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1993 documents found for International Journal
High-frequency diffraction contribution by planar metallic?DNG metamaterial junctions
G. Gennarelli, G. Riccio
Published online : 01-12-2020
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The plane wave diffraction by a planar junction consisting of a thick metallic sheet and a lossy double-negative metamaterial slab is studied by using the Uniform Asymptotic Physical Optics approach. This approach assumes the radiation integral as a starting point and uses the physical optics surface currents as sources to be integrated. The integral is manipulated by taking advantage of useful ap
The plane -polarized electromagnetic wave scattering by pre-fractal grating of impedance strips
George I. Koshovy
Published online : 01-12-2020
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The problem of the plane -polarized electromagnetic wave scattering by flat pre-fractal impedance strips' gratings is examined. For this purpose, a mathematical model in the form of the first kind singular integral equation system is modified for correct usage. Considerable attention is focused on the asymptotic model of the -polarized electromagnetic wave scattering by sparsely filled grating, wh
Increasing the -factor of thin planar dielectric resonator with whispering gallery modes
A. E. Kogut, M. T. Islam, E. A. Kogut, Z. E. Eremenko, R. S. Dolia
Published online : 01-12-2020
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The spectral and energy characteristics of the tunable thin planar dielectric resonator with the movable metal mirror are researched. It is found that the high--polarized whispering gallery modes (WGMs) are effectively excited in such a resonator by the dielectric waveguide. A mode set of the tunable thin planar dielectric resonator depends on the presence of an air gap in its design. Changing the
Scattering matrix solution for an ideal star-junction multiplexer based on ladder-type filters
Patricia Silveira, Jordi Verdú, Pedro de Paco
Published online : 01-12-2020
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Multiplexer design is a challenging task due to the high number of variables involved, raising the difficulty as the numbers of filters increase. Numerical computing tools provide a suitable environment to evaluate topologies and technologies before starting the long journey to the device. A direct scattering matrix solution for a star-junction multiplexer, based on the circuit theory, is presente
A highly efficient GHz switching GaN-based synchronous buck converter module
Andreas Wentzel, Oliver Hilt, Joachim Würfl, Wolfgang Heinrich
Published online : 01-12-2020
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The paper presents a highly efficient GaN-based synchronous buck converter suitable for switching in the lower GHz range. The module includes a very compact 2-stage GaN half-bridge converter MMIC (monolithic microwave integrated circuit) for low parasitic inductances between switches and drivers and a hybrid output network with core-less inductors to avoid ferrite losses. At 1 GHz switching freque
A rectangular slot antenna with perfectly conducting superstrate and reflector sheets for superior radiation in the 6?9 GHz band
Ritish Kumar, A. V. Praveen Kumar
Published online : 01-12-2020
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This paper presents the design and analysis of a rectangular slot antenna for producing a directional radiation pattern over a wide bandwidth of 6?9 GHz. A basic wideband slot antenna is designed for the desired frequency band by microstrip offset feed technique. This antenna is then loaded with a superstrate and a reflector, both made of conducting sheets. Analogous to a three-element Yagi antenn
Complementary Sierpinski Knopp fractal antenna for emergency management system
Paulkani Iyampalam, Indumathi Ganesan
Published online : 01-12-2020
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In this paper, the design and analysis of a complementary Sierpinski Knopp fractal antenna are presented. It is realized by applying the Sierpinski Knopp space-filling curve on the basic square monopole antenna. The performance metrics of the antenna such as (reflection coefficient), voltage standing wave ratio, radiation pattern, gain and current distribution at resonant frequencies are analyzed
A compact wideband circularly polarized quadrifilar antenna with PIFA elements for UHF RFID readers
Chawanat Lerkbangplad, Alongkorn Namahoot, Prayoot Akkaraekthalin, Suramate Chalermwisutkul
Published online : 01-12-2020
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In this paper, a compact circularly polarized quadrifilar antenna with planar inverted-F antenna (PIFA) elements is presented. The proposed antenna consists of four PIFA elements and a Wilkinson divider-based feed network fabricated on FR-4 substrate ( = 4.4, loss tangent = 0.02, thickness = 1.6 mm). The total size of the antenna is 120 × 120 × 13.2 mm. Impedance matching with a reflection coeffic
The 1st EuMCE 2019 Special Issue
Jan Machá?, Milan ?vanda, Jan Vrba
Published online : 01-11-2020
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MRF volume 12 issue 9 Cover and Back matter
J. Machá?, M. ?vanda, J. Vbra
Published online : 01-11-2020
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MRF volume 12 issue 9 Cover and Front matter
J. Machá?, M. ?vanda, J. Vbra
Published online : 01-11-2020
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Investigation on the scattering characteristics and unsupervised clustering of 3D printed samples
Mostafa Elsaadouny, Jan Barowski, Jochen Jebramcik, Ilona Rolfes
Published online : 01-11-2020
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In this work, the scattering characteristics of 3D-printed samples are being investigated by using a single-polarized and a cross-polarized radar system. The 3D-printed technology participates in a wide range of applications nowadays. The idea of synthetic aperture radar (SAR) has been utilized to investigate the reflected electromagnetic energy from the 3D-printed samples by setting each of the r
Drop deformation estimate with multi-polarization radar
Yuliya Averyanova, Anna Rudiakova, Felix Yanovsky
Published online : 01-11-2020
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This paper considers the ability of polarization measurements for microwave remote sensing of clouds and precipitation. The simulation of reflections from liquid hydrometeors with a multi-polarization radar system is presented. The mathematical expression of energy received by a radar antenna with arbitrary polarization is obtained. The simulation of the energy redistribution of the signal reflect
Calibration of the loop probe for the near-field measurement
Tijana Dimitrijevi?, Aleksandar Atanaskovic, Neboj?a S. Don?ov, David W. P. Thomas, Christopher Smartt, Mohd Hafiz Baharuddin
Published online : 01-11-2020
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Accurate near-field measurements for either deterministic or stochastic electromagnetic fields characterization require a relevant process that removes the influence of the probes, transmission lines, and measurement circuits. The main part of the experimental work presented here is related to a calibration procedure of a test setup consisting of a microstrip test structure and a scanning loop pro
High loss liquid dielectric characterization: Comparison of microwave waveguide and resonator measurement techniques
Z. E. Eremenko, A. I. Shubnyi, A. Y. Kogut, R. S. Dolia
Published online : 01-11-2020
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The microwave waveguide and resonator methods are compared as applied to the experimental determination of the dielectric properties of high loss liquids. A differential microwave waveguide cavity for measuring high loss liquids complex permittivity in a small volume has been designed and studied. This cavity consists of two circular waveguide cells with central rods made of quartz and surrounded
Radar for projectile impact on granular media
Felix Rech, Kai Huang
Published online : 01-11-2020
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From the prevention of natural disasters such as landslide and avalanches, to the enhancement of energy efficiencies in chemical and civil engineering industries, understanding the collective dynamics of granular materials is a fundamental question that are closely related to our daily lives. Using a recently developed multi-static radar system operating at 10 GHz (X-band), we explore the possibil
Electromagnetic communication between cells through tunneling nanotubes
Jan Pokorný, Ji?í Pokorný, Jan Vrba
Published online : 01-11-2020
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Structures of tunneling nanotubes (TNTs) of the circular cross-section of 50 and 200 nm and length up to 1 mm form a communication system between cells. While transport of material such as endocytic vesicles, mitochondria, proteins, cytoplasmic molecules, etc., is experimentally proven, a possible transfer of electric and electromagnetic energy across TNTs corresponding to electrotechnical process
Novel monopole antenna on a single AMC cell for low SAR
G. Bulla, A. A. de Salles, C. Fernández-Rodríguez
Published online : 01-11-2020
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The design, simulations, and optimized results for a novel low specific absorption rate (SAR) monopole antenna on a single artificial magnetic conductor (AMC) cell are described in this paper. Simulated results show a reduction close to 70% in the 1 g ps SAR for the developed monopole antenna with the AMC in comparison to the monopole antenna without AMC. This allows higher radiation efficiency, b
Characterization of electrolyte content in urine samples through a differential microfluidic sensor based on dumbbell-shaped defected ground structures
J. Muñoz-Enano, P. Vélez, M. Gil, E. Jose-Cunilleras, A. Bassols, F. Martín
Published online : 01-11-2020
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In this paper, a differential microfluidic sensor and comparator based on a pair of microstrip lines loaded with dumbbell-shaped defected ground structure resonators is applied to the characterization of electrolyte concentration in samples of horse urine. Since variations in the total electrolyte content in urine may be indicative of certain pathologies, the interest is to use the device as a com
Scattering of a Gaussian beam by an anisotropic-coated eccentric conducting circular cylinder
Shi-Chun Mao, Zhen-Sen Wu, Zhaohui Zhang, Jiansen Gao, Lijuan Yang
Published online : 01-11-2020
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A solution to the problem of Gaussian beam scattering by a circular perfect electric conductor coated with eccentrically anisotropic media is presented. The incident Gaussian beam source is expanded as an approximate expression in the simple form with Taylor's series. The transmitted field in the anisotropically coated region is expressed as an infinite summation of Eigen plane waves with differen
The impact of the inverse chirp -transform on breast microwave radar image reconstruction
Tyson Reimer, Mario Solis-Nepote, Stephen Pistorius
Published online : 01-11-2020
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This work examines the impact of the inverse chirp -transform (ICZT) for frequency-to-time-domain conversion during image reconstruction of a pre-clinical radar-based breast microwave imaging system operating over 1?8 GHz. Two anthropomorphic breast phantoms were scanned with this system, and the delay-multiply-and-sum beamformer was used to reconstruct images of the phantoms, after using either t
A review on circularly polarized antennas, trends and advances
Utsab Banerjee, Anirban Karmakar, Anuradha Saha
Published online : 01-11-2020
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This literature presents a comprehensive, technical review of circularly polarized (CP) antennas for different applications in wireless communication, emphasizing on the recent developments in the concerned research. The article also presents a comparative study of various works reported in the open literature, with an aim to highlight the contribution of CP antenna systems in the chronological de
Dedicated 70 MHz RF systems for hyperthermia of challenging tumor locations
Johannes Crezee, Remko Zweije, Jan Sijbrands, H. Petra Kok
Published online : 01-11-2020
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Hyperthermia (i.e. heating of tumor tissue to 40?43°C) is used in clinical oncology to enhance the therapeutic effect of chemotherapy and radiotherapy. Many tumor sites are heated either by a single RF or MW antenna positioned on the tumor location, or by a phased array positioned around the patient. Superficial tumors are generally heated with MW antennas (434?2450 MHz) and deep-seated tumors wit
An X-band gain-enhanced bidirectional antenna array using strip-loaded dielectric resonator operating in TE mode
Ling-Ling Yang, Yan-Hui Ke, Jian-Xin Chen
Published online : 01-11-2020
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A bidirectional dielectric resonator (DR) antenna array using back-to-back quasi-Yagi antenna configuration is proposed and implemented for the first time. The DR operating at higher-order TE mode is used as a magnetic dipole, applying for the driver of quasi-Yagi antenna. Due to the high-order mode employment, the antenna gain can be enhanced. By partially loading the metallic strip on the side w
Bandwidth improvement of planar antennas using a single-layer metamaterial substrate for X-band application
O. Borazjani, M. Naser-Moghadasi, J. Rashed-Mohassel, R. A. Sadeghzadeh
Published online : 01-11-2020
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To prevent far-field radiation characteristics degradation while increasing bandwidth, an attempt has been made to design and fabricate a microstrip antenna. An electromagnetic band gap (EBG) structure, including a layer of a metallic ring on a layer of Rogers 4003C substrate, is used. For a better design, a patch antenna with and without the EBG substrate has been simulated. The results show that
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