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COMPUTER SCIENCE (1196 journals)                  1 2 3 4 5 6 | Last

Showing 1 - 200 of 872 Journals sorted alphabetically
3D Printing and Additive Manufacturing     Full-text available via subscription   (Followers: 20)
Abakós     Open Access   (Followers: 4)
ACM Computing Surveys     Hybrid Journal   (Followers: 22)
ACM Journal on Computing and Cultural Heritage     Hybrid Journal   (Followers: 8)
ACM Journal on Emerging Technologies in Computing Systems     Hybrid Journal   (Followers: 11)
ACM Transactions on Accessible Computing (TACCESS)     Hybrid Journal   (Followers: 3)
ACM Transactions on Algorithms (TALG)     Hybrid Journal   (Followers: 15)
ACM Transactions on Applied Perception (TAP)     Hybrid Journal   (Followers: 5)
ACM Transactions on Architecture and Code Optimization (TACO)     Hybrid Journal   (Followers: 9)
ACM Transactions on Autonomous and Adaptive Systems (TAAS)     Hybrid Journal   (Followers: 7)
ACM Transactions on Computation Theory (TOCT)     Hybrid Journal   (Followers: 12)
ACM Transactions on Computational Logic (TOCL)     Hybrid Journal   (Followers: 3)
ACM Transactions on Computer Systems (TOCS)     Hybrid Journal   (Followers: 17)
ACM Transactions on Computer-Human Interaction     Hybrid Journal   (Followers: 14)
ACM Transactions on Computing Education (TOCE)     Hybrid Journal   (Followers: 5)
ACM Transactions on Design Automation of Electronic Systems (TODAES)     Hybrid Journal   (Followers: 3)
ACM Transactions on Economics and Computation     Hybrid Journal  
ACM Transactions on Embedded Computing Systems (TECS)     Hybrid Journal   (Followers: 3)
ACM Transactions on Information Systems (TOIS)     Hybrid Journal   (Followers: 19)
ACM Transactions on Intelligent Systems and Technology (TIST)     Hybrid Journal   (Followers: 7)
ACM Transactions on Interactive Intelligent Systems (TiiS)     Hybrid Journal   (Followers: 3)
ACM Transactions on Multimedia Computing, Communications, and Applications (TOMCCAP)     Hybrid Journal   (Followers: 9)
ACM Transactions on Reconfigurable Technology and Systems (TRETS)     Hybrid Journal   (Followers: 6)
ACM Transactions on Sensor Networks (TOSN)     Hybrid Journal   (Followers: 7)
ACM Transactions on Speech and Language Processing (TSLP)     Hybrid Journal   (Followers: 8)
ACM Transactions on Storage     Hybrid Journal  
ACS Applied Materials & Interfaces     Full-text available via subscription   (Followers: 27)
Acta Automatica Sinica     Full-text available via subscription   (Followers: 2)
Acta Universitatis Cibiniensis. Technical Series     Open Access  
Ad Hoc Networks     Hybrid Journal   (Followers: 11)
Adaptive Behavior     Hybrid Journal   (Followers: 11)
Advanced Engineering Materials     Hybrid Journal   (Followers: 28)
Advanced Science Letters     Full-text available via subscription   (Followers: 9)
Advances in Adaptive Data Analysis     Hybrid Journal   (Followers: 7)
Advances in Artificial Intelligence     Open Access   (Followers: 15)
Advances in Calculus of Variations     Hybrid Journal   (Followers: 2)
Advances in Catalysis     Full-text available via subscription   (Followers: 5)
Advances in Computational Mathematics     Hybrid Journal   (Followers: 18)
Advances in Computer Science : an International Journal     Open Access   (Followers: 15)
Advances in Computing     Open Access   (Followers: 2)
Advances in Data Analysis and Classification     Hybrid Journal   (Followers: 51)
Advances in Engineering Software     Hybrid Journal   (Followers: 27)
Advances in Geosciences (ADGEO)     Open Access   (Followers: 13)
Advances in Human Factors/Ergonomics     Full-text available via subscription   (Followers: 23)
Advances in Human-Computer Interaction     Open Access   (Followers: 19)
Advances in Materials Sciences     Open Access   (Followers: 14)
Advances in Operations Research     Open Access   (Followers: 12)
Advances in Parallel Computing     Full-text available via subscription   (Followers: 6)
Advances in Porous Media     Full-text available via subscription   (Followers: 5)
Advances in Remote Sensing     Open Access   (Followers: 43)
Advances in Science and Research (ASR)     Open Access   (Followers: 4)
Advances in Technology Innovation     Open Access   (Followers: 5)
AEU - International Journal of Electronics and Communications     Hybrid Journal   (Followers: 8)
African Journal of Information and Communication     Open Access   (Followers: 6)
African Journal of Mathematics and Computer Science Research     Open Access   (Followers: 4)
AI EDAM     Hybrid Journal  
Air, Soil & Water Research     Open Access   (Followers: 11)
AIS Transactions on Human-Computer Interaction     Open Access   (Followers: 5)
Algebras and Representation Theory     Hybrid Journal   (Followers: 1)
Algorithms     Open Access   (Followers: 11)
American Journal of Computational and Applied Mathematics     Open Access   (Followers: 5)
American Journal of Computational Mathematics     Open Access   (Followers: 4)
American Journal of Information Systems     Open Access   (Followers: 5)
American Journal of Sensor Technology     Open Access   (Followers: 4)
Anais da Academia Brasileira de Ciências     Open Access   (Followers: 2)
Analog Integrated Circuits and Signal Processing     Hybrid Journal   (Followers: 7)
Analysis in Theory and Applications     Hybrid Journal   (Followers: 1)
Animation Practice, Process & Production     Hybrid Journal   (Followers: 5)
Annals of Combinatorics     Hybrid Journal   (Followers: 3)
Annals of Data Science     Hybrid Journal   (Followers: 11)
Annals of Mathematics and Artificial Intelligence     Hybrid Journal   (Followers: 12)
Annals of Pure and Applied Logic     Open Access   (Followers: 2)
Annals of Software Engineering     Hybrid Journal   (Followers: 13)
Annual Reviews in Control     Hybrid Journal   (Followers: 6)
Anuario Americanista Europeo     Open Access  
Applicable Algebra in Engineering, Communication and Computing     Hybrid Journal   (Followers: 2)
Applied and Computational Harmonic Analysis     Full-text available via subscription   (Followers: 1)
Applied Artificial Intelligence: An International Journal     Hybrid Journal   (Followers: 13)
Applied Categorical Structures     Hybrid Journal   (Followers: 2)
Applied Clinical Informatics     Hybrid Journal   (Followers: 2)
Applied Computational Intelligence and Soft Computing     Open Access   (Followers: 11)
Applied Computer Systems     Open Access   (Followers: 2)
Applied Informatics     Open Access  
Applied Mathematics and Computation     Hybrid Journal   (Followers: 33)
Applied Medical Informatics     Open Access   (Followers: 10)
Applied Numerical Mathematics     Hybrid Journal   (Followers: 5)
Applied Soft Computing     Hybrid Journal   (Followers: 16)
Applied Spatial Analysis and Policy     Hybrid Journal   (Followers: 4)
Applied System Innovation     Open Access  
Architectural Theory Review     Hybrid Journal   (Followers: 3)
Archive of Applied Mechanics     Hybrid Journal   (Followers: 5)
Archive of Numerical Software     Open Access  
Archives and Museum Informatics     Hybrid Journal   (Followers: 130)
Archives of Computational Methods in Engineering     Hybrid Journal   (Followers: 5)
arq: Architectural Research Quarterly     Hybrid Journal   (Followers: 7)
Artifact     Hybrid Journal   (Followers: 2)
Artificial Life     Hybrid Journal   (Followers: 7)
Asia Pacific Journal on Computational Engineering     Open Access  
Asia-Pacific Journal of Information Technology and Multimedia     Open Access   (Followers: 1)
Asian Journal of Computer Science and Information Technology     Open Access  
Asian Journal of Control     Hybrid Journal  
Assembly Automation     Hybrid Journal   (Followers: 2)
at - Automatisierungstechnik     Hybrid Journal   (Followers: 1)
Australian Educational Computing     Open Access   (Followers: 1)
Automatic Control and Computer Sciences     Hybrid Journal   (Followers: 4)
Automatic Documentation and Mathematical Linguistics     Hybrid Journal   (Followers: 5)
Automatica     Hybrid Journal   (Followers: 11)
Automation in Construction     Hybrid Journal   (Followers: 6)
Autonomous Mental Development, IEEE Transactions on     Hybrid Journal   (Followers: 9)
Basin Research     Hybrid Journal   (Followers: 5)
Behaviour & Information Technology     Hybrid Journal   (Followers: 53)
Big Data and Cognitive Computing     Open Access   (Followers: 2)
Biodiversity Information Science and Standards     Open Access  
Bioinformatics     Hybrid Journal   (Followers: 281)
Biomedical Engineering     Hybrid Journal   (Followers: 15)
Biomedical Engineering and Computational Biology     Open Access   (Followers: 13)
Biomedical Engineering, IEEE Reviews in     Full-text available via subscription   (Followers: 19)
Biomedical Engineering, IEEE Transactions on     Hybrid Journal   (Followers: 35)
Briefings in Bioinformatics     Hybrid Journal   (Followers: 43)
British Journal of Educational Technology     Hybrid Journal   (Followers: 142)
Broadcasting, IEEE Transactions on     Hybrid Journal   (Followers: 10)
c't Magazin fuer Computertechnik     Full-text available via subscription   (Followers: 1)
CALCOLO     Hybrid Journal  
Calphad     Hybrid Journal  
Canadian Journal of Electrical and Computer Engineering     Full-text available via subscription   (Followers: 14)
Capturing Intelligence     Full-text available via subscription  
Catalysis in Industry     Hybrid Journal   (Followers: 1)
CEAS Space Journal     Hybrid Journal   (Followers: 2)
Cell Communication and Signaling     Open Access   (Followers: 2)
Central European Journal of Computer Science     Hybrid Journal   (Followers: 5)
CERN IdeaSquare Journal of Experimental Innovation     Open Access   (Followers: 2)
Chaos, Solitons & Fractals     Hybrid Journal   (Followers: 3)
Chemometrics and Intelligent Laboratory Systems     Hybrid Journal   (Followers: 14)
ChemSusChem     Hybrid Journal   (Followers: 7)
China Communications     Full-text available via subscription   (Followers: 7)
Chinese Journal of Catalysis     Full-text available via subscription   (Followers: 2)
CIN Computers Informatics Nursing     Full-text available via subscription   (Followers: 11)
Circuits and Systems     Open Access   (Followers: 15)
Clean Air Journal     Full-text available via subscription   (Followers: 1)
CLEI Electronic Journal     Open Access  
Clin-Alert     Hybrid Journal   (Followers: 1)
Cluster Computing     Hybrid Journal   (Followers: 1)
Cognitive Computation     Hybrid Journal   (Followers: 4)
COMBINATORICA     Hybrid Journal  
Combinatorics, Probability and Computing     Hybrid Journal   (Followers: 4)
Combustion Theory and Modelling     Hybrid Journal   (Followers: 14)
Communication Methods and Measures     Hybrid Journal   (Followers: 12)
Communication Theory     Hybrid Journal   (Followers: 20)
Communications Engineer     Hybrid Journal   (Followers: 1)
Communications in Algebra     Hybrid Journal   (Followers: 3)
Communications in Computational Physics     Full-text available via subscription   (Followers: 2)
Communications in Partial Differential Equations     Hybrid Journal   (Followers: 3)
Communications of the ACM     Full-text available via subscription   (Followers: 52)
Communications of the Association for Information Systems     Open Access   (Followers: 16)
COMPEL: The International Journal for Computation and Mathematics in Electrical and Electronic Engineering     Hybrid Journal   (Followers: 3)
Complex & Intelligent Systems     Open Access   (Followers: 1)
Complex Adaptive Systems Modeling     Open Access  
Complex Analysis and Operator Theory     Hybrid Journal   (Followers: 2)
Complexity     Hybrid Journal   (Followers: 6)
Complexus     Full-text available via subscription  
Composite Materials Series     Full-text available via subscription   (Followers: 8)
Computación y Sistemas     Open Access  
Computation     Open Access  
Computational and Applied Mathematics     Hybrid Journal   (Followers: 2)
Computational and Mathematical Methods in Medicine     Open Access   (Followers: 2)
Computational and Mathematical Organization Theory     Hybrid Journal   (Followers: 2)
Computational and Structural Biotechnology Journal     Open Access   (Followers: 2)
Computational and Theoretical Chemistry     Hybrid Journal   (Followers: 9)
Computational Astrophysics and Cosmology     Open Access   (Followers: 1)
Computational Biology and Chemistry     Hybrid Journal   (Followers: 11)
Computational Chemistry     Open Access   (Followers: 2)
Computational Cognitive Science     Open Access   (Followers: 2)
Computational Complexity     Hybrid Journal   (Followers: 4)
Computational Condensed Matter     Open Access  
Computational Ecology and Software     Open Access   (Followers: 9)
Computational Economics     Hybrid Journal   (Followers: 9)
Computational Geosciences     Hybrid Journal   (Followers: 15)
Computational Linguistics     Open Access   (Followers: 23)
Computational Management Science     Hybrid Journal  
Computational Mathematics and Modeling     Hybrid Journal   (Followers: 8)
Computational Mechanics     Hybrid Journal   (Followers: 5)
Computational Methods and Function Theory     Hybrid Journal  
Computational Molecular Bioscience     Open Access   (Followers: 2)
Computational Optimization and Applications     Hybrid Journal   (Followers: 7)
Computational Particle Mechanics     Hybrid Journal   (Followers: 1)
Computational Research     Open Access   (Followers: 1)
Computational Science and Discovery     Full-text available via subscription   (Followers: 2)
Computational Science and Techniques     Open Access  
Computational Statistics     Hybrid Journal   (Followers: 14)
Computational Statistics & Data Analysis     Hybrid Journal   (Followers: 30)
Computer     Full-text available via subscription   (Followers: 94)
Computer Aided Surgery     Hybrid Journal   (Followers: 6)
Computer Applications in Engineering Education     Hybrid Journal   (Followers: 8)
Computer Communications     Hybrid Journal   (Followers: 10)
Computer Engineering and Applications Journal     Open Access   (Followers: 5)
Computer Journal     Hybrid Journal   (Followers: 9)
Computer Methods in Applied Mechanics and Engineering     Hybrid Journal   (Followers: 23)
Computer Methods in Biomechanics and Biomedical Engineering     Hybrid Journal   (Followers: 12)
Computer Methods in the Geosciences     Full-text available via subscription   (Followers: 2)
Computer Music Journal     Hybrid Journal   (Followers: 19)

        1 2 3 4 5 6 | Last

Journal Cover AEU - International Journal of Electronics and Communications
  [SJR: 0.318]   [H-I: 36]   [8 followers]  Follow
   Hybrid Journal Hybrid journal (It can contain Open Access articles)
   ISSN (Print) 1434-8411
   Published by Elsevier Homepage  [3175 journals]
  • Design of active inductor-based current-controlled oscillators using gm/Id
    • Authors: Mohammad Samiei; Omid Hashemipour
      Pages: 1 - 9
      Abstract: Publication date: April 2018
      Source:AEU - International Journal of Electronics and Communications, Volume 87
      Author(s): Mohammad Samiei, Omid Hashemipour
      This paper presents a novel design procedure based on gm/Id methodology to achieve a trade-off between tuning range, phase noise and output swing of active-inductor-based current-controlled oscillators (CCOs). It is shown that equations for the phase noise and corner frequency of the selected CCO configuration are related to the gm/Id parameters. In accordance with the above relations, the designed CCO is simulated using 0.18 µm TSMC CMOS technology parameters. The simulation exhibits a tuning range of 432 MHz to 3.54 GHz, a phase noise in the range of −84 dBc/Hz to −104.6 dBc/Hz at 1 MHz offset from carrier and a figure of merit of 178.4 dB in 1.453 GHz.

      PubDate: 2018-02-25T17:05:35Z
      DOI: 10.1016/j.aeue.2018.01.029
      Issue No: Vol. 87 (2018)
  • A novel turbo GFDM-IM receiver for MIMO communications
    • Authors: Yu-Kuan Chang; Fang-Biau Ueng
      Pages: 22 - 32
      Abstract: Publication date: April 2018
      Source:AEU - International Journal of Electronics and Communications, Volume 87
      Author(s): Yu-Kuan Chang, Fang-Biau Ueng
      Generalized frequency-division multiplexing (GFDM) is a candidate waveform for the fifth generation (5G) wireless communication systems. However, the carrier frequency offset (CFO) causing synchronization problem is very important for GFDM system. In this paper, we propose a turbo receiver with channel estimation, equalization and CFO compensation for MIMO (multiple input multiple output) GFDM system with index modulation (IM). So far, no related researches exist. This paper proposes a novel receiver to solve CFO compensation with two-path transmission and proposes a modified phase rotated conjugate cancellation (PRCC) algorithm for the receiver. On the other hand, GFDM with index modulation (GFDM-IM) can achieve better performance and lower peak-to-average power ratio (PAPR) than those of GFDM by using active index subcarrier. To reduce the system complexity, the log-likelihood ratio (LLR) criteria is also employed to search which subcarrier is active. Moreover, the Kalman filter is employed to trace the time-varying channels. The initial channel estimation is performed by the sparse pilot signals. In the simulations, we compare the proposed receiver with several existing schemes in different time-varying channels and modulations. The proposed scheme outperforms the existing schemes.

      PubDate: 2018-02-25T17:05:35Z
      DOI: 10.1016/j.aeue.2018.01.021
      Issue No: Vol. 87 (2018)
  • A unified approach to modelling of probability of detection over α-μ/IG,
           κ-μ/IG, and η-μ/IG composite fading channels with application to
           co-operative system
    • Authors: Puspraj Singh Chauhan; Priyanka Negi; Sanjay Kumar Soni
      Pages: 33 - 42
      Abstract: Publication date: April 2018
      Source:AEU - International Journal of Electronics and Communications, Volume 87
      Author(s): Puspraj Singh Chauhan, Priyanka Negi, Sanjay Kumar Soni
      In this paper, the performance analysis of the energy detector based on the three composite fading channels such as α - μ /IG, η - μ /IG,and κ - μ /IG is investigated. First, a unified probability distribution function (PDF) of the three composite fading channels is developed based on Gauss-Laguerre integration and is expressed in the form of the mixture of IG distributions. Subsequently, the PDF is used for deriving the analytical forms of the average probability of detection (PD) along with the upper bound of the truncation error, optimization of the energy detection threshold, and the average area under receiver operating characteristic curve (AUC). Moreover, the simplified closed-form asymptotic expressions of the PD and the average AUC are also derived. Finally, the derived result is utilized to assess the performance of the cooperative spectrum sensing (CSS) under the various practical channel conditions such as infrequent light shadowing, average shadowing, and frequent heavy shadowing. Optimization of the threshold parameter and total number of cognitive radios utilizing n-out-of-M voting rule for CSS by minimising the total error rate (TER) is carried out. The accuracy of the derived analytical expressions has been corroborated with Monte-Carlo simulation and exact numerical results.

      PubDate: 2018-02-25T17:05:35Z
      DOI: 10.1016/j.aeue.2018.01.035
      Issue No: Vol. 87 (2018)
  • The LPF with improved stopband response designed for wideband microwave
    • Authors: Xin Feng; Yonghong Zhang; Daotong Li; Yin Tian; Yang Yang; Yong Fan
      Pages: 43 - 47
      Abstract: Publication date: April 2018
      Source:AEU - International Journal of Electronics and Communications, Volume 87
      Author(s): Xin Feng, Yonghong Zhang, Daotong Li, Yin Tian, Yang Yang, Yong Fan
      To achieve an improved stopband response including expanded stopband width, increased rejection level, and a smooth S 11 phase response, a lowpass filter (LPF) is proposed based on the suspended microstrip line with naturally high characteristic impedance and the radial stub with intrinsic transmission zero. The usually unmentioned phase response, are critical to obtaining a wide and flat operating band for the microwave detector, since a smooth phase response exerts small load effects to the diode. As a demonstration, a detector employing the LPF is fabricated and measured. The measured results show that a wide operating band from 1.8 to 13.5 GHz with flat detection outputs of ripple less than 1 dB is obtained for the detector, which coincides with the smooth-phase range of the LPF.

      PubDate: 2018-02-25T17:05:35Z
      DOI: 10.1016/j.aeue.2018.01.034
      Issue No: Vol. 87 (2018)
  • Component value selection for active filters based on minimization of GSP
           and E12 compatible using Grey Wolf and Particle Swarm Optimization
    • Authors: Byamakesh Nayak; Tanmoy Roy Choudhury; Banishree Misra
      Pages: 48 - 53
      Abstract: Publication date: April 2018
      Source:AEU - International Journal of Electronics and Communications, Volume 87
      Author(s): Byamakesh Nayak, Tanmoy Roy Choudhury, Banishree Misra
      The component value selection for active analogue filter design is an important issue to improve the performances and to make compatible with existing parameters value. The Particle Swarm Optimization (PSO) and Grey Wolf Optimization (GWO) are efficient intelligent evolutionary algorithms for solving optimization problems. Both techniques are used to minimize the total design error of a 4th order Butterworth low pass active filter. This would be realized with component values which are compatible with E12 series. In addition, stability of filter is guaranteed by minimization of gain sensitivity product. By considering the minimization of Gain Sensitivity Product (GSP), the sixteen variables of objective function are reduced to eight variables which speed up the iteration process. The simulation results prove the efficiency of algorithms for the design of analogue active filter by optimizing the component values based on E12 compatible with minimization of GSP by minimising the design error.

      PubDate: 2018-02-25T17:05:35Z
      DOI: 10.1016/j.aeue.2018.02.005
      Issue No: Vol. 87 (2018)
  • Compact wideband bandpass filter using quad mode resonator
    • Authors: Vinay Kumar Killamsetty; Biswajeet Mukherjee
      Pages: 54 - 59
      Abstract: Publication date: April 2018
      Source:AEU - International Journal of Electronics and Communications, Volume 87
      Author(s): Vinay Kumar Killamsetty, Biswajeet Mukherjee
      This paper presents a compact wideband bandpass filter for TETRA band applications. The proposed filter design is based on a quad mode resonator designed using small rectangular loop loaded with four Stepped Impedance Stubs (SISs) and a short circuit stub. The four modes of the resonator help in generating a wide passband. The use of SISs makes the filter compact. In addition to four transmission poles, the resonator inherently generates a transmission zero above the higher end of passband. Two transmission zeros are generated by the input/output coupling which helps in increasing the selectivity and also for achieving wide stopband. This filter provides a 3 dB fractional bandwidth of 30.33% and maximum insertion loss of 1.3 dB at the center frequency 0.36 GHz with a compact size of 0.125 λg × 0.085 λg (4.1 × 2.78 cm2).

      PubDate: 2018-02-25T17:05:35Z
      DOI: 10.1016/j.aeue.2017.12.007
      Issue No: Vol. 87 (2018)
  • Broadband SIW cavity-backed triangular-ring-slotted antenna for Ku-band
    • Authors: Arvind Kumar; S. Raghavan
      Pages: 60 - 64
      Abstract: Publication date: April 2018
      Source:AEU - International Journal of Electronics and Communications, Volume 87
      Author(s): Arvind Kumar, S. Raghavan
      In this letter, a broadband substrate integrated waveguide (SIW) cavity-backed triangular-ring-slotted antenna is demonstrated for planar integration. Instead, using a conventional triangular-ring-slot, a modified triangular-ring-slot is employed to achieve a broader bandwidth response. The conventional triangular-ring-slot generates two hybrid-modes in the vicinity of TE110 and TE120 cavity modes owing to strong loading effect in the SIW cavity resonator. The modified-slot helps to tune the individual resonant frequency of these hybrid modes below −10 dB, which leads broadband impedance bandwidth. The antenna is fabricated and tested, and the experimental results show a bandwidth of 2.09 GHz (13.53%) and a gain of 4 dBi over the entire bandwidth. Moreover, antenna exhibits unidirectional radiation characteristics with uniform gain.

      PubDate: 2018-02-25T17:05:35Z
      DOI: 10.1016/j.aeue.2018.02.016
      Issue No: Vol. 87 (2018)
  • Ultra-high current efficiency single-stage class-AB OTA with completely
           symmetric slew rate
    • Authors: Xiao Zhao; Yongqing Wang; Dawei Jia; Liyuan Dong
      Pages: 65 - 69
      Abstract: Publication date: April 2018
      Source:AEU - International Journal of Electronics and Communications, Volume 87
      Author(s): Xiao Zhao, Yongqing Wang, Dawei Jia, Liyuan Dong
      An ultra-high current efficiency single-stage class-AB OTA with completely symmetric slew rate is presented. Based on adaptive biasing and nonlinear current mirror techniques employed in a proposed symmetric current recycling structure, the proposed OTA not only achieves the maximum output current proportional to Vin 8 , but also has the symmetric positive and negative slew rates. Also, the proposed self-biasing output stage makes the slew rate unconstrained. Simulation results demonstrate that the slew rate of the proposed OTA is enhanced by 1500% over that of the conventional folded cascode counterpart with a little increased power, which is suitable for large capacitive load applications.

      PubDate: 2018-02-25T17:05:35Z
      DOI: 10.1016/j.aeue.2018.02.012
      Issue No: Vol. 87 (2018)
  • Fault tolerant backbone construction in cognitive radio networks
    • Authors: Santosh Kumar; Awadhesh Kumar Singh
      Pages: 76 - 86
      Abstract: Publication date: April 2018
      Source:AEU - International Journal of Electronics and Communications, Volume 87
      Author(s): Santosh Kumar, Awadhesh Kumar Singh
      A cluster based backbone formation protocol is proposed for cognitive radio networks, where nodes are allowed to use the channels not occupied by primary users. It is based on the idea of finding the neighbors, choosing the best nodes as cluster heads and connecting clusterheads with the help of intermediate nodes to construct the backbone. We have proposed an efficient approach for neighbor discovery as well as cluster formation in cognitive radio network. We present the analytic as well as simulation study of the protocol. In the end, we indicate a method to handle the dynamic changes in the constructed backbone.
      Graphical abstract image

      PubDate: 2018-02-25T17:05:35Z
      DOI: 10.1016/j.aeue.2018.02.010
      Issue No: Vol. 87 (2018)
  • SU throughput enhancement in a decision fusion based cooperative sensing
    • Authors: Shivanshu Shrivastava; D.P. Kothari
      Pages: 95 - 100
      Abstract: Publication date: April 2018
      Source:AEU - International Journal of Electronics and Communications, Volume 87
      Author(s): Shivanshu Shrivastava, D.P. Kothari
      Wireless communication systems primarily depend on the availability of bandwidth. Cognitive radio has been realized as an effective means to maximize the bandwidth for internet and other communication applications. Multiple cognitive radios perform spectrum sensing in cooperation to mitigate the effects of fading. A specific number of cooperating cognitive radio users are responsible to form the decision at the fusion center for spectrum occupancy and is called the global decision threshold. In this letter, we find the global threshold which maximizes the throughput of the cognitive radio users while keeping a constraint on the interference to the licensed primary user. It is observed that for every interference value below the constraint, the throughput of the cognitive radio users maximizes at a particular value of the global decision threshold.

      PubDate: 2018-02-25T17:05:35Z
      DOI: 10.1016/j.aeue.2018.01.036
      Issue No: Vol. 87 (2018)
  • Channel and delay estimation for asynchronous physical layer network
    • Authors: Xiaoyu Hu; Zhe Chen; Fuliang Yin
      Pages: 101 - 106
      Abstract: Publication date: April 2018
      Source:AEU - International Journal of Electronics and Communications, Volume 87
      Author(s): Xiaoyu Hu, Zhe Chen, Fuliang Yin
      Relative Delay estimation is an important issue for asynchronous physical layer network coding (PLNC). In this paper, an fast Fourier transform (FFT) based channel and delay estimation method for asynchronous PLNC is proposed. The extended properties of discrete Fourier transform are exploited to design the pilots, which makes the pilots from different nodes orthogonal in frequency domain. Then channels between relay and different terminal nodes are estimated separately in frequency domain. Finally, after inverse FFT, the relative delay is extracted from the estimated time domain channel information. Compared with the existing approaches, the proposed method can achieve almost the same performance, but with significant improvement in computational complexity.

      PubDate: 2018-02-25T17:05:35Z
      DOI: 10.1016/j.aeue.2017.12.010
      Issue No: Vol. 87 (2018)
  • A hybrid genetic algorithm for analog active filter component selection
    • Authors: Turgay Kaya; Hasan Guler
      Pages: 1 - 7
      Abstract: Publication date: March 2018
      Source:AEU - International Journal of Electronics and Communications, Volume 86
      Author(s): Turgay Kaya, Hasan Guler
      Analog filters are circuits that process electrical signals on a frequency-dependent basis. Analog filter circuits can be implemented using resistors, capacitors and inductors and they can also be implemented with only resistors and capacitors with the use of active circuit equipments. The selection of optimum component values is difficult because of the number of possible filter combinations. This paper presents an effective algorithm that hybridizes the Genetic Algorithm (GA) to form a Hybrid Genetic Algorithm (HGA) and proposes the use of Tabu Search (TS) for the analog active filter component selection. The GA has a powerful global searching ability and so is used to perform exploitation and because TS also has good local searching ability, it too is applied to perform exploitation. Thus, the proposed HGA will have very good searching ability. In this study, a band-pass Sallen-Key filter circuit was used, and the filter component values were found using HGA with LabVIEW. The results are compared to other reported state-of-the-art algorithms, such as the artificial bee colony (ABC) and differential evaluation (DE) to demonstrate the effectiveness and efficiency of the developed method. It can be said that the developed LabVIEW based HGA gives satisfactory results with regard to amplitude response, the minimum fitness values and the computational time.

      PubDate: 2018-02-25T17:05:35Z
      DOI: 10.1016/j.aeue.2018.01.015
      Issue No: Vol. 86 (2018)
  • Improved spectrum sensing and achieved throughput of multiband cognitive
           radio systems under probabilistic spectrum access
    • Authors: Mohammad Karimi; Seyed Mohammad Sajad Sadough
      Pages: 8 - 16
      Abstract: Publication date: March 2018
      Source:AEU - International Journal of Electronics and Communications, Volume 86
      Author(s): Mohammad Karimi, Seyed Mohammad Sajad Sadough
      We investigate wideband spectrum sensing for multiband cognitive radio (CR) to opportunistically detect spectrum holes without causing harmful interference to licensed (primary) subchannels. In classical wideband energy detection, primary subchannels are absolutely classified into vacant or occupied according to the measured energy. CR signal transmission is then performed over all vacant subchannels. In this paper, we first introduce a probabilistic spectrum access method, which assigns a probability for CR signal transmission over each primary subchannel. More precisely, in our proposed method, each primary subchannel is likely to be classified into vacant or occupied via the definition of a spectrum access probability for CR transmission, in contrast to absolute sub-channel classification used in classical methods. Second, we derive the secondary information rates achieved by the proposed spectrum sensing method and compare it to those provided by classical wideband spectrum sensing. Third, we perform optimal power allocation to maximize the CR achievable rates constrained on the total power and interference introduced to the primary network. Numerical results indicate that the proposed spectrum access outperforms the classically-used spectrum sensing in terms of secondary achievable data rates.

      PubDate: 2018-02-05T14:10:19Z
      DOI: 10.1016/j.aeue.2018.01.012
      Issue No: Vol. 86 (2018)
  • Realization of dielectric loaded waveguide filter with substrate
           integrated waveguide technique based on incorporation of two substrates
           with different relative permittivity
    • Authors: Hassan Aghayari; Javad Nourinia; Changiz Ghobadi; Bahman Mohammadi
      Pages: 17 - 24
      Abstract: Publication date: March 2018
      Source:AEU - International Journal of Electronics and Communications, Volume 86
      Author(s): Hassan Aghayari, Javad Nourinia, Changiz Ghobadi, Bahman Mohammadi
      In this paper a new structure based on substrate integrated waveguide (SIW), called incorporated substrate integrated waveguide (ISIW), has been used to implement the dielectric loaded waveguide filter in planar structure. Conventional waveguide filter and dielectric loaded waveguide filter have been realized with SIW and ISIW technique, respectively. The use of ISIW structure has reduced the size of the filter, required precision in designing process and the cost of manufacturing process, at the cost of increasing the losses. Thus, while the size of filter and the cost of manufacturing process reduce significantly, there is no need to build the particular dielectric material as resonator and integration with other microstrip devices will be much easier too. Two different excitation mechanism have been considered to cancel the spurious response in the desired frequency band. The SIW and ISIW filters have been fabricated and fairly compared with waveguide filters. Advantages and disadvantages of ISIW structure have been scrutinized in detail. Good agreement between the simulated and measured frequency response of proposed filters has been shown.

      PubDate: 2018-02-05T14:10:19Z
      DOI: 10.1016/j.aeue.2018.01.008
      Issue No: Vol. 86 (2018)
  • Analysis of Load Frequency Control in a restructured multi-area power
           system with the Kalman filter and the LQR controller
    • Authors: Seyed Hamid Shahalami; Davoud Farsi
      Pages: 25 - 46
      Abstract: Publication date: March 2018
      Source:AEU - International Journal of Electronics and Communications, Volume 86
      Author(s): Seyed Hamid Shahalami, Davoud Farsi
      The performance of power systems in restructured environments has become increasingly more complex due to the technical limitations and traditional requirements. To this end, electrical power systems act independently in the generation, transmission and distribution of electricity, leading to restructuring and deregulation. On the one hand, technical requirements for transmission lines and renewable energies will contribute to HVDC transmission. On the other hand, one of the main goals of the Automatic Generation Control (AGC) is to manage Load Frequency Control (LFC) in a multi-area power system. In order to examine the internal and intrinsic stability, the Linear Quadratic Regulator (LQR) control method was used but since neither all the state variables were available nor their measurements were noise-free, the LQR controller was used with the Kalman filter (KF) for the real-time control for solving the LFC problem. Finally in the section on the simulation, a comparison was made using MATLAB, between two multi-area power systems consisting of thermal and hydroelectric generation units, one of which with the HVDC transmission lines and the other one without them, in terms of frequency stability. Moreover, the simulation results indicated that the introduced control method led to the improved LFC performance in a multi-area power system with HVDC transmission links.

      PubDate: 2018-02-05T14:10:19Z
      DOI: 10.1016/j.aeue.2018.01.011
      Issue No: Vol. 86 (2018)
  • A Built-In Self-Test structure for measuring gain and 1-dB compression
           point of Power Amplifier
    • Authors: Mehdi Ehsanian; Masoud Askari-Raad
      Pages: 47 - 54
      Abstract: Publication date: March 2018
      Source:AEU - International Journal of Electronics and Communications, Volume 86
      Author(s): Mehdi Ehsanian, Masoud Askari-Raad
      This paper proposes a Built-In Self-Test (BIST) structure for measuring the gain and the 1-dB compression point of the Power Amplifier (PA) in transceiver ICs. In this structure, it is not necessary to use the external devices for mapping and DC measuring because of linearity of blocks, comparative performance in the linear region and the digital representation of the 1-dB compression point and gain value. The BIST Circuit is designed and simulated in 180 nm RF-CMOS process with Spectre-RF for a 900 MHz PA while it can achieve an acceptable accuracy which the input referred 1-dB compression point and gain value can be obtained with an error of about 0.2 dBm and 0.18 dB, respectively and the testing time is about 25 µs depends on resolution. Finally, in order to verify the proposed approach, we implemented practically a similar discrete circuit as proof-of-concept prototype that it obtained input referred 1-dB compression point value with an error of about 0.15 dBm.

      PubDate: 2018-02-25T17:05:35Z
      DOI: 10.1016/j.aeue.2018.01.019
      Issue No: Vol. 86 (2018)
  • Dual band notched UWB-BPF based on hybrid microstrip-to-CPW transition
    • Authors: Abu Nasar Ghazali; Mohd Sazid; Srikanta Pal
      Pages: 55 - 62
      Abstract: Publication date: March 2018
      Source:AEU - International Journal of Electronics and Communications, Volume 86
      Author(s): Abu Nasar Ghazali, Mohd Sazid, Srikanta Pal
      The research paper proposes a compact dual notched band ultra-wideband (UWB) bandpass filter (BPF). The basic architecture of the filter is developed using the hybrid microstrip-to-coplanar waveguide (CPW) technology, wherein a short circuited CPW in ground is coupled vertically via the dielectric to the microstrip lines on the top plane. The broadside alignment generates a three pole BPF with dual transmission zeros (TZs) on either passband/stopband edges which leads to minimum insertion loss passband and sharp roll-offs. Later, multiple spirals and split ring resonators (SRRs) are embedded in the CPW of the UWB filter to introduce the dual notches and widen the stopband respectively. The proposed filter is fabricated to justify its measured response. The proposed filter measures only 14.6 × 7.3 mm2.

      PubDate: 2018-02-25T17:05:35Z
      DOI: 10.1016/j.aeue.2018.01.009
      Issue No: Vol. 86 (2018)
  • Microstrip lowpass filter with flexible roll-off rates
    • Authors: Kanaparthi V. Phani Kumar; S.S. Karthikeyan
      Pages: 63 - 68
      Abstract: Publication date: March 2018
      Source:AEU - International Journal of Electronics and Communications, Volume 86
      Author(s): Kanaparthi V. Phani Kumar, S.S. Karthikeyan
      This paper presents the design of a compact, ultra-sharp roll-off lowpass filter using stepped impedance modified T-type with stepped impedance stub (SMTS). The position of the transmission zero obtained due to the SMTS transmission line can be varied by changing the impedances and electrical lengths of the stepped impedance shunt stub (SIS) of SMTS and therefore, different roll-off rates can be obtained. The design equations used to obtain the parameters of the proposed SMTS structure are derived using the even and odd mode analysis and this enables the designers to calculate the parameters for a specific cut-off frequency ( f C ). Two SISs are connected, one at the input and another at the output side of SMTS to achieve good stopband characteristics. Finally, a lowpass filter with f C = 1.24 GHz and having a transition band of 0.11 GHz from 1.24 to 1.35 GHz with corresponding attenuation levels of 3–40 dB (roll-off rate is 336.36 dB/GHz) is designed, fabricated and tested. Good agreement is found between the simulated and experimental results.

      PubDate: 2018-02-25T17:05:35Z
      DOI: 10.1016/j.aeue.2018.01.025
      Issue No: Vol. 86 (2018)
  • A simple fractional-order chaotic system without equilibrium and its
    • Authors: Viet-Thanh Pham; Adel Ouannas; Christos Volos; Tomasz Kapitaniak
      Pages: 69 - 76
      Abstract: Publication date: March 2018
      Source:AEU - International Journal of Electronics and Communications, Volume 86
      Author(s): Viet-Thanh Pham, Adel Ouannas, Christos Volos, Tomasz Kapitaniak
      There has been an increasing interest in discovering no-equilibrium chaotic systems recently. In this paper, a novel three dimensional fractional-order chaotic system, which has no equilibrium, is introduced. Dynamics of the system has been studied. It is interesting that the system can exhibit coexisting chaotic attractors for the order as low as 2.7. The adjustable feature of a variable is studied by introducing a single controlled constant. Circuit implementation of the system is proposed to show its feasibility. In addition, we have designed the controllers to investigate coexisting synchronization types of such a new fractional-order system. Numerical examples have verified the proposed synchronization schemes.

      PubDate: 2018-02-25T17:05:35Z
      DOI: 10.1016/j.aeue.2018.01.023
      Issue No: Vol. 86 (2018)
  • Dual-band UWB bandpass filter with triangular DB-DGS for WLAN applications
           in DSRC band
    • Authors: Zain Hashim; Nishu Gupta; Arun Prakash; Rajeev Tripathi
      Pages: 77 - 85
      Abstract: Publication date: March 2018
      Source:AEU - International Journal of Electronics and Communications, Volume 86
      Author(s): Zain Hashim, Nishu Gupta, Arun Prakash, Rajeev Tripathi
      A dual-band Ultra-wideband (UWB) bandpass microstrip filter with triangular dumbbell shaped defected ground structure (DB-DGS) for wireless local area network applications in DSRC band is proposed in this article. The proposed dual-band filter has center frequencies at 2.67 GHz and 4.68 GHz, return loss obtained is −33.40 dB and −16.55 dB respectively, wide bandwidth of 1.21 GHz (26%), pass band between 2.14 GHz and 6.44 GHz and high gain of 10.30 dB which makes it suitable for modern applications in dedicated short range communication operating in 5.8 GHz band. To further validate the design concept, a microstrip UWB filter is designed, fabricated and tested. Comparison is made among circular, square and triangular dumbbell shaped DGS on the basis of scattering parameters and bandwidth, in which triangular shaped DB-DGS outperforms the other two. Further, parametric analysis of triangular DB-DGS has been performed and comparison is made with filters of similar nature. Experimental results are in good agreement with simulations. The fabricated filter is compact in size, has low insertion loss, exhibits high selectivity and demonstrates excellent out of-band performance.

      PubDate: 2018-02-25T17:05:35Z
      DOI: 10.1016/j.aeue.2018.01.026
      Issue No: Vol. 86 (2018)
  • Signal enhancement techniques for through-the-earth communication based on
           multiple references and beamforming
    • Authors: Yu-zhong Jiang; Peng Zhao; Qi Zhai; Wen-wei Ying; Qiao-lin Hu
      Pages: 86 - 91
      Abstract: Publication date: March 2018
      Source:AEU - International Journal of Electronics and Communications, Volume 86
      Author(s): Yu-zhong Jiang, Peng Zhao, Qi Zhai, Wen-wei Ying, Qiao-lin Hu
      Through-the-Earth Communication (TEC) is very vulnerable to electromagnetic interference (EMI) and the conventional signal enhancement techniques employing local primary and remote reference antennas are unfeasible for downlink signal reception due to the limited space and complicated terrain on the receiving sites. In this paper, a novel magnetic field sensing system for downlink reception, in which multiple reference sensors are deployed locally and orthogonally with the primary receiving sensor, is introduced and the signal model is constructed from a perspective of array reception. A modified minimum variance distortionless response (MVDR) beamformer is designed by exploiting the TEC operating conditions for suppressing the EMIs and enhancing the signal. Real tests with power line harmonic interferences (PLHIs) from household wiring in laboratory and an additional wideband jamming demonstrated a great reduction of the EMIs and thus reliable downlink signal reception could be obtained.

      PubDate: 2018-02-25T17:05:35Z
      DOI: 10.1016/j.aeue.2018.01.014
      Issue No: Vol. 86 (2018)
  • Performance of antenna selection schemes in dual hop full-duplex
           decode-and-forward relaying over Nakagami-m fading channels
    • Authors: Mesut Toka; Oğuz Kucur
      Pages: 92 - 102
      Abstract: Publication date: March 2018
      Source:AEU - International Journal of Electronics and Communications, Volume 86
      Author(s): Mesut Toka, Oğuz Kucur
      In this paper, we investigate the outage performance of several antenna selection (AS) schemes in dual hop full-duplex (FD) multiple-input multiple-output (MIMO) relay networks in which the relay adopts decode-and-forward (DF) protocol over Nakagami-m fading channels. In the network, the source (S), destination (D) and relay (R) are assumed to be equipped with multiple antennas. We assume that the line-of-sight component between S and D cannot be established due to the poor fading environment conditions. For signal transmission-reception during the training period, only a single antenna at each node is selected according to selection techniques, and then with the help of an error-free feedback channel the selected antenna index is sent to the related node. Outage probability (OP) expressions related to AS schemes are obtained in closed forms and asymptotic OPs are also derived in order to get more meaningful insights into OP and diversity behaviour. The theoretical results are verified by Monte Carlo simulations. We show that performance of the FD relay can be significantly improved by using selection techniques compared to half-duplex (HD), especially at low signal-to-noise ratio (SNR) region. In addition, results show that the performance floor level meaning zero diversity at high SNR region, which is also confirmed by asymptotic analysis and is an inherent disadvantage of FD relay, can be decreased. Moreover, it is shown that the FD relay with AS schemes outperforms HD as the target rate increases for a certain value of SNR and residual self-interference power.

      PubDate: 2018-02-05T14:10:19Z
      DOI: 10.1016/j.aeue.2018.01.018
      Issue No: Vol. 86 (2018)
  • An approach to essentially improve current efficiency for bulk-driven OTA
    • Authors: Xiao Zhao; Qisheng Zhang; Yongqing Wang; Liyuan Dong
      Pages: 103 - 107
      Abstract: Publication date: March 2018
      Source:AEU - International Journal of Electronics and Communications, Volume 86
      Author(s): Xiao Zhao, Qisheng Zhang, Yongqing Wang, Liyuan Dong
      An approach to essentially improve the current efficiency for the bulk-driven circuits is presented. By employing an auxiliary amplifier cross-coupled to the gate of bulk-driven flipped voltage follower and input differential pairs, it achieves not only the gain-bandwidth improved, but also the slew rate significantly enhanced, which leads to a great boost in current efficiency. To validate our introduced method, the conventional and the proposed bulk-driven amplifiers are both designed under the CSMC 0.18  μ m technology. Simulation results demonstrate that bulk-driven amplifier based on the proposed method achieves an 8 times slew rate and a 4 times bandwidth improvement with only a negligible increase in power consumption.

      PubDate: 2018-02-05T14:10:19Z
      DOI: 10.1016/j.aeue.2018.01.028
      Issue No: Vol. 86 (2018)
  • A sub-wavelength polarization insensitive X-band absorber based on
           interleaved concept
    • Authors: Seyed Vahid Masumina; Javad Nourinia; Changiz Ghobadi; Mohsen Karamirad; Bahman Mohammadi
      Pages: 108 - 116
      Abstract: Publication date: March 2018
      Source:AEU - International Journal of Electronics and Communications, Volume 86
      Author(s): Seyed Vahid Masumina, Javad Nourinia, Changiz Ghobadi, Mohsen Karamirad, Bahman Mohammadi
      In this paper, a miniaturized absorber realized on interleaved structure across X-band is reported. The presented absorber has been designed based on the concept of complementary interleaved Brigid’s cross. Results show that the structure rejects 9.88 GHz with absorption rate of almost 99%. Moreover, the absorber is polarization independent, as it maintains stability against TE- and TM-polarizations. The results from waveguide simulator and space wave measurements provide an efficient absorber at sub-wavelength spacing.

      PubDate: 2018-02-05T14:10:19Z
      DOI: 10.1016/j.aeue.2018.01.013
      Issue No: Vol. 86 (2018)
  • Tri-layer linearly-polarized discrete lens antenna operating in X-band,
           design & characterization
    • Authors: Hamza Kaouach; Mohamed Ali Belaid
      Pages: 117 - 124
      Abstract: Publication date: March 2018
      Source:AEU - International Journal of Electronics and Communications, Volume 86
      Author(s): Hamza Kaouach, Mohamed Ali Belaid
      This research work presents the design and characterization of planar discrete lens antennas (TA Transmit-Array antennas) based on a simple tri-layer elementary cell operating in the 10-GHz band. The structure of the proposed elementary cell allows 1-bit and 2-bit phase quantization and easy fabrication with a simple printed-circuit board. The linear/circular polarization can be generated with 1-bit/2-bit configuration. The elementary cell consists of two C-slot loaded patch antennas interconnected by a metalized via hole. The simulation of the elementary cell has been validated by the measurement that confirmed a good accord in terms of return loss (10 dB-bandwidth is equal to 9%) and insertion loss (0.35 dB at 10 GHz). The linearly-polarized transmit-array achieves a maximum directivity of 25.1 dBi and a gain of 22.7 dBi. The 1-dB gain bandwidth is up to 9.6% around 9.8 GHz with 56.3% of radiation efficiency. Beam-steering up to 30° is achieved by tilting the focal source.

      PubDate: 2018-02-05T14:10:19Z
      DOI: 10.1016/j.aeue.2018.01.032
      Issue No: Vol. 86 (2018)
  • A Miniaturized inductive – Loaded narrow strip wide band-notched
           ultra-wideband monopole antenna with dual-mode resonator
    • Authors: Hefilia Asokan; Srivatsun Gopalakrishnan
      Pages: 125 - 132
      Abstract: Publication date: March 2018
      Source:AEU - International Journal of Electronics and Communications, Volume 86
      Author(s): Hefilia Asokan, Srivatsun Gopalakrishnan
      A new miniaturized ultra-wideband (UWB) monopole antenna with a broad band, sharp roll-off frequency notch function is presented. A narrow, stepped impedance strip is the radiating element of the antenna similar to conventional narrowband antennas, in order to retain the conventional antenna characteristics such as polarization purity, omnidirectional radiation pattern, etc. The strip is split to create multiple closed resonances and inductors are loaded in series to achieve wide bandwidth. The split portions are inserted one over the other to make the antenna very compact. A new compact dual mode wide band parasitic resonator placed along the feed line, rejects the frequency band ranging from 5.15 to 5.825 GHz which has been allocated for IEEE 802.11a and High Performance Radio Local Area Network (HIPERLAN). The designed antenna was fabricated and the results were measured in an anechoic chamber. The measured results show the ultra-wideband resonance with reflection coefficient values below −10 dB over 3–10.5 GHz with a sharp roll off notch band.

      PubDate: 2018-02-05T14:10:19Z
      DOI: 10.1016/j.aeue.2018.01.024
      Issue No: Vol. 86 (2018)
  • Concentric circular antenna array synthesis for side lobe suppression
           using moth flame optimization
    • Authors: Avishek Das; D. Mandal; S.P. Ghoshal; R. Kar
      Pages: 177 - 184
      Abstract: Publication date: March 2018
      Source:AEU - International Journal of Electronics and Communications, Volume 86
      Author(s): Avishek Das, D. Mandal, S.P. Ghoshal, R. Kar
      This paper presents an accurate approach for Concentric Circular Antenna Array (CCAA) synthesis to improve the far-field radiation characteristics of the antenna using a meta-heuristic optimization technique called Moth Flame Optimization (MFO). The far-field radiation pattern improves with lower Side Lobe Level (SLL) which is essential for the reduction of interference in the entire side lobe regions. MFO algorithm is a recently proposed evolutionary algorithm which is applied to determine the optimum sets of current excitation weights and to find the optimal inter-element spacing between the array elements in the 3-rings structure of CCAA design. In this context, the design examples of two 3-ring CCAAs, one having the set of 4, 6, 8 elements and the other having the set of 8, 10, 12 elements, with and without centre element, are presented by optimizing the array parameters. The results obtained by using MFO algorithm based approach show a considerable improvement of SLL with respect to that of the uniform array pattern and those of the approaches reported in the recent literature.

      PubDate: 2018-02-25T17:05:35Z
      DOI: 10.1016/j.aeue.2018.01.017
      Issue No: Vol. 86 (2018)
  • Impact of secondary user mobility on spectrum handoff under generalized
           residual time distributions in cognitive radio networks
    • Authors: Shanidul Hoque; Wasim Arif
      Pages: 185 - 194
      Abstract: Publication date: March 2018
      Source:AEU - International Journal of Electronics and Communications, Volume 86
      Author(s): Shanidul Hoque, Wasim Arif
      Cognitive Radio is an emerging technology to accommodate the growing demand for wireless technology via dynamic spectrum access to enhance spectrum efficiency. Spectrum handoff is an important component of Cognitive Radio technology for practical implementation of radio frequency access strategy and better utilization of spectrum in both primary and secondary networks. The probability of spectrum handoff and expected number of spectrum handoffs are key parameters in performance analysis and design of the cognitive radio network. This work presents an analytical model to evaluate the impact of secondary users’ mobility on intra-cell spectrum handoff considering primary users’ activity model in a cognitive radio network. A standard form of intra-cell spectrum handoff probability and expected number of intra-cell spectrum handoffs are derived for complete call duration of a non-stationary secondary user. The probability and expected number of intra-cell spectrum handoffs of a post inter-cell handoff call are also derived for generalized residual time distributions of call holding time and spectrum holes. A detailed analysis of these performance measuring metrics is presented under the impact of departure rate and cell crossing rate of secondary users. The accuracy of the derived analytical result is validated by Monte-Carlo simulation of the model.

      PubDate: 2018-02-25T17:05:35Z
      DOI: 10.1016/j.aeue.2018.01.031
      Issue No: Vol. 86 (2018)
  • A novel voltage-mode universal filter composed of two terminal active
    • Authors: Erkan Yuce; Serdar Tez
      Pages: 202 - 209
      Abstract: Publication date: March 2018
      Source:AEU - International Journal of Electronics and Communications, Volume 86
      Author(s): Erkan Yuce, Serdar Tez
      A novel voltage-mode (VM) universal filter is proposed in this work. A voltage follower (VF) and a negative impedance converter (NIC) which are two terminal active elements are used in the implementation of the proposed filter. Also, two capacitors and three resistors are employed in the proposed filter as passive circuit elements. On the other hand, each of the VF and NIC can be easily constructed by using a plus-type second-generation current conveyor. One of the main advantages of the proposed filter is the feature of low output impedance resulting in easy cascadability with other VM circuits. Moreover, the quality factor of the proposed filter can be easily adjusted by changing value of only one of the resistors without disturbing its angular resonance frequency. Nonetheless, it requires a single resistive matching condition for proper circuit operation and a unity gain inverting amplifier for only all-pass filter responses. A number of simulation results are achieved by using 0.13 μm IBM CMOS technology parameters with ±0.75 V DC power supply voltages. Power consumption of the proposed filter is approximately found as 3.65 mW through SPICE simulations. Furthermore, experimental test results are included to confirm the theory.

      PubDate: 2018-02-25T17:05:35Z
      DOI: 10.1016/j.aeue.2018.01.010
      Issue No: Vol. 86 (2018)
  • Analysis of Effective Capacity for Visible Light Communication Systems
           with Mobility Support
    • Authors: Lei Qian; Xuefen Chi; Linlin Zhao
      Abstract: Publication date: Available online 25 February 2018
      Source:AEU - International Journal of Electronics and Communications
      Author(s): Lei Qian, Xuefen Chi, Linlin Zhao
      Visible light communications (VLCs) are competitive and attractive candidates for next generation indoor communication networks which are required to support mobility and guarantee delay QoS (Quality of Service) for users. User movement in VLC systems changes the propagation path, including the distance, the angle of incidence and irradiance, all of which have a significant impact on channel gain and link capacity. In this paper, we present a user mobility model for indoor VLC systems with the help of discrete time Markov chain theory. Considering a service process with temporal correlation caused by user mobility, we derive the effective capacity (EC) for VLC systems which characterizes the capacity performance subject to the user’s statistical delay QoS. Moreover, the effect of the user’s mobility on effective capacity is revealed.

      PubDate: 2018-02-25T17:05:35Z
      DOI: 10.1016/j.aeue.2018.02.017
  • Lower Mode Excitation in Vertex-Fed Slotted Hexagonal S-Band Antenna
    • Authors: Abhishek Joshi; Rahul Singhal
      Abstract: Publication date: Available online 25 February 2018
      Source:AEU - International Journal of Electronics and Communications
      Author(s): Abhishek Joshi, Rahul Singhal
      Direct-fed hexagonal patch antenna are limited to S11 ≥ -10 dB at lower modes, especially when fed at the vertex of the hexagon. This paper demonstrates a technique to compensate impedance mismatch at a lower mode in a vertex-fed slotted hexagonal antenna. A circular parallel-plate capacitor (PPC) is introduced to the antenna structure that improves impedance matching to excite a lower mode for a probe-fed hexagonal patch antenna. With an overall size of 50 × 50 mm2, the proposed antenna is compact and can operate at 2.4 GHz in presence of PPC with a gain of 2.11 dB and is suitable for various S-band applications.

      PubDate: 2018-02-25T17:05:35Z
      DOI: 10.1016/j.aeue.2018.02.008
  • A 220 mV Robust Read-Decoupled Partial Feedback Cutting based Low-Leakage
           9T SRAM for Internet of Things (IoT) Applications
    • Authors: Vishal Sharma; Maisagalla Gopal; Pooran Singh; Santosh Kumar Vishvakarma
      Abstract: Publication date: Available online 24 February 2018
      Source:AEU - International Journal of Electronics and Communications
      Author(s): Vishal Sharma, Maisagalla Gopal, Pooran Singh, Santosh Kumar Vishvakarma
      In this work, a 9T subthreshold SRAM cell is proposed with the reduced leakage power and improved stability against the PVT variations. The proposed cell employs the read decoupling to improve the read stability, and the partial feedback cutting approach to control the leakage power with improved read/write ability. The incorporated stacking effect further improves the leakage power. The simulated leakage power for the proposed cell is 0.61 × , 0.49 × , 0.80 × and 0.55 × , while the read static noise margin (RSNM) is 2.5 × , 1 × , 1.05 × and 0.96 × , write static noise margin (WSNM) 0 is 1.5 × , 1.8 × , 1.68 × and 1.9 × and WSNM 1 is 0.95 × , 1.2 × , 1.05 × , and 1.2 × at 0.4V when compared with the conventional 6T and state of arts (single ended 6T, PPN based 10T and data aware write assist (DAWA) 12T SRAM architectures) respectively. The minimum supply voltage at which this cell can successfully operate is 220mV.A 4Kb memory array has also been simulated using proposed cell and it consumes 0.63 × , 0.67 × and 0.63 × less energy than 6T during read, write 1 and write 0 operations respectively for supply voltage of 0.3V.

      PubDate: 2018-02-25T17:05:35Z
      DOI: 10.1016/j.aeue.2018.01.030
  • Diversity Embedded Rate Configurable GSM and a Low Complexity Detection
    • Authors: Bindu.P. Palakkal; Jibukumar .M.G
      Abstract: Publication date: Available online 23 February 2018
      Source:AEU - International Journal of Electronics and Communications
      Author(s): Bindu.P. Palakkal, Jibukumar .M.G
      This paper presents an energy efficient transmission method that is suitable for emerging large scale MIMO scenario, by combining space time coding and spatial multiplexing with GSM. The proposed Diversity Embedded SM (DESM) provides required Quality of Service (QoS) for a high priority data and at the same time maintains a fair transmission rate by spatial multiplexing a low priority data. Only limited feedback is required and the system can be configured for different diversity/non-diversity stream rates, as per the required QoS. Utilizing some peculiarities of the channel matrix of the system, a QR decomposition based detection method that requires only four receiving antennas is shown to have good performance. The computational complexity of detection is less compared to the existing GSM detection schemes, for reasonable number of transmit and active antennas. The effect of incorporating diversity on the rate of the system is also analysed.

      PubDate: 2018-02-25T17:05:35Z
      DOI: 10.1016/j.aeue.2018.02.020
  • A High Gain Dual-band Printed Antenna for LTE Base Stations with a Corner
    • Authors: Elnaz Najafnezhad; Javad Nourinia; Changiz Ghobadi; Maryam Majidzadeh; Farnaz Mirzamohammadi
      Abstract: Publication date: Available online 23 February 2018
      Source:AEU - International Journal of Electronics and Communications
      Author(s): Elnaz Najafnezhad, Javad Nourinia, Changiz Ghobadi, Maryam Majidzadeh, Farnaz Mirzamohammadi
      A high gain dual-band printed antenna is proposed for LTE base stations applications. The established 60×60 mm2 broadband antenna structure is composed of two perpendicular U-shaped and L-shaped monopole antennas which are located vertically on ground plane printed on 1.6 mm thick FR4 substrate. A metallized wall is connected to the substrate which forms a corner reflector. A coaxial cable at the common center of the monopoles is adopted to excite the antenna. Wise implementation of the conductive elements and finely tuning of the monopoles dimensions yield the excitation of two resonances and dual band operation achievement. The presented antenna achieves bandwidths of 1.61-1.86 GHz and 2.25-2.45 GHz suitable for LTE applications. Stable radiation pattern, small size, cost effective fabrication, and high peak gain values of 10 dBi and 9.5 dBi at two operating bands are the prominent features of the proposed antenna topology.

      PubDate: 2018-02-25T17:05:35Z
      DOI: 10.1016/j.aeue.2018.02.024
  • Non-data aided Joint Estimation of Symbol Timing Offset and Carrier
           Frequency Offset for OFDM/OQAM Systems
    • Authors: Mingqian Liu; Ju Wang; Bingbing Li
      Abstract: Publication date: Available online 23 February 2018
      Source:AEU - International Journal of Electronics and Communications
      Author(s): Mingqian Liu, Ju Wang, Bingbing Li
      This paper deals with the problem of blind synchronization for orthogonal frequency division multiplexing based on offset quadrature amplitude (OFDM/OQAM) systems without the prior information of the channel response and transmitting signals power. A novel non-data aided (NDA) joint estimation method of symbol timing offset (STO) and carrier frequency offset (CFO) for OFDM/OQAM is conceived in multipath fading channels condition. The multipath fading channels are equivalent to multiple parallel sub-channels with flat Rayleigh fading characteristics firstly, and then STO and CFO are estimated by the second-order cyclic-cumulant with different cycle frequency values and time delay values. Moreover, the modified Cramer-Rao Bound (MCRB) of NDA joint STO and CFO estimation is presented. The simulation results demonstrate that the proposed method is effective and feasible over frequency selective fading channels.

      PubDate: 2018-02-25T17:05:35Z
      DOI: 10.1016/j.aeue.2018.02.021
  • Visual Tracking via Salient Feature Extraction and Sparse Collaborative
    • Authors: Yang Liu; Feng Yang; Cheng Zhong; Ying Tao; Bing Dai; Mengxiao Yin
      Abstract: Publication date: Available online 21 February 2018
      Source:AEU - International Journal of Electronics and Communications
      Author(s): Yang Liu, Feng Yang, Cheng Zhong, Ying Tao, Bing Dai, Mengxiao Yin
      Object tracking is always a very attractive research topic in computer vision and image processing. In this paper, an innovative method called salient-sparse-collaborative tracker (SSCT) is put forward, which exploits both object saliency and sparse representation. Within the proposed collaborative appearance model, the object salient feature map is built to create a salient-sparse discriminative model (SSDM) and a salient-sparse generative model (SSGM). In the SSDM module, the presented sparse model effectively distinguishes the target region from its background by using the salient feature map that further helps locate the object in complex environment. In the SSGM module, a sparse representation method with salient feature map is designed to improve the effectiveness of the templates and deal with occlusions. The update scheme takes advantage of salient correction, thus the SSCT algorithm can both handle the appearance variation as well as reduce tracking drifts effectively. Plenty of experiments with quantitative and qualitative comparisons on benchmark reveal the SSCT tracker is more competitive than several popular approaches.

      PubDate: 2018-02-25T17:05:35Z
      DOI: 10.1016/j.aeue.2018.02.019
  • Online model parameter identification for supercapacitor based on
           weighting bat algorithm
    • Authors: Geng Sun; Yanheng Liu; Ruizhi Chai; Fang Mei; Ying Zhang
      Abstract: Publication date: Available online 16 February 2018
      Source:AEU - International Journal of Electronics and Communications
      Author(s): Geng Sun, Yanheng Liu, Ruizhi Chai, Fang Mei, Ying Zhang
      To support real-time power management of the supercapacitor-powered embedded systems, an online model parameter identification method is proposed for predicting the supercapacitor behavior. In the proposed method, an optimization problem is formulated based on our previously developed supercapacitor model, and a weighting bat algorithm (WBA) with the weighting solution update method is proposed for solving this problem in each model parameter updating time window. Simulation and experimental results show that the proposed online model parameter identification method can accurately capture the terminal behavior of a supercapacitor, and the proposed WBA-based optimization method has better performance for the supercapacitor model parameter identification compared with other benchmark algorithms.

      PubDate: 2018-02-25T17:05:35Z
      DOI: 10.1016/j.aeue.2018.02.015
  • Energy Harvest and Information Transmission Design in Internet-of-Things
           Wireless Communication Systems
    • Authors: Baofeng Ji; Kang Song; Chunguo Li; Wei-ping Zhu; Luxi Yang
      Abstract: Publication date: Available online 15 February 2018
      Source:AEU - International Journal of Electronics and Communications
      Author(s): Baofeng Ji, Kang Song, Chunguo Li, Wei-ping Zhu, Luxi Yang
      Wireless energy transmission is considered in the Internet-of-Things (IoT) dual-hop communication systems. The power splitting method is employed at the relay node to receive the wireless energy and the wireless information simultaneously from the source to the relay node in the first resource block. With the harvested energy at the relay node, one wireless information node and one wireless energy harvest node are served simultaneously by the relay node in the second resource block. The optimization problem is formulated to maximize the energy efficiency defined as the ratio of the wireless information throughput of the first destination node over the power consumed by the whole IoT systems, which is subject to the required minimum energy harvested at the second destination node of the energy transfer. To tackle the non-convex problem, the exact expression of the wireless information throughput is approximated by the high signal to noise ratio (SNR) approximation method, which is shown very tight to the exact expression. Hence, the asymptotically optimal solution is derived in analytical expression by employing the Lagrangian method. Numerical simulations verify the performance of the proposed scheme.

      PubDate: 2018-02-25T17:05:35Z
      DOI: 10.1016/j.aeue.2018.01.038
  • Modified hexagonal triple-band metamaterial absorber with wide-angle
    • Authors: Reza Asgharian; Bijan Zakeri; Omid Karimi
      Abstract: Publication date: Available online 13 February 2018
      Source:AEU - International Journal of Electronics and Communications
      Author(s): Reza Asgharian, Bijan Zakeri, Omid Karimi
      In this work, a T-shaped and square-liked ring resonator Metamaterial absorber has been presented. The unit cell consists components based on three hexagonal closed rings. Excellent absorption has been resulted by modifying hexagonal cell. The absorption rates are 95, 97 and 99% at 5.8, 9.52 and 11.97GHz, respectively. The structure has been implemented on 1mm-thick FR4 substrate considering low cost and simple process in the fabrication. The results show a wide-angle stability under TE and TM polarizations. The numerical simulation agrees the corresponding measurement.

      PubDate: 2018-02-25T17:05:35Z
      DOI: 10.1016/j.aeue.2018.02.013
  • NLOS Identification for UWB Localization Based on Import Vector Machine
    • Authors: Xiaofeng Yang; Feng Zhao; Tiejun Chen
      Abstract: Publication date: Available online 10 February 2018
      Source:AEU - International Journal of Electronics and Communications
      Author(s): Xiaofeng Yang, Feng Zhao, Tiejun Chen
      Ultra-Wide Band (UWB) based localization is one of the most promising techniques for high accuracy localization. The crucial factor that aggravates the localization precision is None-Line-of-Sight (NLOS) propagation. To address this issue, we propose a novel NLOS identification algorithm with feature selection strategy and a localization algorithm based on Import Vector Machine (IVM) with high accuracy and low complexity. The feature selection strategy further meliorates the classification accuracy. The probability outputs of IVM is employed by the localization algorithm and yields higher positioning accuracy than its counterpart methods— Support Vector Machine (SVM) and Relevance Vector Machine (RVM). Simulation results prove that IVM is a robust and efficient method for NLOS identification and localization.

      PubDate: 2018-02-25T17:05:35Z
      DOI: 10.1016/j.aeue.2018.02.003
  • A fast hybrid method for the bandgap analysis of 2D photonic crystals
           based on EMT and AFGSM methods
    • Authors: Onur Erkan; Mehmet Nuri Akıncı; Serkan Şimşek
      Abstract: Publication date: Available online 6 February 2018
      Source:AEU - International Journal of Electronics and Communications
      Author(s): Onur Erkan, Mehmet Nuri Akıncı, Serkan Şimşek
      Fast analysis of photonic crystals is important due to increasing demand in optical systems that utilize photonic crystals as their subblocks. In this paper, we present a hybrid method (HM) to analyze photonic bandgaps of two-dimensional (2D) photonic crystals. The proposed technique allows to evaluate bandgap edges by designing only the parameters of a unit cell. The approach employs effective-medium theory (EMT) to reduce 2D geometry to one-dimensional (1D) multilayer equivalence to avoid the dimensional complexity of the problem. Then, bandgap edges of the equivalent 1D structure are determined by the auxiliary functions of generalized scattering matrix (AFGSM) method. Developed combined technique is applied to square and circular shaped PCs for bandgap analysis. Results show that computation times remarkably shortened, and HM offers an effective usage. We believe findings should make an important contribution to the field of 2D PC bandgap analysis and further design studies.

      PubDate: 2018-02-25T17:05:35Z
      DOI: 10.1016/j.aeue.2018.01.033
  • An Offset CPW-Fed Triple-Band Circularly Polarized Printed Antenna for
           Multiband Wireless Applications
    • Authors: Ashok Kumar; Venuka Sankhla; Jitendra Kumar Deegwal; Arjun Kumar
      Abstract: Publication date: Available online 3 February 2018
      Source:AEU - International Journal of Electronics and Communications
      Author(s): Ashok Kumar, Venuka Sankhla, Jitendra Kumar Deegwal, Arjun Kumar
      An offset coplanar waveguide (CPW)-fed triple-band circularly polarized tilted asymmetrical E-shaped printed antenna for multiband wireless applications is presented in this paper. The antenna mainly consists of a tilted asymmetrical E-shaped patch and excite by a 50 Ω offset CPW feed line using a transformer for impedance matching to generate wide quad operating bands. By properly embedding rectangular slots in the tilted asymmetrical E-shaped patch and triangular stubs loaded modified CPW ground plane, the antenna reveals triple-band circular polarization (CP) features. Numerical analysis and experimental validation of the antenna structure have been carried out and results are presented. The mechanism of triple-band CP operation, analysis of surface current distributions, design procedure and parametric study of the design is discussed in details. It is well suited for the application of UMTS-2100, 3.5/5.5 GHz WiMAX, 5.2/5.8 GHz WLAN, ITS, downlink of X-band satellite communication, and ITU 8 GHz bands.

      PubDate: 2018-02-05T14:10:19Z
      DOI: 10.1016/j.aeue.2018.02.002
  • Non-Orthogonal Multiple Access Protocol for Overlay Cognitive Radio
           Networks Using Spatial Modulation and Antenna Selection
    • Authors: Said Emam; M.E. Çelebi
      Abstract: Publication date: Available online 3 February 2018
      Source:AEU - International Journal of Electronics and Communications
      Author(s): Said Emam, M.E. Çelebi
      In this paper we propose a novel spectrum sharing protocol for overlay cognitive radio networks using non-orthogonal multiple access (NOMA), spatial modulation (SM) and antenna selection (AS). The proposed protocol allows a secondary transmitter (ST) to transmit simultaneously to both a primary receiver (PR) and a secondary receiver (SR) using SM. The usage of NOMA and SM will increase the spectral efficiency for both PR and SR with reduced detection complexity than the case without NOMA in which the detectors are required to jointly detect both SM symbols at each receiver. The application of AS at ST with regards to PR provides higher quality transmission for PR without affecting the performance of SR. The performance of the proposed protocol is investigated by derivations of upper bounds on the average symbol error probabilities at PR and SR and by Monte Carlo simulations. Analytical and simulation results show that the proposed protocol offers efficient spectrum utilization over spectrum sharing protocols proposed recently that uses SM – to convey the primary data to PR through the amplitude phase modulation technique and the secondary data to SR through the index of the active antenna.

      PubDate: 2018-02-05T14:10:19Z
      DOI: 10.1016/j.aeue.2018.02.006
  • Microstrip Bandpass Filters using Coupled Feed Lines for Third and Fourth
           Generation Communications
    • Authors: Amirhossein Ghaderi; Alireza Golestanifar; Farzin Shama
      Abstract: Publication date: Available online 3 February 2018
      Source:AEU - International Journal of Electronics and Communications
      Author(s): Amirhossein Ghaderi, Alireza Golestanifar, Farzin Shama
      In this paper, two compact tuneable bandpass filters (BPFs) based on the coupled feed lines are introduced. To approach a compact size, the coupled feed lines are bended. To design a high performance single-band bandpass filter (BPF), coupled feed lines are loaded by T-shaped stubs (as main resonators) and rectangular stubs (as suppressor stubs). Also, the mechanism of coupled feed lines combining with T-shaped open stubs is analyzed to show a tunable passband. The dual-band BPF includes two big radial-stubs, two small radial-stubs, two T-shaped structures and spiral coupled feed lines. The LC model of big radial-stubs is analyzed to compute the equation of transmission zero using its transfer function. The passband frequency of single-band BPF resonates at 2.12 GHz (3G) with corresponded insertion loss of 0.83 dB. Also, for dual-band BPF, the measured insertion-losses of first and second passbands are close to 0.8 and 1.1 dB, respectively. The frequency responses of BPFs are easily adjusted by altering the physical dimensions, demonstrating a adjustable performance. To verify the correct operation of circuits, the proffered filters are implemented and tested.

      PubDate: 2018-02-05T14:10:19Z
      DOI: 10.1016/j.aeue.2018.02.007
  • A Miniaturized Lowpass Bandpass Diplexer with high Isolation
    • Authors: Hossein Heshmati; Sobhan Roshani
      Abstract: Publication date: Available online 3 February 2018
      Source:AEU - International Journal of Electronics and Communications
      Author(s): Hossein Heshmati, Sobhan Roshani
      A new compact and wide band lowpass-bandpass diplexer with simple structure is designed and fabricated in this paper. T shaped and Z shaped resonators are used in the lowpass channel and two coupled open stubs are used in the bandpass channel. The designed diplexer has 3 dB cutoff frequency of 1GHz in the lowpass channel and operating frequency of 2.4GHz in the bandpass channel. The obtained insertion losses in the lowpass and bandpass channels are 0.25 dB and 0.58 dB, respectively. The obtained isolation between the two output ports is better than 35 dB. The overall size of the fabricated lowpass bandpass diplexer is obtained 45.6mm× 28.6mm, which shows good miniaturization, compared with other similar diplexers.

      PubDate: 2018-02-05T14:10:19Z
      DOI: 10.1016/j.aeue.2018.02.004
  • Isolation and Gain Enhancement of Patch Antennas using EMNZ Superstrate
    • Authors: Prakash Kumar Panda; Debalina Ghosh
      Abstract: Publication date: Available online 2 February 2018
      Source:AEU - International Journal of Electronics and Communications
      Author(s): Prakash Kumar Panda, Debalina Ghosh
      A system comprising of multiple antennas demonstrate performance degradation due to the adverse effects of mutual coupling. This work describes an isolation enhancement technique using an epsilon-and-mu-near-zero (EMNZ) metamaterial as superstrate. The method is demonstrated for closely packed H-plane microstrip patch antennas. The EMNZ superstrate is placed at a height of 10 mm (equivalent to λ 0 / 12 ) above the antennas which have an edge to edge separation of 4mm (equivalent to λ 0 / 30 ). The EMNZ superstrate enhances the isolation to -30dB at the resonant frequency. At the same time metamaterial demonstrates NZRI (near zero refractive index) properties due to which the directivity of the antennas is enhanced. Additionally, the generation of cavity effect due to the placement of the superstrate leads to an increase in the gain and efficiency of the antenna by 3.4dBi and 20% respectively. The overall design is very compact and can be easily incorporated in a multi antenna system.

      PubDate: 2018-02-05T14:10:19Z
      DOI: 10.1016/j.aeue.2018.01.037
  • A 12-bit 100MS/s Pipelined ADC without Using Front-End SHA
    • Authors: H. Imanpoor; M. Mehranpouy; P. Torkzadeh; A. Jannesari
      Abstract: Publication date: Available online 2 February 2018
      Source:AEU - International Journal of Electronics and Communications
      Author(s): H. Imanpoor, M. Mehranpouy, P. Torkzadeh, A. Jannesari
      This paper presents a model and a novel architecture of a low-power pipelined analog-to-digital converter (ADC) without using front-end Sample and Hold Amplifier (SHA) stage. The Modeling of all ADC building blocks along with their non-ideal effects have been implemented in MATLAB SIMULINK environment and the main transistor level circuits have been implemented in H-SPICE environment using 180-nm TSMC CMOS Technology. The maximum DNL and INL amounts are equal to ± 0.9 LSB and ± 2.3 LSB, respectively. Applying a 33.1MHz with 1.4 V p - p (-6dBFS) input signal, achieved SNDR is 61dB resulting in 9.8Bits ENOB with total power consumption of 42mW.

      PubDate: 2018-02-05T14:10:19Z
      DOI: 10.1016/j.aeue.2018.01.027
  • Ku Band Pattern Reconfigurable Substrate Integrated Waveguide Leaky Wave
           Horn Antenna
    • Authors: Tanvi Agrawal; Shweta Srivastava
      Abstract: Publication date: Available online 2 February 2018
      Source:AEU - International Journal of Electronics and Communications
      Author(s): Tanvi Agrawal, Shweta Srivastava
      A dual band substrate integrated waveguide H plane sectoral horn antenna with reconfigurable radiation characteristics has been proposed in this paper. Designed antenna acts as a perfect broadside radiator at 16.1 GHz and perfect endfire radiator at 14.4 GHz frequency. Broadside radiation has been achieved by etching rectangular slots in the flared section of horn exhibiting a gain of 8.87 dBi. To achieve perfect endfire radiation, dielectric loading is done at the edge of horn and at this frequency antenna shows a gain of 11.3 dBi. The horn and the loaded dielectric are integrated by using the same single substrate resulting in easy fabrication and low cost. The proposed design has been fabricated and measured results are in good agreement with the simulated results.

      PubDate: 2018-02-05T14:10:19Z
      DOI: 10.1016/j.aeue.2018.01.022
  • A Fully Integrated RSSI and an Ultra-Low Power SAR ADC for 5.8GHz DSRC ETC
    • Authors: Meijuan Zhang; Ruifeng Liu; Yuanzhi Zhang; Wenshen Wang; Huimin Liu; Chao Lu
      Abstract: Publication date: Available online 2 February 2018
      Source:AEU - International Journal of Electronics and Communications
      Author(s): Meijuan Zhang, Ruifeng Liu, Yuanzhi Zhang, Wenshen Wang, Huimin Liu, Chao Lu
      This study presents a monolithic received signal strength indicator (RSSI) and an ultra-low power SAR ADC for 5.8GHz DSRC transceiver in China electronic toll collection systems. In order to meet the stringent requirement of wide input range for the transceiver, two RSSIs collaborate with auxiliary ADC circuits to provide the digitalized received signal strength to the digital baseband of a transceiver. The RSSI design achieves fast transient response and low power consumption with a small die area by using internal active low-pass filters instead of external passive ones. The proposed design has been fabricated using a 0.13µm 2P6M CMOS technology. Measurement results show that the overall input dynamic range is 86dB with an accuracy of ±1.72dB and a transient response of less than 2µs. Compared with the state-of-the-art designs in the literature, the overall input range and transient settling time are improved by at least 14.6%, and 300%, respectively.

      PubDate: 2018-02-05T14:10:19Z
      DOI: 10.1016/j.aeue.2018.01.020
    • Authors: Deniz Ustun; Ali Akdagli
      Abstract: Publication date: Available online 2 February 2018
      Source:AEU - International Journal of Electronics and Communications
      Author(s): Deniz Ustun, Ali Akdagli
      In this study, a novel UWB antenna with dual band–rejection is designed by using a new hybrid optimization algorithm based artificial bee colony algorithm (ABC) and differential evolution (DE). The hybrid performance of ABC and DE (H–ABCDE) is tested on well–known benchmark functions. To show its performance on a design problem, an optimization interface (OI) which simultaneously communicates with H–ABCDE and an electromagnetic simulation tool is developed. Hence OI integrating H–ABCDE and HyperLynx® 3D EM is used to design and optimize an antenna. A low profile UWB monopole antenna operating over the frequency range of 2.9–13.0 GHz is then designed through OI. In order to achieve band–rejection operation, various slits and strips have been loaded on the antenna. It thus rejects the dual–band of 3.3–3.6 GHz and 5.15–5.825 GHz corresponds to the operation bands of WLAN and WiMAX. Furthermore, the optimized antenna is prototyped to investigate the measurement performance and it is compared with several designs in the literature. Therefore, H–ABCDE can successfully adapt to the extended electromagnetic problem as well as engineering optimization tasks.

      PubDate: 2018-02-05T14:10:19Z
      DOI: 10.1016/j.aeue.2018.02.001
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