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COMPUTER SCIENCE (1157 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: 13)
Abakós     Open Access   (Followers: 3)
Academy of Information and Management Sciences Journal     Full-text available via subscription   (Followers: 69)
ACM Computing Surveys     Hybrid Journal   (Followers: 22)
ACM Journal on Computing and Cultural Heritage     Hybrid Journal   (Followers: 9)
ACM Journal on Emerging Technologies in Computing Systems     Hybrid Journal   (Followers: 13)
ACM Transactions on Accessible Computing (TACCESS)     Hybrid Journal   (Followers: 3)
ACM Transactions on Algorithms (TALG)     Hybrid Journal   (Followers: 16)
ACM Transactions on Applied Perception (TAP)     Hybrid Journal   (Followers: 6)
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: 11)
ACM Transactions on Computational Logic (TOCL)     Hybrid Journal   (Followers: 4)
ACM Transactions on Computer Systems (TOCS)     Hybrid Journal   (Followers: 18)
ACM Transactions on Computer-Human Interaction     Hybrid Journal   (Followers: 13)
ACM Transactions on Computing Education (TOCE)     Hybrid Journal   (Followers: 3)
ACM Transactions on Design Automation of Electronic Systems (TODAES)     Hybrid Journal   (Followers: 1)
ACM Transactions on Economics and Computation     Hybrid Journal  
ACM Transactions on Embedded Computing Systems (TECS)     Hybrid Journal   (Followers: 4)
ACM Transactions on Information Systems (TOIS)     Hybrid Journal   (Followers: 20)
ACM Transactions on Intelligent Systems and Technology (TIST)     Hybrid Journal   (Followers: 8)
ACM Transactions on Interactive Intelligent Systems (TiiS)     Hybrid Journal   (Followers: 3)
ACM Transactions on Multimedia Computing, Communications, and Applications (TOMCCAP)     Hybrid Journal   (Followers: 10)
ACM Transactions on Reconfigurable Technology and Systems (TRETS)     Hybrid Journal   (Followers: 7)
ACM Transactions on Sensor Networks (TOSN)     Hybrid Journal   (Followers: 8)
ACM Transactions on Speech and Language Processing (TSLP)     Hybrid Journal   (Followers: 11)
ACM Transactions on Storage     Hybrid Journal  
ACS Applied Materials & Interfaces     Full-text available via subscription   (Followers: 21)
Acta Automatica Sinica     Full-text available via subscription   (Followers: 3)
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: 26)
Advanced Science Letters     Full-text available via subscription   (Followers: 7)
Advances in Adaptive Data Analysis     Hybrid Journal   (Followers: 8)
Advances in Artificial Intelligence     Open Access   (Followers: 16)
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: 15)
Advances in Computer Science : an International Journal     Open Access   (Followers: 13)
Advances in Computing     Open Access   (Followers: 2)
Advances in Data Analysis and Classification     Hybrid Journal   (Followers: 53)
Advances in Engineering Software     Hybrid Journal   (Followers: 25)
Advances in Geosciences (ADGEO)     Open Access   (Followers: 10)
Advances in Human-Computer Interaction     Open Access   (Followers: 20)
Advances in Materials Sciences     Open Access   (Followers: 16)
Advances in Operations Research     Open Access   (Followers: 11)
Advances in Parallel Computing     Full-text available via subscription   (Followers: 7)
Advances in Porous Media     Full-text available via subscription   (Followers: 4)
Advances in Remote Sensing     Open Access   (Followers: 37)
Advances in Science and Research (ASR)     Open Access   (Followers: 6)
Advances in Technology Innovation     Open Access   (Followers: 1)
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)
Air, Soil & Water Research     Open Access   (Followers: 7)
AIS Transactions on Human-Computer Interaction     Open Access   (Followers: 6)
Algebras and Representation Theory     Hybrid Journal   (Followers: 1)
Algorithms     Open Access   (Followers: 11)
American Journal of Computational and Applied Mathematics     Open Access   (Followers: 4)
American Journal of Computational Mathematics     Open Access   (Followers: 4)
American Journal of Information Systems     Open Access   (Followers: 7)
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: 9)
Annals of Mathematics and Artificial Intelligence     Hybrid Journal   (Followers: 6)
Annals of Pure and Applied Logic     Open Access   (Followers: 2)
Annals of Software Engineering     Hybrid Journal   (Followers: 12)
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: 2)
Applied Artificial Intelligence: An International Journal     Hybrid Journal   (Followers: 14)
Applied Categorical Structures     Hybrid Journal   (Followers: 2)
Applied Clinical Informatics     Hybrid Journal   (Followers: 2)
Applied Computational Intelligence and Soft Computing     Open Access   (Followers: 12)
Applied Computer Systems     Open Access   (Followers: 1)
Applied Informatics     Open Access  
Applied Mathematics and Computation     Hybrid Journal   (Followers: 32)
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)
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: 125)
Archives of Computational Methods in Engineering     Hybrid Journal   (Followers: 4)
Artifact     Hybrid Journal   (Followers: 2)
Artificial Life     Hybrid Journal   (Followers: 6)
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  
Automatic Control and Computer Sciences     Hybrid Journal   (Followers: 3)
Automatic Documentation and Mathematical Linguistics     Hybrid Journal   (Followers: 5)
Automatica     Hybrid Journal   (Followers: 9)
Automation in Construction     Hybrid Journal   (Followers: 6)
Autonomous Mental Development, IEEE Transactions on     Hybrid Journal   (Followers: 8)
Basin Research     Hybrid Journal   (Followers: 5)
Behaviour & Information Technology     Hybrid Journal   (Followers: 52)
Bioinformatics     Hybrid Journal   (Followers: 308)
Biomedical Engineering     Hybrid Journal   (Followers: 16)
Biomedical Engineering and Computational Biology     Open Access   (Followers: 13)
Biomedical Engineering, IEEE Reviews in     Full-text available via subscription   (Followers: 17)
Biomedical Engineering, IEEE Transactions on     Hybrid Journal   (Followers: 31)
Briefings in Bioinformatics     Hybrid Journal   (Followers: 46)
British Journal of Educational Technology     Hybrid Journal   (Followers: 123)
Broadcasting, IEEE Transactions on     Hybrid Journal   (Followers: 10)
c't Magazin fuer Computertechnik     Full-text available via subscription   (Followers: 2)
CALCOLO     Hybrid Journal  
Calphad     Hybrid Journal  
Canadian Journal of Electrical and Computer Engineering     Full-text available via subscription   (Followers: 14)
Catalysis in Industry     Hybrid Journal   (Followers: 1)
CEAS Space Journal     Hybrid Journal  
Cell Communication and Signaling     Open Access   (Followers: 1)
Central European Journal of Computer Science     Hybrid Journal   (Followers: 5)
CERN IdeaSquare Journal of Experimental Innovation     Open Access  
Chaos, Solitons & Fractals     Hybrid Journal   (Followers: 3)
Chemometrics and Intelligent Laboratory Systems     Hybrid Journal   (Followers: 15)
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: 12)
Circuits and Systems     Open Access   (Followers: 16)
Clean Air Journal     Full-text available via subscription   (Followers: 2)
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  
Combustion Theory and Modelling     Hybrid Journal   (Followers: 13)
Communication Methods and Measures     Hybrid Journal   (Followers: 11)
Communication Theory     Hybrid Journal   (Followers: 20)
Communications Engineer     Hybrid Journal   (Followers: 1)
Communications in Algebra     Hybrid Journal   (Followers: 3)
Communications in Partial Differential Equations     Hybrid Journal   (Followers: 3)
Communications of the ACM     Full-text available via subscription   (Followers: 53)
Communications of the Association for Information Systems     Open Access   (Followers: 18)
COMPEL: The International Journal for Computation and Mathematics in Electrical and Electronic Engineering     Hybrid Journal   (Followers: 3)
Complex & Intelligent Systems     Open Access  
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: 9)
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: 12)
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: 14)
Computational Linguistics     Open Access   (Followers: 23)
Computational Management Science     Hybrid Journal  
Computational Mathematics and Modeling     Hybrid Journal   (Followers: 8)
Computational Mechanics     Hybrid Journal   (Followers: 4)
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: 13)
Computational Statistics & Data Analysis     Hybrid Journal   (Followers: 31)
Computer     Full-text available via subscription   (Followers: 84)
Computer Aided Surgery     Hybrid Journal   (Followers: 3)
Computer Applications in Engineering Education     Hybrid Journal   (Followers: 6)
Computer Communications     Hybrid Journal   (Followers: 10)
Computer Engineering and Applications Journal     Open Access   (Followers: 5)
Computer Journal     Hybrid Journal   (Followers: 7)
Computer Methods in Applied Mechanics and Engineering     Hybrid Journal   (Followers: 22)
Computer Methods in Biomechanics and Biomedical Engineering     Hybrid Journal   (Followers: 10)
Computer Methods in the Geosciences     Full-text available via subscription   (Followers: 1)
Computer Music Journal     Hybrid Journal   (Followers: 16)
Computer Physics Communications     Hybrid Journal   (Followers: 6)
Computer Science - Research and Development     Hybrid Journal   (Followers: 7)
Computer Science and Engineering     Open Access   (Followers: 17)
Computer Science and Information Technology     Open Access   (Followers: 11)
Computer Science Education     Hybrid Journal   (Followers: 12)
Computer Science Journal     Open Access   (Followers: 20)
Computer Science Master Research     Open Access   (Followers: 10)
Computer Science Review     Hybrid Journal   (Followers: 10)

        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  [3044 journals]
  • Floating active inductor based Class-C VCO with 8 digitally tuned
    • Authors: Rishab Mehra; Vikash Kumar; Aminul Islam
      Pages: 1 - 10
      Abstract: Publication date: January 2018
      Source:AEU - International Journal of Electronics and Communications, Volume 83
      Author(s): Rishab Mehra, Vikash Kumar, Aminul Islam
      A fully integrated floating active inductor based voltage-controlled oscillator (VCO) is presented. The active inductor employs voltage differencing transconductance amplifier (VDTA) asa building block. The designed VCO achieves frequency tuning by varying the bias current through the VDTA and utilizes a Class-C topology for improving the phase noise performance. The inductor-less VCO is designed and implemented in a 45-nm CMOS process and its performance is estimated using Virtuoso ADE of Cadence. Operating at a supply voltage of ±1V, the proposed VCO consumes 0.44–1.1mW corresponding to the oscillation frequency of 1.1–1.8GHz thereby exhibiting a tuning range of 48.27%. The phase noise of the VCO lies in the range of −94.12 to −98.37 dBc/Hz at 1MHz offset resulting in a FOM of −172.14 to −176.69 dBc/Hz.

      PubDate: 2017-08-28T00:59:50Z
      DOI: 10.1016/j.aeue.2017.08.018
      Issue No: Vol. 83 (2017)
  • Trident-shape strip loaded dual band-notched UWB MIMO antenna for portable
           device applications
    • Authors: Chandrasekhar Rao Jetti; Venkateswara Rao Nandanavanam
      Pages: 11 - 21
      Abstract: Publication date: January 2018
      Source:AEU - International Journal of Electronics and Communications, Volume 83
      Author(s): Chandrasekhar Rao Jetti, Venkateswara Rao Nandanavanam
      In this paper, a novel compact dual band-notched ultra-wideband (UWB) multiple-input multiple-output (MIMO) antenna of size 22×26×0.8mm3 is proposed for portable devices. The antenna comprises of two stepped slot UWB antennas fed by 50ohms microstrip line, T-shape slot and narrow slot. Dual band-notches from 5.4 to 5.86GHz and 7.6–8.4GHz are achieved by loading trident-shape strips on microstrip line. A T-shape slot is used on the ground plane to enhance impedance matching characteristics and to minimize mutual coupling above 4GHz. To improve isolation further at 3–4GHz, a narrow slot is used on ground. The proposed antenna is giving a good bandwidth ranging from 3.1 to 11.8GHz with S11 >10dB and mutual coupling larger than 20dB in the entire operating band except at two rejected bands. The simulation and measurement results demonstrate that the antenna is more suitable for portable device applications.

      PubDate: 2017-08-28T00:59:50Z
      DOI: 10.1016/j.aeue.2017.08.021
      Issue No: Vol. 83 (2017)
  • A high performance differential input CMOS current buffer
    • Authors: Emre Arslan
      Pages: 1 - 6
      Abstract: Publication date: December 2017
      Source:AEU - International Journal of Electronics and Communications, Volume 82
      Author(s): Emre Arslan
      In this paper, a high accuracy CMOS differential input current buffer (CB) is proposed which employs super source followers (SSF) as input stage and regulated cascode (RGC) current mirrors as output stage. High accuracy requires very high output resistance and low input resistance. Small signal analysis is performed and it is shown that the proposed CB circuit has very low input impedances at ports n and p due to SSF transistors and also very high output impedance at output port due to RGC current mirrors. The simulation results show 9.72Ω input resistances at ports n and p, 454MΩ output resistance at output port with only 625μW power consumption under ±0.9V power supplies. The simulations are performed with HSpice using TSMC 0.18μm process parameters and it is shown that the simulation results are in very good agreement with the theoretical ones.

      PubDate: 2017-08-28T00:59:50Z
      DOI: 10.1016/j.aeue.2017.07.037
      Issue No: Vol. 82 (2017)
  • A compact double-sided MIMO antenna with an improved isolation for UWB
    • Authors: Wael A.E. Ali; Ahmed A. Ibrahim
      Pages: 7 - 13
      Abstract: Publication date: December 2017
      Source:AEU - International Journal of Electronics and Communications, Volume 82
      Author(s): Wael A.E. Ali, Ahmed A. Ibrahim
      This paper presents compact size 4×4cm2 MIMO antenna for UWB applications. The proposed antenna consists of four symmetric circular elements printed on low cost FR4 substrate with partial slotted ground plane. The two sides of the substrate are symmetric and each side is consisting of two radiators with the partial ground planes associated to the two other elements mounted on the other side. The two elements of the front side are orthogonal to the two other elements of the back side in order to increase the isolation between elements. For further reduction in the mutual coupling between elements, decoupling structures are presented in the top and bottom layers of the substrate. The simulated and measured results are investigated to study the effectiveness of the MIMO-UWB antenna. The results demonstrate the satisfactory performance of MIMO-UWB antenna, which has a return loss less than −10dB from approximately 3.1GHz to more than 11GHz with an insertion loss lower than −20dB through the achieved frequency band, and a correlation less than 0.002. Moreover, the proposed MIMO model exhibits a nearly omni-directional radiation pattern with almost constant gain of average value 3.28dBi.

      PubDate: 2017-08-28T00:59:50Z
      DOI: 10.1016/j.aeue.2017.07.031
      Issue No: Vol. 82 (2017)
  • On the error rate of coherent binary modulation techniques in mobile
           communication systems over generalized fading channels impaired by
           generalized Gaussian noise
    • Authors: Fares S. Almehmadi; Osamah S. Badarneh
      Pages: 14 - 19
      Abstract: Publication date: December 2017
      Source:AEU - International Journal of Electronics and Communications, Volume 82
      Author(s): Fares S. Almehmadi, Osamah S. Badarneh
      In the this paper, the performance of coherent binary digital modulation techniques is investigated. Specifically, we derive exact closed-form expressions for the average bit error rate (BER) of coherent binary phase shift keying (BPSK) and frequency shift keying (BFSK) in the α - μ fading channels impaired by generalized Gaussian noise. The derived expressions take into account the mobility of the wireless receiver. In this paper, we employ the random waypoint (RWP) model to study the effect of mobility on the system performance. Some representative analytical results are presented to investigate the effects of the fading parameters, noise shaping parameter, and network topology on the system performance. In addition, Monte-Carlo simulations are provided to validate the accuracy of the analytical results.

      PubDate: 2017-08-28T00:59:50Z
      DOI: 10.1016/j.aeue.2017.07.021
      Issue No: Vol. 82 (2017)
  • Efficient integrated bus coding scheme for low-power I/O
    • Authors: Tareq Muhammad Supon; Iftekhar Ibne Basith; Esam Abdel-Raheem; Rashid Rashidzadeh
      Pages: 30 - 36
      Abstract: Publication date: December 2017
      Source:AEU - International Journal of Electronics and Communications, Volume 82
      Author(s): Tareq Muhammad Supon, Iftekhar Ibne Basith, Esam Abdel-Raheem, Rashid Rashidzadeh
      Bus-Invert (BI) coding schemes have been used in the circuit design to save power usage by minimizing the number of transitions between successive words. With an increased number of bits for bus width, many other coding schemes like Bus-Shift (BS) and Shift-Invert (SINV) have been proposed for better power saving. In this paper, we are proposing a new Successive Shift-Invert (SSINV) coding scheme where the transmitting data will first be inverted. Then both the original and the inverted word will be shifted circularly for each bit and compared with the data just sent for least hamming distance. Thus, the combination having the least hamming distance with the last sent data will be selected and sent. The proposed method exhibits better power saving compared to other reported methods, but needs one extra control bit than BS; which add to the computation time. Simulation results show a saving margin of 5–15% in average cases in comparison with BI, BS, and SINV for higher bus width. A VerilogA implementation of SSINV using TSMC 65nm technology is also presented as a proof of concept.

      PubDate: 2017-08-28T00:59:50Z
      DOI: 10.1016/j.aeue.2017.07.020
      Issue No: Vol. 82 (2017)
  • Chaos synchronization using the Fourier series expansion with application
           to secure communications
    • Authors: Saeed Khorashadizadeh; Mohammad-Hassan Majidi
      Pages: 37 - 44
      Abstract: Publication date: December 2017
      Source:AEU - International Journal of Electronics and Communications, Volume 82
      Author(s): Saeed Khorashadizadeh, Mohammad-Hassan Majidi
      In this paper, a new method for secure communication based on chaos synchronization is proposed. It is consisted of a state feedback controller and a robust control term using the Fourier series expansion for compensation of uncertainties. In comparison with other uncertainty estimators such as neural networks and fuzzy systems, Fourier series are more efficient, since they have fewer tuning. Thus, their tuning process is simpler. Similar to the parameters of fuzzy systems, Fourier series coefficients are estimated online using the adaptation rule obtained from stability analysis. The case study is the Duffing–Holmes oscillator. Also, observer-based secure communication using the Fourier series expansion has been proposed. Simulation results and comparisons, reveal the superiority of the proposed approach.

      PubDate: 2017-08-28T00:59:50Z
      DOI: 10.1016/j.aeue.2017.07.032
      Issue No: Vol. 82 (2017)
  • Realization of current-mode fully integrated full-wave rectifier
    • Authors: Muhammed Emin Başak; Fırat Kaçar
      Pages: 45 - 51
      Abstract: Publication date: December 2017
      Source:AEU - International Journal of Electronics and Communications, Volume 82
      Author(s): Muhammed Emin Başak, Fırat Kaçar
      In this paper, a new fully integrated high frequency current-mode full-wave rectifiers are presented. The proposed circuits rectify the input signals without diode, so the output signal confronts zero-crossing distortions because of the diode characteristics have been solved with this rectifier even in high frequencies. While the current rectifier has dual output, the voltage rectifier has one output. The presented circuits have a vastly superior zero crossing performance, good linearity, minimum number of transistors, wide frequency range, and they are suitable for monolithic integrated implementation. The performances of the proposed circuits are investigated through LTSpice. Monte-Carlo and Noise analyses have also been performed to show the effectiveness of the proposed circuits.

      PubDate: 2017-08-28T00:59:50Z
      DOI: 10.1016/j.aeue.2017.07.036
      Issue No: Vol. 82 (2017)
  • Low input resistance current buffer stage using a controllable positive
           feedback loop, and applications of current conveyor based filters
    • Authors: Ali Dogus Gungordu; Mustafa Altun; Ismail Cevik
      Pages: 58 - 65
      Abstract: Publication date: December 2017
      Source:AEU - International Journal of Electronics and Communications, Volume 82
      Author(s): Ali Dogus Gungordu, Mustafa Altun, Ismail Cevik
      A novel current buffer stage with very low input resistance is proposed. Low input resistance is achieved using a potentially instable positive feedback loop. Stability of the circuit under different operating conditions is examined in details. A feedback control block using a bipolar 4-bit current steering DAC as a control mechanism is added to the buffer to control the input resistance and assure stability. The proposed technology-independent design methodology always ensures precision and stability for all different parasitic capacitor and resistor values of the driving signal source as well as for process, mismatch, and environmental variations. Additionally, a novel second generation current conveyor circuit based on this novel input buffer is presented to demonstrate how this buffer makes almost ideal current mode circuits possible. Filter applications using the proposed CCII are performed for further justification. The current buffer and CCII were built in AMS 0.35μm 2P4M CMOS technology. Measurement results are presented for the current buffer, the CCII circuit, and the filters.

      PubDate: 2017-08-28T00:59:50Z
      DOI: 10.1016/j.aeue.2017.07.034
      Issue No: Vol. 82 (2017)
  • PR-based SAR reconstruction algorithm for phase noise mitigation based on
           the hidden convexity
    • Authors: Qing Zhang; Yue Yang; Wei Xie; Xun-Chao Cong; Ke-Yu Long; Qun Wan
      Pages: 66 - 73
      Abstract: Publication date: December 2017
      Source:AEU - International Journal of Electronics and Communications, Volume 82
      Author(s): Qing Zhang, Yue Yang, Wei Xie, Xun-Chao Cong, Ke-Yu Long, Qun Wan
      The performance of synthetic aperture radar (SAR) reconstruction is significantly deteriorated by the random phase noises arising from the atmospheric turbulence or frequency jitter of the transmit signal. Recently, the emerging phase retrieval (PR) technique is gradually extended to the SAR reconstruction problem via the phase-corrupted data attributing to its alluring potential for phase noise mitigation. In this paper, a novel PR-based SAR reconstruction algorithm for phase noise mitigation is proposed by jointing alternating direction method of multipliers (ADMM) and Kolmogorov spectral factorization (KoSF). Owing to the exploiting of the hidden convexity of PR-based SAR reconstruction problem and the structure advantage of the quadratic magnitude measurement, the proposed algorithm acquires better robustness for the complex-valued Gaussian white noises and the random phase noises than the existing PR-based SAR reconstruction algorithms. In the experiments, the synthetic scene data and the moving and stationary target recognition Sandia laboratories implementation of cylinders (MSTAR SLICY) target data are provided to verify the validity of the proposed algorithm.

      PubDate: 2017-08-28T00:59:50Z
      DOI: 10.1016/j.aeue.2017.08.003
      Issue No: Vol. 82 (2017)
  • Tunable impedance matching network with wide impedance coverage for multi
           frequency standards RF front-end
    • Authors: Yan Chiew Wong; Ranjit Singh Sarban Singh; Syafeeza Binti Ahmad Radzi; Norihan Binti Abdul Hamid
      Pages: 74 - 82
      Abstract: Publication date: December 2017
      Source:AEU - International Journal of Electronics and Communications, Volume 82
      Author(s): Yan Chiew Wong, Ranjit Singh Sarban Singh, Syafeeza Binti Ahmad Radzi, Norihan Binti Abdul Hamid
      Tunability in RF front-end improves the link quality by maintaining low VSWR in operating environment through correcting the impedance to counteract the sudden impedance change in a user fluctuating operating environment. Introducing tunability to the RF front-end provides great benefits but carries also losses in the impedance network. A large number of RF switches tend to be used in impedance networks in order to achieve large impedance coverage at multi-operating frequencies. However, this increases the losses, sizes and also the implementation complexity of an impedance network. For this reason, a design technique is proposed in order to achieve a wide impedance coverage with a reduced number of RF switches in the impedance network through identifying the electrical distance for the maximum impedance coverage. The required electrical distance of series transmission line of the Pi-network topology for the maximum impedance coverage has first been determined at a single operating frequency and then the electrical length has been reconfigured when switching to other operating frequency. Nearly 85% of the impedance coverage has been conserved by using the proposed technique compared to only 30% of the coverage remained in the conventional Pi-network while switching to other frequency. This technique significantly enhances the impedance coverage and reduces the number of RF switches needed in the impedance matching network especially at the multi frequency standards.

      PubDate: 2017-08-28T00:59:50Z
      DOI: 10.1016/j.aeue.2017.08.004
      Issue No: Vol. 82 (2017)
  • MOS-only complex filter design for dual-band GNSS receivers
    • Authors: Omer Aydin; Hacer A. Yildiz; Serdar Ozoguz; Ali Toker
      Pages: 83 - 92
      Abstract: Publication date: December 2017
      Source:AEU - International Journal of Electronics and Communications, Volume 82
      Author(s): Omer Aydin, Hacer A. Yildiz, Serdar Ozoguz, Ali Toker
      In this paper, the use of MOS-only active filters in the implementation of area-effective low-IF image reject filters is discussed. For this purpose, complex filter design procedure is considered regarding MOS-only filter realization techniques and a new second-order filter topology which favors filter’s area-effective implementation is proposed. Owing to the presented approach, a new complex image-reject filter with reduced chip area, which can be used in dual-band GNSS receivers, is obtained. Issues related to IQ imbalance are briefly discussed and a calibration imbalance circuit is proposed. By virtue of the current-mode design technique, the IQ imbalance circuit is embedded with the complex filter, simplifying the system topology. In order to illustrate the feasibility of the filter, post-layout simulation results of a fourth-order Butterworth-type image reject filter designed for dual-band GNSS receivers are provided using SPECTRE simulation tool in CADENCE design environment.

      PubDate: 2017-08-28T00:59:50Z
      DOI: 10.1016/j.aeue.2017.07.035
      Issue No: Vol. 82 (2017)
  • UWB Metamaterial-based miniaturized planar monopole antennas
    • Authors: Venkata Rajasekhar Nuthakki; Sriramkumar Dhamodharan
      Pages: 93 - 103
      Abstract: Publication date: December 2017
      Source:AEU - International Journal of Electronics and Communications, Volume 82
      Author(s): Venkata Rajasekhar Nuthakki, Sriramkumar Dhamodharan
      In this paper, ultra wide band (UWB) metamterial based compact planar antennas have been designed and experimentally verified. Four novel unit cells have been realized and each unit cell dispersion characteristics are numerically calculated which follows CRLH-TL properties. These four CRLH-TL unit cells are loaded into monopole antennas which result, four open-ended MTM antennas respectively. Further, a novel via free version of CRLH-TL unit cells have been designed, which increases the fabrication flexibility. The compactness has been achieved by realizing ZOR (zeroth order resonance) mode and its bandwidth is increased by realizing small shunt capacitance and large shunt inductance. Further, by optimizing CRLH-TL unit cells, two closely spaced zeroth-order and first-order resonance modes are merged into a single pass band, which gives wide bandwidth. The each proposed antenna has a compact dimension of 0.27 λ0 ×0.19 λ0 ×0.02 λ0 (22×15×1.6mm3), where λ0 is a free space wavelength at 3.8GHz. The four proposed antennas have S11 <−10dB impedance bandwidths of 8.4GHz, 8.5GHz, 8.2GHz and 8.3GHz respectively. The optimum gain, good efficiency, desired radiation characteristics in frequency domain analysis and less distortion of waves in time domain analysis have been achieved for proposed antennas, which are most suitable for UWB applications. The CST-MWS has been used for the parametric study of the proposed antennas. A good agreement has been observed between simulated and experimental results.

      PubDate: 2017-08-28T00:59:50Z
      DOI: 10.1016/j.aeue.2017.08.002
      Issue No: Vol. 82 (2017)
  • Performance analysis of SIMO spectrum sharing networks over correlated
           κ-μ shadowed fading relying on MRC reception
    • Authors: Sikandar Kumar; Sonali Chouhan
      Pages: 104 - 108
      Abstract: Publication date: December 2017
      Source:AEU - International Journal of Electronics and Communications, Volume 82
      Author(s): Sikandar Kumar, Sonali Chouhan
      The real-world wireless channels are accurately modeled by the composite multipath fading and shadowing channel models. The performance of a typical cognitive spectrum sharing (SS) network under a composite fading and shadowing model is rarely analyzed, and hence, needs considerable attention. In this paper, a cognitive SS network is considered having multiantenna at the secondary/cognitive receiver (SR), and the signals received at different antennas are combined using maximal ratio combining scheme. The channels at SR are considered to be spatially correlated κ - μ shadowed distributed. The analytical expressions for the outage probability and the ergodic capacity are derived under peak interference power constraint (PIPC) of the primary receiver (PR). It is shown that the performance of the SS network degrades as the spatial correlation increases at SR. It is also observed that the severity of fading/shadowing at the interfering link is favorable to the secondary user’s communication up to a certain value of PIPC of PR.

      PubDate: 2017-08-28T00:59:50Z
      DOI: 10.1016/j.aeue.2017.08.005
      Issue No: Vol. 82 (2017)
  • Memristor emulator circuits using single CBTA
    • Authors: Umut Engin Ayten; Shahram Minaei; Mehmet Sağbaş
      Pages: 109 - 118
      Abstract: Publication date: December 2017
      Source:AEU - International Journal of Electronics and Communications, Volume 82
      Author(s): Umut Engin Ayten, Shahram Minaei, Mehmet Sağbaş
      In this paper, new analog memristor emulator circuits based on current backward transconductance amplifier (CBTA) and passive elements are proposed. They emulate both types of memristor (incremental and decremental) just by interchanging the CBTA output terminals. It uses only one CBTA, two resistors, one capacitor and one multiplier emulating grounded memristor. They consist of less CMOS transistors and have wider output ranges compared to other designed emulator circuits. The CMOS implementation of the CBTA using 0.18μm level-7 TSMC CMOS technology parameters is also proposed. It uses 23 CMOS transistors operating with the ±0.9V DC supply voltage. Theoretical derivations and related results are validated using SPICE simulations.

      PubDate: 2017-08-28T00:59:50Z
      DOI: 10.1016/j.aeue.2017.08.008
      Issue No: Vol. 82 (2017)
  • A CMOS current mode four quadrant analog multiplier free from mobility
    • Authors: Imen Aloui; Néjib Hassen; Kamel Besbes
      Pages: 119 - 126
      Abstract: Publication date: December 2017
      Source:AEU - International Journal of Electronics and Communications, Volume 82
      Author(s): Imen Aloui, Néjib Hassen, Kamel Besbes
      This paper describes a simple technique for reducing the mobility degradation effect. A current mode squarer circuit and a four quadrant analog multiplier are designed using this technique. The proposed circuits are designed and simulated using the ELDO simulator in 0.18µm CMOS technology with a power supply of ±0.75V. The simulation results of analog multiplier for an input range of ±10 µA that demonstrates a −3dB bandwidth of 300MHz, a 0.15mW of maximum power consumption, a low nonlinearity error of 1.1% and a THD of 0.8% in 1MHz. Monte Carlo simulation of the proposed multiplier is analysed to verify the robustness of the circuit versus the technological process.

      PubDate: 2017-08-28T00:59:50Z
      DOI: 10.1016/j.aeue.2017.08.006
      Issue No: Vol. 82 (2017)
  • Fractional order multifunction filter with 3 degrees of freedom
    • Authors: Gagandeep Kaur; A.Q. Ansari; M.S. Hashmi
      Pages: 127 - 135
      Abstract: Publication date: December 2017
      Source:AEU - International Journal of Electronics and Communications, Volume 82
      Author(s): Gagandeep Kaur, A.Q. Ansari, M.S. Hashmi
      In this paper the design procedure and performance of the third order multifunction filter based on Current Differencing Buffered Amplifier (CDBA) using Fractional Elements of Different Order (FOE) is presented. Three fractional elements of different order α, β, γ are used and peak value frequencies and cut-off frequencies are computed for the multifunction filter from the fractional order transfer function. The frequency response of the filters is obtained using FOMCON toolbox of MATLAB and also with PSPICE using fractional order elements. Stability and sensitivity analysis are also examined. The Power dissipation, Total Harmonic Distortion (THD), and Noise Analysis demonstrate a very good agreement between the theoretical and simulation results. It is also observed from the simulations that the CDBA based third order multifunction filter in fractional domain is suitable for integrated circuits.

      PubDate: 2017-08-28T00:59:50Z
      DOI: 10.1016/j.aeue.2017.08.010
      Issue No: Vol. 82 (2017)
  • Design of a low voltage low power self-biased OTA using independent gate
           FinFET and PTM models
    • Authors: Mahdi Shirazi; Alireza Hassanzadeh
      Pages: 136 - 144
      Abstract: Publication date: December 2017
      Source:AEU - International Journal of Electronics and Communications, Volume 82
      Author(s): Mahdi Shirazi, Alireza Hassanzadeh
      In this paper a low power low voltage operational transconductance amplifier has been designed using IGFinFET. Pseudo differential pair and self-biased techniques have been used for rail-to-rail input operation of the OTA. The new technique used in this paper has the advantage of bulk-drive technique for low voltage analog designs without bulk-drive limitations. Using double gate FinFET, one gate has been used to adjust threshold voltage, while the input signal is applied to the other gate. Optimum g m and r o have been investigated for different gate configurations of the IGFinFET. Power consumption of the IGFinFET circuit is lower than its CMOS counterpart and shows good merits for analog design in analog and mixed signal applications. DFC method has been used for frequency compensation that needs smaller capacitors. Predictive Technology Model (PTM) 20nm IGFinFET has been employed for HSPICE simulations. The designed amplifier has 39.27dB gain with 45.05 ° phase margin and unity-gain bandwidth of 8.26MHz with 37.75μW power dissipation from a single 0.5V power supply.

      PubDate: 2017-08-28T00:59:50Z
      DOI: 10.1016/j.aeue.2017.08.013
      Issue No: Vol. 82 (2017)
  • Numerical design of a 100W, 38dB gain, W-band multi-section serpentine
           waveguide vacuum electronic TWT
    • Authors: Anurag Srivastava
      Pages: 145 - 151
      Abstract: Publication date: December 2017
      Source:AEU - International Journal of Electronics and Communications, Volume 82
      Author(s): Anurag Srivastava
      The serpentine waveguide circuit is a robust beam-wave interaction circuit for W-band TWTs. Here presented the electromagnetic properties and design methodology for W-band multi-section SWG traveling wave tube. Cold-test (in absence of electron beam) numerical design performed theoretically and further optimized/validated with standard simulation code to predict the dispersion, interaction impedance, ohmic-loss and small-signal gain. Numerical simulation for the quarter wave transformer couplers with SWG circuit geometry shown the return-loss less than −20dB for the 5% frequency band. Later, in systematic manner, hot-test (in presence of electron beam) numerical design performed for multi-section TWT by using standard particle-in-cell 3-D simulation code. The three section, 60 periods SWG TWT predicted peak radiation power 130W at target frequency 94GHz, 39.5dB saturated gain, 5.3% instantaneous 3-dB frequency bandwidth, and 6.5% electronic efficiency.

      PubDate: 2017-08-28T00:59:50Z
      DOI: 10.1016/j.aeue.2017.08.017
      Issue No: Vol. 82 (2017)
  • Industrial liquid characterization enhancement using microwave sensor
           equipped with electronic band gap structure
    • Authors: Fereshteh Sadat Jafari; Javad Ahmadi-Shokouh
      Pages: 152 - 159
      Abstract: Publication date: December 2017
      Source:AEU - International Journal of Electronics and Communications, Volume 82
      Author(s): Fereshteh Sadat Jafari, Javad Ahmadi-Shokouh
      In this paper, we present a novel sensor for permittivity measurement of the industrial liquids to achieve more sensitivity. An electronic band gap (EBG) structure is used. The simulation results show that applying EBG scheme enhances the electric field strength at the measuring part. This issue causes a significant shift in resonant frequency and therefore an increased sensitivity of the designed sensor. The proposed sensor is tested for characterization of liquids with various permittivity and loss tangent values, and the results show the proposed sensor can precisely classify a wide range of liquids in terms of electromagnetic properties. Measurement results indicate that the presented sensor is well suited for transformer oil aging applications.

      PubDate: 2017-08-28T00:59:50Z
      DOI: 10.1016/j.aeue.2017.08.016
      Issue No: Vol. 82 (2017)
  • Novel electronically controlled current-mode Schmitt trigger based on
           single active element
    • Authors: Atul Kumar; Bhartendu Chaturvedi
      Pages: 160 - 166
      Abstract: Publication date: December 2017
      Source:AEU - International Journal of Electronics and Communications, Volume 82
      Author(s): Atul Kumar, Bhartendu Chaturvedi
      In this paper, a simple circuit of current-mode Schmitt trigger consists of only single dual-X current conveyor transconductance amplifier (DXCCTA) is proposed. The proposed Schmitt trigger does not need any passive component for its realization. Its threshold levels and output current amplitude are electronically and independently adjustable with the help of corresponding input bias currents. The proposed circuit also has the features of good operational frequency range, ease of cascadability and low power consumption. The effects of non-idealities of DXCCTA and the effects of MOS transistors mismatch on the proposed Schmitt trigger are investigated. Moreover, the output current amplitude is less affected by temperature variation. HSPICE simulation results are shown to verify the performance of the proposed Schmitt trigger.

      PubDate: 2017-08-28T00:59:50Z
      DOI: 10.1016/j.aeue.2017.08.007
      Issue No: Vol. 82 (2017)
  • Simplified approximations to the average of some useful forms of Gaussian
           Q functions with MRC diversity reception over Nakagami-q and Rician fading
           channels and their applications
    • Authors: Dharmendra Sadhwani; Ram Narayan Yadav
      Pages: 167 - 176
      Abstract: Publication date: December 2017
      Source:AEU - International Journal of Electronics and Communications, Volume 82
      Author(s): Dharmendra Sadhwani, Ram Narayan Yadav
      In this paper, using an accurate exponential based approximation on the Gaussian Q function, the simplified novel approximations to the average of some useful forms of Gaussian Q functions, with maximal-ratio combining (MRC) diversity reception, over independent but not necessarily identical Nakagami-q (Hoyt) and Rician fading channels are proposed. The results proved to be useful in accurate estimation of the symbol error probability (SEP) for various digital modulation schemes like cross-QAM, triangular-QAM (TQAM), rectangular-QAM and square-QAM (SQAM), over the same fading statistics. Asymptotic expressions of the proposed approximations are also derived in this paper. Various simulation results are provided to verify the accuracy and significance of the proposed work.

      PubDate: 2017-08-28T00:59:50Z
      DOI: 10.1016/j.aeue.2017.08.014
      Issue No: Vol. 82 (2017)
  • Single DVCCTA based high frequency incremental/decremental memristor
           emulator and its application
    • Authors: Rajeev Kumar Ranjan; Niranjan Raj; Nidhi Bhuwal; Fabian Khateb
      Pages: 177 - 190
      Abstract: Publication date: December 2017
      Source:AEU - International Journal of Electronics and Communications, Volume 82
      Author(s): Rajeev Kumar Ranjan, Niranjan Raj, Nidhi Bhuwal, Fabian Khateb
      Memristor emulator based on TiO2 model is introduced. The proposed circuit uses current mode building block DVCCTA (Differential Voltage Current Conveyor Transconductance Amplifier) using 0.25µm CMOS technology. The presented circuit uses single CMOS based DVCCTA, three resistors and one capacitor. It can operate up to 1MHz in both the incremental and decremental configuration by interchanging the connections. Theoretical analysis of the proposed circuit resulting in the equivalent memristance equation is done and non-ideal analysis is also included. PSPICE simulations are performed. Simulation results agree well with theoretical assumption. To verify the practicability of the circuit, PCB prototype has been made using AD844AN and CA3080. The experimental demonstration is carried out for 50kHz and 100kHz. Moreover, the circuit has also been tested for non-volatility features. It is observed from the experimental test result and using 0.25µm CMOS technology that maximum frequency is 10kHz and 50kHz respectively. To check the functionality of the circuit two combinations of memristor are connected in serial and parallel and desired results are obtained. Memristor based high pass filter is also discussed so as to study the memristor behavior in comparison to the resistor.

      PubDate: 2017-08-28T00:59:50Z
      DOI: 10.1016/j.aeue.2017.07.039
      Issue No: Vol. 82 (2017)
  • MISO current mode bi-quadratic filter employing high performance inverting
           second generation current conveyor circuit
    • Authors: Néjib Hassen; Thouraya Ettaghzouti; Karima Garradhi; Kamel Besbes
      Pages: 191 - 201
      Abstract: Publication date: December 2017
      Source:AEU - International Journal of Electronics and Communications, Volume 82
      Author(s): Néjib Hassen, Thouraya Ettaghzouti, Karima Garradhi, Kamel Besbes
      This paper presents static and dynamic studies of a new CMOS realization for the inverting second generation current conveyor circuit (ICCII). The proposed design offers enhanced functionalities compared to ICCII circuits previously presented in the literature. It is characterized by a rail to rail dynamic range with high accuracy, a low parasitic resistor at terminal X (1.6Ω) and low power consumption (0.31mW) with wide current mode (3.32GHz) and voltage mode (3.9GHz) bandwidths. Furthermore, a new MISO current mode bi-quadratic filter based on using ICCII circuits asactive elements is proposed. This filter can realize all standard filter responses without changing the circuit topology. It is characterized by active and passive sensitivities less than unity and an adjustment independently between pole frequency and quality factor. The operating frequency limit of this filter is about 0.8GHz with 0.674mW power consumption. The proposed current conveyor circuits and bi-quadratic filter are tested by TSPICE using CMOS 0.18µm TSMC technology with ±0.8V supply voltage to verify the theoretical results.

      PubDate: 2017-09-06T02:06:09Z
      DOI: 10.1016/j.aeue.2017.08.044
      Issue No: Vol. 82 (2017)
  • Adaptive notch filter design under multiple identical bandwidths
    • Authors: Qiusheng Wang; Xiaolan Gu; Jinyong Lin
      Pages: 202 - 210
      Abstract: Publication date: December 2017
      Source:AEU - International Journal of Electronics and Communications, Volume 82
      Author(s): Qiusheng Wang, Xiaolan Gu, Jinyong Lin
      Digital notch filters are applied to remove or suppress the narrow-band interferences in digital signals, while preserving other components unchanged. Under the condition of the identical notch bandwidths, a novel design method is put forward in this paper to realize the adaptive notch filter with infinite-impulse response (IIR). Firstly, a specially simplified all-pass filter is introduced to construct an IIR non-adaptive notch filter, which serves as the core part in the adaptive one. Secondly, the criterion of least-mean-square (LMS) is applied to design the desired adaptive notch filter (ANF). The designed ANF can track and suppress multiple non-harmonic interference components simultaneously. Finally, the effectiveness and practicability of the proposed design method are verified by a set of experimental results.

      PubDate: 2017-09-06T02:06:09Z
      DOI: 10.1016/j.aeue.2017.08.054
      Issue No: Vol. 82 (2017)
  • FPGA based hardware and device-independent implementation of chaotic
    • Authors: Abdelkader Senouci; Hamza Bouhedjeur; Kamal Tourche; Abdelkrim Boukabou
      Pages: 211 - 220
      Abstract: Publication date: December 2017
      Source:AEU - International Journal of Electronics and Communications, Volume 82
      Author(s): Abdelkader Senouci, Hamza Bouhedjeur, Kamal Tourche, Abdelkrim Boukabou
      In this paper we will describe the use of Matlab/Simulink without third party toolboxes as a single integrated environment to study and generate the HDL description of chaotic systems for rapid prototyping purposes. We will provide a review of different approaches to implement chaos generators in both analog and digital forms with a focus on digital one. We will present a rapid prototyping method of digital chaos generators on FPGAs that is of great use for a seamless study, simulation and implementation of those systems in one environment. This will ease the design phase of the chaotic systems and will provide more flexibility for their study. Multiple chaos generators, such as Lorenz, Rössler, Chua, Linz-Sprott, and Sprott types have been designed using this method to showcase its effectiveness. In addition, for a better investigation of the chaotic dynamics, this work makes use of an implementation scheme that permits the visualization of the 3D chaotic attractor on the oscilloscope. The main focus of this paper is to provide a common implementation framework of chaos generators to target various applications, mainly cryptographic one. Newcomers to the field will easily dive in and active researchers will be able to speak the same language and build upon one anothers works more efficiently by adopting the presented guidelines.

      PubDate: 2017-09-06T02:06:09Z
      DOI: 10.1016/j.aeue.2017.08.011
      Issue No: Vol. 82 (2017)
  • Analog circuit optimization using adjoint network based sensitivity
    • Authors: Deepak Joshi; Satyabrata Dash; H.S. Jatana; Ratnajit Bhattacharjee; Gaurav Trivedi
      Pages: 221 - 225
      Abstract: Publication date: December 2017
      Source:AEU - International Journal of Electronics and Communications, Volume 82
      Author(s): Deepak Joshi, Satyabrata Dash, H.S. Jatana, Ratnajit Bhattacharjee, Gaurav Trivedi
      Performance optimization as per the desired specifications is a major requirement of analog and mixed signal circuit design process. Rapid scaling of the semiconductor technology demands efficient optimization techniques with minimal manual efforts. In this paper, a gradient based method for analog circuit optimization using adjoint network based sensitivity analysis is presented. The sensitivity of circuit response with respect to the different parameters is computed by using analog circuit and its adjoint transformation. The proposed method is applied to optimize performance of a two stage operational amplifier (OpAmp). Subsequently, the OpAmp circuit is simulated using Cadence Virtuoso for optimized parameters and the results are validated with post fabrication measurement results.

      PubDate: 2017-09-09T05:53:20Z
      DOI: 10.1016/j.aeue.2017.08.053
      Issue No: Vol. 82 (2017)
  • Analog realization of fractional filters: Laguerre approximation approach
    • Authors: Jerzy Baranowski; Mariusz Pauluk; Andrzej Tutaj
      Pages: 1 - 11
      Abstract: Publication date: November 2017
      Source:AEU - International Journal of Electronics and Communications, Volume 81
      Author(s): Jerzy Baranowski, Mariusz Pauluk, Andrzej Tutaj
      Fractional filters are attractive tools for signal processing allowing greater flexibility in shaping the frequency response. Unfortunately they are very difficult to realize directly, as for digital approach they require infinite memory and for analog approach they require fully fractional capacitors or inductors. That is why approximation approaches are so attractive. In this paper we present a method of implementing an analog approximation of fractional filter. Our approach is based on Laguerre Impulse Response Approximation method. We present its modification allowing reduction of the required connections and without problems with signal-to-noise ratios. Our results are illustrated both with simulations and with experiments.

      PubDate: 2017-07-20T16:58:00Z
      DOI: 10.1016/j.aeue.2017.06.011
      Issue No: Vol. 81 (2017)
  • Fractional-order impedance transformation based on three port mutators
    • Authors: Ahmed Soltan; Ahmed M. Soliman; Ahmed G. Radwan
      Pages: 12 - 22
      Abstract: Publication date: November 2017
      Source:AEU - International Journal of Electronics and Communications, Volume 81
      Author(s): Ahmed Soltan, Ahmed M. Soliman, Ahmed G. Radwan
      Due to the importance of the mutators for active circuit realizations, this paper investigates different three port mutator circuits that can be used to implement a floating impedance. The analytical equations that govern the proposed circuits as well as the necessary conditions under different configurations are introduced to realize positive and negative impedances. The proposed circuits are based on second generation current conveyors (CCII) and/or transconductance Amplifier (TA). Moreover, the fractional-order impedance transformation using these mutators are investigated showing the advantages of fractional-order parameters for extra design degrees of freedom. Circuit simulations using Advanced Design System (ADS) for the proposed circuits are made by using 0.25 CMOS technology from MOSIS to implement the active blocks. Also, practical models for the resistances and capacitances are included in the simulation to include the practical effects on the circuit performance. As an application, the proposed circuits are used to implement fractional order filters and oscillators to validate their reliability and the analytical discussion.

      PubDate: 2017-07-20T16:58:00Z
      DOI: 10.1016/j.aeue.2017.06.012
      Issue No: Vol. 81 (2017)
  • Dimension reduction using kernel collaborative representation based
    • Authors: Jun Yin; Zhihui Lai; Hui Yan
      Pages: 23 - 30
      Abstract: Publication date: November 2017
      Source:AEU - International Journal of Electronics and Communications, Volume 81
      Author(s): Jun Yin, Zhihui Lai, Hui Yan
      Dimension reduction plays a key role in pattern recognition. Sparsity preserving projection (SPP) and collaborative representation based projection (CRP) are two up-to-date dimension reduction methods. SPP uses sparse representation for dimension reduction and CRP uses collaborative representation. SPP and CRP both have good performances in dimension reduction and CRP is computationally more efficient than SPP. To make CRP more effective for linear inseparable data, we propose kernel collaborative representation based projection (KCRP) in this paper. In KCRP, the original data is mapped into a higher dimensional space by a nonlinear mapping and collaborative representation is performed in this new space by using kernel trick. Then, the low dimensional features are obtained by preserving the collaborative reconstructive relation. Experiments on AR, ORL and FERET databases show that KCRP performs better than SPP, CRP and some other popular dimension reduction methods.

      PubDate: 2017-07-20T16:58:00Z
      DOI: 10.1016/j.aeue.2017.06.032
      Issue No: Vol. 81 (2017)
  • A compact planar ultra-wideband bandpass filter with multiple resonant and
           defected ground structure
    • Authors: Jagadish Baburao Jadhav; Pramod Jagan Deore
      Pages: 31 - 36
      Abstract: Publication date: November 2017
      Source:AEU - International Journal of Electronics and Communications, Volume 81
      Author(s): Jagadish Baburao Jadhav, Pramod Jagan Deore
      A compact bandpass filter with dumbbell shape Defected Ground Structure (DGS) operating on ultra wide pass band (UWB – 3.1 to 10.6GHz) is proposed. It is based on hybrid microstrip coplanar waveguide (dual sided metal) structure. A Multiple Resonant Structure (MRS) is constructed using coplanar waveguide (CPW) planar transmission line. The MRS makes the resonance using quarter wavelength and half wavelength open-ended CPW. The equispaced three resonances at lower (3.1GHz), center (6.85GHz) and higher edge (10.6GHz) of the whole Ultra Wide Band is achieved using CPW MRS. To make the band as flat as possible, two more resonances are introduced using quarter wavelength microstrip patches on top of the commonly shared substrate, so the proposed filter becomes a five pole bandpass filter. A dumbbell shaped defected ground structure on either side of CPW MRS improves the return loss almost less than 20dB over the whole UWB passband. The simulated results of proposed filter show good transmission response within passband and good rejection in out of the band. The simulated and measured results are very close to each other which proves the efficacy of proposed design.

      PubDate: 2017-07-20T16:58:00Z
      DOI: 10.1016/j.aeue.2017.07.003
      Issue No: Vol. 81 (2017)
  • Current mode first order universal filter and multiphase sinusoidal
    • Authors: Ashok Kumar; Sajal K. Paul
      Pages: 37 - 49
      Abstract: Publication date: November 2017
      Source:AEU - International Journal of Electronics and Communications, Volume 81
      Author(s): Ashok Kumar, Sajal K. Paul
      In this article a new current mode first order universal filter with single input and multiple outputs is proposed. The realization uses single dual-X multiple output second generation current conveyor (DX-MOCCII) and two passive grounded components. The presented circuit provides high-pass, low-pass and non-inverting and inverting all-pass responses simultaneously, all at different high impedance outputs. The realized circuit does not require any component matching constraint and all the sensitivities are found low. As an application the non-inverting all-pass filter is cascaded in a close loop with the current mode non-inverting integrator to design a current mode multiphase sinusoidal oscillator (MSO) having six phases. Voltage mode six phase sinusoidal oscillator is also achieved by resistively loading the current mode outputs. The analysis such as phase noise, non-ideality, stability and Monte Carlo are presented and discussed. The presented theory and its results are validated using 0.25µm process parameters of TSMC in PSPICE simulator.

      PubDate: 2017-07-20T16:58:00Z
      DOI: 10.1016/j.aeue.2017.07.004
      Issue No: Vol. 81 (2017)
  • A covariance matrix shrinkage method with Toeplitz rectified target for
           DOA estimation under the uniform linear array
    • Authors: Yanyan Liu; Xiaoying Sun; Shishun Zhao
      Pages: 50 - 55
      Abstract: Publication date: November 2017
      Source:AEU - International Journal of Electronics and Communications, Volume 81
      Author(s): Yanyan Liu, Xiaoying Sun, Shishun Zhao
      A covariance matrix shrinkage method is proposed to make an improvement of the direction of arrival (DOA) estimation under a uniform linear array in a scenario where the number of sensors is large and the sample size is relatively small. The main contribution is that we provide a shrinkage target with Toeplitz structure and deduce a closed-form estimation of the shrinkage coefficient. The closed-form and the expectation of the shrinkage coefficient estimate are calculated based on the unbiased and consistent estimates of the trace and moments of a Wishart distributed covariance matrix. The statistical property of the shrinkage coefficient estimate is discussed through theoretical analysis and simulations, which demonstrate the shrinkage coefficient estimate can ensure that the proposed covariance matrix estimate is a good compromise between the sample covariance matrix (SCM) and the target. The root-mean-square-error (RMSE) simulations of DOA estimation show that the proposed method can improve the multiple signal classification (MUSIC) DOA estimation performance in the case of low signal-to-noise ratio (SNR) with small sample size, and also can provide a satisfactory performance at high SNR.

      PubDate: 2017-07-20T16:58:00Z
      DOI: 10.1016/j.aeue.2017.06.026
      Issue No: Vol. 81 (2017)
  • On practical construction of electronically controllable compact current
           amplifier based on commercially available elements and its application
    • Authors: Roman Sotner; Norbert Herencsar; Jan Jerabek; Lukas Langhammer; Josef Polak
      Pages: 56 - 66
      Abstract: Publication date: November 2017
      Source:AEU - International Journal of Electronics and Communications, Volume 81
      Author(s): Roman Sotner, Norbert Herencsar, Jan Jerabek, Lukas Langhammer, Josef Polak
      This paper presents a new concept of a current amplifier (CA) with electronically adjustable features (input resistance and current gain) implemented using commercially available devices. Several variations of basic structure are studied, described and the selected solutions verified by PSpice simulations and, moreover, also by lab experiments. Saving one discrete active device in comparison to already known similar topologies of single-input and single-output version (CA-SISO) is significant benefit whereas all other qualitative features remain very similar to previously reported ones. Simple modification of CA concept to multiple-output version (CA-SIMO), having independent adjustable current gain in each of output branches, is easily available. Experimental tests of features of discussed concepts yield adjustability range of input resistance from 100Ω to more than 10kΩ and current gain adjusting from 0.1 to 3.5 with bandwidth (−3dB) of CA transfer response up to 16MHz. As an example of application, proposed CA was successfully implemented in quadrature oscillator with a very wide tunability range from 29kHz to 4.94MHz. It was achieved by electronic control of several adjustable parameters of proposed CA.

      PubDate: 2017-07-20T16:58:00Z
      DOI: 10.1016/j.aeue.2017.07.002
      Issue No: Vol. 81 (2017)
  • Improving energy efficiency using a link adaptation algorithm dedicated
           for 100Gbps wireless communication
    • Authors: Lukasz Lopacinski; Marcin Brzozowski; Rolf Kraemer; Steffen Büchner; Jörg Nolte
      Pages: 67 - 73
      Abstract: Publication date: November 2017
      Source:AEU - International Journal of Electronics and Communications, Volume 81
      Author(s): Lukasz Lopacinski, Marcin Brzozowski, Rolf Kraemer, Steffen Büchner, Jörg Nolte
      This paper presents a link adaptation algorithm dedicated for 100Gbps wireless transmission. Interleaved Reed-Solomon codes are selected as forward error correction (FEC) algorithms. The redundancy of the codes is selected according to the channel bit error rate (BER). The uncomplicated FEC scheme allows implementing a complete data link layer processor in an FPGA (field programmable gate array). In our case, we use the Virtex7 FPGA to validate the functionality of our implementation. The proposed FPGA-processor achieves 169Gbps throughput. Moreover, the implementation is synthesized into 40nm CMOS technology and the described link adaptation algorithm allows reducing consumed energy per bit to values below 1pJ/bit at BER <1e−4. With higher BER, the energy increases up to ∼13pJ/bit.

      PubDate: 2017-07-20T16:58:00Z
      DOI: 10.1016/j.aeue.2017.07.005
      Issue No: Vol. 81 (2017)
  • Current conveyor-based differential capacitance analog interface for
           displacement sensing application
    • Authors: Giuseppe Ferri; Francesca Romana Parente; Vincenzo Stornelli
      Pages: 83 - 91
      Abstract: Publication date: November 2017
      Source:AEU - International Journal of Electronics and Communications, Volume 81
      Author(s): Giuseppe Ferri, Francesca Romana Parente, Vincenzo Stornelli
      A current conveyor-based analog electronic interface for differential capacitive sensors is here shown. The read-out circuit that utilizes second generation Current Conveyors (CCIIs) as active blocks is able to evaluate differential capacitive variations performing a capacitance-to-voltage conversion. This solution has been implemented both in a discrete element board and as integrated version in a standard 350 nm CMOS technology. Simulations and experimental resultshave shown a linear input/output characteristic and a good agreement with theoretical expectations, being the former performed for both the designed solutions, whereas the latter only for a discrete prototype board (employing a low cost commercial component (AD844). Sensitivity and resolution data on a practical case-study of a displacement sensor are constant and their values are satisfactory. Both simulated and measured results make the proposed architecture a good candidate as first stage of analog front-ends to be employed in differential capacitive instrumentation.

      PubDate: 2017-07-20T16:58:00Z
      DOI: 10.1016/j.aeue.2017.07.014
      Issue No: Vol. 81 (2017)
  • Dual band monopole antenna based on metamaterial structure with narrowband
           and UWB resonances with reconfigurable quality
    • Authors: Samaneh Heydari; Kioumars Pedram; Zeeshan Ahmed; Ferdows B. Zarrabi
      Pages: 92 - 98
      Abstract: Publication date: November 2017
      Source:AEU - International Journal of Electronics and Communications, Volume 81
      Author(s): Samaneh Heydari, Kioumars Pedram, Zeeshan Ahmed, Ferdows B. Zarrabi
      In this article, an Ultra Wide Band (UWB) monopole antenna based on Metamaterial (MTM) unit cell with reconfigurable feature has been developed. The proposed antenna covers 3.1–10.6GHz for UWB applications and it has a reconfigurable narrow-band for L-band (1.27GHz) and wireless applications. The gaps in Split Rings Resonator (SRR) element are made for the Left-hand capacitance and Ω-shape strip layer by four via junctions are used for Left-hand inductance. The antenna is printed on FR-4 low cost substrate with relative permittivity of 4.4 and thickness of 1.6mm. The total size of the antenna is 40mm×40mm. The simulation is carried out using HFSS commercial full-wave software. In addition, the experimental results are presented and compared with simulated results. The antenna gives a maximum peak gain of 6dBi with Omni-Directional radiation pattern and high efficiency of more than 70%. By embedding four switches in Ω-shape strip layer, a reconfigurable antenna has been successfully designed for wireless applications with sufficient qualification. The monopole part covers the UWB spectrum and the CRLH is responsible for the controllable narrowband resonance. The simulation and experimental results are confirmed by the numerical results.

      PubDate: 2017-07-20T16:58:00Z
      DOI: 10.1016/j.aeue.2017.07.015
      Issue No: Vol. 81 (2017)
  • Memristor emulator with tunable characteristic and its experimental
    • Authors: Yunus Babacan; Abdullah Yesil; Firat Kacar
      Pages: 99 - 104
      Abstract: Publication date: November 2017
      Source:AEU - International Journal of Electronics and Communications, Volume 81
      Author(s): Yunus Babacan, Abdullah Yesil, Firat Kacar
      In this study, operational transconductance amplifier (OTA) based simple and practical TiO2 memristor emulator is presented. The proposed memristor emulator employs a multi-outputs OTA, an analog multiplier and a resistor and a capacitor. The parameters of the proposed memristor emulator can be tuned electronically by changing the biasing current of the OTA. Change of the transconductance gain of the OTA provides an advantage: “externally controllable memristor”. Non-volatile resistive switching characteristics and an application of this proposed memristor are given. Also, the memristor emulator is implemented using the commonly available OPA860. The effectiveness of the proposed memristor emulator is verified by the experimental results, which show good agreement with the theoretical and simulation results.

      PubDate: 2017-07-27T20:29:39Z
      DOI: 10.1016/j.aeue.2017.07.012
      Issue No: Vol. 81 (2017)
  • Evaluation of gain enhancement in improved size microstrip antenna arrays
           for millimetre-wave applications
    • Authors: Muhammad Saqib Rabbani; Hooshang Ghafouri-Shiraz
      Pages: 105 - 113
      Abstract: Publication date: November 2017
      Source:AEU - International Journal of Electronics and Communications, Volume 81
      Author(s): Muhammad Saqib Rabbani, Hooshang Ghafouri-Shiraz
      A number of microstrip antenna arrays have been designed based on the improved size patch elements with different substrate heights to evaluate the gain enhancement in practical measurements. Initially, microstrip patch antenna arrays (MPAAs) have been designed, analysed and tested at 10GHz frequency and then the optimised high gain (∼21dBi) array is fabricated and tested at 60GHz-band frequencies. It has been found that the loss emergence due to the long feeding transmission line (TL) network severely degrades the antenna gain in large MPAAs on the thicker substrates. However, the gain can be significantly enhanced in large MPAAs by employing relatively thinner substrate but it shrinks the return loss (S11) bandwidth (BW) and increases the side lob level (SLL).

      PubDate: 2017-07-27T20:29:39Z
      DOI: 10.1016/j.aeue.2017.07.017
      Issue No: Vol. 81 (2017)
  • Sampling theorems for bandlimited random signals in the offset linear
           canonical transform domain
    • Authors: Shuiqing Xu; Feng Li; Yi Chai; Youqiang Hu; Lei Huang
      Pages: 114 - 119
      Abstract: Publication date: November 2017
      Source:AEU - International Journal of Electronics and Communications, Volume 81
      Author(s): Shuiqing Xu, Feng Li, Yi Chai, Youqiang Hu, Lei Huang
      Sampling theorems for deterministic signals in the offset linear canonical transform (OLCT) domain have been widely proposed in the literature. In this paper, we consider the sampling and reconstruction schemes for random signals in the OLCT domain. We first define the power spectral density and correlation function for random signals in the OLCT domain. By utilizing the definitions, the power spectral density relations for the OLCT filter are derived. Subsequently, the multichannel sampling theorem for bandlimited random signals in the OLCT domain is derived. In addition, some sampling theorems for bandlimited random signals associated with the OLCT are also presented by designing different OLCT filters. Finally, the simulation results are presented to show the advantage and effectiveness of the theorems.

      PubDate: 2017-07-27T20:29:39Z
      DOI: 10.1016/j.aeue.2017.07.001
      Issue No: Vol. 81 (2017)
  • Special issue on recent advances in the design and applications of
           fractional-order circuits and systems
    • Authors: Costas Psychalinos; Ahmed S Elwakil; Anis Allagui; Aleksei Tepljakov
      Pages: 132 - 135
      Abstract: Publication date: November 2017
      Source:AEU - International Journal of Electronics and Communications, Volume 81
      Author(s): Costas Psychalinos, Ahmed S Elwakil, Anis Allagui, Aleksei Tepljakov

      PubDate: 2017-07-27T20:29:39Z
      DOI: 10.1016/j.aeue.2017.07.016
      Issue No: Vol. 81 (2017)
  • On the study of cognitive two-way relaying using a denoise-and-forward
    • Authors: Ruifeng Gao; Xiaodong Ji; Zhihua Bao
      Pages: 150 - 157
      Abstract: Publication date: November 2017
      Source:AEU - International Journal of Electronics and Communications, Volume 81
      Author(s): Ruifeng Gao, Xiaodong Ji, Zhihua Bao
      In this paper, we consider a cognitive cooperative wireless system consisting of two primary users, a cognitive base station (CBS) and a secondary user. A cognitive two-way relaying (CTWR) scheme is proposed, where the secondary user tries to assist the primary users to meet their target quality of service (QoS) by acting as a cognitive two-way relay, when the direct link of the two primary users cannot meet the target QoS. As a return, the primary network shares its transmission time-slot with the secondary user. First, the system outage probabilities of traditional direct transmission and CTWR scheme are analyzed, giving both the exact and approximated expressions. Second, a transmission time-slot splitting algorithm between the primary and secondary users is proposed. Third, the ergodic capacity of the secondary user under the CTWR scheme is examined. Finally, simulation results show that the proposed scheme cannot only help the primary users to meet their target QoS, but also improve the communication opportunities of the secondary user.

      PubDate: 2017-07-27T20:29:39Z
      DOI: 10.1016/j.aeue.2017.07.006
      Issue No: Vol. 81 (2017)
  • Minimum passive components based lossy and lossless inductor simulators
           employing a new active block
    • Abstract: Publication date: December 2017
      Source:AEU - International Journal of Electronics and Communications, Volume 82
      Author(s): Faseehuddin Mohammad, Jahariah Sampe, Sadia Shireen, Sawal Hamid Md Ali
      In this paper a new active element namely Dual X current conveyor differential input transconductance amplifier (DXCCDITA) is proposed. The DXCCDITA is utilized in designing eight topologies of lossy and lossless grounded inductor simulators and two topologies of floating inductor simulators. All the designed grounded simulators require only two passive elements and a single active block. The two floating inductor simulators require a single active block and one or three grounded passive elements. In addition, all the designs make use of only grounded capacitors for implementation which is advantageous for fabrication. All the proposed active inductors, except two, did not require any component matching conditions for realization and all the inductor simulators are perfectly tunable. The effect of non-idealities on the proposed grounded simulator structures is also studied. To demonstrate the workability of the inductor simulators they are used in design of second order low pass filter, parallel RLC resonance circuit, third order Butterworth high pass filter, parallel RLC current mode multifunction filter and a voltage mode band pass filter. The DXCCDITA is implemented in 0.35μm TSMC CMOS technology parameters and tested in Tanner EDA. Sufficient number of simulations are provided to establish the functionality of the active inductor structures.

      PubDate: 2017-09-18T08:20:37Z
  • Inside Front Cover - Editorial Board Page/Cover image legend if applicable
    • Abstract: Publication date: November 2017
      Source:AEU - International Journal of Electronics and Communications, Volume 81

      PubDate: 2017-09-18T08:20:37Z
  • Design of microstrip wide stopband quad-band bandpass filters for
           multi-service communication systems
    • Abstract: Publication date: November 2017
      Source:AEU - International Journal of Electronics and Communications, Volume 81
      Author(s): Leila Noori, Abbas Rezaei
      This paper presents two planar high performance quad-channel bandpass filters, which are designed based on a novel circular multi-mode resonator. In this paper and for the first time, the proposed resonator is utilized to achieve quad passbands. It consists of diverged feeding lines that are coupled to etched circular cells. The first filter has quite close channels at 2.62, 2.88, 4.34 and 4.67GHz, which make it appropriate for frequency division duplex (FDD) scheme. Meanwhile, the second filter is designed for WCDMA and WiMAX applications. Both filters are able to attenuate the harmonics up to 19GHz with a maximum harmonic level of −20dB. The insertion losses and return losses of both filters at all channels are better than 1.2dB and 17.5dB, respectively. The harmonic attenuation method is presented employing a LC equivalent circuit of the proposed resonator. In order to verify the designing methodology, the proposed filters are fabricated and measured where there are good agreements between the simulation and measurement results.

      PubDate: 2017-09-18T08:20:37Z
  • Channel estimation with ISFLA based pilot pattern optimization for MIMO
           OFDM system
    • Abstract: Publication date: November 2017
      Source:AEU - International Journal of Electronics and Communications, Volume 81
      Author(s): Harjeet Singh, Savina Bansal
      In multiple input multiple output orthogonal frequency division multiplexing (MIMO-OFDM) systems, the channel state information should be known by the receiver for obtaining transmitted data. Channel estimation algorithms are used to examine the multipath effects of frequency selective Rayleigh fading channels. In this paper, Compressed Sensing (CS) based channel estimation technique is considered for reconstructing the signal with improved spectral efficiency. It requires transmitting the known pilot data to the receiver for estimating channel information. The optimum pilot patterns are selected through reducing the mutual coherence of measurement matrix. In order to maximize the accuracy of sparse channel estimation and to reduce the computational complexity, an optimization algorithm Improved Shuffled Frog Leaping (ISFL) is proposed. When compared with the traditional estimation methods like least squares (LS), and minimal mean square error (MMSE), 4.7% of spectral efficiency is increased with ISFLA based channel estimation. Implementation results show that, by using the proposed algorithm, the bit error rate (BER) and Mean Square Error (MER) performance of the system is increased with 1.5dB and 2dB respectively.

      PubDate: 2017-09-18T08:20:37Z
  • A miniaturized Vivaldi antenna by loading with parasitic patch and lumped
    • Abstract: Publication date: November 2017
      Source:AEU - International Journal of Electronics and Communications, Volume 81
      Author(s): Jie Ao, Jingjian Huang, Weiwei Wu, Naichang Yuan
      A miniaturized Vivaldi antenna is presented in the paper. On the basis of original antenna, the miniaturized Vivaldi antenna applies parasitic patch and lumped resistor to improve impedance characteristics. The proposed load can expand the lower operating frequency to 1.96GHz without changing antenna dimensions. The size of antenna is set as 43×40mm2. This size is about 0.28λL ×0.26λL, where λL is the free space wavelength at 1.96GHz. The loaded Vivaldi antenna is fabricated and measured. The simulated and measured results clarify the viability and effectiveness of the proposed design. The measured impedance bandwidth (VSWR≤2) is from 2GHz to more than 18GHz. In addition, the measured radiation patterns and a peak gain between −1 and 9dB can be obtained in the band of 2–18GHz.

      PubDate: 2017-09-18T08:20:37Z
  • On-body investigation of a compact planar antenna on multilayer polymer
           composite for body-centric wireless communications
    • Authors: Abdullah Al-Sehemi; Ahmed Al-Ghamdi Nikolay Dishovsky Nikolay Atanasov Gabriela Atanasova
      Abstract: Publication date: December 2017
      Source:AEU - International Journal of Electronics and Communications, Volume 82
      Author(s): Abdullah Al-Sehemi, Ahmed Al-Ghamdi, Nikolay Dishovsky, Nikolay Atanasov, Gabriela Atanasova
      A compact wearable flexible antenna, designed for optimal on-body performance in the 2.45GHz Industrial, Scientific and Medical (ISM) band, is proposed. Three different human body models (numerical three-layer and homogeneous tissue-equivalent model, and fabricated homogeneous tissue-equivalent phantom) are used to analyze the on-body performance of the antenna and specific absorption rate (SAR). The proposed antenna achieves more than 15.7% on-body radiation efficiency in the whole ISM frequency band and the peak 1g average SAR less than 0.18W/kg when it is placed directly over the skin of body model. The measured results are presented to demonstrate the validity of the proposed antenna. Furthermore, the proposed antenna offer advantages of being low profile, cheap and easy to fabricate. Low SAR values and high on-body antenna efficiency, making such an antenna a suited candidate for incorporation into various wearable devices for body-centric communications.

      PubDate: 2017-08-28T00:59:50Z
  • Performance analysis of space shift keying for AF relaying with relay
    • Authors: Ferhat Yarkin; Ibrahim Altunbas Ertugrul Basar
      Abstract: Publication date: November 2017
      Source:AEU - International Journal of Electronics and Communications, Volume 81
      Author(s): Özgür Can Öztoprak, Ferhat Yarkin, Ibrahim Altunbas, Ertugrul Basar
      In this paper, we propose an amplify-and-forward multiple-input multiple-output (MIMO) relaying scheme, which combines space shift keying (SSK) with the best and partial relay selection. In this scheme, SSK transmission is considered by using the source (S) transmit antennas. Besides the direct link transmission, a relay, which is selected according to the best or partial relay selection techniques, amplifies the data received from S and forwards it to the destination (D). Theoretical error probability expressions of the proposed cooperative SSK systems are derived and an asymptotic diversity analysis is also performed to demonstrate the achievable diversity orders of the systems. It is shown that the proposed SSK systems outperform the conventional cooperative single-input multiple-output (SIMO) systems. It is also revealed that there is an interesting trade-off between SSK with the best and the partial relay selection in terms of error performance and complexity as in conventional cooperative SIMO systems. However, it is shown that the partial relay selection provides an almost identical error performance compared to the best relay selection with a considerably lower complexity when the number of relays is less than or equal to the number of receive antennas at D in the cooperative SSK system.

      PubDate: 2017-07-20T16:58:00Z
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