Publisher: Hindawi   (Total: 343 journals)

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Showing 1 - 200 of 343 Journals sorted alphabetically
Abstract and Applied Analysis     Open Access   (Followers: 3, SJR: 0.343, CiteScore: 1)
Active and Passive Electronic Components     Open Access   (Followers: 8, SJR: 0.136, CiteScore: 0)
Advances in Acoustics and Vibration     Open Access   (Followers: 51, SJR: 0.147, CiteScore: 0)
Advances in Aerospace Engineering     Open Access   (Followers: 67)
Advances in Agriculture     Open Access   (Followers: 12)
Advances in Artificial Intelligence     Open Access   (Followers: 22)
Advances in Astronomy     Open Access   (Followers: 51, SJR: 0.257, CiteScore: 1)
Advances in Bioinformatics     Open Access   (Followers: 20, SJR: 0.565, CiteScore: 2)
Advances in Biology     Open Access   (Followers: 11)
Advances in Chemistry     Open Access   (Followers: 35)
Advances in Civil Engineering     Open Access   (Followers: 51, SJR: 0.539, CiteScore: 1)
Advances in Computer Engineering     Open Access   (Followers: 8)
Advances in Condensed Matter Physics     Open Access   (Followers: 11, SJR: 0.315, CiteScore: 1)
Advances in Decision Sciences     Open Access   (Followers: 4, SJR: 0.303, CiteScore: 1)
Advances in Electrical Engineering     Open Access   (Followers: 52)
Advances in Electronics     Open Access   (Followers: 101)
Advances in Emergency Medicine     Open Access   (Followers: 16)
Advances in Endocrinology     Open Access   (Followers: 6)
Advances in Environmental Chemistry     Open Access   (Followers: 10)
Advances in Epidemiology     Open Access   (Followers: 9)
Advances in Fuzzy Systems     Open Access   (Followers: 5, SJR: 0.161, CiteScore: 1)
Advances in Geology     Open Access   (Followers: 19)
Advances in Geriatrics     Open Access   (Followers: 6)
Advances in Hematology     Open Access   (Followers: 13, SJR: 0.661, CiteScore: 2)
Advances in Hepatology     Open Access   (Followers: 3)
Advances in High Energy Physics     Open Access   (Followers: 26, SJR: 0.866, CiteScore: 2)
Advances in Human-Computer Interaction     Open Access   (Followers: 21, SJR: 0.186, CiteScore: 1)
Advances in Materials Science and Engineering     Open Access   (Followers: 31, SJR: 0.315, CiteScore: 1)
Advances in Mathematical Physics     Open Access   (Followers: 9, SJR: 0.218, CiteScore: 1)
Advances in Medicine     Open Access   (Followers: 3)
Advances in Meteorology     Open Access   (Followers: 24, SJR: 0.48, CiteScore: 1)
Advances in Multimedia     Open Access   (Followers: 1, SJR: 0.173, CiteScore: 1)
Advances in Nonlinear Optics     Open Access   (Followers: 7)
Advances in Numerical Analysis     Open Access   (Followers: 9)
Advances in Nursing     Open Access   (Followers: 37)
Advances in Operations Research     Open Access   (Followers: 13, SJR: 0.205, CiteScore: 1)
Advances in Optical Technologies     Open Access   (Followers: 4, SJR: 0.214, CiteScore: 1)
Advances in Optics     Open Access   (Followers: 9)
Advances in OptoElectronics     Open Access   (Followers: 6, SJR: 0.141, CiteScore: 0)
Advances in Orthopedics     Open Access   (Followers: 11, SJR: 0.922, CiteScore: 2)
Advances in Pharmacological and Pharmaceutical Sciences     Open Access   (Followers: 9, SJR: 0.591, CiteScore: 2)
Advances in Physical Chemistry     Open Access   (Followers: 13, SJR: 0.179, CiteScore: 1)
Advances in Polymer Technology     Open Access   (Followers: 14, SJR: 0.299, CiteScore: 1)
Advances in Power Electronics     Open Access   (Followers: 44, SJR: 0.184, CiteScore: 0)
Advances in Preventive Medicine     Open Access   (Followers: 6)
Advances in Public Health     Open Access   (Followers: 28)
Advances in Regenerative Medicine     Open Access   (Followers: 4)
Advances in Software Engineering     Open Access   (Followers: 11)
Advances in Statistics     Open Access   (Followers: 10)
Advances in Toxicology     Open Access   (Followers: 4)
Advances in Tribology     Open Access   (Followers: 15, SJR: 0.265, CiteScore: 1)
Advances in Urology     Open Access   (Followers: 13, SJR: 0.51, CiteScore: 1)
Advances in Virology     Open Access   (Followers: 8, SJR: 0.838, CiteScore: 2)
AIDS Research and Treatment     Open Access   (Followers: 2, SJR: 0.758, CiteScore: 2)
Analytical Cellular Pathology     Open Access   (Followers: 3, SJR: 0.886, CiteScore: 2)
Anatomy Research Intl.     Open Access   (Followers: 4)
Anemia     Open Access   (Followers: 6, SJR: 0.669, CiteScore: 2)
Anesthesiology Research and Practice     Open Access   (Followers: 15, SJR: 0.501, CiteScore: 1)
Applied and Environmental Soil Science     Open Access   (Followers: 20, SJR: 0.451, CiteScore: 1)
Applied Bionics and Biomechanics     Open Access   (Followers: 7, SJR: 0.288, CiteScore: 1)
Applied Computational Intelligence and Soft Computing     Open Access   (Followers: 15)
Archaea     Open Access   (Followers: 4, SJR: 0.852, CiteScore: 2)
Autism Research and Treatment     Open Access   (Followers: 36)
Autoimmune Diseases     Open Access   (Followers: 3, SJR: 0.805, CiteScore: 2)
Behavioural Neurology     Open Access   (Followers: 9, SJR: 0.786, CiteScore: 2)
Biochemistry Research Intl.     Open Access   (Followers: 6, SJR: 0.437, CiteScore: 2)
Bioinorganic Chemistry and Applications     Open Access   (Followers: 11, SJR: 0.419, CiteScore: 2)
BioMed Research Intl.     Open Access   (Followers: 5, SJR: 0.935, CiteScore: 3)
Biotechnology Research Intl.     Open Access   (Followers: 1)
Bone Marrow Research     Open Access   (Followers: 2, SJR: 0.531, CiteScore: 1)
Canadian J. of Gastroenterology & Hepatology     Open Access   (Followers: 4, SJR: 0.867, CiteScore: 1)
Canadian J. of Infectious Diseases and Medical Microbiology     Open Access   (Followers: 8, SJR: 0.548, CiteScore: 1)
Canadian Respiratory J.     Open Access   (Followers: 3, SJR: 0.474, CiteScore: 1)
Cardiology Research and Practice     Open Access   (Followers: 11, SJR: 1.237, CiteScore: 4)
Cardiovascular Therapeutics     Open Access   (Followers: 2, SJR: 1.075, CiteScore: 2)
Case Reports in Anesthesiology     Open Access   (Followers: 11)
Case Reports in Cardiology     Open Access   (Followers: 8, SJR: 0.219, CiteScore: 0)
Case Reports in Critical Care     Open Access   (Followers: 12)
Case Reports in Dentistry     Open Access   (Followers: 8, SJR: 0.229, CiteScore: 0)
Case Reports in Dermatological Medicine     Open Access   (Followers: 2)
Case Reports in Emergency Medicine     Open Access   (Followers: 19)
Case Reports in Endocrinology     Open Access   (Followers: 2, SJR: 0.209, CiteScore: 1)
Case Reports in Gastrointestinal Medicine     Open Access   (Followers: 3)
Case Reports in Genetics     Open Access   (Followers: 2)
Case Reports in Hematology     Open Access   (Followers: 9)
Case Reports in Hepatology     Open Access   (Followers: 2)
Case Reports in Immunology     Open Access   (Followers: 6)
Case Reports in Infectious Diseases     Open Access   (Followers: 6)
Case Reports in Medicine     Open Access   (Followers: 3)
Case Reports in Nephrology     Open Access   (Followers: 5)
Case Reports in Neurological Medicine     Open Access   (Followers: 1)
Case Reports in Obstetrics and Gynecology     Open Access   (Followers: 11)
Case Reports in Oncological Medicine     Open Access   (Followers: 2, SJR: 0.204, CiteScore: 1)
Case Reports in Ophthalmological Medicine     Open Access   (Followers: 3)
Case Reports in Orthopedics     Open Access   (Followers: 6)
Case Reports in Otolaryngology     Open Access   (Followers: 7)
Case Reports in Pathology     Open Access   (Followers: 7)
Case Reports in Pediatrics     Open Access   (Followers: 8)
Case Reports in Psychiatry     Open Access   (Followers: 18)
Case Reports in Pulmonology     Open Access   (Followers: 3)
Case Reports in Radiology     Open Access   (Followers: 12)
Case Reports in Rheumatology     Open Access   (Followers: 10)
Case Reports in Surgery     Open Access   (Followers: 12)
Case Reports in Transplantation     Open Access  
Case Reports in Urology     Open Access   (Followers: 12)
Case Reports in Vascular Medicine     Open Access  
Case Reports in Veterinary Medicine     Open Access   (Followers: 5)
Child Development Research     Open Access   (Followers: 21, SJR: 0.144, CiteScore: 0)
Chinese J. of Engineering     Open Access   (Followers: 2, SJR: 0.114, CiteScore: 0)
Chinese J. of Mathematics     Open Access  
Chromatography Research Intl.     Open Access   (Followers: 5)
Complexity     Hybrid Journal   (Followers: 8, SJR: 0.531, CiteScore: 2)
Computational and Mathematical Methods in Medicine     Open Access   (Followers: 2, SJR: 0.403, CiteScore: 1)
Computational Biology J.     Open Access   (Followers: 7)
Computational Intelligence and Neuroscience     Open Access   (Followers: 15, SJR: 0.326, CiteScore: 1)
Concepts in Magnetic Resonance Part A     Open Access   (Followers: 1, SJR: 0.354, CiteScore: 1)
Concepts in Magnetic Resonance Part B, Magnetic Resonance Engineering     Open Access   (Followers: 1, SJR: 0.26, CiteScore: 1)
Conference Papers in Science     Open Access   (Followers: 2)
Contrast Media & Molecular Imaging     Open Access   (Followers: 2, SJR: 0.842, CiteScore: 3)
Critical Care Research and Practice     Open Access   (Followers: 13, SJR: 0.499, CiteScore: 1)
Current Gerontology and Geriatrics Research     Open Access   (Followers: 10, SJR: 0.512, CiteScore: 2)
Depression Research and Treatment     Open Access   (Followers: 19, SJR: 0.816, CiteScore: 2)
Dermatology Research and Practice     Open Access   (Followers: 4, SJR: 0.806, CiteScore: 2)
Diagnostic and Therapeutic Endoscopy     Open Access   (SJR: 0.201, CiteScore: 1)
Discrete Dynamics in Nature and Society     Open Access   (Followers: 6, SJR: 0.279, CiteScore: 1)
Disease Markers     Open Access   (Followers: 1, SJR: 0.9, CiteScore: 2)
Economics Research Intl.     Open Access   (Followers: 1)
Education Research Intl.     Open Access   (Followers: 19)
Emergency Medicine Intl.     Open Access   (Followers: 9, SJR: 0.298, CiteScore: 1)
Enzyme Research     Open Access   (Followers: 5, SJR: 0.653, CiteScore: 3)
Evidence-based Complementary and Alternative Medicine     Open Access   (Followers: 30, SJR: 0.683, CiteScore: 2)
Game Theory     Open Access   (Followers: 1)
Gastroenterology Research and Practice     Open Access   (Followers: 1, SJR: 0.768, CiteScore: 2)
Genetics Research Intl.     Open Access   (Followers: 1, SJR: 0.61, CiteScore: 2)
Geofluids     Open Access   (Followers: 5, SJR: 0.952, CiteScore: 2)
Hepatitis Research and Treatment     Open Access   (Followers: 6, SJR: 0.389, CiteScore: 2)
Heteroatom Chemistry     Open Access   (Followers: 3, SJR: 0.333, CiteScore: 1)
HPB Surgery     Open Access   (Followers: 9, SJR: 0.824, CiteScore: 2)
Infectious Diseases in Obstetrics and Gynecology     Open Access   (Followers: 5, SJR: 1.27, CiteScore: 2)
Interdisciplinary Perspectives on Infectious Diseases     Open Access   (Followers: 1, SJR: 0.627, CiteScore: 2)
Intl. J. of Aerospace Engineering     Open Access   (Followers: 81, SJR: 0.232, CiteScore: 1)
Intl. J. of Agronomy     Open Access   (Followers: 6, SJR: 0.311, CiteScore: 1)
Intl. J. of Alzheimer's Disease     Open Access   (Followers: 12, SJR: 0.787, CiteScore: 3)
Intl. J. of Analytical Chemistry     Open Access   (Followers: 22, SJR: 0.285, CiteScore: 1)
Intl. J. of Antennas and Propagation     Open Access   (Followers: 13, SJR: 0.233, CiteScore: 1)
Intl. J. of Atmospheric Sciences     Open Access   (Followers: 21)
Intl. J. of Biodiversity     Open Access   (Followers: 3)
Intl. J. of Biomaterials     Open Access   (Followers: 5, SJR: 0.511, CiteScore: 2)
Intl. J. of Biomedical Imaging     Open Access   (Followers: 3, SJR: 0.501, CiteScore: 2)
Intl. J. of Breast Cancer     Open Access   (Followers: 14, SJR: 1.025, CiteScore: 2)
Intl. J. of Cell Biology     Open Access   (Followers: 4, SJR: 1.887, CiteScore: 4)
Intl. J. of Chemical Engineering     Open Access   (Followers: 8, SJR: 0.327, CiteScore: 1)
Intl. J. of Chronic Diseases     Open Access   (Followers: 1)
Intl. J. of Combinatorics     Open Access   (Followers: 1)
Intl. J. of Computer Games Technology     Open Access   (Followers: 10, SJR: 0.287, CiteScore: 2)
Intl. J. of Corrosion     Open Access   (Followers: 11, SJR: 0.194, CiteScore: 1)
Intl. J. of Dentistry     Open Access   (Followers: 8, SJR: 0.649, CiteScore: 2)
Intl. J. of Differential Equations     Open Access   (Followers: 8, SJR: 0.191, CiteScore: 0)
Intl. J. of Digital Multimedia Broadcasting     Open Access   (Followers: 5, SJR: 0.296, CiteScore: 2)
Intl. J. of Electrochemistry     Open Access   (Followers: 10)
Intl. J. of Endocrinology     Open Access   (Followers: 4, SJR: 1.012, CiteScore: 3)
Intl. J. of Engineering Mathematics     Open Access   (Followers: 7)
Intl. J. of Food Science     Open Access   (Followers: 5, SJR: 0.44, CiteScore: 2)
Intl. J. of Forestry Research     Open Access   (Followers: 3, SJR: 0.373, CiteScore: 1)
Intl. J. of Genomics     Open Access   (Followers: 2, SJR: 0.868, CiteScore: 3)
Intl. J. of Geophysics     Open Access   (Followers: 5, SJR: 0.182, CiteScore: 1)
Intl. J. of Hepatology     Open Access   (Followers: 4, SJR: 0.874, CiteScore: 2)
Intl. J. of Hypertension     Open Access   (Followers: 8, SJR: 0.578, CiteScore: 1)
Intl. J. of Inflammation     Open Access   (SJR: 1.264, CiteScore: 3)
Intl. J. of Inorganic Chemistry     Open Access   (Followers: 4)
Intl. J. of Manufacturing Engineering     Open Access   (Followers: 2)
Intl. J. of Mathematics and Mathematical Sciences     Open Access   (Followers: 3, SJR: 0.177, CiteScore: 0)
Intl. J. of Medicinal Chemistry     Open Access   (Followers: 6, SJR: 0.31, CiteScore: 1)
Intl. J. of Metals     Open Access   (Followers: 7)
Intl. J. of Microbiology     Open Access   (Followers: 8, SJR: 0.662, CiteScore: 2)
Intl. J. of Microwave Science and Technology     Open Access   (Followers: 6, SJR: 0.136, CiteScore: 1)
Intl. J. of Navigation and Observation     Open Access   (Followers: 20, SJR: 0.267, CiteScore: 2)
Intl. J. of Nephrology     Open Access   (Followers: 2, SJR: 0.697, CiteScore: 1)
Intl. J. of Oceanography     Open Access   (Followers: 8)
Intl. J. of Optics     Open Access   (Followers: 10, SJR: 0.231, CiteScore: 1)
Intl. J. of Otolaryngology     Open Access   (Followers: 3)
Intl. J. of Partial Differential Equations     Open Access   (Followers: 2)
Intl. J. of Pediatrics     Open Access   (Followers: 6)
Intl. J. of Peptides     Open Access   (Followers: 2, SJR: 0.46, CiteScore: 1)
Intl. J. of Photoenergy     Open Access   (Followers: 3, SJR: 0.341, CiteScore: 1)
Intl. J. of Plant Genomics     Open Access   (Followers: 4, SJR: 0.583, CiteScore: 1)
Intl. J. of Polymer Science     Open Access   (Followers: 28, SJR: 0.298, CiteScore: 1)
Intl. J. of Population Research     Open Access   (Followers: 4)
Intl. J. of Quality, Statistics, and Reliability     Open Access   (Followers: 17)
Intl. J. of Reconfigurable Computing     Open Access   (SJR: 0.123, CiteScore: 1)
Intl. J. of Reproductive Medicine     Open Access   (Followers: 6)
Intl. J. of Rheumatology     Open Access   (Followers: 4, SJR: 0.645, CiteScore: 2)
Intl. J. of Rotating Machinery     Open Access   (Followers: 2, SJR: 0.193, CiteScore: 1)
Intl. J. of Spectroscopy     Open Access   (Followers: 8)
Intl. J. of Stochastic Analysis     Open Access   (Followers: 3, SJR: 0.279, CiteScore: 1)
Intl. J. of Surgical Oncology     Open Access   (Followers: 1, SJR: 0.573, CiteScore: 2)
Intl. J. of Telemedicine and Applications     Open Access   (Followers: 7, SJR: 0.403, CiteScore: 2)
Intl. J. of Vascular Medicine     Open Access   (SJR: 0.782, CiteScore: 2)
Intl. J. of Zoology     Open Access   (Followers: 2, SJR: 0.209, CiteScore: 1)
Intl. Scholarly Research Notices     Open Access   (Followers: 231)

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Similar Journals
Journal Cover
International Journal of Antennas and Propagation
Journal Prestige (SJR): 0.233
Citation Impact (citeScore): 1
Number of Followers: 13  

  This is an Open Access Journal Open Access journal
ISSN (Print) 1687-5869 - ISSN (Online) 1687-5877
Published by Hindawi Homepage  [343 journals]
  • Right/Left-Handed Leaky Rectangular Waveguide with Broadside Radiation
           Property

    • Abstract: When a leaky rectangular waveguide is used to realize the coverage of radio wave in the small confined spaces, there will be a shadow region, which influences the coverage performance. In this paper, the traditional leaky rectangular waveguide is improved according to the principle of the equivalent circuit, by cutting interdigital slots in the upper wall and adding uniserial metal vias between the upper and lower walls of the rectangular waveguide. Thus, the right/left-handed transmission line property is introduced to the periodic leaky-waveguide (LWG), realizing the broadside radiation with relatively high gain (15.7 dBi), good cross polarization (−50 dB), and narrow half-power beamwidth (10.9°) at 6.97 GHz and providing a method for a uniform coverage of the radio wave in rooms without a shadow region.
      PubDate: Thu, 21 Jan 2021 07:35:00 +000
       
  • Research on 2.4 GHz Wireless Channel Propagation Characteristics in
           a Steel Ship Cabin

    • Abstract: Wireless sensor network (WSN) has become a popular technology and has a good potential application in naval architecture and marine engineering field. Analysis of transmission ability of wireless signal in steel ship environment is important for network deployment including base station and node installation, which would directly impact network performance and has become a hot research field. This paper investigates 2.4 GHz frequency wireless signal propagation characteristics in the steel ship cabin. A 3D ray-tracing model of 2.4 GHz wave propagation in the ship cabin is established, a multipath propagation prediction is carried on, and receiving power is calculated. Besides, the experimental test is performed in the real ship. The simulated and experimental results are processed and compared; the influence law of large obstacles on the signal is discussed, and the guidance scheme for node and base station deployment of the wireless sensor network is proposed. The results show that this analysis could provide valid interpretation of wireless channel propagation characteristics in steel ships.
      PubDate: Tue, 19 Jan 2021 13:35:01 +000
       
  • Three Configurations of Compact Planar Multistub Microstrip Antennas for
           mmW Mobile Applications

    • Abstract: Three configurations of compact planar multistub antennas are proposed in the frequency range of 27–29.5 GHz as candidates for the 5G standard frequency band. Each antenna consists of the same feeding part configuration but different structures for the dipole, director, and reflector parts. The feeding part is based on the substrate integrated waveguide (SIW) technology which results in compact size. The TE10 dominant mode is considered in the design procedure by HFSS software simulations. The proposed antennas have been simulated, fabricated, and measured (for S11, E, and H pattern). The simulation and measurement results show reasonable agreement for S11 and radiation patterns of E- and H-planes and impedance bandwidths. Moreover, for specific absorption rate (SAR) estimation, a three-layer human head model (skin, skull, and brain) is placed next to the antennas as the exposure source. The simulation results show the performance of the proposed antennas for low-SAR, which make them good candidates for safe usage concerning the negative impact of millimeter waves (mmWs) on human health. Finally, a comparison table is presented which verifies the compact size of our proposed antennas.
      PubDate: Sat, 16 Jan 2021 12:35:01 +000
       
  • A Compact, Bistatic Antenna System with Very High Interport Isolation for
           2.4 GHz In-Band Full Duplex Applications

    • Abstract: This paper presents a compact, dual polarized bistatic (two closely spaced transmit and receive radiators) patch antenna with excellent interport isolation performance. The presented antenna system employs differential receive mode operation for the cancellation of self-interference (SI) to achieve very high interport isolation for 2.4 GHz in-band full duplex (IBFD) applications. The presented antenna is based on two closely spaced radiators and a simple 3 dB/180° coupler for differentially excited receive mode operation. The 3 dB/180° coupler performs as a passive self-interference cancellation (SIC) circuit for the presented antenna. The small form-factor structure is realized through via interconnections between the receiving patch and SIC circuit. The prototype of the presented antenna characterizes better than 105 dB peak interport isolation. Moreover, the recorded interport isolation is more than 90 dB and 95 dB within 60 MHz and 40 MHz bandwidths, respectively. The measured gain and cross-polarization levels reflect superior radiation performance for the validation model of the proposed antenna. The presented antenna offers DC interport isolation too, which is required for active antenna applications. The novelty of this work is a compact (small form-factor) antenna structure with very high peak interport isolation along with wider SIC bandwidth as compared to previously reported antennas for full duplex applications.
      PubDate: Sat, 16 Jan 2021 10:20:00 +000
       
  • Thinned Virtual Array for Cramer Rao Bound Optimization in MIMO Radar

    • Abstract: By transmitting multiple independent waveforms at the transmit side and processing echoes of spatial targets at the receive side, Multiple Input Multiple Output (MIMO) radar enjoys virtual array aperture expansion and more degree of freedom (DOF), both of which favors the application of direction finding or estimation of direction of arrival (DOA). The expanded virtual aperture provides higher angular resolution which also promotes the precision of DOA estimation, and the extra DOF brought by waveform diversity can be leveraged to focus energy in certain spatial region for better direction-finding capacity. However, beamspace methods which match certain beampatterns suffer from deteriorated performance and complexity in implementation, and the advantage of virtual array aperture is limited by its virtual element redundancy. As an important performance indicator of DOA estimation, Cramer–Rao Bound (CRB) is closely connected to the array configuration of the system. To reduce the complexity of the system and improve CRB performance at the same time, in this paper, the virtual array of MIMO radar is designed directly by selecting outputs from matched filters at the receive side. For the sake of fair comparison, both scenarios with and without priori directions are considered to obtain optimized virtual array configuration, respectively. The original combinatorial problems are approximated by sequential convex approximations methods which produce solutions with efficiency. Numerical results demonstrate that the proposed method can provide thinned virtual arrays with excellent CRB performance.
      PubDate: Fri, 15 Jan 2021 09:50:01 +000
       
  • Analytical Nonstationary 3D MIMO Channel Model for Vehicle-to-Vehicle
           Communication on Slope

    • Abstract: Vehicle-to-vehicle communication plays a strong role in modern wireless communication systems, appropriate channel models are of great importance in future research, and propagation environment with slope is one special kind. In this study, a novel three-dimensional nonstationary multiple-input multiple-output channel model for the sub-6 GHz band is proposed. This model is a regular-shaped multicluster geometry-based analytical model, and it combines the line-of-sight component and multicluster scattering rays as the nonline-of-sight components. Each cluster of scatterers represents the influence of different moving vehicles on or near a slope, and scatterers are, respectively, distributed within two spheres around the transmitter and the receiver. In this model, it is considered that the azimuth and elevation angles of departure and arrival are jointly distributed and conform to the von Mises–Fisher distribution, which can easily control the range and concentration of the scatterers within spheres to mimic the real-world situation well. Moreover, the impulse response and the autocorrelation function of the corresponding channel is derived and proposed; then, the Doppler power spectrum density of the channel is simulated and analyzed. In addition, the nonstationary characteristics of the presented channel model are observed through simulations. Finally, the simulation results are compared with measurement data in order to validate the utility of the proposed model.
      PubDate: Wed, 13 Jan 2021 04:50:01 +000
       
  • Corrigendum to “Research on the Impact of Marine Environment on ICPT
           Transmission Efficiency”

    • PubDate: Mon, 11 Jan 2021 13:05:01 +000
       
  • Lowering the Sidelobe Level of a Two-Way Pattern in Shared Aperture Radar
           Arrays

    • Abstract: A study of lowering the peak SLL of shared aperture radar arrays is presented. A two-weight amplitude distribution for the elements of transmit and receive arrays is used. Imposing certain conditions, the relation of the number of elements of the arrays was found. One condition imposes the appearance of a minor lobe position of transmit or receive array pattern at a certain null of receive or transmit array pattern. A second condition imposes the equal sidelobe level of two consecutive minor lobes either near the main beam of the two-way array pattern or at certain positions of receive or transmit array pattern. The resulting peak SLL of the two-way radar array pattern depending on the conditions reaches from −47 dB up to less than −50 dB.
      PubDate: Wed, 06 Jan 2021 13:35:02 +000
       
  • Development of a Pin Diode-Based Beam-Switching Single-Layer Reflectarray
           Antenna

    • Abstract: This paper presents a practical demonstration for the design and development of a switchable planar reflectarray using PIN diodes in the X-band frequency range. Waveguide scattering parameter measurements for the unit cells and far-field measurements of the periodic reflectarrays have been carried out to verify the predicted results. Reflectarray unit cell measurements demonstrated a frequency tunability of 0.36 GHz with a dynamic phase range of 226°. On the other hand, the designed 6 × 6 periodic reflectarray has been shown to achieve beam switching from +6° to −6° with different switching states of PIN diodes. This type of beam switching can be used in satellite communication for specific region coverage.
      PubDate: Tue, 29 Dec 2020 08:05:01 +000
       
  • Radio Propagation Measurements in the Indoor Stairwell Environment at 3.5
           and 28 GHz for 5G Wireless Networks

    • Abstract: To cover the high demand for wireless data services for different applications in the wireless networks, different frequency bands below 6 GHz and in millimeter-wave (mm-Wave) above 24 GHz are proposed for the fifth generation (5G) of communication. The communication network is supposed to handle, among others, indoor traffic in normal situations as well as during emergencies. The stairway is one of those areas which has less network traffic during normal conditions but increases significantly during emergencies. This paper presents the radio propagation in an indoor stairway environment based on wideband measurements in the line of sight (LOS) at two candidate frequencies for 5G wireless networks, namely, 3.5 GHz and 28 GHz. The path loss, root mean square (RMS) delay spread, K-factor results, and analysis are provided. The close-in free-space reference distance (CI), floating intercept (FI), and the close-in free-space reference distance with frequency weighting (CIF) path loss models are provided. The channel parameters such as the number of clusters, the ray and cluster arrival rates, and the ray and cluster decay factors are also obtained for both frequencies. The findings of the path loss show that the CI, FI, and CIF models fit the measured data well in both frequencies with the path loss exponent identical to the free-space path loss. Based on clustering results, it is found that the cluster decay rates are identical at both bands. The results from this and previous measurements indicate that at least one access point is required for every two sections of the stairway to support good coverage along the stairwell area in 5G wireless networks. Moreover, for 5G systems utilizing mm-Wave frequency bands, one access point for each stair section might be necessary for increased reliability of the 5G network in stairwell environments.
      PubDate: Mon, 28 Dec 2020 14:05:01 +000
       
  • Diffuse Scattering Directive Model Parameterization Method for
           Construction Materials at mmWave Frequencies

    • Abstract: The determination for diffuse scattering model parameters is of critical importance to improve the accuracy of prediction and analysis for millimeter-wave radio propagation. In this paper, a reliable parameterization method with a simplified tuning procedure for a diffuse scattering model is proposed and validated based on measurements and ray-tracing simulations. Typical construction materials are measured from 40 GHz to 50 GHz, and the complex permittivity is estimated by the propagation coefficients match method. The directive model, which can better characterize the scattering patterns of construction materials in this paper, is adopted to calibrate the ray-tracing simulation. Model parameterization is performed and simulated results with the optimal model parameters show distinct accuracy improvement.
      PubDate: Wed, 23 Dec 2020 07:35:01 +000
       
  • A Low-Profile Antenna Based on Single-Layer Metasurface for Ku-Band
           Applications

    • Abstract: Improvement in the antenna gain is usually achieved at the expense of bandwidth and vice versa. This is where the realization of this enhancement can be made through compromising the antenna profile. In this work, we propose a new design of incorporating periodic metasurface array to enhance the bandwidth and gain while keeping the antenna to a low-profile scheme. The proposed antenna was simulated and fabricated in order to validate the results in the operating frequency range from 10 MHz to 43.5 GHz. Computer simulation technology (CST) microwave studio software was used to design and simulate the proposed antenna, while LPKF prototyping PCB machine was utilized to fabricate the antenna. Results showed that the antenna generated a gain and bandwidth of 14.2 dB and 2.13 GHz, respectively. Following the good agreement between the numerical and measurement results, it is believed that the proposed antenna can be potentially attractive for the application of satellite communications in Ku-band electromagnetic wave.
      PubDate: Wed, 16 Dec 2020 13:05:01 +000
       
  • Novel Low-Cost Integrated Multiband Antenna Design Customized for
           Smartwatch Applications with SAR Evaluation

    • Abstract: This paper presents a novel low-cost integrated multiband antenna design customized for smartwatch applications and wearable devices. The design consists in using a broadband planar patch antenna with circular microstrip lines and a miniaturized feeding-point with a structure of 30 × 30 × 1.6 mm3, and it is easy to deploy inside the smartwatch and cost-effective for the wearable device industry. The parametric study and final dimensions of the design and the measured results of the reflection and radiation pattern are discussed. The antenna with maximum gain up to 6.6 dBi and S11 up to −22 dB exhibits excellent performance for all the frequencies required in wearable systems such as 1.9 GHz, 2.3 GHz, 2.4 GHz, 2.6 GHz, 5.2 GHz, and 5.8 GHz. We drew a comparison between similar research and this work in terms of antenna performance. Furthermore, we investigate the specific absorption rate (SAR) performance of the antenna for the smartwatch application, using both human hand wrist multilayer and SAM head mouth models. The SAR results in different positions for all the frequencies are compared to the Federal Communication Commission (FCC) standards.
      PubDate: Tue, 15 Dec 2020 05:05:01 +000
       
  • A Compact Triple Band EBG Using Interdigital Coplanar Waveguide Structure
           for Antenna Gain Enhancement

    • Abstract: A new triple band EBG unit cell with compact size has been designed, fabricated, and tested. The proposed EBG unit cell is based on a square mushroom-like EBG (M-EBG) structure with an interdigital coplanar waveguide (ICPW). With this technique, the size of the proposed ICPW-EBG structure has been reduced from λ/2 to λ/4 compared with the conventional M-EBG unit cell dimension, which is 18 × 18 mm2. The proposed unit cell was designed in order to respond for three frequency bands at 1.8 GHz, 2.45 GHz, and 3.7 GHz. An array of 10 × 10 unit cell was also designed as a reflector with an overall dimension of 181.8 × 181.8 mm2. The dipole antennas were implemented over the designed reflector with a short distance of λ/8 to radiate electromagnetic wave. The simulation results showed that the ICPW-EBG reflector can improve directivity of the dipole antenna to be 9.12 dB at 1.8 GHz, 9.02 dB at 2.45 GHz, and 8.40 dB at 3.7 GHz. The measurement directivities agreed well with simulation results including 8.72 dB at 1.8 GHz, 8.56 dB at 2.4 GHz, and 8.1 dB at 3.7 GHz. This is the first design of triple band EBG unit cell with 50% size reduction compared with the conventional structure at the same frequency. The designed ICPW-EBG reflector with dipole antenna results in the triple band operation, low-profile and high gain suitable for modern wireless communication systems.
      PubDate: Fri, 11 Dec 2020 13:05:02 +000
       
  • Design of a 324 MHz 200 kW CW Waveguide-to-Coaxial Adaptor for Radio
           Frequency Quadrupole Microwave System

    • Abstract: A 324 MHz 200 kW waveguide-to-coaxial adaptor has been designed and fabricated for a microwave coupler in a radio frequency quadrupole system. Optimization of the adaptor is performed by the numerical study and experimental test. High-power measurements show that the reflection coefficient of the adaptor is less than −30 dB at the RFQ operating frequency, and there is no breakdown in the 228 kW pulse test. The measurement results are consistent with the simulation results, indicating that the adaptor has good high-power transmission performance. This work provides theoretical and experimental bases for a rectangular-to-coaxial adaptor design, especially in high-power steady-state operation.
      PubDate: Thu, 10 Dec 2020 13:20:00 +000
       
  • On-Chip Antenna Design Using the Concepts of Metamaterial and SIW
           Principles Applicable to Terahertz Integrated Circuits Operating over
           0.6–0.622 THz

    • Abstract: This research work presents the investigation of realizing an on-chip antenna based on the metamaterial concept, which is working over the terahertz (THz) band for applications in integrated circuits. The proposed on-chip antenna is constructed of five stacked layers of polyimide and aluminum as top and bottom substrates, radiation patches, ground plane, and feed line. The four square-shaped radiation patches are implemented on the 50 m top-polyimide substrate, and the feed line is realized on the 50 m bottom-polyimide layer by designing the simple square microstrip lines, which are all connected to each other and then excited by waveguide port. The ground plane including a coupling square slot has sandwiched between the top- and bottom-polyimide layers. The coupling square slot etched on the ground plane is exactly placed under the patch to optimum transfer the electromagnetic signal from the bottom feed line to the top radiation patch. To achieve high performance parameters without increasing the antenna's physical dimensions, the metamaterial and substrate integrated waveguide properties have been applied to the antenna structure by implementing linear tapered slots on the patch top surfaces and metallic via holes throughout the middle ground plane connecting top and bottom substrates to each other. The slots play the role of series left-handed (LH) capacitors (CL) and the via holes act as shunt LH inductors (LL). The overall dimension of the proposed metamaterial-based on-chip antenna is 1000 × 1000 × 100 μm3. This antenna can cover the frequency band from 0.6 THz to 0.622 THz, which is equal to 20 GHz bandwidth. The radiation gain and efficiency across the operating frequency band varies from 1.1 dBi to 1.8 dBi, and from 58% to 60.5%, respectively. The results confirm that the proposed on-chip antenna with compact dimensions, wide bandwidth over the terahertz domain, low profile, cost effective, simple configuration, and easy to manufacture can be potentially appropriate for terahertz integrated circuits.
      PubDate: Tue, 08 Dec 2020 05:20:01 +000
       
  • Design and Analysis of a Five-Band Polarization-Insensitive Metamaterial
           Absorber

    • Abstract: A five-band metamaterial absorber (MMA) is presented. The proposed absorber consists of a three-layer structure of the top metal resonator, intermediate dielectric layer, and bottom metal plane. The top structure takes the centroid as the center and spreads out in a three-pronged shape with an average of 360°, and the ends bifurcate again. The calculation was carried out by the professional software to iteratively optimize the absorption effect of MMA in the microwave range. The results show that the MA has five peaks at resonant frequencies of 5.984 GHz, 12.232 GHz, 18.128 GHz, 18.414 GHz, and 20.592 GHz, with peaks of 0.9925, 0.9968, 0.9783, 0.9754, and 0.9975. By analyzing the electromagnetic field and surface current distribution of the absorber, the absorption mechanism is further verified, and the corresponding influence on the absorption spectrum is studied according to different polarization angles and incident angles. The effects of different resonator structure size and dielectric layer thickness on absorption rate were also discussed, and the distribution of electromagnetic fields is analyzed to reveal the existence of electric dipole resonance and magnetic resonance. Through comparing experiments and simulations, it is found that the peaks of the 1st, 2nd, and 5th have smaller absorption errors and frequency deviation, while the peaks of the 3rd and 4th have large ones. The five-band absorber has potential application in multiband electromagnetic stealth, bionic sensor, thermal radiation measuring instrument, and so on.
      PubDate: Tue, 08 Dec 2020 05:20:01 +000
       
  • Measurement and Statistical Analysis of Distinguishable Multipaths in
           Underground Tunnels

    • Abstract: Compared with the line-of-sight (LOS) condition, the multipath effect is more serious in the non-line-of-sight (NLOS) condition. Therefore, the LOS and NLOS identification is necessary for the multipath analysis of signal propagation. The commonly used method is the support vector machine (SVM) method with high computational complexity. To tackle this problem, this paper adopts the SVM classifier based on fewer selected features of the normalized power delay profile (PDP). Therein, the PDP can be obtained using the sliding correlation method. The results show that the SVM-based classifier can achieve high accuracy on LOS and NLOS identification. We then analyze the impact of the signal-to-noise ratio (SNR) and transmitting-receiving (Tx-to-Rx) distance on distinguishable multipaths under LOS and NLOS conditions. According to statistical measurement results, a function of distinguishable multipath numbers is established. Finally, we investigate the multipath power and delay parameters of average delay spread and root mean square (RMS) delay spread based on multipath results. The outcomes of this paper provide a useful support for analyzing signal propagation characteristics.
      PubDate: Mon, 07 Dec 2020 07:35:01 +000
       
  • Bandwidth Enhancement on Half-Mode Substrate Integrated Waveguide Antenna
           Using Cavity-Backed Triangular Slot

    • Abstract: This paper proposes bandwidth enhancement of a cavity-backed slot antenna using a triangular slot on a half-mode substrate integrated waveguide structure antenna. The bandwidth enhancement was achieved by combining the fixed TE101 and the downward shifting TE102 modes, resulting in hybrid modes. The design evolution of the slot antenna from a half nonresonating rectangular slot to a triangular slot antenna increased the fractional bandwidth. The simulation result showed that fractional bandwidth increased from 6.27% to 9.1%. It was confirmed by measurement that the fractional bandwidth of 9.87% was achieved which reflects a 350 MHz bandwidth with center frequency at 3.84 GHz. The measured gain at center frequency was 4.2 dBi. It is shown that the radiation characteristics obtained from both measurement and simulation results are in very good agreement.
      PubDate: Thu, 03 Dec 2020 05:20:00 +000
       
  • Performance Analysis of Conventional Beamforming Algorithm for
           Angle-of-Arrival Estimation under Measurement Uncertainty

    • Abstract: The performance of the conventional beamforming for angle-of-arrival (AOA) estimation algorithm under measurement uncertainty is analyzed. Gaussian random variables are used for modeling measurement noises. Analytic expression of the mean square error (MSE) is obtained via Taylor series expansion. In traditional performance analysis, estimation accuracy in terms of the MSEs is usually obtained from the Monte Carlo simulation, which is computationally intensive especially for large number of repetitions in the Monte Carlo simulation. For reliable MSE in the Monte Carlo simulation, the number of repetitions should be very large. To circumvent this problem, analytic performance analysis which is less computationally intensive than the Monte Carlo simulation-based performance analysis is proposed in this paper. After some approximations, we derive the closed form expression of the mean square error (MSE) for each incident signal. The validity of the derived expressions is shown by comparing an analytic MSE with an empirical MSEs. The Cramer–Rao bound is also used to further validate the derived analytic expression.
      PubDate: Wed, 02 Dec 2020 15:05:02 +000
       
  • Design of a Broadband Radome-Enclosed Dual-Polarization Antenna Array
           Covering Sub-6 GHz Band with Differential Feeding

    • Abstract: A differentially fed dual-polarized antenna with low cross-polarization is proposed for sub-6 GHz applications. The main patch is fed through two pairs of symmetrical ports, and annular-ring slits are etched around the feedings. The broadband 180° phase shifter provides a stable differential feeding structure, and a 1 mm thick radome with a parasitic patch printed on its inner surface is utilized to expand the impedance bandwidth. The impedance bandwidth of the proposed antenna ranges from 3.3 to 6.0 GHz, covering the entire sub-6 GHz band. The 4-element antenna array features low profile, wide bandwidth, low cross-polarization level, and stable gain over the entire operating band. The prototype of the antenna array is fabricated and measured, and the design is well validated by experimental results.
      PubDate: Tue, 01 Dec 2020 06:05:01 +000
       
  • Dual-Band 2 × 2 MIMO Antenna with Compact Size and High Isolation
           Based on Half-Mode SIW

    • Abstract: This paper presents a close-spaced dual-band 2 × 2 multiple-input multiple-output (MIMO) antenna with high isolation based on half-mode substrate integrated waveguide (HMSIW). The dual-band operation of the antenna element is achieved by loading a rectangular patch outside the radiating aperture of an HMSIW cavity. The HMSIW cavity is excited by a coaxial probe, whereas the rectangular patch is energized through proximity coupling by the radiating aperture of HMSIW. The antenna elements can be closely placed using the rotation and orthogonal arrangement for a 2 × 2 array. Small neutralization lines at the center of the MIMO antenna can increase the isolation among its elements by around 10 dB in the lower band and 5 dB in the higher band. A prototype of the MIMO antenna is fabricated and its performance is measured. The measured results show that the resonant frequencies are centered at 4.43 and 5.39 GHz with bandwidths of 110 and 80 MHz and peak gains of 6 and 6.4 dBi, respectively. The minimum isolation in both bands is greater than 35 dB. The envelope correlation coefficient is lower than 0.005 within two operating bands.
      PubDate: Fri, 27 Nov 2020 06:35:00 +000
       
  • Parametric Analysis of Negative and Positive Refractive Index Lens Antenna
           by ANSYS HFSS

    • Abstract: Lens antennas with multibeam, high gain, and low sidelobe level are potential candidates for base station antennas in 5G mobile communication. In this paper, the authors perform simulation and parametric analysis of a lens antenna with positive and negative refractive indexes (NRI) using the modern electromagnetic field simulation software ANSYS HFSS. The simulation results of structures and theoretical calculations are analyzed and compared. The simulation results show the effectiveness of using negative refractive index lens antennas to minimize the dimension. The lens thickness with a negative refractive index decreased from 24.5 mm to 6.1 mm compared to the positive refractive index lens’s thickness. The results also indicate the similarities in gain, sidelobe level, amplitude, and electric field distribution on the aperture plane of the negative and positive refractive indexes (PRI) lens antennas compared to the theoretical calculation. In addition, the authors simulate a lens structure with additional quarter wavelength matching layers (MLs) to estimate the antireflection performance.
      PubDate: Wed, 25 Nov 2020 05:35:01 +000
       
  • Optimization of Wireless Communication Coverage in Underground Tunnels
           Based on Zone Division

    • Abstract: In order to reduce the path loss of the wireless communication signal in the underground tunnel, a scheme for configuring the antenna polarization of wireless systems based on a zone-division method is proposed. A multimodal method is used to estimate the effect of antenna polarization on the wireless propagation. When the optimal polarization of the antenna leading to low path loss is different in the zones near and far from the transmitting antenna, a dividing point is used to separate the zones. Experiments are conducted in an underground mine. It shows that the results by the multimodal method are consistent with the real data. Compared with the existing coverage schemes, the proposed scheme can obtain better coverage. Meanwhile, zone division has an important influence on the optimized performance of the wireless coverage. The zones divided based on Fresnel zone clearance and system identification are too small or too large, which result in incorrect polarization switching and high path loss.
      PubDate: Mon, 23 Nov 2020 14:50:02 +000
       
  • A Conceptual Investigation of a Large Radio Telescope Support Point Number
           Effect on Its Pointing Accuracy

    • Abstract: The purpose of this paper is to investigate a large radio telescope support point number effect on its pointing accuracy and provide a useful guideline for the large radio telescope design engineer. In a large radio telescope system, the azimuth track is used to support the whole telescope structure and the mounting error as well as the telescope wheel-track contact in a long term can cause unevenness on the azimuth track, which can further deteriorate the telescope pointing accuracy. Even though various compensation methods have been proposed to compensate for this pointing error, it remains as one of the challenges for the telescope pointing error reduction. In this paper, a general telescope pointing error estimation formula has been proposed to investigate different telescope support-point number designs on its pointing accuracy. In this approach, the azimuth track unevenness has been modelled as the Fourier function using the least square method after the raw track profile has been measured. Next, the elevation position matrix, azimuth position matrix, and the azimuth profile matrix can be constructed for different telescope support point numbers, and the telescope pointing error can then be obtained based on the proposed general formula. The telescope pointing error root mean square (RMS) value is used to quantify the effect of the telescope support point number on the pointing accuracy. Two interesting results can be observed in the numerical example. The first one is that the telescope pointing error curves have different dominant peaks during one azimuth track rotation, which is corresponding to the support point number. Another interesting finding is that the RMS value experienced a complex trend with the support point number change, and they are not a simple monotonous increasing or decreasing relationship with the support number. All the results in this paper can provide a useful guideline for reducing the telescope pointing error in the initial design stage.
      PubDate: Mon, 23 Nov 2020 06:20:00 +000
       
  • Ship Velocity Estimation in Airborne Along-Track Interferometric SAR
           Imagery Based on the Fractional Fourier Transform

    • Abstract: Synthetic aperture radar (SAR) was originally exploited to image stationary scenes. However, it is important to derive target information of velocity for many applications. The fractional Fourier transform (FrFT) is a generalization of the classical Fourier transform and is well-known as a useful tool to estimate the chirp rate of linear frequency-modulated (LFM) signals. Motion compensation is critical to moving target imaging. It is difficult for us to obtain the actual motion parameters in real scenarios. Based on the moving target echo model in airborne along-track interferometric SAR (ATI-SAR) and expression of the ATI phase, a method is proposed to estimate the ship velocity by combining the ATI phase with FrFT. First, we use the FrFT to evaluate the chirp rate of the moving target echo. Then, we construct an equation to estimate the ship velocity using the chirp rate estimation, peak response time, and ATI phase. Finally, the simulation experiments are used to validate the effectiveness of the proposed method.
      PubDate: Mon, 16 Nov 2020 07:50:01 +000
       
  • Antenna Optimization Design Based on Deep Gaussian Process Model

    • Abstract: When using Gaussian process (GP) machine learning as a surrogate model combined with the global optimization method for rapid optimization design of electromagnetic problems, a large number of covariance calculations are required, resulting in a calculation volume which is cube of the number of samples and low efficiency. In order to solve this problem, this study constructs a deep GP (DGP) model by using the structural form of convolutional neural network (CNN) and combining it with GP. In this network, GP is used to replace the fully connected layer of the CNN, the convolutional layer and the pooling layer of the CNN are used to reduce the dimension of the input parameters and GP is used to predict output, while particle swarm optimization (PSO) is used algorithm to optimize network structure parameters. The modeling method proposed in this paper can compress the dimensions of the problem to reduce the demand of training samples and effectively improve the modeling efficiency while ensuring the modeling accuracy. In our study, we used the proposed modeling method to optimize the design of a multiband microstrip antenna (MSA) for mobile terminals and obtained good optimization results. The optimized antenna can work in the frequency range of 0.69–0.96 GHz and 1.7–2.76 GHz, covering the wireless LTE 700, GSM 850, GSM 900, DCS 1800, PCS1900, UMTS 2100, LTE 2300, and LTE 2500 frequency bands. It is shown that the DGP network model proposed in this paper can replace the electromagnetic simulation software in the optimization process, so as to reduce the time required for optimization while ensuring the design accuracy.
      PubDate: Thu, 12 Nov 2020 13:20:01 +000
       
  • Terahertz Sensor Study Based on Spoof Surface Plasmon Polaritons

    • Abstract: The spoof surface plasmon polaritons (SSPPs) structure can be used as a sensor in THz region for the biosensing. The accuracy of resonance and amplitude for sensor is very important for biosensing. The momentum matching of SSPPs determines the resonance position and the gap distance determines the amplitude. For the biomolecular sensing, the sample is positioned between the prism base and the SSPPs structure. The momentum matching condition at the current study does not consider the effect of sample refractive index and the resonance position has a significant error. Here the correction is made to the momentum matching condition which considers the effect of the sample refractive index. A comparative study of surface plasmon resonance (SPR) sensing performance based on frequency and angle variations shows that the sensing sensitivity for frequency region is superior to that of angle region; in the meanwhile, as an application of biosensors, we have detected different types of brain lesions in the frequency range. Furthermore, the reflection amplitude is related to gap size between the prism and SSPPs. The relationship of gap size and reflection amplitude is studied. By using the relationship between gap size and reflection amplitude, the amplitudes at different frequencies or incident angles for different refractivities have the same reflection dips compared to the other published results. The simulation is performed and the results proved the theory.
      PubDate: Thu, 12 Nov 2020 05:35:00 +000
       
  • A Balun Bandpass Filter to Facilitate the Design of Dual-Polarized Dipole
           Antenna

    • Abstract: A dipole antenna based on a balun bandpass filter (BPF) is developed in this paper. The balun BPF employs two U-shaped resonators settled on the left side of the open-circuited transmission line and two L-shaped stubs to produce signals with equal amplitude and inverse phase. In this way, the volume of the balun BPF is reduced by half, and the distance between two output ports is dramatically decreased. Then, the balun BPF is integrated with a dipole. Instead of the traditional Γ-shaped line with a wide balun ground, two thin microstrip lines with width of 1 mm are adopted to connect the dipole and the balun BPF. The antenna bandwidth is further extended due to the fusion of the resonance of the dipole and balun BPF. As a result, the proposed antenna can operate from 4350 to 5025 MHz (covering the n79 band of 5G NR, 4400 MHz–5000 MHz), yielding a good filtering performance in the stopband. The measured half-power beamwidth is ranging from 61° to 63° and the measured gain is ranging from 7.95 to 8.5 dBi in the passband. This new balun BPF and the dual-polarized dipole based on it have great potential to be applied in 5G MIMO systems.
      PubDate: Thu, 05 Nov 2020 13:20:01 +000
       
  • Research on the Impact of Marine Environment on ICPT Transmission
           Efficiency

    • Abstract: ICPT is one of the most influential solutions in the field of wireless power transmission, but it is also very susceptible to the working environment. The complicated marine environment has a great influence on the performance of ICPT. In the deep-sea high-pressure environment, due to the piezomagnetic effect, the magnetic core in the coupling structure will suddenly change the permeability, and the coupling coefficient, self-inductance, and other parameters will also change accordingly. At the same time, changes in ocean currents in the ocean will cause the ICPT coils to be misaligned, thereby affecting the magnetic field distribution between the coils and the transmission efficiency of the system. In order to provide theoretical support for optimum design of ICPT system in ocean environment, the influence of core performance changes and ICPT coil misalignment on system transmission efficiency is studied.
      PubDate: Fri, 30 Oct 2020 07:50:01 +000
       
 
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