bluuebunny/crossref_metadata_2025_split huggingface dataset:
Small‐size coupled‐fed shorted T‐monopole for internal WWAN antenna in the thin‐profile mobile phone
Authors: Chen Wei‐Yu , Wong Kin‐Lu 
Published: December 2009

AbstractA coupled‐fed shorted T‐monopole with a small size of 15× 26 mm2 (390 mm2) printed on the system circuit board of the mobile phone for WWAN operation is presented. By using a simple inverted‐L feeding strip to capacitively excite the shorted T‐monopole, two wide operating bands at about 900 and 1900 MHz, respectively, to cover GSM850/900 and GSM1800/1900/UMTS operations are obtained. The antenna is an all‐printing structure, with no external matching circuit on the system circuit board or lumped circuit elements embedded in the antenna required for size reduction or bandwidth enhancement. The antenna is hence easy to fabricate at low cost and is especially suited for thin‐profile mobile phone applications. The occupied area (less than 400 mm2) of the antenna printed on the system circuit board of the mobile phone in this study is among the smallest for the internal uniplanar printed antenna capable of penta‐band WWAN operation that have been reported. Details of the proposed antenna are described, and the obtained results, including its SAR (specific absorption rate) study, are presented and discussed. © 2009 Wiley Periodicals, Inc. Microwave Opt Technol Lett 52: 257–262, 2010; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.24907
Fiber Bragg grating sensor network based on code division multiple access using a reflective semiconductor optical amplifier
Authors: Ko Jongkyung , Kim Youngbok , Park Chang‐Soo 
Published: December 2009

AbstractWe propose a multiplexed fiber Bragg grating sensor network based on code division multiple access (CDMA) using a self‐injection locked reflective semiconductor optical amplifier. The proposed system shows improved scanning time without requiring a tunable laser source or a Fabry‐Perot filter. CDMA was used to separate each reflected sensor signal and it shows a high dynamic range of over 40°C and a crosstalk ratio of 27.7:1. © 2009 Wiley Periodicals, Inc. Microwave Opt Technol Lett 52: 378–381, 2010; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.24913
The design of high‐performance Doherty power amplifier
Authors: Xiang Yong‐Bo , Wang Guang‐Ming 
Published: December 2009

AbstractThe article presents a Doherty power amplifier (DPA) with both high efficiency and good linearity for GSM base station using LDMOS transistors. Prepositive delay line structure (PDL) is proposed to satisfy the performances, both higher efficiency and better linearity are achieved. The test results show the proposed DPA reached an efficiency of 43.2% and an IMD3 of −47 dBc at 6 dB back‐off power, which is about 19% and 6.5 dBc improvement, respectively than the class AB amplifier, and the improvement is about 4% and 12 dBc, respectively compared with the DPA without PDL structure. © 2009 Wiley Periodicals, Inc. Microwave Opt Technol Lett 52: 493–495, 2010; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.24917
Analysis of frequency response of wire bond configurations joining two 50‐Ω microstrip lines
Authors: Mulcahy T. , Song H. 
Published: December 2009

AbstractSmall to medium length wirebond interconnects, which range approximately from 300 to 660 μm are investigated. Wirebond S‐parameters are measured using a parametric vector network analyzer with respect to a 50‐Ω system. Results show that there is degrading performance with increasing wirebond length and decreasing number of bonds. © 2009 Wiley Periodicals, Inc. Microwave Opt Technol Lett 52: 487–490, 2010; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.24919
A 3.51‐to‐3.8 GHz divide‐by‐3 injection‐locked frequency divider
Authors: Chiang Yen‐Chung , Wu Ming‐Fong 
Published: December 2009

AbstractThis article proposes a divide‐by‐3 frequency divider (FD) with quadrature outputs fabricated in the 0.18‐μm CMOS technology. The current reuse and the back‐gate coupling techniques are adopted. Measured results show that the free‐running frequency is from 1.173 to 1.25 GHz. The proposed FD can cover the input frequency from 3.51 to 3.8 GHz at the incident power of −3 dBm. © 2009 Wiley Periodicals, Inc. Microwave Opt Technol Lett 52: 490–493, 2010; Published online in Wiley InterScience (www.interscience. wiley.com). DOI 10.1002/mop.24920
Folded monopole antenna for handheld devices
Authors: Rao Qinjiang , Wen Geyi 
Published: December 2009

AbstractThis article presents a new multiband antenna for handheld devices. The antenna consists of three branches of folded monopoles, and it is designed to operate at most application bands used currently, such as GSM 850/900/1800/1900, UMTS2100, and WLAN 5GHz. The simulated and measured results validate the proposed design. The proposed antenna has better performances than other embedded antenna designs of the same maximum dimension. © 2009 Wiley Periodicals, Inc. Microwave Opt Technol Lett 52: 421–425, 2010; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.24930
A C‐band wideband 360° analog phase shifter design
Authors: Xiao M. X. , Cheung S. W. , Yuk T. I. 
Published: December 2009

AbstractThis article proposes a reflection‐type wideband 360° analogue phase shifter in microstrip form. It employs a 3‐dB branch‐line coupler circuit to achieve a wideband operation and two varactor‐diode circuits to achieve 360° phase shift. Formulas are derived to optimize the dimensions of the microstrip lines in the coupler and the varactor‐diode circuits for wideband operation and minimizing frequency dependency of the output phase. Experimental results show that the design has a 360° phase‐shift range and 1 dB insertion loss, with a 500‐MHz operation bandwidth at the center frequency of 6.5 GHz. ©2009 Wiley Periodicals, Inc. Microwave Opt Technol Lett 52: 355–359, 2010; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.24938
Enhanced EMI shielding efficiency using carbon, graphite, and polyaniline blends
Authors: Mathew Kattackal T. , Kalappura Ullas G. , Augustine Robin , Laheurte Jean‐Marc , Lakshmi Kaimal 
Published: December 2009

AbstractConducting polymers have found significant applications in the past decade in industrial, scientific, and medical (ISM) fields. The characteristic features of conducting polymers like reversible proton doping, variable conductivity, facile synthesis, and low cost make them potential candidates in various microelectronic applications. Conventional microwave absorbing materials such as carbon and graphite in the powder form were blended with polyaniline as base at different proportions and microwave properties such as transmission, reflection, and shielding efficiency (SE) were evaluated from S parameter measurements using HP 8714ET network analyzer. The newly developed polyaniline blend exhibits high‐electromagnetic interference shielding efficiency when compared with previously developed materials and is a promising candidate for shielding applications. © 2009 Wiley Periodicals, Inc. Microwave Opt Technol Lett 52: 393–397, 2010; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.24939
Compact microstrip low‐pass filter using complementary split ring resonators with ultra‐wide stopband and high selectivity
Authors: Zeng Hui‐Yong , Wang Guang‐Ming , Zhang Chen‐Xin , Zhu Li 
Published: December 2009

AbstractThe transmission characteristic of the microstrip with complementary split ring resonator (CSRR) is researched. Compared with the conventional structure, this filter can achieve a wider bandgap by shifting the gap of CSRR from the side of the microstrip to the underside. And then, a lower transmission zero can be realized by loading a pair of narrow slots in the gap of the ring. The equivalent circuit model of the structure is provided. By cascading CSRR cells with different transmission zeros, a ultra‐wide bandgap low‐pass filter (LPF), which has a cutoff frequency at 4.3 GHz is designed. The designed LPF has a high performance with an insertion loss lower than 0.3 dB in pass band, a high out‐band suppression more than 20 dB (4.55–25 GHz), and a very sharp transition band about 0.25 GHz (4.3–4.55 GHz). © 2009 Wiley Periodicals, Inc. Microwave Opt Technol Lett 52: 430–433, 2010; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.24942
Designs of ultra wideband (UWB) printed elliptical monopole antennas with slots
Authors: Zhang Hualiang , Zhou Rongguo , Wu Ziran , Xin Hao , Ziolkowski Richard W. 
Published: December 2009

AbstractPrinted elliptical monopole antennas are discussed for ultra wideband (UWB) applications. To enhance the design flexibility of the UWB antennas, two slots are incorporated along the edges of the elliptically shaped monopole. By adjusting the size of the slots, the overall performance of the proposed antenna can be improved. Full wave electromagnetic simulations have been used to investigate the effects of different parameters (feed‐line length, monopole shape, etc.) on the antenna performance. To verify the design concept, a prototype antenna was designed on the Rogers' RT/Duroid 5880 substrate, fabricated and characterized experimentally. The measured properties of the antenna, including return loss, radiation pattern, and gain, show good agreement with the predicted UWB behavior. Moreover, as a result of the flexibility provided by the proposed designs, an antenna that incorporates a notch frequency within the UWB band is easily achieved. This notch‐filter antenna design is also presented along with its simulated performance. © 2009 Wiley Periodicals, Inc. Microwave Opt Technol Lett 52: 466–471, 2010; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.24943
Linear random vibration by stochastic reduced‐order models
Authors: Grigoriu Mircea 
Published: December 2009

AbstractA practical method is developed for calculating statistics of the states of linear dynamic systems with deterministic properties subjected to non‐Gaussian noise and systems with uncertain properties subjected to Gaussian and non‐Gaussian noise. These classes of problems are relevant as most systems have uncertain properties, physical noise is rarely Gaussian, and the classical theory of linear random vibration applies to deterministic systems and can only deliver the first two moments of a system state if the noise is non‐Gaussian.The method (1) is based on approximate representations of all or some of the random elements in the definition of linear random vibration problems by stochastic reduced‐order models (SROMs), that is, simple random elements having a finite number of outcomes of unequal probabilities, (2) can be used to calculate statistics of a system state beyond its first two moments, and (3) establishes bounds on the discrepancy between exact and SROM‐based solutions of linear random vibration problems. The implementation of the method has required to integrate existing and new numerical algorithms. Examples are presented to illustrate the application of the proposed method and assess its accuracy. Copyright © 2009 John Wiley & Sons, Ltd.
Doping of processable conducting poly(m‐aminophenol) with silver nanoparticles
Authors: Kar Pradip , Pradhan Narayan C. , Adhikari Basudam 
Published: December 2009

AbstractProcessable poly(m‐aminophenol) (PmAP) was synthesized using ammonium persulfate (APS) oxidant in 0.6 M sodium hydroxide solution at room temperature. Soluble silver hydroxide ammonium complex was formed by dissolving silver nitrate in excess liquor ammonia and the thermal decomposition of this complex easily produced silver nanoparticle. Then, in situ silver nanoparticle‐doped PmAP film was obtained by casting PmAP film from dimethyl sulfoxide (DMSO) with silver hydroxide ammonia complex mixture at 140°C. The nanocomposite was characterized by ultraviolet‐visible spectroscopy, Fourier transformed spectroscopy, transmission electron microscopy (TEM), scanning electron microscopy, electron dispersion spectroscopy, thermogravimetric analysis, and X‐ray diffraction analysis. The average size of the nanoparticle was around 130–140 nm as confirmed by the TEM analysis. Synthesized PmAP silver nanocomposite showed the highest DC‐conductivity of 1.03 × 10−6 S/cm. From the above characterizations, it can be said that silver nanoparticle shows some doping effect on the conductivity of PmAP. The doping level of the silver nanoparticle inside the polymer was optimized in terms of DC‐conductivity of the silver nanoparticle‐doped PmAP film. Copyright © 2009 John Wiley & Sons, Ltd.
A review on wound dressings with an emphasis on electrospun nanofibrous polymeric bandages
Authors: Zahedi Payam , Rezaeian Iraj , Ranaei‐Siadat Seyed‐Omid , Jafari Seyed‐Hassan , Supaphol Pitt 
Published: December 2009

AbstractWound dressings have experienced continuous and significant changes since the ancient times. The development starts with the use of natural materials to simply cover the wounds to the materials of the present time that could be specially made to exhibit various extraordinary functions. The modern bandage materials made of electrospun biopolymers contain various active compounds that are beneficial to the healing of wounds. These materials are fibrous in nature, with the size of fibers segments ranging from tens of nanometers to micrometers. With the right choices of biopolymers used for these fibrous materials, they could enhance the healing of wounds significantly compared with the conventional fibrous dressing materials, such as gauze. These bandages could be made such that they contain bioactive ingredients, such as antimicrobial, antibacterial, and anti‐inflammatory agents, which could be released to the wounds enhancing their healing. In an active wound dressing (AWD), the main purpose is to control the biochemical states of a wound in order to aid its healing process. This review provides an overview of different types of wounds, effective parameters in wound healing and different types of wound dressing materials with a special emphasis paid to those prepared by electrospinning. Copyright © 2009 John Wiley & Sons, Ltd.
Cyclic polymers: Synthetic strategies and physical properties
Authors: Kricheldorf Hans R. 
Published: December 2009

AbstractSyntheses of cyclic polymers including cyclic homopolymers, cyclic block copolymers, sun‐shaped polymers, and tadpole polymers are discussed on the basis of a differentiation between synthetic methods and synthetic strategies (e.g., polycondensation, ring–ring equilibration, or ring‐expansion polymerization). Furthermore, all synthetic methods are classified as kinetically or thermodynamically controlled reactions. Characteristic properties of cyclic polymers such as smaller hydrodynamic volume, lower melt viscosities, and higher thermostabilities are compared to the properties of their linear counterparts. Furthermore, the nanophase separation of cyclic diblock copolymers is discussed. © 2009 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 48: 251–284, 2010
Ethylene polymerization by the chromium catalysts based on bidentate [O, PO] or [S, P] ligands
Authors: He Li‐Peng , Mu Hong‐Liang , Li Bai‐Xiang , Li Yue‐Sheng 
Published: December 2009

AbstractNovel chromium catalysts based on bidentate phenoxy‐phosphinoyl (HO‐2R1‐4R2‐6(Ph2PO)C6H2: R1 = R2 = H, 3a; R1 = tBu, R2 = H, 3b; R1 = R2 = tBu, 3c; R1 = R2 = cumyl, 3d; R1 = anthracenyl, R2 = H, 3e) and thiophenol‐phosphine (HS‐2R1‐4R2‐6(Ph2P)C6H2: R1 = R2 = H, 4a; R1 = SiMe3, R2 = H, 4b) were prepared and characterized. Treatment with modified methyaluminoxane, these catalysts displayed moderate to high‐catalytic activities for ethylene polymerization. The activities of them were higher than those of the corresponding catalysts based on bidentate phenoxy‐phosphine ligands. Both the coordinated donors and the ortho‐substituent of the ligands played an important role in improving catalytic activity. The effects of reaction parameters, such as cocatalyst and Al/Cr molar ratio as well as reaction temperature, on ethylene polymerization behaviors were investigated in detail for two favorable catalytic systems, 3b/CrCl3(thf)3 and 4b/CrCl3(thf)3. Catalyst 4b/CrCl3(thf)3 displayed higher catalytic activity and better temperature tolerance for ethylene polymerization than 3b/CrCl3(thf)3. © 2009 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 48: 311–319, 2010
Vibrational dynamics of poly(L‐histidine)
Authors: La'verne Sanjeev J. , Srivastava Seema , Srivastava Shinoo , Srivastava Shweta , Gupta V. D. 
Published: December 2009

AbstractNormal mode analysis and their dispersion for poly(L‐histidine) (PLH) are reported by using Urey Bradley force field and Fourier Transform IR PLH exists in the α helical form. There are 17 atoms in one residue, which gives rise to 51 dispersion curves. To simplify, it is convenient to discuss the normal frequencies under three separate heads namely amide modes, side chain modes, and mixed mode. The calculated frequencies are found to be in reasonably good agreement with the Fourier Transform IR spectra. There exists exchange of character, attraction, and repulsion for selective dispersion curves with change in the phase value. Contributions to the heat capacity were calculated separately for the side chain, backbone, and mixed modes. The major contribution comes from the side chain and mixed modes. The sum of these three contributions gives the total heat capacity, which is in agreement with the reported experimental value. © 2009 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 48: 128–137, 2010
Electrochemical properties for ionic liquid/polymer electrolyte systems
Authors: Park Nam Ku , Bae Young Chan 
Published: December 2009

AbstractThe ionic liquid (1‐ethyl‐3‐methylimidazolium hexafluorouphophate) ([emim][PF6]) with different molecular weights of poly(ethylene oxide) (PEO) (MW = 4600; 10,000; 14,000; 20,000; 35,000, and 100,000) has been characterized at various temperatures and compositions using phase behaviors and ionic conductivity. A molecular thermodynamic model based on a combination of the previous theory (BH model) by Chang et al., a nonrandomness theory (NR model), and the Pitzer‐Debye‐Hückel theory modified by Guggenheim (PDH model) considered not only short‐range specific interactions between the polymer and a cation of the ionic liquid (IL), but also long‐range electrostatic forces between anions and cations within the IL. We have derived a new melting point depression theory based on this BH‐NR‐PDH model. We also established an ionic conductivity model, based on the Nernst‐Einstein equation, in which the diffusion coefficient is derived from the BH‐NR‐PDH model. The proposed model takes into account that the mobility of cations in the IL and the motions of the polymer host by expressing the effective chemical potential as the sum of the chemical potentials of the polymer and the IL. To describe the segmental motion of the cation and polymer chain, the effective coordinated unit parameter is introduced. The derived coordinated unit parameter for each state is used to determine the ionic conductivities of the given systems. Quantitative results from the proposed model are in good agreement with experimental data. The results indicate that the molecular weight of the polymer and the surrounding temperature play important roles in determining eutectic points and ionic conductivities of the given systems. © 2009 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 48: 212–219, 2010
Influence of local chain dynamics on diffusion of gases in polymers as determined by pulsed field gradient NMR
Authors: Garrido Leoncio , López‐González Mar , Riande Evaristo 
Published: December 2009

AbstractDiffusion of gases in polymers below the glass transition temperature,Tg, is strongly modulated by local chain dynamics. For this reason, an analysis of pulsed field gradient (PFG) nuclear magnetic resonance (NMR) diffusion measurements considering the viscoelastic behavior of polymers is proposed. Carbon‐13 PFG NMR measurements of [13C]O2diffusion in polymer films at 298 K are performed. Data obtained in polymers withTgabove (polycarbonate) and below (polyethylene) the temperature set for diffusion measurements are analyzed with a stretched exponential. The results show that the distribution of diffusion coefficients in amorphous phases belowTgis wider than that above it. Moreover, from a PFG NMR perspective, full randomization of the dynamic processes in polymers belowTgrequires long diffusion times, which suggests fluctuations of local chain density on a macroscopic scale may occur. © 2009 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 48: 231–235, 2010
A comparative study of laser‐ and electric‐field‐induced effects on the crystallinity, surface morphology and plasmon resonance of indium and gold thin films
Authors: Kumar Prashant , Krishna M. Ghanashyam 
Published: December 2009

AbstractThe effects of post‐deposition treatment of In and Au thin films by excimer laser and electric field are reported. The films were subjected to an electric field in the range of 0.1–3.3 kV/cm and laser irradiation in the range from 0.01 to 0.1 J/cm2. The effect of this treatment on the morphology and crystallinity of indium and gold thin films (10–100 nm thickness) is investigated. Indium films exhibited a three‐fold grain growth at an electric field of 3.3 kV/cm. Gold thin film, on the other hand, showed significant grain growth at a much lower field of 0.6 kV/cm. The as‐deposited thin films of indium and gold were amorphous but turned nanocrystalline with average crystallite sizes of 57 nm at 3.33 kV/cm and 35 nm at 0.66 kV/cm, respectively. When indium thin films were laser irradiated, flat disc‐shaped grains for as‐deposited thin films were transformed to spherical grains at a laser fluence of 0.02 J/cm2 and cubical grains at 0.05 J/cm2. At 0.05 J/cm2, as‐deposited amorphous indium and gold thin films turned nanocrystalline with crystallite sizes of 50 nm and 10 nm, respectively. Significantly, laser treatment causes the grain‐size distribution to become narrower with a shift in mean size to larger values. Electric‐field treatment on the other hand leads to a shifting of the mean grain size to larger values without affecting the distribution.
Hyperspectral retrieval of land surface emissivities using ARIES
Authors: Thelen Jean‐Claude , Havemann Stephan , Newman Stuart M. , Taylor Jonathan P. 
Published: December 2009

AbstractHere we demonstrate the feasibility of applying a fast radiative transfer code, based on empirical orthogonal functions, in conjunction with a 1D‐Var physical retrieval system to hyperspectral data taken from space/airborne radiance measurements in order to retrieve the emissivity spectra of the underlying surface.This approach was successfully tested using hyperspectral data obtained during the JAIVEx campaign in 2007 with the Airborne Research Interferometer Evaluation System (ARIES) on board of the UK Atmospheric Research aircraft. Using ARIES has the advantage that, during low‐level flights, the surface emissivities can be derived directly from the hyperspectral data. Thus ARIES is capable of providing both the hyperspectral radiance data and the ‘true’ surface emissivity which has obvious advantages for validating the retrieval of the surface emissivity spectra. © Crown Copyright 2009. Published by John Wiley & Sons, Ltd.