bluuebunny/crossref_metadata_2025_split huggingface dataset:
Design of a band‐notched broadband series‐fed two dipole array antenna
Authors: Yeo Junho , Lee Jong‐Ig 
Published: February 2013

AbstractIn this article, a band‐notched broadband series‐fed two dipole array (STDA) antenna is proposed. A design method to obtain a band rejection in the 2.4–2.484 GHz WLAN band is investigated for an STDA antenna consisting of two dipoles and a ground reflector operating in the frequency range between 1.7 and 2.7 GHz for mobile communication applications. The notch band is achieved by inserting U‐shaped slots on the coplanar strip line connecting the two dipole elements. The effects of the location and dimension of the slots on the notch band characteristics are investigated. A prototype of the proposed antenna is fabricated on an FR4 substrate. Experimental results show that the proposed antenna presents a broad bandwidth of 1.65–2.78 GHz (51.02%) for a voltage standing wave ratio < 2 and a rejection band of 2.39–2.54 GHz, which covers the desired notch band. © 2012 Wiley Periodicals, Inc. Microwave Opt Technol Lett 55:911–915, 2013; View this article online at wileyonlinelibrary.com. DOI: 10.1002/mop.27439
Dispersive optical fiber for measuring frequency response of electro‐optical phase modulators
Authors: Zhang Shangjian , Bao Xiaobin , Zhang Yali , Zhang Xiaoxia , Liu Yong 
Published: February 2013

AbstractA simple method based on the use of a fold‐loop dispersive fiber path is proposed for measuring high‐frequency modulation response of electro‐optical phase modulators.The method requires only a length of single‐mode fiber and allows high resolution swept frequency measurement with a vector network analyzer. © 2012 Wiley Periodicals, Inc. Microwave Opt Technol Lett 55:909–911, 2013; View this article online at wileyonlinelibrary.com. DOI: 10.1002/mop.27440
A novel TRI‐band planar inverted‐F antenna for GSM/DCS/PCS operation in mobile handsets
Authors: Seko Murilo Hiroaki , Correra Fatima Salete 
Published: February 2013

AbstractIn this article, a novel mobile handset planar inverted‐F antenna (PIFA) for tri‐band operation in GSM, DCS, and PCS bands is presented. This PIFA comprises a rectangular folded planar radiator, which has a J‐shaped slot, suspended above a partially grounded substrate. In this antenna, two resonant modes are excited and originate a lower band for GSM and an upper band for DCS and PCS. The influence of several geometrical parameters of the antenna on its performance was investigated to achieve an optimal design. The fabricated prototype of the proposed PIFA has overall dimensions of 45 × 90 × 6.6 mm3. The measured 10 dB return loss bands of the antenna are 880–892 MHz and 1658–2079 MHz. © 2012 Wiley Periodicals, Inc. Microwave Opt Technol Lett 55:821–825, 2013; View this article online at wileyonlinelibrary.com. DOI: 10.1002/mop.27441
Design of branch line coupler loaded capacitively with interdigitated fingers by using microstrip fed coplanar structures (L‐shaped conductor backed asymmetric CPS and U‐shaped conductor backed CPW)
Authors: Karpuz Ceyhun , Ozturk Pinar 
Published: February 2013

AbstractIn this letter, L‐shaped conductor backed asymmetric coplanar stripline (LSCBACPS) and U‐shaped conductor backed coplanar waveguide (USCBCPW) branch line coupler fed by microstrip transmission line have been investigated for the miniaturization. The number of interdigital finger unit cells located at the branch and through lines of the conventional branch line coupler is used to provide a desired miniaturization. The proposed branch line couplers in which all ports are formed by microstrip line have been constructed in two different configurations depending on the placement of the capacitively loaded fingers. The effects of the change of the cell number located at the branch and through lines on the center frequency and the propagation velocity are investigated. These effects are expressed by a simple formula depends on the cell number to use in the theoretical model obtained from the even‐odd mode analysis of LSCBACPS and USCBCPW configurations. Proposed couplers are designed, fabricated, and tested for the experimental verification to compare with the simulation and theoretical results. Measured, theoretical, and simulation results are in a very good agreement. © 2012 Wiley Periodicals, Inc. Microwave Opt Technol Lett 55:816–820, 2013; View this article online at wileyonlinelibrary.com. DOI: 10.1002/mop.27442
A novel compact configuration for dual‐mode microstrip resonators and dual‐band bandpass filter applications
Authors: Karpuz Ceyhun , Gorur Ali Kursad 
Published: February 2013

AbstractIn this article, a novel compact dual‐mode resonator formed by a square loop having folded arms and mitered bends is proposed.Degenerate modes can be excited by shifting the gaps between the folds. Thus, the center frequency can be arranged at a fixed value because the total electrical length of the proposed configuration is not changed. A novel compact dual‐mode dual‐band bandpass filter is also designed by locating the one resonator within the other. Additionally, to suppress the harmonic of the first passband, open‐circuited stubs are connected to the end of the feedlines. Two dual‐mode dual‐band bandpass filters with the elliptical and linear phase filtering characteristics for both passbands have been designed, fabricated, and tested. Calculated, simulated, and measured results are in a good agreement. © 2012 Wiley Periodicals, Inc. Microwave Opt Technol Lett 55:775–779, 2013; View this article online at wileyonlinelibrary.com. DOI: 10.1002/mop.27444
DC‐20 GHz 5‐BIT CMOS digital step attenuator with low insertion loss and phase error
Authors: Cho Moon‐Kyu , Baek Donghyun , Kim Jeong‐Geun 
Published: February 2013

AbstractThis article presents a 5‐bit broadband digital step attenuator with low insertion loss and phase error using a standard 0.13 μm CMOS process for the phased array antenna.The maximum attenuation of 31 dB with the LSB of 1 dB is achieved at DC‐20 GHz. The measured insertion loss of the reference state is <11 dB and the input and output return losses are <−10 dB at DC‐20 GHz. The root mean square (RMS) phase and amplitude errors are <2.5° and <0.7 dB, respectively. The current consumption is near zero with 1.2 V supply. The chip size is 1.04 × 0.48 mm2including pads. © 2012 Wiley Periodicals, Inc. Microwave Opt Technol Lett 55:762–764, 2013; View this article online at wileyonlinelibrary.com. DOI: 10.1002/mop.27448
Enhanced wideband performance of coupled frequency selective surfaces using metaheuristics
Authors: Lins H. W. C. , Barreto E. L. F. , d'Assunção A. G. 
Published: February 2013

AbstractThis article presents a bandwidth optimization study of two coupled frequency selective surfaces (FSS).The optimization is performed in two steps. In the first step, a genetic algorithm is developed to synthesize two single FSS crossed dipoles with resonant frequencies equal to 9.5 and 10.5 GHz, to be used in a broadside coupled geometry, separated by an air gap. In the second step, a particle swarm optimization algorithm is developed to determine the optimal value for the air gap length to optimize the geometry bandwidth. Prototypes are fabricated and measured to validate the optimization study results for the two coupled FSS structure. © 2012 Wiley Periodicals, Inc. Microwave Opt Technol Lett 55:711–715, 2013; View this article online at wileyonlinelibrary.com. DOI: 10.1002/mop.27451
Broadband four‐element multi‐layer multi‐permittivity cylindrical dielectric resonator antenna
Authors: Chaudhary Raghvendra Kumar , Srivastava Kumar Vaibhav , Biswas Animesh 
Published: February 2013

AbstractIn this article, a four‐element multi‐layer multi‐permittivity (MLMP) cylindrical dielectric resonator antenna (CDRA) for broadband application is proposed. The proposed antenna provides the measured input impedance bandwidth of 58.1% (at resonance frequency 4.03 GHz) from 3.48 GHz to 5.82 GHz for input reflection coefficient (S11) less than −10 dB. The measured average gain is 4.82 dB in the frequency range of 3.48 to 5.82 GHz. The design provides consistent omnidirectional characteristics and low cross polarization within the operating band. Design details of the proposed antenna and the results of both simulation and experiment are presented and discussed. © 2012 Wiley Periodicals, Inc. Microwave Opt Technol Lett 55:932–937, 2013; View this article online at wileyonlinelibrary.com. DOI: 10.1002/mop.27452
Transverse magnetic wave reflection from a metamaterial
Authors: Southall Hugh L. , Wu Bae‐Ian , Allen Jeffery W. 
Published: February 2013

AbstractIt has been shown that transverse electric plane waves reflect from certain types of metamaterials with a unit magnitude reflection coefficient (Smith and Schurig, Phys Rev Lett 90 &899;2003), 077405‐1–077405‐4).Here we investigate the reflection of transverse magnetic plane waves using a Hertzian dipole over a semi‐infinite slab of metamaterial, which is used as a ground plane. © 2012 Wiley Periodicals, Inc. Microwave Opt Technol Lett 55:899–903, 2013; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.27454
Mutual information in weak‐coherent‐state detection using a homodyne optical costas loop with different phase errors
Authors: López Josue A. , Garcia Edith , Arvizu Arturo , Mendieta Francisco J. , Gallion Phillipe , Conte Roberto 
Published: February 2013

AbstractA free‐space experimental set‐up for measuring the quadrature components of weak‐coherent‐state laser signals, based on a homodyne Costas loop configuration is presented. Loop parameters are optimized as a trade‐off between quantum and phase noises. Using binary phase‐shift‐keying modulation, measurements on the mutual information are presented for different photon numbers and phase errors. © 2012 Wiley Periodicals, Inc. Microwave Opt Technol Lett 55:769–772, 2013; View this article online at wileyonlinelibrary.com. DOI: 10.1002/mop.27459
Printed planar UWB antenna with rejection of WLAN and WiMAX bands
Authors: Subbarao Akkala , Raghavan Singaravelu 
Published: February 2013

AbstractA novel ultra‐wide band planar antenna with dual band‐notched characteristics is presented in this article.The antenna has compact size of 23 × 28 × 0.8 mm3 and it consists of novel patch. The measured antenna has impedance bandwidth of 3–10.7 GHz with dual notched bands of 3.3–3.7 GHz and 5.1–5.9 GHz to avoid interference from WiMAX and WLAN bands, respectively. A set of spiral slots and novel pulse‐shaped slots are etched in ground plane to obtain the dual notched bands. The effects of different geometrical parameters on various characteristics of antenna are investigated. The proposed antenna has consistent gain and stable radiation pattern. The measured group delay indicates that the antenna has good time domain response.© 2012 Wiley Periodicals, Inc. Microwave Opt Technol Lett 55:740–744, 2013; View this article online at wileyonlinelibrary.com. DOI: 10.1002/mop.27461
Tunable narrow dispersion compensation for independent CWDM channels using the acousto‐optic modulation
Authors: Marques Carlos A.F. , Oliveira Roberson A. , Nogueira Rogério N. 
Published: February 2013

AbstractA new method for dynamic control of the group delay of a fiber Bragg grating (FBG) is presented. It is based on an acoustic wave applied to the fiber. Tunability is obtained through adjustment of the intensity and/or frequency of the acoustic wave. The experimental results were verified by theoretical simulation. Application as a tunable narrow dispersion compensator for independent coarse wavelength division multiplexing (CWDM) channels is discussed. © 2012 Wiley Periodicals, Inc. Microwave Opt Technol Lett 55:929–932, 2013; View this article online at wileyonlinelibrary.com. DOI: 10.1002/mop.27463
A highly attenuative CMOS LNA at 5–6 GHz using negative GM circuit for UWB applications
Authors: Koirala Nischal , Anand A. , Pokharel Ramesh K. , Kanaya H. , Yoshida K. 
Published: February 2013

AbstractThis paper presents a UWB low noise amplifier (LNA) for 3.1–10.6 GHz applications, with an excellent attenuation at 5–6 GHz for rejecting the wireless local area network (WLAN) interference. A method of canceling the on‐chip inductive resistance has been employed in this work to make the inductor an extremely low loss inductor with a very high quality factor. The fully integrated UWB LNA is designed in the CMOS 0.18 μm Taiwan Semiconductor Manufacturing Company (TSMC) technology. Measurement results show that the LNA achieves attenuation of up to 39 dB at 5.4 GHz, while the 1 dB power gain is 10 dB. The measured return losses (S11 and S22) are better than −7.4 dB while the noise figure is 5–6.1 dB in the range of operation. The measured input P1dB and IIP3 measured at 6.5 GHz are −12.2 and 2 dBm, respectively. The designed LNA occupies an area of 1.105 × 0.68 mm2. © 2012 Wiley Periodicals, Inc. Microwave Opt Technol Lett 55:894–899, 2013; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.27464
Formulation of a three‐dimensional constitutive model for unsaturated soils incorporating mechanical–water retention couplings
Authors: Lloret‐Cabot Martí , Sánchez Marcelo , Wheeler Simon J. 
Published: February 2013

SUMMARYWheeler, Sharma and Buisson proposed an elasto‐plastic constitutive model for unsaturated soils that couples the mechanical and water retention behaviours. The model was formulated for isotropic stress states and adopts the mean Bishop's stress and modified suction as stress state variables. This paper deals with the extension of this constitutive model to general three‐dimensional stress conditions, proposing the generalized stress–strain relationships required for the numerical integration of the constitutive model. A characteristic of the original model is the consideration of a number of elasto‐plastic mechanisms to describe the complex behaviour of unsaturated soils. This work presents the three‐dimensional formulation of these coupled irreversible mechanisms in a generalized way including anisotropic loading. The paper also compares the results from the model with published experiments performed under different loading conditions. The response of the model is very satisfactory in terms of both mechanical and water retention behaviours. Copyright © 2013 John Wiley & Sons, Ltd.
Germline and somatic polymerase ϵ and δ mutations define a new class of hypermutated colorectal and endometrial cancers
Authors: Briggs Sarah , Tomlinson Ian 
Published: February 2013

AbstractPolymerases ϵ and δ are the main enzymes that replicate eukaryotic DNA. Accurate replication occurs through Watson–Crick base pairing and also through the action of the polymerases' exonuclease (proofreading) domains. We have recently shown that germline exonuclease domain mutations (EDMs) of POLE and POLD1 confer a high risk of multiple colorectal adenomas and carcinoma (CRC). POLD1 mutations also predispose to endometrial cancer (EC). These mutations are associated with high penetrance and dominant inheritance, although the phenotype can be variable. We have named the condition polymerase proofreading‐associated polyposis (PPAP). Somatic POLE EDMs have also been found in sporadic CRCs and ECs, although very few somatic POLD1 EDMs have been detected. Both the germline and the somatic DNA polymerase EDMs cause an ‘ultramutated’, apparently microsatellite‐stable, type of cancer, sometimes leading to over a million base substitutions per tumour. Here, we present the evidence for POLE and POLD1 as important contributors to the pathogenesis of CRC and EC, and highlight some of the key questions in this emerging field. Copyright © 2013 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.
Nucleotide resolution analysis of TMPRSS2 and ERG rearrangements in prostate cancer
Authors: Weier Christopher , Haffner Michael C , Mosbruger Timothy , Esopi David M , Hicks Jessica , Zheng Qizhi , Fedor Helen , Isaacs William B , De Marzo Angelo M. , Nelson William G , Yegnasubramanian Srinivasan 
Published: February 2013

AbstractTMPRSS2–ERG rearrangements occur in approximately 50% of prostate cancers and therefore represent one of the most frequently observed structural rearrangements in all cancers. However, little is known about the genomic architecture of such rearrangements. We therefore designed and optimized a pipeline involving target capture of TMPRSS2 and ERG genomic sequences coupled with paired‐end next‐generation sequencing to resolve genomic rearrangement breakpoints in TMPRSS2 and ERG at nucleotide resolution in a large series of primary prostate cancer specimens (n = 83). This strategy showed > 90% sensitivity and specificity in identifying TMPRSS2–ERG rearrangements, and allowed identification of intra‐ and inter‐chromosomal rearrangements involving TMPRSS2 and ERG with known and novel fusion partners. Our results indicate that rearrangement breakpoints show strong clustering in specific intronic regions of TMPRSS2 and ERG. The observed TMPRSS2–ERG rearrangements often exhibited complex chromosomal architecture associated with several intra‐ and inter‐chromosomal rearrangements. Nucleotide resolution analysis of breakpoint junctions revealed that the majority of TMPRSS2 and ERG rearrangements (∼88%) occurred at or near regions of microhomology or involved insertions of one or more base pairs. This architecture implicates non‐homologous end joining (NHEJ) and microhomology‐mediated end joining (MMEJ) pathways in the generation of such rearrangements. These analyses have provided important insights into the molecular mechanisms involved in generating prostate cancer‐specific recurrent rearrangements. Copyright © 2013 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.
Coarse‐ and fine‐grained models for proteins: Evaluation by decoy discrimination
Authors: Kauffman Chris , Karypis George 
Published: February 2013

AbstractCoarse‐grained models for protein structure are increasingly used in simulations and structural bioinformatics. In this study, we evaluated the effectiveness of three granularities of protein representation based on their ability to discriminate between correctly folded native structures and incorrectly folded decoy structures. The three levels of representation used one bead per amino acid (coarse), two beads per amino acid (medium), and all atoms (fine). Multiple structure features were compared at each representation level including two‐body interactions, three‐body interactions, solvent exposure, contact numbers, and angle bending. In most cases, the all‐atom level was most successful at discriminating decoys, but the two‐bead level provided a good compromise between the number of model parameters which must be estimated and the accuracy achieved. The most effective feature type appeared to be two‐body interactions. Considering three‐body interactions increased accuracy only marginally when all atoms were used and not at all in medium and coarse representations. Though two‐body interactions were most effective for the coarse representations, the accuracy loss for using only solvent exposure or contact number was proportionally less at these levels than in the all‐atom representation. We propose an optimization method capable of selecting bead types of different granularities to create a mixed representation of the protein. We illustrate its behavior on decoy discrimination and discuss implications for data‐driven protein model selection. Proteins 2013. © 2012 Wiley Periodicals, Inc.
Disorder and order in unfolded and disordered peptides and proteins: A view derived from tripeptide conformational analysis. I. Tripeptides with long and predominantly hydrophobic side chains
Authors: Schweitzer‐Stenner Reinhard , Hagarman Andrew , Toal Siobhan , Mathieu Daniel , Schwalbe Harald 
Published: February 2013

AbstractWe performed a conformational analysis of the central residues of three tripeptides glycyl‐L‐isoleucyl‐glycine (GIG), glycyl‐L‐tyrosyl‐glycine (GYG) and glycyl‐L‐arginyl‐glycine (GRG) in aqueous solution, based on a global analysis of amide I′ band profiles and NMR J‐coupling constants. The results are compared with recently reported distributions of GVG, GFG and GEG. For GIG and GYG, we found that even though the polyproline II (pPII) fraction is below 0.5, it is still the most populated conformation, whereas GVG and GFG show both a larger β‐strand fraction. For GRG, we observed a clear dominance of pPII over β‐strand, reminiscent of observations for GEG and GKG. This finding indicates that terminal charges on otherwise hydrophobic residue side chains stabilize pPII over β‐strand conformations. For all peptides investigated we found that a variety of compact and turn‐like conformations constitute nearly 20 percent of their conformational distributions. Attempts to analyze our data with a simple two‐state pPII⇔︁β model therefore do not yield any satisfactory reproduction of experimental results. A comparison of the obtained GxG ensembles with conformational distributions of GxG segments in truncated coil libraries (helices and sheets omitted) revealed a much larger fraction of type II βi+2 and type III β like conformations for the latter. Thus, a comparison of conformational distributions of unfolded peptide segments in solution and in coil libraries reveal interesting information on how the interplay between intrinsic propensities of amino acid residues and non‐local interactions in polypeptide chains determine the conformations of loop segments in proteins. Proteins 2013; © 2012 Wiley Periodicals, Inc.
A probabilistic model for secondary structure prediction from protein chemical shifts
Authors: Mechelke Martin , Habeck Michael 
Published: February 2013

AbstractProtein chemical shifts encode detailed structural information that is difficult and computationally costly to describe at a fundamental level. Statistical and machine learning approaches have been used to infer correlations between chemical shifts and secondary structure from experimental chemical shifts. These methods range from simple statistics such as the chemical shift index to complex methods using neural networks. Notwithstanding their higher accuracy, more complex approaches tend to obscure the relationship between secondary structure and chemical shift and often involve many parameters that need to be trained. We present hidden Markov models (HMMs) with Gaussian emission probabilities to model the dependence between protein chemical shifts and secondary structure. The continuous emission probabilities are modeled as conditional probabilities for a given amino acid and secondary structure type. Using these distributions as outputs of first‐ and second‐order HMMs, we achieve a prediction accuracy of 82.3%, which is competitive with existing methods for predicting secondary structure from protein chemical shifts. Incorporation of sequence‐based secondary structure prediction into our HMM improves the prediction accuracy to 84.0%. Our findings suggest that an HMM with correlated Gaussian distributions conditioned on the secondary structure provides an adequate generative model of chemical shifts. Proteins 2013; © 2012 Wiley Periodicals, Inc.