bluuebunny/crossref_metadata_2025_split huggingface dataset:
Compact stub‐loaded meander‐line antenna for wireless USB dongle devices
Authors: Byul Kim Han , Cheol Hwang Keum , Bae Park Yong 
Published: July 2010

AbstractA planar meander‐line monopole antenna was designed for wireless Universal Serial Bus (USB) dongle devices. The proposed antenna shows dual‐wideband resonant characteristics and supports the WiBro, Bluetooth, WLAN, WiMAX, and S‐DMB (Satellite Digital Multimedia Broadcast) services. The designed antenna measures 19 × 50 × 1 mm3, which is suitable for compact USB dongles. The measured 2:1 bandwidths of the voltage standing wave ratio are 18.1% (2.26–2.71 GHz) and 16.4% (5.09–6.0 GHz). The measured peak gain is 3.49 dBi, and efficiency is higher than 56%. The radiation patterns are also nearly omni‐directional. © 2010 Wiley Periodicals, Inc. Microwave Opt Technol Lett 52:2279–2282, 2010; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.25430
Small‐size internal eight‐band LTE/WWAN mobile phone antenna with internal distributed LC matching circuit
Authors: Wong Kin‐Lu , Chen Wei‐Yu , Wu Chun‐Yih , Li Wei‐Yu 
Published: July 2010

AbstractA coupled‐fed planar inverted‐F antenna (PIFA) to be mounted at the small no‐ground portion of the system circuit board of the mobile phone with a low profile of 10 mm to the system ground plane and a thin profile of 3 mm to the system circuit board is presented.The proposed small‐size PIFA is formed by a simple structure of two radiating strips of different lengths, both capacitively fed by a coupling feed and short circuited to the system ground plane by a shorting strip. The coupling feed and shorting strip together function as an internal distributed LC matching circuit, with the coupling feed as a capacitive element and the shorting strip as an inductive element. This internal distributed LC matching circuit has an equivalent layout as the conventional external high‐pass LC matching circuit with lumped elements; both are effective in tuning the antenna's lower band bandwidth. In addition, the antenna with the proposed internal distributed LC matching circuit, in this study, can lead to much widened bandwidths in both the antenna's lower and upper bands to cover the 698–960 and 1710–2690 MHz bands, respectively. That is, eight‐band LTE/WWAN operation can be achieved. Results of the proposed antenna with the internal distributed LC matching circuit are presented. © 2010 Wiley Periodicals, Inc. Microwave Opt Technol Lett 52:2244–2250, 2010; Published online in Wiley InterScience (www.interscience. wiley.com). DOI 10.1002/mop.25431
New stubless compact low‐pass filter using lumped shunt capacitors and coupled slots
Authors: Abdel‐Rahman Adel 
Published: July 2010

AbstractThis article introduces an improved performance stubless low‐pass filter by using lumped capacitors as shunt capacitances elements.The filter has a cut off frequency of 4 GHz and a wide stopband up to more than 13 GHz with a rejection better than 26 dB. The measured insertion loss of the filter within the passband is less than 0.3 dB. The filter has a length of just 6.5 mm. The experimental results agree well with the predicted ones. © 2010 Wiley Periodicals, Inc. Microwave Opt Technol Lett 52:2209–2212, 2010; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.25434
Walking intrusion signal recognition method based on gait characteristic for fiber fence system
Authors: Fang Nian , Wang Lutang , Jia Dongjian , Shan Chao , Huang Zhaoming 
Published: July 2010

AbstractA recognition method based on the gait characteristic for walking intrusion signal of a fiber fence system is presented, which can reduce the rate of false alarm. The gait characteristic of human is mainly embodied in an intermittent and quasi‐periodic contact with the floor when he walks. It can be expressed in terms of step period and foot‐strike time. They are, on average, about 0.63 s and 0.2 s for a normal walker in the nature state, respectively. According this intermittent and quasi‐periodic feature and local characteristic gait times imbedded in a fiber fence system output waveform, a disturbance source can be adjudged as a human intrusion, not as an animal or other random one. Two types of experimental results show that the proposed method is effective and universal for different systems and races. © 2010 Wiley Periodicals, Inc. Microwave Opt Technol Lett 52:2381–2384, 2010; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.25437
Band‐pass filters using high‐permittivity ceramics substrate
Authors: Huang Cheng‐Liang , Tasi Shin‐Tung , Chen Yuan‐Bin 
Published: July 2010

AbstractThe miniaturization of ring band‐pass filters by employing high‐permittivity ceramic substrates (with respective dielectric constants of 9.7 and 23.5) are investigated. Microwave dielectric ceramics with high‐permittivity are commonly applied in several microwave communication components. With the advantages of compact size, high‐permittivity ceramics can be used as the substrate for band‐pass filters. Moreover, the fundamental characteristics of newly developed compact ring resonators have also been described and applied to the design of band‐pass filters. In this article, the designed ring resonators structures are simulated using an HFSS simulator. The responses of the fabricated band‐pass filters using Al2O3 (εr = 9.7, tanδ = 0.0001) and 0.875Mg0.95Zn0.05TiO3‐0.125Ca0.8Sm0.4/3TiO3 (εr = 23.5, tanδ = 0.000083) ceramic substrates are designed at the center frequency of 2.4 GHz. This compact size, low loss band‐pass filter should be useful in many wireless communication systems. © 2010 Wiley Periodicals, Inc. Microwave Opt Technol Lett 52:2344–2347, 2010; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.25439
Dielectric properties characterization of high dielectric constant thick films
Authors: Demenicis Luciene S. , Marulanda José Ignacio , Lima Rodolfo A. A. , Carvalho Maria Cristina R. 
Published: July 2010

AbstractA technique for the characterization of microwave dielectric properties of high dielectric constant thick films at room temperature is proposed, using multilayered coplanar waveguide transmission lines with high dielectric constant thick films deposited over the lines.Besides the simplicity, the technique allows the characterization of the films under similar conditions to those in which they will operate as compact devices in multilayered configurations. Time domain analysis and experimental results for 61‐micron thick Barium Titanate films have confirmed the relative dielectric constant and loss tangent values (respectively, 100 and 0.3) predicted by the frequency domain characterization proposed. © 2010 Wiley Periodicals, Inc. Microwave Opt Technol Lett 52:2339–2344, 2010; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.25440
Bandwidth enhancement of a planar sleeve monopole antenna for wireless communication applications
Authors: Zuo Shaoli , Zhang Zhiya , Yin Yingzeng 
Published: July 2010

AbstractA planar sleeve monopole antenna for bandwidth enhancement is proposed and experimentally studied.By embedding a concavity sleeve in the ground plane and etching two pairs of L‐shaped slots on a printed circuit board, it is found that the operating bandwidth can be significantly enhanced and the impedance bandwidth could cover the GSM, DCS, PCS, ISM/Bluetooth (2400–2480 MHz), WLAN (2400–2484 MHz), and WiMAX (2500–2690 MHz) bands. By using a capacity load on the top of the antenna, the dimension of the antenna is reduced largely. The proposed antenna has good omnidirectional radiation characteristics and achieves gains to be 2.6, 3.2, and 3.5 dBi at 900, 1800, and 2450 MHz, respectively. © 2010 Wiley Periodicals, Inc. Microwave Opt Technol Lett 52:2235–2238, 2010; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.25445
A compact pentagonal monopole antenna for portable UWB systems
Authors: Thomas Paulbert , Gopikrishna M. , Aanandan C. K. , Mohanan P. , Vasudevan K. 
Published: July 2010

AbstractDesign of a compact microstrip‐fed ultra‐wideband antenna suitable for USB dongle and other such space constraint applications is presented. The structure consists of a pentagonal monopole element and a modified ground plane that gives an impedance bandwidth from 2.8 to 12 GHz. Radiation patterns are stable and omni‐directional throughout the band with an average gain of 2.84 dBi. The antenna occupies only 11 × 30 mm2 on FR4 substrate with permittivity 4.4. © 2010 Wiley Periodicals, Inc. Microwave Opt Technol Lett 52:2390–2393, 2010; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.25449
Circularly polarized space‐fed microstrip antenna arrays
Authors: Bhide Rahul , Kumar Girish 
Published: July 2010

AbstractA high‐gain circularly polarized microstrip antenna array is proposed using space‐fed configuration. In planar arrays, the design of feed network to generate circular polarization becomes extremely complex. The proposed configuration eliminates the feed network, which gives high efficiency and gain. Simulated and measured results are presented. © 2010 Wiley Periodicals, Inc. Microwave Opt Technol Lett 52:2221–2223, 2010; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.25451
DUAL‐BAND antenna for WLAN/UWB applications
Authors: Park Sang Yong , Jeong Oh Seon , Park Jong Kweon 
Published: July 2010

AbstractIn this article, we have proposed a dual‐band (WLAN/UWB) antenna with open stub for WLAN/UWB applications. The designed dual‐band antenna consists of a rectangular radiating patch, open stub, three steps for impedance matching, and coplanar waveguide feeding. The proposed antenna is fabricated and measured. Parametric studies and radiation characteristics for the designed antenna were presented. The designed antenna has the characteristics of wide bandwidth and negligible dispersion over the UWB frequency band and omnidirectional characteristics in the WLAN band. © 2010 Wiley Periodicals, Inc. Microwave Opt Technol Lett 52:2188–2191, 2010; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.25452
Compact wide upper‐stopband BPF using open stub loaded dual‐mode resonator
Authors: Deng Hong‐Wei , Zhao Yong‐Jiu , Zhang Xue‐Shun , Zhang Lu , Gao Si‐Ping 
Published: July 2010

AbstractA novel compact bandpass filter (BPF) with good in band and wide upper‐stopband performances is realized using open stub loaded dual‐mode resonator.The resonator generates two operating modes in the desired band and the even‐mode resonance frequency can be flexibly controlled by the disc‐shaped open stub at central plane, whereas the odd‐mode one is fixed. By simply adjusting the dimension of the disc‐shaped open stub, the even resonant mode falls down and works together with the odd mode to form a BPF. Two other pairs of open stubs are mainly applied to suppress the high harmonic resonant modes and obtain good match, respectively. Experimental results of the fabricated filter show good agreement with the simulated results. © 2010 Wiley Periodicals, Inc. Microwave Opt Technol Lett 52:2185–2188, 2010; Published online in Wiley InterScience (www.interscience. wiley.com). DOI 10.1002/mop.25453
On the comparison between multiple‐region and dual‐grid finite‐difference time‐domain methods for the analysis of antenna arrays
Authors: Pascaud Romain , Gillard Raphaël , Loison Renaud 
Published: July 2010

AbstractA comparison between the multiple‐region (MR) and dual‐grid (DG) finite‐difference time‐domain (FDTD) methods for the analysis of antenna arrays is presented.The application of both methods shows that the DG‐FDTD method is more accurate when computing the mutual coupling between antennas. Besides, it exhibits multi‐surface capabilities that make possible the fast and accurate analysis of antenna arrays, including mutual coupling and edge effects. © 2010 Wiley Periodicals, Inc. Microwave Opt Technol Lett 52:2316–2319, 2010; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.25456
Negative refraction imaging by three‐dimensional metamaterial at microwave frequencies
Authors: Zhao Wangshi , Lu Zhaolin 
Published: July 2010

AbstractWe experimentally demonstrate negative refraction imaging at microwave frequencies by a three‐dimensional (3D) metamaterial with simple cubic unit structure, which is fabricated based on the electronic textile technology.A four‐layer metamaterial sample was tested in a series of experiments. The experimental result of the characteristic plasma frequency of the metamaterial was in good agreement with the theoretical result. The fabrication approach for 3D metamaterial may find many novel applications at microwave frequencies. © 2010 Wiley Periodicals, Inc. Microwave Opt Technol Lett 52:2253–2256, 2010; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.25459
Bandwidth enhancement of a coplanar waveguide‐fed asymmetrical slot antenna with a rectangular patch
Authors: Fan Shou‐Tao , Yin Ying‐Zeng , Kang Le , Wei Shi‐Ju , Wang Yao‐Zhao , Song Kun 
Published: July 2010

AbstractA coplanar waveguide‐fed asymmetrical slot antenna with a rectangular patch for bandwidth enhancement is demonstrated.By attaching a rectangular patch to the monopole radiating element, a good performance of bandwidth enhancement for the antenna is achieved. From simulational and experimental results, the enhanced impedance bandwidth of the proposed antenna, defined by −10 dB return loss, can reach 13.1 GHz, from 2.4 to 15.5 GHz, or about 146% with the center frequency 8.95 GHz, which makes it an excellent candidate for the ultra wideband (UWB, 3.1–10.6 GHz) applications. © 2010 Wiley Periodicals, Inc. Microwave Opt Technol Lett 52:2259–2261, 2010; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.25476
Broadband, high‐gain complementary‐symmetry microstrip array antenna
Authors: Sameena N. M. , Konda R. B. , Mulgi S. N. 
Published: July 2010

AbstractA novel complementary‐symmetry microstrip array antenna is presented for broadband operation. The maximum impedance bandwidth of 132.12% and high gain of 10.08 dB is achieved. The radiation patterns are found broadsided across the entire operating band. The design concept of the antenna is described and the experimental results are discussed. The proposed antenna may find applications for the systems operating from C to Ku (3.9 to 18 GHz) band of frequencies. © 2010 Wiley Periodicals, Inc. Microwave Opt Technol Lett 52:2256–2258, 2010; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.25477
Compact ultra‐wideband CPW‐FED printed semicircular slot antenna
Authors: Ranga Y. , Esselle Karu P. , Weily A. R. 
Published: July 2010

AbstractA new compact configuration of a printed CPW‐fed semicircular slot antenna with a CPW‐to‐CPW step transition is presented. Its bandwidth is enhanced for ultra‐wideband (UWB) operation by combining linear and stepped CPW‐to‐CPW transitions along the feed line. Its measured 10 dB return loss bandwidth is 3.1–13.8 GHz (126%). This, together with its nearly constant measured gain of 3.5 dBi ± 1 dB from 3 to 10 GHz, makes it suitable for UWB applications. Details of the proposed antenna are described, and both theoretical and experimental results are presented. © 2010 Wiley Periodicals, Inc. Microwave Opt Technol Lett 52:2367–2372, 2010; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.25481
Compact waveguide bandpass and bandstop filters using negative index material concepts
Authors: Lam Tai , Greegor Robert B. , Parazzoli Claudio G. , Tanielian Minas H. 
Published: July 2010

AbstractSplit ring resonators (SRR) and complementary SRRs (CSRR) are used to design bandstop and bandpass filters in waveguides. These filters are more compact than existing waveguide filters and have no appreciable weight of their own. They have been fabricated and tested showing good agreement between simulations and experiments. © 2010 Wiley Periodicals, Inc. Microwave Opt Technol Lett 52:2336–2339, 2010; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.25482
Millimeter‐wave power module combiner junction for high resolution advanced radar and communications
Authors: Spears M. , Van Gorden C. , Wehnes D. , Song H. 
Published: July 2010

AbstractPower combiner junctions based on hybrid waveguide structures were designed, fabricated, and characterized for advanced radar and communications millimeter‐wave power modules.Various structures of the four port combiners were investigated at Ka‐ and V‐bands. The measurement results were compared with the three‐dimensional full wave finite element method solutions. © 2010 Wiley Periodicals, Inc. Microwave Opt Technol Lett 52:2227–2231, 2010; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.25488
Balanced SSFP transient imaging using variable flip angles for a predefined signal profile
Authors: Worters Pauline W. , Hargreaves Brian A. 
Published: July 2010

AbstractVariable flip angles are used in steady‐state free precession (SSFP) acquisitions (e.g., time‐of‐flight) but to a lesser extent than in spin echo acquisitions. In balanced steady‐state free precession, imaging is often assumed to occur during the steady state, which has been well described in the literature. However, in many cases, imaging occurs during the transient stage, and the use of variable flip angles can improve signal and thus image quality. Here, we present the calculation of flip angles in transient balanced steady‐state free precession to generate a predefined signal profile. The signal profile was iteratively optimized to maximize the integral of the signal versus time curve. The key contribution of this work is the formulation of the flip angle as a deterministic function of the preceding and desired magnetization. Catalyzation schemes, e.g., Kaiser‐windowed ramp, can be combined with variable flip angles balanced steady‐state free precession to reduce signal oscillations. A uniform signal profile was used as an example to demonstrate the variable flip angle algorithm. Accuracy of the algorithm and Bloch simulations were verified with MRI phantom acquisitions. Renal angiograms were acquired using an inflow‐based balanced steady‐state free precession MR angiography technique; improved small‐vessel depiction was observed in volunteer examinations. Magn Reson Med, 2010. © 2010 Wiley‐Liss, Inc.
Fast 3D chemical exchange saturation transfer (CEST) imaging of the human brain
Authors: Zhu He , Jones Craig K. , van Zijl Peter C. M. , Barker Peter B. , Zhou Jinyuan 
Published: July 2010

AbstractChemical exchange saturation transfer magnetic resonance imaging can detect low‐concentration compounds with exchangeable protons through saturation transfer to water. This technique is generally slow, as it requires acquisition of saturation images at multiple frequencies. In addition, multislice imaging is complicated by saturation effects differing from slice to slice because of relaxation losses. In this study, a fast three‐dimensional chemical exchange saturation transfer imaging sequence is presented that allows whole‐brain coverage for a frequency‐dependent saturation spectrum (z‐spectrum, 26 frequencies) in less than 10 min. The approach employs a three‐dimensional gradient‐ and spin‐echo readout using a prototype 32‐channel phased‐array coil, combined with two‐dimensional sensitivity encoding accelerations. Results from a homogenous protein‐containing phantom at 3T show that the sequence produced a uniform contrast across all slices. To show translational feasibility, scans were also performed on five healthy human subjects. Results for chemical exchange saturation transfer images at 3.5 ppm downfield of the water resonance, so‐called amide proton transfer images, show that lipid signals are sufficiently suppressed and artifacts caused by B0 inhomogeneity can be removed in postprocessing. The scan time and image quality of these in vivo results show that three‐dimensional chemical exchange saturation trasfer MRI using gradient‐ and spin‐echo acquisition is feasible for whole‐brain chemical exchange saturation transfer studies at 3T in a clinical time frame. Magn Reson Med, 2010. © 2010 Wiley‐Liss, Inc.
Quarzmikrowaage für elektrochemische Anwendungen
Authors: Wudy Franz , Bublitz Dirk 
Published: July 2010

AbstractFranz Wudy, Dirk BublitzImpedanzspektroskopisch vermessen, lassen sich Schwingquarze auch in flüssigen Medien verwenden und detektieren Masseänderungen im Nanogrammbereich.
Uran und Fluor – zwei eng verwobene Elemente
Authors: Kraus Florian 
Published: July 2010

AbstractFlorian KrausUran und Fluor sind heute zwei intensiv genutzte Elemente. Seit mehr als 50 Jahren bildet UF6das zentrale Element bei der Isotopentrennung des Urans. Gegenwärtig lagern große Mengen abgereichertes UF6 ungenutzt − eine Chance für die moderne Fluorchemie.
Neues aus dem Reich der Viren
Authors: Gross Michael 
Published: July 2010

AbstractMichael GroßViren spielen eine Rolle für die Nahrungsketten in der Tiefsee, und sie können andere Viren befallen: Das waren vor kurzem zwei Entdeckungen in schneller Folge. Außerdem lässt sich gegen von Viren erzeugte Krankheiten wie Grippe wohl bald effektiver vorbeugen.
An Wert verloren – Chancen gewonnen
Authors: Hübel Marcus 
Published: July 2010

AbstractMarcus HübelDie chemische Industrie spürt die sinkende Nachfrage in Märkten wie der Automobil‐, Bau‐ und Textilindustrie − nicht nur in den USA. Die Chemiebranche erwartet ein durch die globale Finanzkrise verschlechtertes Geschäftsumfeld.
Anisotropic viscoplastic modeling of rate‐dependent behavior of clay
Authors: Ou C. Y. , Liu C. C. , Chin C. K. 
Published: July 2010

AbstractThe objective of this study is to derive an effective stress‐based constitutive law capable of predicting rate‐dependent stress–strain, stress path and undrained shear strength and creep behavior. The flow rule used in the MIT‐E3 model and viscoplasticity theory is employed in the derivation. The model adopts the yield surface capable of representing the yield behavior of the Taipei silty clay and assumes that it is initially symmetric about the K0‐line. A method is then developed to compute the gyration and expansion of the loading surface to simulate the anisotropic behavior due to the principal stress rotation after shear. There are 11 parameters required for the model to describe the soil behavior and six of them are exactly the same as those used in the Modified Cam‐clay model. The five additional parameters can be obtained by parametric studies or conventional soil tests, such as consolidation tests, triaxial compression and extension tests. Finally, verification of the model for the anisotropic behavior, creep behavior and the rate‐dependent undrained stress–strain and shear strength of the Taipei silty clay is conducted. Copyright © 2010 John Wiley & Sons, Ltd.
A thermo‐hydro‐mechanical model for unsaturated soils based on the effective stress concept
Authors: Dumont Matthieu , Taibi Said , Fleureau Jean‐Marie , Abou‐Bekr Nabil , Saouab Abdelghani 
Published: July 2010

AbstractA simple thermo‐hydro‐mechanical (THM) constitutive model for unsaturated soils is described. The effective stress concept is extended to unsaturated soils with the introduction of a capillary stress. This capillary stress is based on a microstructural model and calculated from attraction forces due to water menisci. The effect of desaturation and the thermal softening phenomenon are modelled with a minimal number of material parameters and based on existing models. THM process is qualitatively and quantitatively modelled by using experimental data and previous work to show the application of the model, including a drying path under mechanical stress with transition between saturated and unsaturated states, a heating path under constant suction and a deviatoric path with imposed suction and temperature. The results show that the present model can simulate the THM behaviour in unsaturated soils in a satisfactory way. Copyright © 2010 John Wiley & Sons, Ltd.