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  Subjects -> ELECTRONICS (Total: 179 journals)
Showing 1 - 200 of 277 Journals sorted alphabetically
Acta Electronica Malaysia     Open Access  
Advances in Biosensors and Bioelectronics     Open Access   (Followers: 7)
Advances in Electrical and Electronic Engineering     Open Access   (Followers: 5)
Advances in Electronics     Open Access   (Followers: 78)
Advances in Magnetic and Optical Resonance     Full-text available via subscription   (Followers: 8)
Advances in Microelectronic Engineering     Open Access   (Followers: 13)
Advances in Power Electronics     Open Access   (Followers: 33)
Advancing Microelectronics     Hybrid Journal  
Aerospace and Electronic Systems, IEEE Transactions on     Hybrid Journal   (Followers: 313)
American Journal of Electrical and Electronic Engineering     Open Access   (Followers: 24)
Annals of Telecommunications     Hybrid Journal   (Followers: 9)
APSIPA Transactions on Signal and Information Processing     Open Access   (Followers: 9)
Archives of Electrical Engineering     Open Access   (Followers: 13)
Autonomous Mental Development, IEEE Transactions on     Hybrid Journal   (Followers: 8)
Bell Labs Technical Journal     Hybrid Journal   (Followers: 28)
Bioelectronics in Medicine     Hybrid Journal  
Biomedical Engineering, IEEE Reviews in     Full-text available via subscription   (Followers: 19)
Biomedical Engineering, IEEE Transactions on     Hybrid Journal   (Followers: 36)
Biomedical Instrumentation & Technology     Hybrid Journal   (Followers: 6)
Broadcasting, IEEE Transactions on     Hybrid Journal   (Followers: 12)
BULLETIN of National Technical University of Ukraine. Series RADIOTECHNIQUE. RADIOAPPARATUS BUILDING     Open Access   (Followers: 1)
Bulletin of the Polish Academy of Sciences : Technical Sciences     Open Access   (Followers: 1)
Canadian Journal of Remote Sensing     Full-text available via subscription   (Followers: 47)
China Communications     Full-text available via subscription   (Followers: 8)
Chinese Journal of Electronics     Hybrid Journal  
Circuits and Systems     Open Access   (Followers: 15)
Consumer Electronics Times     Open Access   (Followers: 5)
Control Systems     Hybrid Journal   (Followers: 266)
Edu Elektrika Journal     Open Access   (Followers: 1)
Electrica     Open Access  
Electronic Design     Partially Free   (Followers: 105)
Electronic Markets     Hybrid Journal   (Followers: 7)
Electronic Materials Letters     Hybrid Journal   (Followers: 4)
Electronics     Open Access   (Followers: 86)
Electronics and Communications in Japan     Hybrid Journal   (Followers: 10)
Electronics For You     Partially Free   (Followers: 92)
Electronics Letters     Hybrid Journal   (Followers: 26)
Elkha : Jurnal Teknik Elektro     Open Access  
Embedded Systems Letters, IEEE     Hybrid Journal   (Followers: 51)
Energy Harvesting and Systems     Hybrid Journal   (Followers: 4)
Energy Storage Materials     Full-text available via subscription   (Followers: 3)
EPJ Quantum Technology     Open Access  
EURASIP Journal on Embedded Systems     Open Access   (Followers: 11)
Facta Universitatis, Series : Electronics and Energetics     Open Access  
Foundations and Trends® in Communications and Information Theory     Full-text available via subscription   (Followers: 6)
Foundations and Trends® in Signal Processing     Full-text available via subscription   (Followers: 10)
Frequenz     Hybrid Journal   (Followers: 1)
Frontiers of Optoelectronics     Hybrid Journal   (Followers: 1)
Geoscience and Remote Sensing, IEEE Transactions on     Hybrid Journal   (Followers: 189)
Haptics, IEEE Transactions on     Hybrid Journal   (Followers: 4)
IACR Transactions on Symmetric Cryptology     Open Access  
IEEE Antennas and Propagation Magazine     Hybrid Journal   (Followers: 97)
IEEE Antennas and Wireless Propagation Letters     Hybrid Journal   (Followers: 77)
IEEE Journal of Emerging and Selected Topics in Power Electronics     Hybrid Journal   (Followers: 46)
IEEE Journal of the Electron Devices Society     Open Access   (Followers: 9)
IEEE Journal on Exploratory Solid-State Computational Devices and Circuits     Hybrid Journal   (Followers: 1)
IEEE Power Electronics Magazine     Full-text available via subscription   (Followers: 66)
IEEE Transactions on Antennas and Propagation     Full-text available via subscription   (Followers: 70)
IEEE Transactions on Automatic Control     Hybrid Journal   (Followers: 56)
IEEE Transactions on Circuits and Systems for Video Technology     Hybrid Journal   (Followers: 19)
IEEE Transactions on Consumer Electronics     Hybrid Journal   (Followers: 40)
IEEE Transactions on Electron Devices     Hybrid Journal   (Followers: 19)
IEEE Transactions on Information Theory     Hybrid Journal   (Followers: 26)
IEEE Transactions on Power Electronics     Hybrid Journal   (Followers: 71)
IEEE Transactions on Signal and Information Processing over Networks     Full-text available via subscription   (Followers: 12)
IEICE - Transactions on Electronics     Full-text available via subscription   (Followers: 12)
IEICE - Transactions on Information and Systems     Full-text available via subscription   (Followers: 5)
IET Cyber-Physical Systems : Theory & Applications     Open Access   (Followers: 1)
IET Microwaves, Antennas & Propagation     Hybrid Journal   (Followers: 35)
IET Nanodielectrics     Open Access  
IET Power Electronics     Hybrid Journal   (Followers: 46)
IET Smart Grid     Open Access  
IET Wireless Sensor Systems     Hybrid Journal   (Followers: 18)
IETE Journal of Education     Open Access   (Followers: 4)
IETE Journal of Research     Open Access   (Followers: 11)
IETE Technical Review     Open Access   (Followers: 13)
IJEIS (Indonesian Journal of Electronics and Instrumentation Systems)     Open Access   (Followers: 3)
Industrial Electronics, IEEE Transactions on     Hybrid Journal   (Followers: 58)
Industry Applications, IEEE Transactions on     Hybrid Journal   (Followers: 24)
Informatik-Spektrum     Hybrid Journal   (Followers: 2)
Instabilities in Silicon Devices     Full-text available via subscription   (Followers: 1)
Intelligent Transportation Systems Magazine, IEEE     Full-text available via subscription   (Followers: 13)
International Journal of Advanced Research in Computer Science and Electronics Engineering     Open Access   (Followers: 18)
International Journal of Advances in Telecommunications, Electrotechnics, Signals and Systems     Open Access   (Followers: 10)
International Journal of Antennas and Propagation     Open Access   (Followers: 11)
International Journal of Applied Electronics in Physics & Robotics     Open Access   (Followers: 5)
International Journal of Computational Vision and Robotics     Hybrid Journal   (Followers: 6)
International Journal of Control     Hybrid Journal   (Followers: 12)
International Journal of Electronics     Hybrid Journal   (Followers: 7)
International Journal of Electronics and Telecommunications     Open Access   (Followers: 13)
International Journal of Granular Computing, Rough Sets and Intelligent Systems     Hybrid Journal   (Followers: 2)
International Journal of High Speed Electronics and Systems     Hybrid Journal  
International Journal of Image, Graphics and Signal Processing     Open Access   (Followers: 14)
International Journal of Microwave and Wireless Technologies     Hybrid Journal   (Followers: 8)
International Journal of Nano Devices, Sensors and Systems     Open Access   (Followers: 12)
International Journal of Nanoscience     Hybrid Journal   (Followers: 1)
International Journal of Numerical Modelling: Electronic Networks, Devices and Fields     Hybrid Journal   (Followers: 4)
International Journal of Power Electronics     Hybrid Journal   (Followers: 24)
International Journal of Review in Electronics & Communication Engineering     Open Access   (Followers: 4)
International Journal of Sensors, Wireless Communications and Control     Hybrid Journal   (Followers: 10)
International Journal of Systems, Control and Communications     Hybrid Journal   (Followers: 4)
International Journal of Wireless and Microwave Technologies     Open Access   (Followers: 6)
International Transaction of Electrical and Computer Engineers System     Open Access   (Followers: 2)
JAREE (Journal on Advanced Research in Electrical Engineering)     Open Access  
Journal of Biosensors & Bioelectronics     Open Access   (Followers: 3)
Journal of Advanced Dielectrics     Open Access   (Followers: 1)
Journal of Artificial Intelligence     Open Access   (Followers: 10)
Journal of Circuits, Systems, and Computers     Hybrid Journal   (Followers: 4)
Journal of Computational Intelligence and Electronic Systems     Full-text available via subscription   (Followers: 1)
Journal of Electrical and Electronics Engineering Research     Open Access   (Followers: 24)
Journal of Electrical Bioimpedance     Open Access   (Followers: 2)
Journal of Electrical Engineering & Electronic Technology     Hybrid Journal   (Followers: 7)
Journal of Electrical, Electronics and Informatics     Open Access  
Journal of Electromagnetic Analysis and Applications     Open Access   (Followers: 7)
Journal of Electromagnetic Waves and Applications     Hybrid Journal   (Followers: 8)
Journal of Electronic Design Technology     Full-text available via subscription   (Followers: 6)
Journal of Electronics (China)     Hybrid Journal   (Followers: 4)
Journal of Energy Storage     Full-text available via subscription   (Followers: 4)
Journal of Engineered Fibers and Fabrics     Open Access  
Journal of Field Robotics     Hybrid Journal   (Followers: 2)
Journal of Guidance, Control, and Dynamics     Hybrid Journal   (Followers: 167)
Journal of Information and Telecommunication     Open Access   (Followers: 1)
Journal of Intelligent Procedures in Electrical Technology     Open Access   (Followers: 3)
Journal of Low Power Electronics     Full-text available via subscription   (Followers: 7)
Journal of Low Power Electronics and Applications     Open Access   (Followers: 9)
Journal of Microelectronics and Electronic Packaging     Hybrid Journal  
Journal of Microwave Power and Electromagnetic Energy     Hybrid Journal  
Journal of Microwaves, Optoelectronics and Electromagnetic Applications     Open Access   (Followers: 10)
Journal of Nuclear Cardiology     Hybrid Journal  
Journal of Optoelectronics Engineering     Open Access   (Followers: 4)
Journal of Physics B: Atomic, Molecular and Optical Physics     Hybrid Journal   (Followers: 28)
Journal of Power Electronics & Power Systems     Full-text available via subscription   (Followers: 11)
Journal of Semiconductors     Full-text available via subscription   (Followers: 5)
Journal of Sensors     Open Access   (Followers: 26)
Journal of Signal and Information Processing     Open Access   (Followers: 9)
Jurnal Rekayasa Elektrika     Open Access  
Jurnal Teknik Elektro     Open Access  
Jurnal Teknologi Elektro     Open Access  
Kinetik : Game Technology, Information System, Computer Network, Computing, Electronics, and Control     Open Access  
Learning Technologies, IEEE Transactions on     Hybrid Journal   (Followers: 12)
Magnetics Letters, IEEE     Hybrid Journal   (Followers: 7)
Majalah Ilmiah Teknologi Elektro : Journal of Electrical Technology     Open Access   (Followers: 2)
Metrology and Measurement Systems     Open Access   (Followers: 5)
Microelectronics and Solid State Electronics     Open Access   (Followers: 18)
Nanotechnology Magazine, IEEE     Full-text available via subscription   (Followers: 33)
Nanotechnology, Science and Applications     Open Access   (Followers: 6)
Nature Electronics     Hybrid Journal  
Networks: an International Journal     Hybrid Journal   (Followers: 5)
Open Electrical & Electronic Engineering Journal     Open Access  
Open Journal of Antennas and Propagation     Open Access   (Followers: 8)
Optical Communications and Networking, IEEE/OSA Journal of     Full-text available via subscription   (Followers: 15)
Paladyn. Journal of Behavioral Robotics     Open Access   (Followers: 1)
Power Electronics and Drives     Open Access   (Followers: 1)
Problemy Peredachi Informatsii     Full-text available via subscription  
Progress in Quantum Electronics     Full-text available via subscription   (Followers: 7)
Pulse     Full-text available via subscription   (Followers: 5)
Radiophysics and Quantum Electronics     Hybrid Journal   (Followers: 2)
Recent Advances in Communications and Networking Technology     Hybrid Journal   (Followers: 3)
Recent Advances in Electrical & Electronic Engineering     Hybrid Journal   (Followers: 9)
Research & Reviews : Journal of Embedded System & Applications     Full-text available via subscription   (Followers: 5)
Security and Communication Networks     Hybrid Journal   (Followers: 2)
Selected Topics in Applied Earth Observations and Remote Sensing, IEEE Journal of     Hybrid Journal   (Followers: 53)
Semiconductors and Semimetals     Full-text available via subscription   (Followers: 1)
Sensing and Imaging : An International Journal     Hybrid Journal   (Followers: 2)
Services Computing, IEEE Transactions on     Hybrid Journal   (Followers: 4)
Software Engineering, IEEE Transactions on     Hybrid Journal   (Followers: 75)
Solid-State Circuits Magazine, IEEE     Hybrid Journal   (Followers: 13)
Solid-State Electronics     Hybrid Journal   (Followers: 9)
Superconductor Science and Technology     Hybrid Journal   (Followers: 2)
Synthesis Lectures on Power Electronics     Full-text available via subscription   (Followers: 3)
Technical Report Electronics and Computer Engineering     Open Access  
TELE     Open Access  
Telematique     Open Access  
TELKOMNIKA (Telecommunication, Computing, Electronics and Control)     Open Access   (Followers: 9)
Universal Journal of Electrical and Electronic Engineering     Open Access   (Followers: 6)
Visión Electrónica : algo más que un estado sólido     Open Access   (Followers: 1)
Wireless and Mobile Technologies     Open Access   (Followers: 6)
Wireless Power Transfer     Full-text available via subscription   (Followers: 4)
Women in Engineering Magazine, IEEE     Full-text available via subscription   (Followers: 11)
Електротехніка і Електромеханіка     Open Access  

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Similar Journals
Journal Cover
IEEE Antennas and Wireless Propagation Letters
Journal Prestige (SJR): 1.047
Citation Impact (citeScore): 4
Number of Followers: 77  
 
  Hybrid Journal Hybrid journal (It can contain Open Access articles)
ISSN (Print) 1536-1225
Published by IEEE Homepage  [191 journals]
  • IEEE Antennas and Wireless Propagation Letters
    • Abstract: Provides a listing of current staff, committee members and society officers.
      PubDate: April 2019
      Issue No: Vol. 18, No. 4 (2019)
       
  • RSS-Based DoA Estimation for ESPAR Antennas Using Support Vector Machine
    • Authors: M. Tarkowski;L. Kulas;
      Pages: 561 - 565
      Abstract: In this letter, it is shown how direction-of-arrival (DoA) estimation for electronically steerable parasitic array radiator (ESPAR) antennas, which are designed to be integrated within wireless sensor network nodes, can be improved by applying support vector classification approach to received signal strength (RSS) values recorded at an antenna's output port. The proposed method relies on ESPAR antenna's radiation patterns measured during the initial calibration phase of the DoA estimation process. These patterns are then used in the support vector machine (SVM) training process adapted to handle ESPAR antenna-based DoA estimation. Measurements using a fabricated ESPAR antenna indicate that the proposed SVM approach provides more accurate results than available RSS-based estimation algorithms relying on power pattern cross-correlation method.
      PubDate: April 2019
      Issue No: Vol. 18, No. 4 (2019)
       
  • A Shared Aperture 1 Bit Metasurface for Orbital Angular Momentum
           Multiplexing
    • Authors: Di Zhang;Xiangyu Cao;Jun Gao;Huanhuan Yang;Wenqiang Li;Tong Li;Jianghao Tian;
      Pages: 566 - 570
      Abstract: In this letter, a shared aperture 1 bit metasurface for orbital angular momentum (OAM) multiplexing is studied. A phased array antenna fed by the phase shift network is embedded on the reflective aperture of the 1 bit metasurface. The proposed device can work on reflectarray mode and phased array mode from 7.1 to 7.5 GHz and 7 to 7.5 GHz, respectively. Correspondingly, OAM vortex beam with topological charge l = −1 and 1 can be generated. The transmission coefficient between the two working modes is below −30 dB, and the envelope correlation coefficient is quite close to 0, which reveals the excellent isolation and diversity performance. A prototype of the proposed device is fabricated and tested. The measured S-parameters and radiation patterns agree well with the simulation results.
      PubDate: April 2019
      Issue No: Vol. 18, No. 4 (2019)
       
  • Beamwidth Control of an Impulse Radiating Antenna Using a Liquid Metal
           Reflector
    • Authors: Arim Ha;Myung Ho Chae;Kangwook Kim;
      Pages: 571 - 575
      Abstract: In this letter, a beamwidth controllable impulse-radiating antenna (IRA) was proposed. The typical solid reflector of the IRA was replaced with a wired reflector corresponding to the current flow on the reflector surface. The performance of the wired-reflector IRA (WIRA) was shown to be essentially the same as that of the conventional IRA through simulation and measurement. Then, liquid metal was used to replace the solid wires, and a beamwidth controllable WIRA was implemented. The electrical size of the reflector could be expanded up to approximately 400 mm in the H-plane. The beamwidth control capability was validated through simulation and measurement. It was shown that the beamwidth could be varied in the H-plane up to 44% while other parameters, such as the input impedance and E-plane beamwidth, remained almost constant.
      PubDate: April 2019
      Issue No: Vol. 18, No. 4 (2019)
       
  • Bandwidth-Enhanced Electrically Large Microstrip Antenna Loaded With SRR
           Structures
    • Authors: Wenquan Cao;Wenyu Ma;Wenfang Peng;Zhi Ning Chen;
      Pages: 576 - 580
      Abstract: In this letter, microstrip-line-slot feed patch antenna element and array with electrically large property (ELP) are designed and discussed. Periodic three-dimensional split-ring resonator (SRR) structures are introduced as inclusions to realize the ELP. By tuning the structure parameters, their effective permittivity (ϵeff0) could meet the requirement of –1
      PubDate: April 2019
      Issue No: Vol. 18, No. 4 (2019)
       
  • Broadband Circularly Polarized Planar Monopole Antenna With G-Shaped
           Parasitic Strip
    • Authors: Manas Midya;Shankar Bhattacharjee;Monojit Mitra;
      Pages: 581 - 585
      Abstract: The design of a broadband circularly polarized compact monopole antenna is proposed in this letter. By protruding a G-shaped parasitic strip into a C-shaped monopole antenna structure, two orthogonal modes are created with equal amplitude and 90° phase difference for circular polarization. A 3 dB axial-ratio bandwidth (ARBW) of the antenna is greatly extended by using a modified ground plane. With the help of these features, a compact broadband circularly polarized antenna is designed and fabricated. Experimental results show that the proposed antenna realizes –10 dB impedance bandwidth of 62.94% (3.92–7.52 GHz) and ARBW of 53.92% (4.28–7.44 GHz). Overall size of the proposed monopole antenna is $0.57{lambda _0} times 0.61{lambda _0} times 0.03{lambda _0}$, where ${lambda _{0;}}$ is the free-space wavelength at the center frequency of the operating bandwidth. The proposed antenna is desirable for WLAN (5.15–5.85 GHz) applications and various wireless communication systems.
      PubDate: April 2019
      Issue No: Vol. 18, No. 4 (2019)
       
  • Wideband Circularly Polarized Fabry–Perot Resonator Antenna in
           Ku-Band
    • Authors: Wenquan Cao;Xinmeng Lv;Qianqian Wang;Yanhui Zhao;Xiaoqin Yang;
      Pages: 586 - 590
      Abstract: A gain enhancement method is proposed for the circularly polarized (CP) magneto-electric dipole antenna (MEDA) over the whole Ku-band in this letter. Together with the CP MEDA as a feeding antenna, a single-layer partially reflecting surface made by a substrate with arrays of metal patches printed on both the top and bottom forms a Fabry–Perot resonator antenna. Five types of symmetrical patch, i.e., double printed circular, square, circular-ring, square-ring patches, and single printed circular patch, are compared and optimized for a better reflective phase property. Finally, the circular patch type is chosen because of its gentler reflective phase gradient, and hence the gain value of the CP MEDA is much enhanced over the whole operating band. A prototype is optimized and fabricated to verify the analysis. Measured results show that the 10 dB return-loss bandwidth is about 54% (11.7–19.8 GHz), the 3 dB gain bandwidth is 42.3% (11.7–17.2 GHz), and the 3 dB axial-ratio bandwidth is about 29.3% (12.4–16.8 GHz). The overlapped bandwidth of the three is 29.3%, and the maximum CP gain is 11.45 dBic at 14 GHz. A gain enhancement of about 2.1–5.2 dB is achieved as compared with the unloaded type. This method is a good option to design antennas in satellite communication with the merits of wide CP bandwidth.
      PubDate: April 2019
      Issue No: Vol. 18, No. 4 (2019)
       
  • Dual-Band Substrate-Integrated Waveguide Leaky-Wave Antenna With a Simple
           Feeding Way
    • Authors: Du-Juan Wei;Jianying Li;Jie Liu;Guangwei Yang;Wei Zhang;
      Pages: 591 - 595
      Abstract: A dual-band leaky-wave antenna (LWA) based on substrate-integrated waveguide (SIW) is presented in this letter. The proposed antenna consists of two back-to-back slotted SIW arrays fed by two strip lines, which can realize frequency-controlled scanning beams in two bands. The top SIW slotted array working in the low-frequency band radiates scanning beams in the upper-half free space, and the bottom array for the high-frequency band radiates scanning beams in the lower-half free space. The proposed LWA can radiate scanning beams from near broadside to the endfire in two different bands. The realized gains can get 12.9–17.1 dBi in the low band (8.2–9.4 GHz) and 15.9–20.1 dBi in the high band (13.2–15.2 GHz), respectively. The measured results of the fabricated prototype confirm the design theory and simulated results.
      PubDate: April 2019
      Issue No: Vol. 18, No. 4 (2019)
       
  • Dual-Band 3-D Frequency Selective Surface With Multiple Transmission Zeros
    • Authors: Jianping Zhu;Zhongyin Hao;Cheng Wang;Zhengyong Yu;Cheng Huang;Wanchun Tang;
      Pages: 596 - 600
      Abstract: A dual-band three-dimensional (3-D) frequency selective surface (FSS) is presented for dual-polarized applications in this letter. The proposed 3-D FSS is based on simple square coaxial waveguides and employs via holes, H-shaped slots, and centered gaps in a single unit cell for introducing more resonances and couplings, leading to multiple transmission zeros/poles. As a result, two passbands can be obtained, and each passband contains two transmission poles. Meanwhile, a sharp roll-off rejection of two passbands is achieved by the existence of multiple transmission zeros. The measurement results show a stable response under different incident angles up to 40° for both TE and TM polarizations, with a small unit cell size of 0.13λ0 × 0.13λ0 × 0.17λ0.
      PubDate: April 2019
      Issue No: Vol. 18, No. 4 (2019)
       
  • A Compact Tri-Band Horizontally Polarized Omnidirectional Antenna for UAV
           Applications
    • Authors: Yuehui Cui;Peng Luo;Qing Gong;RongLin Li;
      Pages: 601 - 605
      Abstract: A compact tri-band horizontally polarized (HP) omnidirectional antenna is proposed. The HP omnidirectional antenna consists of a folded patch inside a metal box with a vertical slot. The tri-band antenna operates in the first-order resonant mode of the folded patch for the lower band, while it works in the second-order mode for the upper band, featuring a compact size of 0.32λ0 × 0.16λ0 × 0.08λ0. For the middle band, a slot mode is excited by the folded patch. Two slits on the folded patch are introduced to enhance the bandwidths of the tri-band antenna. It is shown by experiment that the tri-band HP antenna covers three frequency bands 840.5–845, 1430–1444, and 2408–2440 MHz specified by the Ministry of Industry and Information of China for unmanned aerial vehicle systems with good omnidirectionality.
      PubDate: April 2019
      Issue No: Vol. 18, No. 4 (2019)
       
  • SIW-Based Leaky-Wave Antenna Supporting Wide Range of Beam Scanning
           Through Broadside
    • Authors: Ratnesh Ranjan;Jayanta Ghosh;
      Pages: 606 - 610
      Abstract: In this letter, a substrate integrated waveguide-based leaky-wave antenna with wide beam scanning is presented to mitigate open stopband (OSB). The unit cell of this proposed antenna consists of a longitudinal slot and a post placed oppositely offset from the center line. By introducing inductive post along with the longitudinal slot in each unit cell, the OSB is suppressed resulting in continuous beam scanning. An equivalent circuit of the proposed unit cell is developed to explain the impedance matching technique used here to suppress OSB. Dispersion diagram is also used to analyze this seamless scanning. This antenna can scan from –49° to +69° through broadside because of wide impedance matching. Finally, the antenna is prototyped and experimentally verified. Measured results are in accord with simulated results. This antenna provides maximum gain of 14.2 dBi and low level of cross polarization.
      PubDate: April 2019
      Issue No: Vol. 18, No. 4 (2019)
       
  • A Compact, Low-Profile Simultaneous Transmit and Receive Antenna With
           Monopole-Like Radiation Characteristics
    • Authors: Di Wu;Yuzhang Zang;Hung Luyen;Mingjian Li;Nader Behdad;
      Pages: 611 - 615
      Abstract: A compact, vertically polarized simultaneous transmit and receive (STAR) antenna with a high transmit–receive isolation level and an omnidirectional radiation pattern in the azimuth plane is presented. The proposed STAR antenna consists of transmit (TX) and receive (RX) antennas whose phase centers are collocated. The TX antenna is a monopole with top-hat loading, placed directly below the central point of the crossed loop. The RX antenna consists of a pair of orthogonal half-loops, each capacitively fed at both of its ends with a $text{180}^circ$ phase difference. The four ports of the RX antenna are fed with the same amplitude and relative phase values of $text{0}^circ$, $text{90}^circ$, $text{180}^circ$, and $text{270}^circ$ to produce an omnidirectional radiation pattern and high isolation with the TX antenna. The STAR antenna was designed for operation in the 2.45 GHz ISM band with electrical dimensions of $D times H=$ $0.44lambda times 0.15lambda$ (diameter × height). A prototype of this antenna was fabricated and experimentally characterized. Measurement results show that the antenna has a TX/RX isolation level better than 38 dB and maintains monopole-like patterns for both TX and RX modes over a frequency range of 2.4–2.7 GHz.
      PubDate: April 2019
      Issue No: Vol. 18, No. 4 (2019)
       
  • An Iterative Transfer Matrix Computation Method for Propagation Graphs in
           Multiroom Environments
    • Authors: Ramoni Adeogun;Ayush Bharti;Troels Pedersen;
      Pages: 616 - 620
      Abstract: This letter presents a reduced complexity method for computing the transfer matrix of wireless channels in complex indoor environments with a large number of rooms using propagation graphs. Multiroom indoor environments can be represented in a vector signal flow graph with rooms in the complex structure as nodes and propagation between rooms as branches. We propose an iterative procedure to compute the transfer matrix of such complex graphs. The state vector for each node in the graph is iteratively computed until convergence. The state vector for the room(s) with the receiver is then used to compute the transfer function. We show via simulations that the proposed approach closely approximates the original model at much reduced complexity.
      PubDate: April 2019
      Issue No: Vol. 18, No. 4 (2019)
       
  • A Magnetoelectric Dipole Antenna With Beamwidth Reconfiguration
    • Authors: Yan Shi;Yi Cai;Jie Yang;Long Li;
      Pages: 621 - 625
      Abstract: This letter proposes a novel magnetoelectric (ME) dipole antenna with reconfigurable beamwidth characteristic in the E-plane, the H-plane, and both the E- and H-planes. In the proposed antenna, two pairs of tunable parasitic patches are placed in close proximity to the driven ME dipole. A varactor diode is inserted into each parasitic patch, and the mutual coupling between the parasitic patch and the ME dipole is tuned by adjusting the capacitances of the varactor diodes. The beamwidths of the proposed ME dipole antenna in the E-plane and the H-plane can not only be individually tuned but also be simultaneously changed. The designed ME dipole antenna has the tunable E-plane half-power beamwidth (HPBW) from 65° to 120°, the H-plane HPBW from 80° to 120°, and both the E-plane and H-plane HPBWs from 65° to 130° in a frequency band covering 2.0–2.1 GHz. A prototype was fabricated and measured. The good agreement between the measurement and the simulation validate the proposed design.
      PubDate: April 2019
      Issue No: Vol. 18, No. 4 (2019)
       
  • 3-D Printed UWB Microwave Bodyscope for Biomedical Measurements
    • Authors: Saba Rashid;Lluis Jofre;Alejandra Garrido;Giselle Gonzalez;Yongsheng Ding;Albert Aguasca;Juan O’Callaghan;Jordi Romeu;
      Pages: 626 - 630
      Abstract: In this letter, a three-dimensional (3-D) printed compact ultrawideband (UWB) extended gap ridge horn (EGRH) antenna designed to be used for biological measurements of the human body is described. The operational frequency covers the microwave band of interest from 0.5 to 3.0 GHz (for an $S_{11}$ under $-$7 dB). The 3-D printed EGRH antenna is dielectrically matched to the permittivity of the human body, and because of its compactness, it can be visualized as a general-purpose microwave probe among the RF biomedical community. The probe has proven its capability as a pass-through propagation sensor for different parts of the human body and as a sensor detecting a 1 cm diameter object placed inside an artificial head phantom.
      PubDate: April 2019
      Issue No: Vol. 18, No. 4 (2019)
       
  • A Millimeter-Wave Multibeam Transparent Transmitarray Antenna at Ka-Band
    • Authors: Guang Liu;Mohammad Reza Dehghani Kodnoeih;Kien Trung Pham;Eduardo Motta Cruz;David González-Ovejero;Ronan Sauleau;
      Pages: 631 - 635
      Abstract: This letter presents a transmitarray antenna (TA) in the 27.5–29.5 GHz frequency band. The proposed TA is optically transparent and offers the possibility of steering the beam in the H-plane from –30° to 30°. One can achieve these properties using a novel unit cell, composed of meshed double-circle rings printed on polymethylmethacrylate substrates, a plastic material transparent to visible light. This unit cell provides a phase shift of 300° for an insertion loss lower than 1 dB at 28.5 GHz. In turn, the TA sources consist of 2 × 2-element arrays of aperture-coupled stacked patch antennas. The choice of a patch array over a horn array allows one to reduce the total profile and weight of the TA. We have fabricated and tested a transparent TA with a diameter of 9.9 wavelengths at 28.5 GHz, yielding a broadside gain of 25 dBi and –1 dB gain bandwidth of 1.8 GHz; the off-axis 30° beam presents a peak gain of 21.5 dBi and –1 dB gain bandwidth of 1.4 GHz. The measured results are in good agreement with the simulated ones all over the frequency band of interest.
      PubDate: April 2019
      Issue No: Vol. 18, No. 4 (2019)
       
  • Analyses of Initial Condition Problem and Linear Loop Modes in the
           Solution of the Derivative Form of Time-Domain Electric Field Integral
           Equation
    • Authors: Yi-Ting Wu;Wei-Xing Sheng;
      Pages: 636 - 640
      Abstract: The marching-on-in-time solution of the derivative form of time-domain electric field integral equation has long been suffering from three typical problems: internal resonant modes, initial condition problem, and linear loop modes. This letter focuses on the last two problems. The possible appearance of initial condition problem is attributed to the inappropriate choice of temporal basis function; to avoid it, a constraint condition for temporal basis functions is presented in this letter. Additionally, linear loop modes defined as the constant and linearly increasing components of current density in time are studied in theory. Theoretical analysis indicates that limitation on machine precision makes linear loop modes approximately belong to the null space of discretized derivative form of time-domain electric field integral equation. It is also shown that errors due to space–time discretization (except time step size) and double surface integration have no visible influence on linear loop modes. As numerical experiments will demonstrate, the magnitudes of linear loop modes are approximately proportional to the incident field at the initial time and the reciprocal of time step size.
      PubDate: April 2019
      Issue No: Vol. 18, No. 4 (2019)
       
  • Analysis and Modeling of Temporal Variation Properties for LF Ground-Wave
           Propagation Delay
    • Authors: Yu-Rong Pu;Hong-Juan Yang;Li-Li Wang;Yu-Chen Zhao;Rui Luo;Xiao-Li Xi;
      Pages: 641 - 645
      Abstract: In order to further improve the predictive accuracy of low-frequency (LF) ground-wave propagation delay, it is necessary to establish a proper model that can take complex temporal variation properties of propagation delay into account. In this letter, we first analyze the relationship between measured propagation delay and five typical meteorological factors. It can be found that propagation delay has strong correlation with meteorological factors, for example, there is a positive linear correlation between propagation delay and temperature. Then, a theoretical model of propagation delay is established by using a backward propagation neural network (BPNN), and its accuracy is validated by the good agreement between predicted results with measured values. Finally, a detailed quantitative comparison shows that on one hand, the more meteorological factors are considered, the more accurate the predictive model is; on the other hand, the BPNN provides a very convenient approach to handle a large number of factors.
      PubDate: April 2019
      Issue No: Vol. 18, No. 4 (2019)
       
  • Determination of Far Fields of Wire Antennas on a PEC Sphere Using
           Spherical Harmonic Expansion
    • Authors: Rajavardhan Talashila;Harishankar Ramachandran;
      Pages: 646 - 650
      Abstract: Far-field patterns of wire antennas on a PEC sphere are calculated from quasi-static near fields using spherical harmonic expansion. Three cases of the wire antennas—F-antenna, dipole, and resonant loop on the PEC sphere—are considered. With the assumed sinusoidal current distribution on the antenna, the method of images is employed to obtain currents and charges on the antenna's image against the sphere. Only from the charge density and current distributions of the wire antenna and its image, ignoring the sphere, the quasi-static near fields are calculated using Coulomb's and Biot–Savart's laws. The fields in a source-free region are expressed in spherical harmonic expansion with the coefficients obtained from the radial components of the calculated quasi-static electric and magnetic near fields. The far fields thus obtained from the expansion match well with that of the simulated patterns. Deviations between simulation and theory are discussed and explained.
      PubDate: April 2019
      Issue No: Vol. 18, No. 4 (2019)
       
  • A Low-Cost, Single-Layer, Dual Circularly Polarized Antenna for
           Millimeter-Wave Applications
    • Authors: Yu-Hang Yang;Bao-Hua Sun;Jing-Li Guo;
      Pages: 651 - 655
      Abstract: This letter presents a low-cost, single-layer, dual circularly polarized (CP) series-fed antenna based on the sequential rotation technique for millimeter-wave (MM-wave) applications. The series-fed working form endows the proposed antenna with more compact structure and lower ohmic, dielectric losses caused by the feeding network compared with parallel-fed antennas. The curved microstrip transmission lines are adopted as radiation elements; therefore, the whole antenna can be etched on a single-layer laminate using standard printed circuit board technology. These characteristics make the antenna a competitive candidate for MM-wave applications. To validate the proposed design, a dual-CP antenna operating at 30 GHz is fabricated. Based on the measurement, the proposed antenna has a 3 dB gain bandwidth of 1.97 GHz, the measured $ {{S_{21}}} $ is lower than −20 dB, and the axial ratios are lower than 3 dB in the aforementioned frequencies.
      PubDate: April 2019
      Issue No: Vol. 18, No. 4 (2019)
       
  • Excitation of Dielectric Resonator Antennas by Loop Coupling
    • Authors: Murilo H. Seko;Fatima S. Correra;
      Pages: 656 - 658
      Abstract: A loop-based excitation scheme for dielectric resonator antennas is presented. The proposed structure consists of a loop-shaped probe terminated in a short circuit. In this feeding technique, the magnetic field induced by the current loop excites the radiator of the antenna by means of electromagnetic coupling. The loop-coupling method is advantageous for the excitation of the $text{TM}_{01delta }$ mode in cylindrical dielectric resonator antennas since it does not require drilling the dielectric resonator, is suitable for antennas with radiator on a ground plane, and works for a variety of dielectric constants and aspect ratios for the dielectric resonator. The close agreement between measured and simulated results validates this feeding mechanism experimentally.
      PubDate: April 2019
      Issue No: Vol. 18, No. 4 (2019)
       
  • Analysis and Validation of an Improved Method for Measuring HF Surface
           Wave Radar Antenna Pattern
    • Authors: Yingwei Tian;Biyang Wen;Ziyan Li;Yukun Yin;Weimin Huang;
      Pages: 659 - 663
      Abstract: Antenna pattern distortion incorporating the systematic differences among array elements is one of the most important factors that decrease the accuracy of radar direction of arrival estimation. In this letter, a new antenna pattern measurement (APM) method based on a fully-digital radar receiver and a portable signal source is presented. Compared with previous methods, the proposed method not only improves the measurement accuracy, but also reduces the complexity and time cost of measurement. APM results of a compact high-frequency (HF) antenna measured in two modes are depicted, both showing that two independent measurements at the same site are highly consistent. Moreover, the method is further verified by a comparison of radar measured radial current velocity with acoustic Doppler current profiler data.
      PubDate: April 2019
      Issue No: Vol. 18, No. 4 (2019)
       
  • Poynting Vector Method for Reflector Beam Shaping
    • Authors: Dong Xia;Ming Jin;Ming Bai;
      Pages: 664 - 668
      Abstract: A reflector beam shaping method is presented, which includes an efficient algorithm. This efficient algorithm based on the Poynting vector tracing method is employed to analyze the procedure of beam propagation and reflection. The Poynting vector ray tracing method is naturally integrated into the reflector reshaping procedure, which brings significant advantage over existing beam shaping methods. The beam shaping process by this algorithm also shows distinct advantage in efficiency over competing integration theories. It has comparable accuracy with typical physical optics. The validity of this reflector shaping method is demonstrated by performing iterative phase correction toward a gyrotron quasi-optical mode converter.
      PubDate: April 2019
      Issue No: Vol. 18, No. 4 (2019)
       
  • Design of Ultrawideband Energy-Selective Surface for High-Power Microwave
           Protection
    • Authors: Ning Hu;Ke Wang;Jihong Zhang;Song Zha;Zhaofeng Wu;Chenxi Liu;Peiguo Liu;
      Pages: 669 - 673
      Abstract: A novel ultrawideband energy-selective surface (ESS) in S-band is presented for adaptive high-power microwave (HPM) protection. Periodic metallic textures are designed and loaded with pin diodes to obtain the nonlinear response, which is dependent on the power intensity of the incident wave. After the equivalent circuit analysis and full-wave simulation, a prototype is fabricated, and experiments are conducted under different power levels, which have a good coincident. The insertion loss is less than 1 dB for low-power signals in an operating band, whereas the shielding effectiveness is more than 20 dB when exposed to HPM. Both the measurement results of frequency and time domains have verified the nonlinear transmission characteristics, which demonstrated the HPM protection abilities of the proposed ESS.
      PubDate: April 2019
      Issue No: Vol. 18, No. 4 (2019)
       
  • Overcoming the Pixel-Density Limit in Plasmonic Absorbing Structure for
           Broadband Absorption Enhancement
    • Authors: Yang Shen;Jieqiu Zhang;Wenjie Wang;Yongqiang Pang;Jiafu Wang;Hua Ma;Shaobo Qu;
      Pages: 674 - 678
      Abstract: In this letter, our investigation shows that the pixel-density limit of wire element in plasmonic absorbing structure (PAS) has always been an obstacle to the achievement of broadband and highly effective absorption. Aiming at this, a comprehensive scheme of PAS based on the combination of multi-meandered wire arrays with deliberately regulated period is proposed that takes the advantage of spatial dispersion engineering to excite more multiple resonances, contributing to an enhancement of average absorbing efficiency in a wider frequency band. Simulation and experimental measurement show that our proposed combined PAS can achieve broadband absorption with the efficiency more than 90% in the frequency band of 9.0–35.0 GHz, which has 5.2% higher averaged absorbing efficiency with respect to the original PAS at the same thickness. Our strategy provides an effective way to overcome pixel-density limit for broadband absorption enhancement in PAS with simultaneous lightweight and easy-fabrication characteristics, enabling a wide range of applications.
      PubDate: April 2019
      Issue No: Vol. 18, No. 4 (2019)
       
  • A Microstrip Yagi Antenna With an Enlarged Beam Tilt Angle via a
           Slot-Loaded Patch Reflector and Pin-Loaded Patch Directors
    • Authors: Jiaqi Shi;Lei Zhu;Neng-Wu Liu;Wen Wu;
      Pages: 679 - 683
      Abstract: In this letter, a microstrip Yagi antenna with a resonating patch driver, one slot-loaded patch reflector, and two pin-loaded patch directors is proposed. Different from all the reported counterpart antennas, the lengths and widths of all the patch elements involved herein are set to be the same, and a parasitic patch reflector and patch directors are realized by loading the slot and shorting pins on the patches, respectively. For a square patch, its resonance frequency can be reduced by etching out a slot, acquiring a reflective function. However, its resonance frequency can be increased by adding a pair of shorting pins underneath the patch, thus acquiring a directive function. By placing these two types of parasitic patches in the two sides of the driving patch radiator, an alternative microstrip Yagi antenna can be constructed to achieve a quasi-endfire radiation pattern with an enlarged beam tilt angle. A prototype operating at 5 GHz is finally fabricated and tested. The measured results achieve an impedance bandwidth of 8%. In addition, the maximum deviation angle reaches approximately 56° from the broad side, and its 3 dB beamwidth in the xoy plane exceeds 62°.
      PubDate: April 2019
      Issue No: Vol. 18, No. 4 (2019)
       
  • A General-Purpose Configurable RFID Epidermal Board With a Two-Way
           Discrete Impedance Tuning
    • Authors: Carolina Miozzi;Simone Nappi;Sara Amendola;Cecilia Occhiuzzi;Gaetano Marrocco;
      Pages: 684 - 687
      Abstract: Current advances of the radio frequency identification (RFID) technology can boost the emerging class of biointegrated skin devices exploiting low-power (even passive) wireless communication and sensing interfaces. This work describes a small-size (3 cm  × 3 cm) flexible UHF RFID board conceived for the rapid laboratory experimentation and suitable to multipurpose monitoring of physical parameters (e.g., temperature and sweat) over the skin and/or over clothing layers and medical plasters. An engineered open-loop antenna is coupled with a two-way discrete (four states) tuning circuit to compensate the frequency shifts that occur in real applications due to the intrinsic variability of the human body. The capability of the tuning mechanism to down/up-shift the operating frequency and to restore the default state is validated by means of both numerical simulation and measurements over some volunteers in realistic conditions.
      PubDate: April 2019
      Issue No: Vol. 18, No. 4 (2019)
       
  • Pattern-Reconfigurable Magnetoelectric Antenna Utilizing Asymmetrical
           Dipole Arms
    • Authors: Sasan Ahdi Rezaeieh;Amin M. Abbosh;
      Pages: 688 - 692
      Abstract: Magnetoelectric (ME)-dipole antennas are designed based on Huygens source theory. ME antennas create a unidirectional radiation by the superposition of perpendicularly located magnetic and electric dipoles’ patterns. If the radiation pattern of any of these two dipoles is altered, the overall radiation pattern of the antenna will change. This phenomenon is utilized in this letter to reconfigure the radiation pattern of the ME-dipole antenna by controlling the effective lengths of the dipole's two arms. As a result, an asymmetry is created in the radiation pattern due to a stronger radiation from one arm than the other. To electronically control the arm lengths of the electric-dipole element, each arm is divided into two pieces that are connected using five strip lines. To control current flow and thus the effective length of the dipole, each line is loaded with three pin-diodes. A Г-shaped probe is utilized to adjust the antenna's matching. The measured results show that the radiation pattern can be reconfigured at ±26° on elevation plane with a peak front-to-back ratio and gain values of more than 18 dB and 6.2 dBi, respectively. Moreover, the antenna maintains wide operating bandwidth at 1–1.82 GHz with peak efficiency of 85%.
      PubDate: April 2019
      Issue No: Vol. 18, No. 4 (2019)
       
  • Low-RCS Reflectarray Antenna Based on Frequency Selective Rasorber
    • Authors: Zhanshan Sun;Qiang Chen;Min Guo;Yunqi Fu;
      Pages: 693 - 697
      Abstract: We design a low-radar-cross-section (RCS) planar reflectarray antenna by using a frequency selective rasorber (FSR). Due to the metal-backed configuration and focusing effect of the phase modulation surface, the RCS of a planar reflectarray antenna is generally quite high. Besides, an out-of-band signal focused by the reflector may cause serious interference to the system and affect the performance of facilities. To reduce the RCS of the reflectarray and suppress out-of-band interference, the FSR with a transmission window is designed and covered in front of the reflectarray. Simulation results show that the out-of-band RCS of the reflectarray is significantly reduced without affecting the radiation performance. To verify the benefits of the structure in antenna's RCS reduction (RCSR) and interference suppression, the reflectarray, the FSR, and the horn antenna work at 8.9 GHz are designed, fabricated, and measured. Measurement results show that the gain of the proposed low-RCS reflectarray antenna has only 0.3 dB decrease compared with the gain of non-FSR configuration. Meanwhile, the RCS of the proposed structure is remarkably reduced, and the –10 dB RCSR is obtained from 4 to 12.5 GHz.
      PubDate: April 2019
      Issue No: Vol. 18, No. 4 (2019)
       
  • Efficient PML Implementation for Approximate CN-FDTD Method
    • Authors: Hao Lin Jiang;Tie Jun Cui;
      Pages: 698 - 701
      Abstract: Instead of applying the standard Crank–Nicolson (CN) method, an efficient perfectly matched layer (PML) based on the CN approximate-factorization-splitting (CNAFS) scheme is proposed to terminate three-dimensional (3-D) finite-difference time-domain lattices. It can not only be free from the Courant– Friedrich–Levy limit, but also has higher efficiency than the standard CN-PML. Considering that its iteration form based on the original CNAFS scheme is still complicated, its calculation speed is further improved via introducing a series of intermediate variables. All mathematical derivations are based on the bilinear transform method to guarantee the accuracy. Finally, the absorption performance, computational efficiency, and unconditional stability of our work are verified through two 3-D numerical examples of electromagnetic waves radiating in homogeneous spaces.
      PubDate: April 2019
      Issue No: Vol. 18, No. 4 (2019)
       
  • Tunable Inverted-F Antenna Using Plasma Technologies
    • Authors: Fatemeh Sadeghikia;Mohammad Reza Dorbin;Ali Karami Horestani;Mahmoud Talafi Noghani;Hajar Ja'afar;
      Pages: 702 - 706
      Abstract: A reconfigurable and tunable inverted-F antenna (IFA) using a plasma technology is proposed. The antenna consists of a cylindrical plasma column supported by two thin conductors and a ground plane. The structure is designed and optimized to achieve a fractional bandwidth of about 10%, while the operating frequency can be tuned between 150 and 270 MHz by changing the plasma excitation power. Results of intensive investigation using numerical simulations show that the height and the feed locations of the antenna have marginal effects on the performance of the proposed antenna. The differences between the proposed structure and a conventional IFA are characterized. It is shown that by increasing the radius of the horizontal part of the antenna, the resonance frequency decreases. However, the dielectric vessel shows no considerable effect on the resonance frequency.
      PubDate: April 2019
      Issue No: Vol. 18, No. 4 (2019)
       
  • A Beamforming-Network-Based Four-Squint-Beam Array Antenna for
           Ceiling-Mount Access Point
    • Authors: Jing-Fong Keh;Ming Chou;Zhi-Chao Zhang;Qian-Xin An;Wen-Jiao Liao;
      Pages: 707 - 711
      Abstract: A novel beamforming network (BFN) applicable to a 2 × 2 array antenna is proposed in this letter. It provides four coexisting squint beams tilted away from the array's boresight and is particularly suitable for ceiling-mount access points. The principle novelty lies in the BFN, which comprises four rat-race couplers and two 90° delay lines. With this circuit, four phase offsets, which are −90°, 0°, 0°, and 90°, can be assigned to the four antennas from the four beam ports in a rotating order. To demonstrate its applicability to ceiling-mount antennas, a 2 × 2 clover-leaf array was devised. Simulations and measurements were conducted to verify the tilting beam feature. A comprehensive coverage with elevated gains can be achieved by merging receptions from the four beams, which are applicable to up-to-date multitransceiver devices.
      PubDate: April 2019
      Issue No: Vol. 18, No. 4 (2019)
       
  • Circularly Polarized Multibeam Antenna Array of ME Dipole Fed by 5
           × 6 Butler Matrix
    • Authors: Ren-Jie Gong;Yong-Ling Ban;Ji-Wei Lian;Yanhui Liu;Zaiping Nie;
      Pages: 712 - 716
      Abstract: A circularly polarized multibeam antenna array based on magnetoelectric (ME) dipole is proposed, which is fed by a substrate integrated waveguide 5 × 6 Butler matrix. There are two points that are key to completing the design—the wide axial-ratio (AR) beamwidth antenna element and the appropriate beamforming network. By adjusting the shape of the radiation patch of ME dipole, the amplitude of the orthogonal field becomes flatter at a wide angle, and the phase difference is maintained at 90°; hence, an antenna element with a wide 3 dB AR beamwidth can be achieved. In order to ensure the generation of normal beam, a 5 × 6 Butler matrix using the 3 × 3 Butler matrix is selected as the beamforming network. The proposed structure operates in the range of 27.5–28.5 GHz and generates five circularly polarized beams that cover the range of ±40°. The gain of all these beams is approximately 12.5 dBi.
      PubDate: April 2019
      Issue No: Vol. 18, No. 4 (2019)
       
  • TCM-Based Hepta-Band Antenna With Small Clearance for Metal-Rimmed Mobile
           Phone Applications
    • Authors: Ying Liu;Jiankang Zhang;Aidi Ren;Hanyang Wang;Chow-Yen-Desmond Sim;
      Pages: 717 - 721
      Abstract: A hepta-band antenna with high efficiency, small clearance, and simple structure for metal-rimmed smartphones is proposed in this letter. The proposed antenna occupies only 71 × 5 mm2 of the total clearance, and it is mainly composed of a system ground, a metal rim with two gaps, and two shorting strips. The theory of characteristic modes is used to analyze the entire structure. All resonant characteristic modes (CMs) in the target frequency are traced, and their characteristic current distributions are analyzed. By using an L-shaped capacitive exciter, three CMs are excited at the lower bands, and an inverted L-shaped branch is utilized for improving the impedance matching at higher bands. The measured 6 dB impedance bandwidths were 800–1000 and 1700–2780 MHz, respectively, and they can cover seven operating bands. The measured efficiencies were 62%–85.7% at the lower band and 66.9%–91% at the higher band.
      PubDate: April 2019
      Issue No: Vol. 18, No. 4 (2019)
       
  • Design and Analysis of a Wideband Multiple-Microstrip Dipole Antenna with
           High Isolation
    • Authors: Zhao Zhou;Zhaohui Wei;Zhaoyang Tang;Yingzeng Yin;
      Pages: 722 - 726
      Abstract: A wideband multiple-microstrip dipole antenna with dual polarization is proposed in this letter. The antenna consists of a radiator, a cross-shaped slot coupler, a pair of microstrip baluns, and a reflector. When baluns are excited, the cross-shaped slot coupler would work as a four-way equal-split power divider and generate four differential signals at four ends of the slotlines. Afterward, the signals would be coupled to four modified dipoles to radiate and synthesize slant ±45° linear polarizations. The proposed design is verified by the fabrication and testing of a prototype antenna. Measured results agree well with the simulated ones, giving a wide impedance bandwidth from 1.68 to 2.75 GHz, a high port-to-port isolation (better than 37 dB) within the operating frequency bandwidth, and a good radiation pattern. Besides, the proposed antenna maintains a compact structure measuring 0.78λ0 × 0.78λ0 × 0.18λ0.
      PubDate: April 2019
      Issue No: Vol. 18, No. 4 (2019)
       
  • Integrated-Antenna-Source of Directive Peak Electric-Field Patterns for
           High-Power Ultrawideband Parabolic Reflector System
    • Authors: Jiheon Ryu;Kiho Kim;Tae Hyun Lim;Hae-Ok Kwon;Jeong Hyeon Kuk;Jin Soo Choi;Sung-Hyun Baek;Jong-Won Yu;
      Pages: 727 - 731
      Abstract: This letter presents a directive integrated-antenna-source (DIAS) for a high-power ultrawideband parabolic reflector system. Unlike the previously developed omnidirectional integrated-antenna-source (OIAS) that leads to spillover loss in a high-power parabolic reflector system, the proposed DIAS reduces the spillover loss in the system. The DIAS is designed by cutting away the halves of the two electrodes in the OIAS. The DIAS-based reflector system was designed through numerical electromagnetic simulations. The proposed DIAS was fabricated for validation. The proposed DIAS shows 3 dB beamwidths on the H-plane and E-plane of 234° and 116°, respectively, in the peak electric-field patterns. In addition, the DIAS has a much smaller capacitance than the OIAS. The proposed DIAS-based reflector system has a peak electric-field strength of 39.5 kV/m at a distance of 40 m. The results show that, although the DIAS has a much smaller capacitance than the OIAS, the DIAS-based reflector system is capable of producing high-power electromagnetic pulses similar to those of the OIAS-based reflector system.
      PubDate: April 2019
      Issue No: Vol. 18, No. 4 (2019)
       
  • Design of Inhomogeneous All-Dielectric Electromagnetic-Wave Diffusive
           Reflectarray Metasurface
    • Authors: Mustafa K. Taher Al-Nuaimi;Yejun He;Wei Hong;
      Pages: 732 - 736
      Abstract: In this letter, inhomogeneous, single-layer, all-dielectric, nonabsorptive 1-bit and 2-bit coding diffusive reflectarray metasurfaces for nearly uniform low-level electromagnetic wave diffusion under a wide range of incident angles (up to 60°) around 12 GHz are proposed. The proposed metasurface consists of a number of small-sized dielectric reflectarrays of unit cells exhibiting a parabolic reflection phase profile, i.e., focusing reflection phase, and these reflectarrays are distributed across the metasurface aperture according to optimized 1-bit and 2-bit coding sequences to ensure a low level of diffusive scattering in all directions in the half-space in front of the surface. The proposed metasurfaces are realized using all-dielectric unit cells of subwavelength periodicity to achieve the required reflection phase correction (and effective permittivity) at each unit cell inside the small-sized dielectric reflectarrays and to realize the coding particles of the 1-bit and 2-bit coding sequences. The final design metasurface is constituted by 4 × 4 small-sized dielectric reflectarrays, and there are 25 (5 × 5) dielectric unit cells in each reflectarray. The powerfulness of the presented diffusive reflectarray metasurface and its ability to achieve low-scattering field patterns under both normal and oblique incidence are demonstrated by means of full-wave simulations and experiments.
      PubDate: April 2019
      Issue No: Vol. 18, No. 4 (2019)
       
  • Circularly Polarized Antenna With Spoof Surface Plasmon Polaritons
           Transmission Lines
    • Authors: Huidong Li;Xiaoyu Du;Tianxi Feng;Lehu Wen;Yingzeng Yin;
      Pages: 737 - 741
      Abstract: A circularly polarized (CP) antenna with spoof surface plasmon polaritons (SSPPs) transmission lines is proposed in this letter. The feeding network is based on the SSPP waveguides and parallel transmission lines. According to the dispersion characteristics of an SSPP unit and a parallel transmission line unit, a phase difference can be tuned by changing the groove depth of the SSPP unit. As a result, a feeding network is designed with SSPP waveguides to realize CP radiation. In addition, two pairs of tightly coupled dipoles are introduced as a compact radiator. The radiator and feeding network are printed on both sides of an FR4 substrate with dimensions of 85 mm × 85 mm $(0.425{{boldsymbol{lambda }}_0} times 0.425{{boldsymbol{lambda }}_0})$. A radiation structure is backed by a metallic ground to provide a unidirectional radiation pattern. To validate this design, the proposed antenna is simulated and measured. Measured results show that a wide impedance bandwidth of 49.4% from 1.19 to 1.97 GHz with a return loss of higher than 10 dB and a 3 dB axial-ratio bandwidth of 18.8% from 1.45 to 1.75 GHz is achieved.
      PubDate: April 2019
      Issue No: Vol. 18, No. 4 (2019)
       
  • A Beam-Shaping Feeding Network in Series Configuration for Antenna Array
           With Cosecant-Square Pattern and Low Sidelobes
    • Authors: Hui Chu;Peng Li;Yong-Xin Guo;
      Pages: 742 - 746
      Abstract: An SIW feeding network is proposed to achieve a cosecant-square beam pattern with low sidelobes. Different from conventional feeding networks in parallel configuration to obtain such a beam pattern, the proposed structure is in series configuration, which can provide higher transmission efficiency. Moreover, power-dividers within this feeding network can provide larger power-division ratio than conventional designs, enabling low-sidelobe levels. Vertical decoupling walls are also utilized for the acceleration of the whole design procedure. A 15 × 22 array prototype operating at Ku-band, which requires cosecant-square radiation pattern for the elevation plane and pencil-beam radiation pattern for the azimuth plane, is designed and fabricated. Measured results show that, within the target frequency range (15 GHz–16 GHz), the achieved maximum gain is larger than 27.4 dBi with sidelobe levels (SLLs) lower than 20 dB for both the elevation and azimuth planes. The excellent performance indicates that the overall design approach is very suitable for such kind of large scale antenna arrays.
      PubDate: April 2019
      Issue No: Vol. 18, No. 4 (2019)
       
  • A MIMO Dielectric Resonator Antenna With Improved Isolation for 5G mm-Wave
           Applications
    • Authors: Yin Zhang;Jing-Ya Deng;Ming-Jie Li;Dongquan Sun;Li-Xin Guo;
      Pages: 747 - 751
      Abstract: A multiple-input–multiple-output dielectric resonator antenna with enhanced isolation is proposed in this letter for the future 5G millimeter (mm)-wave applications. Two rectangular dielectric resonators (DRs) are mounted on a substrate excited by rectangular microstrip-fed slots underneath DRs. Each DR has a metal strip printed on its upper surface moving the strongest part of the coupling field away from the exciting slot to improve the isolation between two antenna elements. The proposed antenna obtains a simulated impedance bandwidth (S11 ≤ –10 dB) from 27.25 to 28.59 GHz, which covers the 28 GHz band (27.5–28.35 GHz) allocated by the Federal Communications Commission for the 5G applications. A maximum improvement of 12 dB on the isolation over 27.5–28.35 GHz is achieved. The mechanism of the isolation improvement and the design procedure are given in this letter. A prototype is manufactured and measured as a validation of the proposed decoupling method.
      PubDate: April 2019
      Issue No: Vol. 18, No. 4 (2019)
       
  • Design of Dual-Mode Arc-Shaped Dipole Arrays for Indoor Base-Station
           Applications
    • Authors: Xiangbin Miao;Wan Wan;Zhu Duan;Wen Geyi;
      Pages: 752 - 756
      Abstract: In this letter, two novel designs of dual-mode beam-steerable antenna arrays using arc-shaped dipoles are proposed for indoor base-station applications. To obtain the optimal distribution of excitations for each array, its gain and front-to-back ratio are optimized by using the method of maximum power transmission efficiency. The first design operates at 2.45 GHz and consists of a circular ring reflector and four arc-shaped dipoles, with the electrical length of one dipole arm being 1/4 wavelength. It can switch between omnidirectional mode and directional mode, and has 360° beam scanning capability in azimuth when operating in the directional mode. The realized omnidirectional gain of the first design is 1.5 dBi, and its peak gain and front-to-back ratio in the directional mode are 7.4 dBi and 15.5 dB, respectively. The second design also operates at 2.45 GHz, composed of two circular ring reflectors and eight arc-shaped dipoles distributed in two substrates, separated by a foam layer. Compared with the first design, it has a higher omnidirectional gain of 2.9 dBi and more uniform gain distribution in azimuth in the directional mode, with a peak gain of 8.4 dBi and a front-to-back ratio of 12.5 dB.
      PubDate: April 2019
      Issue No: Vol. 18, No. 4 (2019)
       
  • An Electronically Steerable Parasitic Array Radiator (ESPAR) Using
           Cavity-Backed Slot Antennas
    • Authors: Wei Ouyang;Xun Gong;
      Pages: 757 - 761
      Abstract: The electronically steerable parasitic array radiator (ESPAR) is an inexpensive way to achieve beam steering. Planar ESPARs usually exhibit narrow fractional bandwidth (FBW) in terms of both impedance matching and beam squinting. Herein, an E-plane three-element ESPAR using cavity-backed slot antennas is presented to demonstrate a wider FBW, i.e., 4%, by investigating not only S11 but also beam squinting. It is found that a tunable load which uses a fixed inductor, a varactor, and a delay line can provide a much larger impedance tuning range compared to that without the inductor. This tunable load is critical to enhance the FBW by considering beam squinting. This ESPAR is able to scan from −26° to 20° in the E-plane, operating around 5.15 GHz. The measured peak gain is between 5.52 and 6.05 dBi at all scan angles. The radiation patterns are measured at different scan angles in the E-plane. In addition, they are measured at different frequencies to demonstrate the beam squinting performance.
      PubDate: April 2019
      Issue No: Vol. 18, No. 4 (2019)
       
  • Highly Isolated Compact Planar Dual-Band Antenna With Polarization/Pattern
           Diversity Characteristics for MIMO Terminals
    • Authors: Deepika Sipal;Mahesh P. Abegaonkar;Shiban K. Koul;
      Pages: 762 - 766
      Abstract: A highly isolated two-element dual-band antenna with polarization/pattern diversity is presented in this letter for multiple-input–multiple-output (MIMO) terminals. The MIMO configuration consists of two orthogonally placed identical monopole antenna elements. In both the bands (2.3–2.5 and 5–5.2 GHz), isolation (|S21| or |S12|) ≥ 20 dB is achieved by using a simple decoupling structure. Measured impedance bandwidth of 200 and 190 MHz is achieved in the lower and upper bands, respectively. The individual antenna element has a size of 14 mm × 14 mm, and the MIMO configuration of two elements covers an area of 38 mm × 18.2  mm. Polarization diversity between the elements is achieved by placing them orthogonal to each other, whereas pattern diversity is verified through measurement of the envelope correlation coefficient and radiation patterns. The elements exhibit good efficiency and gain in spite of being compact. The measured and simulated results verify that the proposed design performs well in both the bands.
      PubDate: April 2019
      Issue No: Vol. 18, No. 4 (2019)
       
  • Wideband Circularly Polarized Antenna With Dual-Mode Operation
    • Authors: Xianling Liang;Jie Ren;Lina Zhang;Chong He;Junping Geng;Weiren Zhu;Ronghong Jin;
      Pages: 767 - 770
      Abstract: This letter presents a simple structure of a single-fed broadband circularly polarized (CP) antenna. The antenna consists of four L-shaped strips that rotate in sequence and a double vacant-quarter ring. The double vacant-quarter ring primarily contributes to the wide axial-ratio bandwidth, while the L-shaped strip primarily contributes to the wide axial-ratio beamwidth, with the two modes combined to achieve a wideband CP operation. A prototype antenna was designed, fabricated, and measured. The measured results show that the proposed antenna yields a 10 dB impedance bandwidth of 92.8$%$ (4.5–12.3 GHz), a 3 dB axial-ratio bandwidth of 67.5$%$ (5.3–10.7 GHz), and a 3 dB gain bandwidth of 62.3$%$ (5.3–10.1 GHz) with a peak gain of 12.4 dBic.
      PubDate: April 2019
      Issue No: Vol. 18, No. 4 (2019)
       
  • Prism-Based DGTD With a Simplified Periodic Boundary Condition to Analyze
           FSS With D2n Symmetry in a Rectangular Array Under Normal Incidence
    • Authors: Wending Mai;Ping Li;Huaguang Bao;Xianjin Li;Lijun Jiang;Jun Hu;Douglas H. Werner;
      Pages: 771 - 775
      Abstract: In this letter, we develop a prism-based discontinuous Galerkin time-domain (DGTD) algorithm with simplified periodic boundary conditions (PBCs) to analyze infinite doubly periodic frequency selective surfaces (FSS). Most FSS structures contain patterned planar conductive layers and supporting dielectric layers. These layers are very thin compared to the wavelength. Therefore, general tetrahedral discretization of space will unnecessarily increase the number of mesh elements, as well as the number of unknowns. Instead, we propose using prismatic elements, which are more optimal for planar structures, resulting in less unknowns, less memory usage, and higher efficiency. The accuracy of the proposed prism-based DGTD method is verified by numerical examples compared with commercial software packages. Moreover, the CPU and memory costs are also compared, demonstrating clear advantages of the proposed prism-based DGTD method.
      PubDate: April 2019
      Issue No: Vol. 18, No. 4 (2019)
       
  • Boundary Extraction Enhanced Distorted Born Iterative Method for Microwave
           Mammography
    • Authors: Kazuki Noritake;Shouhei Kidera;
      Pages: 776 - 780
      Abstract: This letter focuses on improving the accuracy of the distorted Born iterative method (DBIM)-based inverse scattering algorithm, using accurate boundary extraction in microwave mammography. It is well known that the accuracy of inverse scattering algorithms depends on the initial estimate of the region of interest (ROI). The Envelope algorithm is one of the promising algorithms for accurate ROI estimation. However, in the near-field breast imaging scenario, the coupling effect between an antenna and the breast surface incurs a nonnegligible error for Envelope-based boundary extraction, which is mainly caused by the mismatching between the reference and measured waveforms. To address this problem, this letter introduces the finite-difference time-domain-based waveform reconstruction for improving the accuracy of DBIM-based microwave imaging. The two-dimensional numerical simulations, using realistic breast phantoms derived from magnetic resonance images, demonstrate that our proposed algorithm remarkably enhances the accuracy of the DBIM, even in highly heterogeneous cases.
      PubDate: April 2019
      Issue No: Vol. 18, No. 4 (2019)
       
  • Eigenspace Structure Estimation for Dual-Polarized Massive MIMO Systems
           Using an IDM-CGF Technique
    • Authors: Debdeep Sarkar;Said Mikki;Yahia Antar;
      Pages: 781 - 785
      Abstract: In this letter, we propose an infinitesimal dipole model, cross-correlation Green's function algorithm suitable for the efficient determination of spatial correlation matrix data for massive multiple-input–multiple-output (MIMO) antennas with arbitrary element polarization and interelement spacing. Through observations of the dominant eigenspace of the massive MIMO correlation matrix, we show that one can easily assess the available degrees of freedom in channel-hardened scenario of user-equipment-to-base-station communication. We provide several examples featuring $8 times 8$ and $16 times 16$ massive MIMO arrays composed of infinitesimal dipoles, lending crucial insights into the correlation matrix eigenspace structural modifications incurred by changing element polarization, spatial positioning, and interelement spacing.
      PubDate: April 2019
      Issue No: Vol. 18, No. 4 (2019)
       
  • Differentially Coplanar-Fed Filtering Dielectric Resonator Antenna for
           Millimeter-Wave Applications
    • Authors: Chang-Wu Tong;Hui Tang;Jiang Li;Wen-Wen Yang;Jian-Xin Chen;
      Pages: 786 - 790
      Abstract: In this letter, a differentially coplanar-fed filtering dielectric resonator antenna (DRA) is proposed for millimeter-wave applications. To realize a low-profile design, a novel coplanar feeding method is presented by incorporating a dielectric resonator and its feeding structure in the same layer, which minimizes the assembly errors. The DRA is shaped by hollowing out the substrate and can be manufactured with a single-layer laminate using standard printed circuit board technology. The DRA operates at TE111 mode that is excited differentially by a pair of microstrip lines with metallic vias. The filtering function is obtained by etching two pairs of slots with different lengths in the ground plane, resulting in two radiation nulls at both upper and lower band edges. For demonstration, a prototype is designed, fabricated, and measured. Good agreement can be observed between simulated and measured results.
      PubDate: April 2019
      Issue No: Vol. 18, No. 4 (2019)
       
  • On Baseline Weighting for Radiometric Sensitivity Analysis in Microwave
           Interferometric Radiometry
    • Authors: Dong Zhu;Fei Hu;Xiaohui Peng;Hailiang Lu;
      Pages: 791 - 795
      Abstract: This letter presents a study on the effects of baseline weighting on the performance of radiometric sensitivity in interferometric aperture synthesis radiometers (IASRs). After a brief review on the computation of radiometric sensitivity, its theoretical lower bound, associated with the concept of coherent gain, is derived. We also draw attention to the performance tradeoffs between radiometric sensitivity and several spatial-domain properties of IASRs from which different weightings can be compared. Numerical examples are given to demonstrate the significance of the comparative analysis.
      PubDate: April 2019
      Issue No: Vol. 18, No. 4 (2019)
       
  • Electronically Reconfigurable 6 × 6 Element Transmitarray at K-Band Based
           on Unit Cells With Continuous Phase Range
    • Authors: Martin Frank;Fabian Lurz;Robert Weigel;Alexander Koelpin;
      Pages: 796 - 800
      Abstract: This letter describes the design and characterization of a linear polarized 6 × 6 element transmitarray providing a beam-steering range of $text{100}^circ$ at 24.6 GHz. The transmitarray is formed of unit cells providing a continuous electronically reconfigurable phase range of $text{360}^circ$ by using varactor diodes as tunable elements. The unit cell consists of four single RO4350B laminate layers. Unit cell and transmitarray have been characterized by measurements showing good agreement with the numerical results.
      PubDate: April 2019
      Issue No: Vol. 18, No. 4 (2019)
       
  • Structural Design to Control the Microwave Reflection Path in Broadband
           Frequency Using a Dielectric Material
    • Authors: Mingook Jung;Hyundo Shin;Jinwoo Park;Jeonghoon Yoo;
      Pages: 801 - 805
      Abstract: Conventional metamaterials for controlling the reflection path of electromagnetic waves have limitations, such as inevitability of thickness variation according to the frequency of the incident wave, electrical instability, and dependence on the designer. In this study, we propose a dielectric structure to control the reflection path of microwaves while overcoming those limitations. The proposed structure prevents reflected waves from returning to the wave source by scattering the incident waves. It is effective in broadband frequency without changing thickness, and electrically stable because it is composed of a dielectric material. A systematic approach called the phase field design method was employed as a design methodology to reduce the dependence on the designer. A three-dimensional (3-D) shaped prototype was fabricated using a 3-D printer, and numerical results were verified through experiments.
      PubDate: April 2019
      Issue No: Vol. 18, No. 4 (2019)
       
  • A Low-Loss W-Band Frequency-Scanning Antenna for Wideband Multichannel
           Radar Applications
    • Authors: David A. Schneider;Markus Rösch;Axel Tessmann;Thomas Zwick;
      Pages: 806 - 810
      Abstract: A class of nonresonant slotted waveguide antennas particularly suited for wideband millimeter-wave radar and imaging applications is introduced. Inspired by a variation of the classic narrow-wall leaky structure, it possesses a high degree of design flexibility and is easily integrated into steerable arrays. A reliable manufacturing concept is presented and demonstrated by means of simulations and measurements on a first prototype, complemented by an experimental evaluation of the antenna's in-system performance as part of a frequency-modulated continuous-wave radar.
      PubDate: April 2019
      Issue No: Vol. 18, No. 4 (2019)
       
 
 
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