date: Available online 10 May 2019Source: AEU - International Journal of Electronics and CommunicationsAuthor(s): Ibrahim Mohamed, Mahmoud Abdalla, Abd El-Aziz Mitkees A rectangular microstrip patch (RMSP) antenna is designed to be used in a two-element Multi-Input Multi-Output (MIMO) antennas at which they operate at 5.8 GHz. The two antennas are positioned opposite to each other with a separation of 10 mm (0.2 λ0) from their radiating edges. A novel uni-conductor electromagnetic bandgap (UC-EBG) periodic cells are introduced in this paper as effective barriers for surface waves compared to the conventional UC-EBG. Each unit cell has a compact size area 7.3×5.8 mm2 where it is 20 % more compact than the conventional cell. Two of the proposed modified EBG periodic cells are placed in-between the two antennas causing an excellent reduction in the coupled power of 46 dB. This strong isolation definitely enhances the performance of antennas in MIMO communication systems, where 0.0001and 0.03 values for correlation coefficient have obtained from S-parameters and far-field information, respectively, due to this strong isolation.
       
  • Digital Background Calibration of Ultra-High-Speed Time-Interleaved of
           PAM4 2-bit DACs
    • Abstract: Publication date: Available online 10 May 2019Source: AEU - International Journal of Electronics and CommunicationsAuthor(s): Gilad Katz, Russ Romano, Tony Zortea Sample-time error (STE) between time-interleaved channels is one of the main limitations on the performance of time-interleaved digital to analog converters (DACs). This paper presents techniques for detecting and correcting the STE in ultra-high speed 53 GBaud 4-level pulse amplitude modulation (PAM4) with a 2-Bit DAC. Simulation results and lab measurements of a TSMC 16nm CMOS process are presented. Test results show that the peak-to-peak STE of the 53 GBaud DAC is improved by more than one order of magnitude.
       
  • Nanopower Sub-threshold Biquadratic Cells and Its Application to Portable
           ECG System
    • Abstract: Publication date: Available online 9 May 2019Source: AEU - International Journal of Electronics and CommunicationsAuthor(s): Saleha Bano, Ghous Bakhsh Narejo, S.M. Usman Ali This paper presents two different compact nanopower subthreshold biquadratic cells suitable for portable ECG application. First designed filter is a low-pass filter (LPF) to remove out of the band noise while the second designed filter is a notch filter to remove the power line interference. LPF is designed by cascading fully differential subthreshold N-biquad and P-biquad cells. It consists of three MOS transistors for a single ended biquad section while five MOS transistors are utilized for designing notch filter. Both circuits are simulated in 0.13µm CMOS technology in Cadence environment. LPF consumes 7.23nW power with a supply voltage of 1.2V. It is self-compensated with 0 dB gain, provides dynamic range of 62.01dB with input referred noise of 61.7µVrms, HD3 of 58.7 dB with 90mVpp 100Hz frequency while a cut-off frequency of 243 Hz is obtained. For 50 Hz notch filter, depth of -33 dB is obtained. The comparison of both circuits provides the best figure of merit for ECG application and the highest dynamic range for LPF.
       
  • A 261-µW ultra-low power RF Mixer with 26-dBm IIP3 using complementary
           pre-distortion technique for IEEE 802.15.4 applications
    • Abstract: Publication date: Available online 9 May 2019Source: AEU - International Journal of Electronics and CommunicationsAuthor(s): S. Chrisben Gladson, M. Bhaskar, R. Praveen, S. Sudharsan The wireless mobile communication is being replaced by wireless personal communication due to the advent of the Internet-of-things (IoT). The IoT applications in the 2.4GHz band face critical trade-off with respect to signal linearity and battery power. The IoT devices require more power to overcome the nonlinear effects in the channel, resulting in rapid discharge of battery. The wireless industry faces a challenge of providing proper signal processing without draining the battery drastically. In this paper, an ultra-low power RF mixer using complementary pre-distortion (CPD) technique is proposed to overcome the trade-off between linearity and power consumption. The proposed CPD based mixer is designed in UMC 180nm CMOS process, and the post layout simulations using Cadence SpectreRF tool shows an IIP3 of 26.36dBm and an IIP2 of 137.1dBm while consuming only 261.6µW from a 1-V supply. The proposed CPD method gives the better linearity per mW ratio when compared to other recently proposed mixer circuits. The proposed mixer also provides a gain of 11.45dB while contributing a very low double-sideband noise figure (DSB-NF) of 8.5dB. The CPD based mixer has a spurious free dynamic range (SFDR) of 91.57dB which is 10dB higher than the recently proposed RF front-end while occupying a core area of 0.33mm2.
       
  • Performance Analysis of QAM for L-MRC Receiver with Estimation Error over
           Independent Hoyt Fading Channels
    • Abstract: Publication date: Available online 9 May 2019Source: AEU - International Journal of Electronics and CommunicationsAuthor(s): Dimpee Das, Rupaban Subadar In modern wireless communication, smart receivers are used to overcome the effect of fading and includes the estimation of the channels as a part of its signal processing. From a theoretical point of view these type of receivers offer high grade performance, however from practical point of view the performance depends on the accuracy of the estimation of channels. In real practice, ideal channel estimator is very difficult, which leads to some estimation error in both phase and envelope of the estimated channels information. In this paper, a general expression for average bit error rate (ABER) has been presented for arbitrary branch Maximal Ratio Combining (MRC) while taking an Imperfect Channel Estimation (ICE) into consideration over independent Hoyt fading channels. The expression is formulated for M-ary Quadrature Amplitude Modulation (QAM) scheme. The degradation in the receiver operation due to this error estimation has been analyzed in this paper by numerical evaluation of the obtained expressions. From our analysis we have observed that the envelope estimation error is much critical from the receiver performance point of view.
       
  • Area and Power Efficient Flipped Voltage Follower Based Symmetrical
           Floating Impedance Scaler with Improved Accuracy for Fully Differential
           Filters
    • Abstract: Publication date: Available online 8 May 2019Source: AEU - International Journal of Electronics and CommunicationsAuthor(s): V. Senthil Rajan, R. Sanjay, S. Kumaravel, B. Venkataramani A Source Follower based Symmetrical Floating Impedance Scaler (SF-SFIS) circuits are reported in the prior works, which realize large capacitors with the low area for a fully differential filter. In this paper, a novel Flipped Voltage Follower based Symmetrical Floating Impedance Scaler (FVF-SFIS) with high accuracy is presented. The proposed circuit based on flipped voltage follower with cascaded current mirrors can detect low base capacitors which have lower area and power than the prior SF-SFIS circuits. In order to evaluate its performance and comparison, a 500 pF capacitor is realized by multiplying the base capacitor of 10 pF using both FVF-SFIS and SF-SFIS methods. The magnitude and phase of these impedance scalers are obtained through post-layout simulation. It is found that the proposed impedance scaler requires 51.58% lower area, 69.23% lower power dissipation, and 91.33% higher accuracy than the SF-SFIS. The accuracy of the proposed FVF-SFIS is compared with SF-SFIS circuit by designing a 3rd order Chebyshev low pass filter (LPF) using FVF-SFIS and SF-SFIS with cut-off frequency 100 Hz. The circuit has been designed and simulated in UMC 180 nm technology.
       
  • Symmetrical Doherty Power Amplifier Design via Continuous Harmonic-Tuned
           Class-J Mode
    • Abstract: Publication date: Available online 7 May 2019Source: AEU - International Journal of Electronics and CommunicationsAuthor(s): Gideon Naah, Songbai He, Weimin Shi, Caoyu Li This paper proposes bandwidth and efficiency improvements of symmetrical Doherty power amplifiers (SDPAs) using continuous harmonic-tuned Class-J mode (CHTCJM). By this approach, the effects of the CHTCJM on the impedance inverter network and post-matching network in SDPAs are reanalysed using formulated mathematical equations. In this way, to recover and further improve the bandwidth and efficiency performances in the conventional SDPA. The term recovery as proposed in this context is to redefine, reanalyse, retrieve and further enhance the output-power-back-off efficiency and bandwidth performances lost in the conventional SDPAs using an alternative theoretical methodology based on the CHTCJM. Based on the findings, the proposed technique can substantially recover and enhance the bandwidth and efficiency of SDPAs at the desired output-power-back-off level. According to the measurement results, the fabricated SDPA model operates within 1.45-2.45 GHz frequency band with more than 50% peak drain efficiency at 6dB output-power-back-off. Furthermore, more than 60% drain efficiency, 12 dB gain and 43 dBm output power are delivered at saturation. Using digital predistortion with a 20-MHz long-term evolution signal in testing the linearity of the implemented SDPA, the SDPA’s adjacent channel leakage ratio is less than -45 dBc at an average output power of 36 dBm.
       
  • A Wideband 45° Inclined Linear Polarization Travelling-wave Slot Array
           Antenna with Broadside Radiation Pattern
    • Abstract: Publication date: Available online 6 May 2019Source: AEU - International Journal of Electronics and CommunicationsAuthor(s): Meisam Dolati, Mohammad Saeed Majedi In this paper a new slot array antenna with 45° inclined linear polarization for application in collision avoidance systems is presented. The proposed antenna is fed by a travelling wave and hence, in contrast with standing wave arrays, it has a wide impedance bandwidth. However, unlike conventional travelling wave arrays, it has a broadside radiation pattern at center frequency. In order to have a broadside radiation pattern, an in-phase excitation should be applied to slots. This is accomplished by properly determining the length and offset of slots which are separated one half guided wavelength from each other. Also to have a 45° polarization, inclined slots are used. Based on the presented design method, a linear array with nine slots is designed, simulated and fabricated at the center frequency of 10 GHz. Simulated and measured results are in good agreement with each other. The measured -10 dB impedance bandwidth, maximum gain, side lobe level, cross polarization discrimination and simulated radiation efficiency are>3 GHz, 13.66 dBi, 10.88 dB, 16.48 dB and 79.4%, respectively.
       
  • Microstrip Patch Antenna Array with Cosecant-Squared Radiation Pattern
           Profile
    • Abstract: Publication date: Available online 4 May 2019Source: AEU - International Journal of Electronics and CommunicationsAuthor(s): K. Kaboutari, A. Zabihi, B. Virdee, M. Pilevari Salmasi In this paper, the radiation pattern on either side of the main beam, which is created by a standard microstrip patch antenna, is configured to correspond to a cosecant-squared curve. The 8×2 antenna array comprises eight pairs of radiating elements that are arranged in a symmetrical structure and excited through a single common feedline. Interaction of the fields generated by each pair of elements contributes towards the overall radiation characteristics. The proposed array is shown to exhibit an impedance bandwidth of 1.93 GHz from 9.97 to 11.90 GHz for S11⩽-10 dB with a peak gain of 14.95 dBi. The antenna’s radiation pattern follows a cosecant-squared curve over an angular range of ±60.91°. The compact antenna array has dimensions of 106×34×0.813 mm3. These characteristics qualify the antenna for radar applications at the X-band frequency.
       
  • Energy harvesting optimization for built-in power replacement of
           electronic multisensory architecture
    • Abstract: Publication date: Available online 2 May 2019Source: AEU - International Journal of Electronics and CommunicationsAuthor(s): Alfiero Leoni, Iolanda Ulisse, Leonardo Pantoli, Vito Errico, Mariachiara Ricci, Giancarlo Orengo, Franco Giannini, Giovanni Saggio In this work, we present a novel multisensory electronic architecture that can work with very low voltage requirements thus enabling power management directly from harvesting-based low-voltage sources. The harvesting system here proposed relays on thermoelectric generator cells useful for furnishing additional power to an electronic system made of a home-made sensory glove, an inertial measuring unit, and an electromyography device, aimed at providing full measures of the arm-hand dexterities. The thermoelectric generator cells are optimized to work as an array configuration up to 10 cells series-connected and the energy conversion is managed with a commercial DC/DC with MPPT algorithm.Experimental results demonstrate that the harvester can provide a maximum open-circuit voltage of 600 mV and a maximum power level of 9.9 mW for a standard human body temperature of 37 °C and a room temperature of 22 °C. Moreover, the system is able to fully charge an 800 mA/h, single-cell Li-Po battery within 35 hours, showing a 30% efficiency loss. Since all the electronics in the multisensory architecture can run with voltages as low as the 3.7 V Li-Po battery, the harvesting system can be suitable to feed the device with an ad-hoc, high-efficiency boost conversion, thus replacing the USB-oriented built-in supply and recharge.
       
  • Realization of DTMOS Based CFTA and Multiple Input Single Output
           Biquadratic Filter Application
    • Abstract: Publication date: Available online 2 May 2019Source: AEU - International Journal of Electronics and CommunicationsAuthor(s): Muhammed Emin Başak Analog filters can be found in everything from mobile phones to disk drives, from audio systems to power supplies, from telecommunications to broadband internet connection. Analog filters can be formed from a variety of active elements. In this study, the Dynamic Threshold Voltage MOSFET (DTMOS) based Current Follower Transconductance Amplifier (CFTA) active element has been suggested and a multi input single output (MISO) universal biquadratic filter has been obtained with this active element. The proposed circuit operates with ±0.2 V supply voltages and consumes 140 µW power and electronically tunable. All five filtering responses have been realized by selecting the different input signals. All simulations have been performed with LTSpice program using the Predictive Technology Model (PTM) 45 nm Level 54 CMOS process parameters. Analysis of AC/DC, noise, Monte Carlo, temperature, total harmonic distortion (THD) proves that the circuit operates in harmony with the theory. With Monte Carlo analysis, it has been observed that the filter achieves stable output against both passive element and process parameter tolerance. It is hoped that the proposed active element and the filter will be useful in ultra-low voltage, low power, and low frequency analog signal applications.
       
  • A Low-Cost Broadband High Gain Circularly Polarized Cylindrical
           Loop-Monopole Composite Antenna for Satellite Communications
    • Abstract: Publication date: Available online 27 April 2019Source: AEU - International Journal of Electronics and CommunicationsAuthor(s): Subash Chandra Yadav, Siddhartha P Duttagupta, Nagaraju Atmakuru A unidirectional low-cost broadband high gain circularly polarized (CP) cylindrical loop- monopole composite antenna is presented for a navigation system, satellite system, GPS (1.575 GHz) and GLONASS (1.602 GHz) bands. The antenna has a simple structure with coaxial feeding, and is used to achieve circular polarization with an orthogonal shorting strip. The proposed antenna is designed by metal and no external feeding network is used, so antenna is less in cost and low in complexity. An optimized antenna is designed and measured, the measured results agree well with the simulated results. The results show good performance of impendence bandwidth (IBW) with approximately 58.8 % (1.2-2.2) GHz and the simulated 3-dB axial-ratio bandwidth (ARBW) of approximately 18.5 % (1.45-1.75 GHz). Moreover, the measured broadside antenna gain is stable and almost constant of average value 9.5 dBi with less than 0.3dB variation within the 3dB ARBW. The mathematical analysis of resonance frequency is also studied for a cylindrical loop and monopole radiators.
       
  • Investigation on Power Optimization Principles for Series-Configured
           Resonant Coupled Wireless Power Transfer Systems
    • Abstract: Publication date: Available online 25 April 2019Source: AEU - International Journal of Electronics and CommunicationsAuthor(s): Binh Duc Truong This paper is a thorough theoretical analysis of a two-coil wireless power transfer system (WPTS) configured in series with a focus on power optimization rather than maximizing transmission (link) efficiency. Different definitions of the system efficiency in the pertaining literature are distinguished and clarified. The frequency splitting phenomenon is precisely explained, and furthermore, the analytical solutions are derived based on analysis of the input impedance. The effects of this behavior on the power transfer to a load resistance are discussed. Various aspects of the power optimization problem are explored. In particular, for the case when the system is driven at the resonance frequency, (i) the explicit expression of the optimal coupling factor between the two coils for a given load, and (ii) the optimum power with respect to the load are provided. The impedance matching methods using different circuit topologies are analytically or numerically investigated, revealing that the drive frequency can be arbitrarily chosen and not necessarily equal to the resonance frequency. This provides more options for exciting the system apart from the resonance condition, without compromising the delivered power. A comparison between optimization techniques is given in terms of the coupling factor k, showing that the bi-conjugate matching with Π-networks results in the maximum generated power and the transducer power gain (i.e., defined by the ratio between the received power and the power available from the source), which reaches 80% at k=84.4×10-3, for example.
       
  • Array Auto-Calibration Using a Generalized Least-Squares Method
    • Abstract: Publication date: Available online 25 April 2019Source: AEU - International Journal of Electronics and CommunicationsAuthor(s): Mostafa Arjomandi-Lari, Mahmood karimi This paper introduces a new class of auto-calibration algorithms, based on a generalized least-squares (GLS) cost function. This class supports both gain-phase calibration and mutual coupling calibration and it is independent of array shape. The GLS cost function is minimized cyclically with respect to the direction of arrivals (DOA) and calibration parameters. These two minimization steps are repeated until convergence. In the DOA estimation step, minimization leads to the SPICE (SParse Iterative Covariance-based Estimation) DOA estimation algorithm. In fact, the innovation of this paper mainly lies in the calibration step. In the DOA estimation step, a generalized form of the SPICE algorithm should be used in the coherent sources case. Consequently, the proposed auto-calibration algorithm is able to support coherent source cases. Moreover, the proposed algorithm does not need multi-dimensional search. The necessary condition for the existence of a solution is studied as well. Using simulations, the performance of the proposed algorithm is compared with several other auto-calibration algorithms. Simulation results show that the proposed algorithm is more robust than the other algorithms and usually has better performance.
       
  • OTA-Based Switchable Gain and Order Multi-Standard Receiver Analog
           Baseband Chain
    • Abstract: Publication date: Available online 24 April 2019Source: AEU - International Journal of Electronics and CommunicationsAuthor(s): Mohamed B. Elamien, Soliman A. Mahmoud In this paper, we propose a digital programmable OTA-based multi-standard receiver for analog baseband chain. It consists of a switchable-order low-pass filter and two programmable gain amplifiers (PGAs). The low-pass filter has a cutoff frequency that can be digitally tuned from 1 MHz to 10.2 MHz. Thus, it covers Bluetooth, UMTS, DVB-H and IEEE 802.11a/g standards. The gain of each PGA can be varied from 0 dB to 35 dB with a gain step of 5 dB. The proposed multi-standard receiver is designed and simulated in 90 nm CMOS technology under ±0.6 V supply voltage. The overall simulation results show a variable gain from 0 dB to 70 dB, switchable-order (2nd/4th/6th) frequency response, in-band IIP3 of 21.9 dBm, and input referred noise of 102.6 nV/Hz at 1 MHz with total power consumption of 11.77 mW.
       
  • A Novel Cloud Based Self-Adaptive Cognitive Radio Network Architecture
    • Abstract: Publication date: Available online 24 April 2019Source: AEU - International Journal of Electronics and CommunicationsAuthor(s): Ashwini Kumar Varma, Debjani Mitra The constraints of battery, data processing and memory in mobile Secondary User (SU) in a Cognitive Radio Network (CRN) make it essential to move the spectrum sensing functionality from the SUs to the network. The cloud performing the role of the earlier defined “Spectrum Agent” or “Spectrum Monitoring Device” has a scope of taking up the computational tasks of spectrum sensing and path selection. The paper presents a novel cloud based self-adaptive network architecture for a multi-hop cognitive radio system including its communication protocol. A new method of optimal multi-hop relay selection based on Critical Path Method (CPM) is also introduced for execution in the cloud having network connectivity information. The proposed network architecture and relay selection scheme is analyzed and the performance tested with respect to the reported methods to show its strength in terms of end-to-end delay and reliability. A closed-form expression of outage probability of failed transmission for a generic multi-hop network is also analytically derived and used for testing the reliability of the proposed architecture. The results are encouraging to extend the use of CRN in dynamic environment of large deployment areas.
       
  • Characterizing a Decorrelator for Selection Combining Receivers in
           Nakagami-m Fading Channels
    • Abstract: Publication date: Available online 24 April 2019Source: AEU - International Journal of Electronics and CommunicationsAuthor(s): Salam Al-Juboori, Xavier Fernando Correlation among antenna branches has become a major concern in multi-antenna systems, especially in small devices with closely spaced antennas. Since physically distancing the antennas seems impractical, a decorrelator implementation at the receiver will be very beneficial. In this paper, such a decorrelation scheme employed prior to the selection combining (SC) diversity technique is studied. Using the fundamental principles, we derive expressions for the statistics of decorrelating the identical and correlated dual antenna SC receiver in Nakagami-m fading channels. Numerical results show that the probability density function (PDF) of the difference of identical and correlated Nakagami-m bivariate could be perfectly represented by a semi-standard normal distribution with zero mean and constant variance depending on the bivariate’s parameters. This observation could help simplify the design of the decorrelator receiver. Performance of the decorrelator is also verified by evaluating the outage probability which shows improvement.
       
  • Mechanism Analysis and Feature Extraction Algorithm of Communication
           Emitter Fingerprint
    • Abstract: Publication date: Available online 23 April 2019Source: AEU - International Journal of Electronics and CommunicationsAuthor(s): Jie Han, Tao Zhang, Dongfang Ren, Xiaoyu Zheng A fingerprint extraction method based on the fingerprint mechanism (FM) of a communication emitter is proposed to solve the shortcomings of existing emitter identification technology. First, the Taylor polynomial model of the communication emitter fingerprint is established by analyzing the mechanism of the emitter fingerprint. Second, the polynomial coefficients containing the emitter fingerprints are defined with focus on single-frequency and narrow-band signal. Identifiable features are extracted through parameter estimation. Theoretical analysis shows that the FM algorithm focuses on the fingerprint essence of communication emitter, and the effects of modulations are overcome. Experimental results show that the identification performance of the FM algorithm is better than that of three other algorithms due to the high anti-noise performance, inner-class clustering and inter-class scattering of extracted features.
       
  • Modelling Noise and Pulse Width Modulation Interference in Indoor Visible
           Light Communication Channels
    • Abstract: Publication date: Available online 23 April 2019Source: AEU - International Journal of Electronics and CommunicationsAuthor(s): Daniel G. Holmes, Ling Cheng, Mulundumina Shimaponda-Nawa, Ayokunle D. Familua, Adnan M. Abu-Mahfouz Visible light communication (VLC) has the potential to supplement the growing demand for wireless connectivity. In order to achieve the full potential of VLC, channel models are required. Discrete channel models based on semi-hidden Markov models (Fritchman model) for indoor VLC using low data rate LEDs are presented. Each channel considered includes background noise and differing types of interference from fluorescent lights and pulse-width modulated (PWM) LEDs, which could be part of an indoor smart lighting system. Models were developed based on experimental error sequences from a VLC system using an on-off keying (OOK) modulation scheme. The error sequences were input into the Baum-Welch algorithm to determine the model parameters by expectation maximisation. Simulated error sequences generated by the models are compared to and, in most cases, perform better than simpler models with a single bit error rate. The models closely approximate the experimental errors sequences in terms of error distribution. The models performed better in channels where there is less interference. It was also found that periodic errors were introduced as a results of the PWM modulated smart lighting LEDs. These models have use for designing error control codes and simulating indoor VLC environments with different types of interference.
       
  • Compact Triple Band Bandpass Filters Design using Mixed Coupled Resonators
    • Abstract: Publication date: Available online 14 March 2019Source: AEU - International Journal of Electronics and CommunicationsAuthor(s): Vinay Kumar Killamsetty, Biswajeet Mukherjee In this paper a study of designing Triple Band (TB) Bandpass Filter (BPF) by exploiting Triple Mode Resonator (TMR) is presented. By connecting the stepped impedance and radial stubs in a categorical manner a TMR can be obtained which is the basic component for designing the TB BPF. Microstrip lines are tapped over the resonator to work as feed lines and also to generate transmission zeros. The TMRs are Mixed Electric and Magnetic Coupled (MEMC) which help in generating additional Transmission Zeros (TZs) around passbands. As verification, a TB BPF is designed, fabricated and measured. In the designing process, first, a Dual Band (DB) BPF is designed and analyzed completely with the help of even-odd mode analysis. Extraction of lumped component model for the DB BPF is done in order to study the circuit model of the filter. Then the work is extended to design the proposed Triple Band-Band Pass Filter. The fabricated filters offer an advantage in terms of compact size, low insertion loss, good inter band isolation and harmonic suppression.
       
 
 
JournalTOCs
School of Mathematical and Computer Sciences
Heriot-Watt University
Edinburgh, EH14 4AS, UK
Email: journaltocs@hw.ac.uk
Tel: +00 44 (0)131 4513762
Fax: +00 44 (0)131 4513327
 
Home (Search)
Subjects A-Z
Publishers A-Z
Customise
APIs
Your IP address: 54.146.98.143
 
About JournalTOCs
API
Help
News (blog, publications)
JournalTOCs on Twitter   JournalTOCs on Facebook

JournalTOCs © 2009-