bluuebunny/crossref_metadata_2025_split huggingface dataset:
The compact 3‐stage 2.4/5.2 GHz bandpass filter with modified winding hairpin structure and insert coupling
Authors: Kung Cheng‐Yuan , Chen Yin‐Chung , Yang Cheng‐Fu , Huang Chih‐Yu 
Published: March 2010

AbstractTwo hairpin resonators, one “Z‐type” modified stepped‐impedance resonator, and two transmission lines are composed to design the compact and miniature dual‐band bandpass filters (BPFs).The designed BPFs are presented to operate at 2.4/5.2 GHz for industrial, scientific, and medical (ISM, 2.4 GHz) and WLAN applications (2.4/5.2 GHz) without additional impedance matching network. The 2.4 GHz and 5.2 GHz dual‐band can be simultaneously excited and tuned by adjusting the electric length ratio (θ) and characteristic impedance ratio (K) of resonators. Cascaded arrangement is designed for wide bandwidth and high out‐of‐band rejection, and the “Z‐type” resonator and insert coupled modification are used to increase the utility rate of space and reduce the size of designed filter. Al2O3 ceramic with thickness of 0.635 mm and dielectric constant of 9.4 used as the substrate, and the designed filters are fabricated by printing method. Because of higher dielectric constant substrate and modified structure, the proposed filters show the advantages of wide bandwidth, low insertion loss, high out‐of‐band rejection, simple circuit, and tiny size. © 2010 Wiley Periodicals, Inc. Microwave Opt Technol Lett 52: 1156–1159, 2010; Published online in Wiley InterScience (www. interscience.wiley.com). DOI 10.1002/mop.25128
Wideband dual‐polarized stacked‐patch antenna array for base stations
Authors: Serra A.A. , Nepa P. , Manara G. , Cioci S. , Tribellini G. 
Published: March 2010

AbstractIn this article, a 16‐element antenna array for wireless communication services is presented. The antenna operates in the universal mobile telecommunications system (UMTS), ISM, 2.4 GHz worldwide interoperability for microwave access, and in the new UMTS 3G expansion band from 2500 to 2690 MHz. A prototype of the antenna has been realized and measured. © 2010 Wiley Periodicals, Inc. Microwave Opt Technol Lett 52: 1048–1052, 2010; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.25131
Design of experiments as a microwave CAD tool
Authors: Naishadham Krishna 
Published: March 2010

AbstractWith the increase in geometrical and physical complexity of microwave circuits, statistical techniques to reduce the design cycles continue to grow in importance.The objective of this article is to review the theory of a statistical design tool called the design of experiments (DOE) and discuss its utility in developing Computer‐aided design models for microwave circuits. A circuit example of DOE application, pertaining to identification of dominant sources of variation in the return loss of a coplanar waveguide flip‐chip interconnect package, is reviewed. An empirical design formula is developed for the return loss based on regression analysis, which demonstrates that interaction between factors cannot be neglected, as is the norm in trialanderror analysis using one factor at a time. © 2010 Wiley Periodicals, Inc. Microwave Opt Technol Lett 52: 1020–1024, 2010; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.25133
TEM horn antenna for near‐field microwave imaging
Authors: Campbell Mark A. , Okoniewski Michal , Fear Elise C. 
Published: March 2010

AbstractAntennas capable of sending and receiving ultra‐wideband pulses are required for radar‐based microwave breast imaging.This article describes a TEM horn antenna designed to operate over a 2–12 GHz band with specific radiated near‐field characteristics. Simulations and experimental measurements are presented, including detection of objects representing tumors. © 2010 Wiley Periodicals, Inc. Microwave Opt Technol Lett 52: 1164–1170, 2010; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.25136
Planar ultrawideband antenna array for short‐range wireless communications
Authors: Ahmed Osama M. H. , Sebak Abdel‐Razik 
Published: March 2010

AbstractIn this article, novel 2‐element and 4‐element planar ultrawideband (UWB) antenna arrays with bidirectional radiation patterns based on identical UWB antenna elements for UWB communications applications have been proposed, simulated and experimentally investigated. Each array is constructed by means of feeding omni‐directional printed UWB monopole antennas with a UWB power divider. The proposed 2‐element antenna array yields an impedance bandwidth of 110% (3.1–10.6 GHz) covering the whole UWB frequency bandwidth while the impedance bandwidth is multi‐band in case of the 4‐element antenna array because of the increasing effect of mutual coupling among antenna elements. The calculated gain of the 2‐element and 4‐element array is quite stable with about 3 and 6 dB higher than that of the single element, respectively. Both measured and calculated E‐plane radiation patterns of the array and the single element are almost the same while the H‐plane radiation patterns of the array are distinctively bidirectional compared to the omni‐directional pattern of the single element. © 2010 Wiley Periodicals, Inc. Microwave Opt Technol Lett 52: 1061–1066, 2010; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.25140
Dual‐band antenna design using genetic algorithm‐generated topology
Authors: Kim Jae Hee , Park Wee Sang 
Published: March 2010

AbstractThis article represents an antenna topology selection for dual‐band mobile phone using an optimization technique that applies a genetic algorithm (GA) in the early stage of the design. Commercial software (CST MWS) is used to predict the performance of the antenna. Then, the fitness function is evaluated by integrating the CST with the GA using visual basic language. After the antenna topology was selected, a dual‐band antenna for GSM and DCS applications was designed by adding a parasitic line. © 2010 Wiley Periodicals, Inc. Microwave Opt Technol Lett 52: 1170–1174, 2010; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.25141
CPW‐based composite right/left‐handed transmission line and UWB‐filter application
Authors: Liu Chuan‐Yun , Chu Qing‐Xin 
Published: March 2010

AbstractA coplanar‐waveguide‐based (CPW‐based) composite right/left‐handed (CRLH) transmission line (TL) is proposed. By introducing parallel‐plate capacitors to enlarge the distributed series capacitance, it can be exploited in diverse miniaturized components. In addition, planar structure is easier to implement. Using such a structure, an ultra‐wideband (UWB) filter is proposed. Two transmission zeros are located close to the passband edges, which makes a good selectivity and stopband rejection of the filter. The fractional 3‐dB bandwidth is larger than 71%. Agreements between simulated and measured responses of the filter are demonstrated. © 2010 Wiley Periodicals, Inc. Microwave Opt Technol Lett 52: 1024–1027, 2010; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.25143
Concepts for millimeter‐wave waveguide‐MEMS phase shifters
Authors: Hesselbarth Jan , Vahldieck Ruediger 
Published: March 2010

AbstractThis article presents concepts for MEMS‐enabled low‐loss millimeter‐wave metal ridge waveguide phase shifters. Design examples for 80 GHz show 2.6 dB insertion loss for 90° continuously variable phase shift and 1.6 dB insertion loss for 140° phase shift, respectively. © 2010 Wiley Periodicals, Inc. Microwave Opt Technol Lett 52: 1028–1030, 2010; Published online in Wiley InterScience (www. interscience.wiley.com). DOI 10.1002/mop.25144
A novel chirp‐coded en/decoder for coherent 2D time‐wavelength OCDMA systems
Authors: Zheng Jilin , Wang Rong , Pu Tao , Lu Lin , Fang Tao , Cheng Yun , Chen Xiangfei 
Published: March 2010

AbstractA novel fiber Bragg grating (FBG)‐based chirp‐coded en/decoder is proposed for a coherent two‐dimensional (2D) time‐spreading wavelength‐hopping optical code‐division multiple‐access system. Combined with reconstruction‐equivalent‐chirp technology, the proposed coder can be easily realized in a single FBG with a conventional fabrication setup. Compared with other 2D encoders, the chirp‐coded encoders are expected to provide enhanced security, increased power efficiency, expanded code cardinality, and reduced coherent beat noise. Experimental results of such en/decoders and the corresponding system test‐bed at a data rate of 5 Gb/s verify the feasibility. © 2010 Wiley Periodicals, Inc. Microwave Opt Technol Lett 52: 1104–1106, 2010; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.25147
Bandwidth enhancement of small‐size internal WWAN laptop computer antenna using a resonant open slot embedded in the ground plane
Authors: Wong Kin‐Lu , Lee Li‐Chun 
Published: March 2010

AbstractA new bandwidth‐enhancement method of using a resonant open slot embedded in the ground plane or supporting metal frame of the display panel for a small‐size internal wireless wide area network (WWAN) laptop computer antenna is presented.To demonstrate the results, a small‐size printed monopole slot antenna with a length of 50 mm only, which is about the smallest among the internal WWAN laptop computer antenna that have been reported, is applied in this study. For such a small‐size WWAN antenna, the impedance matching in the 900‐MHz band is usually very poor and hence the obtained antenna's lower band cannot cover the desired GSM850/900 operation. By embedding a resonant open slot in the ground plane, which does not increase the size of the internal WWAN antenna, a wideband resonant mode with good impedance matching at about 900 MHz contributed by the resonant open slot can be generated to cover the GSM850/900 operation. Further, a wide upper band for the antenna to cover the GSM1800/1900/UMTS operation can also be obtained. Details of the proposed bandwidth‐enhancement method are studied in this article. © 2010 Wiley Periodicals, Inc. Microwave Opt Technol Lett 52: 1137–1142, 2010; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.25148
Harmonic pass‐band suppression in coupled‐serial‐shunted lines Elliptic band‐pass filters
Authors: Tsai Lin‐Chuan 
Published: March 2010

AbstractA synthesizing method is presented to design Elliptic band‐pass filters in the microwave frequency range. The Elliptic band‐pass filter is implemented by using a coupled‐serial‐shunted line structure. Using a continuous perturbation of wiggly‐groove and ring resonator of the couple line the harmonic pass‐band of the filter is rejected. An Elliptic band‐pass filter is implemented to validate this method correct by measuring. © 2010 Wiley Periodicals, Inc. Microwave Opt Technol Lett 52: 1177–1179, 2010; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.25151
Low mutual coupling 2 × 2 microstrip patch array antenna by using novel shapes of defect ground structure
Authors: Elsheakh Dalia N. , Elsadek Hala A. , Abdallah Esmat A. , Iskander Magdy F. , Elhenawy Hadia 
Published: March 2010

AbstractIn this article, to reduce the mutual coupling between the arrays patch antennas, electromagnetic band‐gap structure has been used as defected ground structure (DGS).Novel shapes of DGS are investigated to provide good band‐gap features and decrease the surface wave propagation. The mutual coupling of microstrip patch array antenna (MPAA) is parametrically studied, including both E‐ and H‐coupling directions, with different substrate thickness and various dielectric constants. The new DGS shapes applied on both 2 × 2 MPAA with line feed and coaxial feed array then applied on 2 × 2 planar‐inverted F antenna array antenna for improved performance and reduced overall size. © 2010 Wiley Periodicals, Inc. Microwave Opt Technol Lett 52: 1208–1215, 2010; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.25152
C‐shaped ultra‐wideband bandpass filter with WLAN notch band
Authors: Hsiao Pai‐Yi , Weng Ro‐Min 
Published: March 2010

AbstractA compact bandpass filter (BPF) embedded with 5.8 GHz wireless‐LAN notch is presented for 3.1–10.6 GHz ultra‐wideband (UWB) systems. The proposed UWB‐BPF based on a defect‐grounded structure is implemented with an FR4 board. Two open‐loop resonators on the top layer provide a narrow notch band whose center frequency can be easily adjusted by varying the sizes of the open‐loop. A simple C‐shaped slot on the bottom ground layer is adopted to improve the bandwidth performance. The characteristics of UWB‐BPF are analyzed and simulated using a circuit model of LC lump elements. The size of the filter is at least 34% less than those filters with the same specification. © 2010 Wiley Periodicals, Inc. Microwave Opt Technol Lett 52: 1215–1218, 2010; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.25153
Structure elucidation of new oleanane‐type glycosides from three species of Acanthophyllum
Authors: Timité Gaoussou , Mitaine‐Offer Anne‐Claire , Miyamoto Tomofumi , Ramezani Mohammad , Rustaiyan Abdolhossein , Mirjolet Jean‐François , Duchamp Olivier , Lacaille‐Dubois Marie‐Aleth 
Published: March 2010

AbstractFrom the roots of three species of Acanthophyllum (Caryophyllaceae), two new gypsogenic acid glycosides, 1 and 2, were isolated, 1 from A. sordidum and A. lilacinum, 2 from A. elatius and A. lilacinum, together with three known saponins, glandulosides B and C, and SAPO50. The structures of 1 and 2 were established mainly by 2D NMR techniques as 23‐O‐β‐D‐galactopyranosylgypsogenic acid‐28‐O‐β‐D‐glucopyranosyl‐(1→3)‐[β‐D‐glucopyranosyl‐(1→6)]‐β‐D‐galactopyranoside (1) and gypsogenic acid‐28‐O‐β‐D‐glucopyranosyl‐(1→3)‐[β‐D‐glucopyranosyl‐(1→6)]‐β‐D‐galactopyranoside (2). The cytotoxicity of several of these saponins was evaluated against two human colon cancer cell lines (HT‐29 and HCT 116). Copyright © 2010 John Wiley & Sons, Ltd.
Numerical optimization for constrained image registration
Authors: Haber Eldad , Horesh Raya , Modersitzki Jan 
Published: March 2010

AbstractImage registration or image matching is a technique to establish meaningful correspondences between points in different scenes. It is a mandatory tool for various applications in medicine, geoscience, and other disciplines. However, obtaining plausible deformations is a complex task. For example, many applications require the transformations to be locally invertible, or even harder, keep volume changes within a reasonable bandwidth.In this work, solutions to the registration problem are obtained by direct imposition of a volume constraint on each voxel in a discretized domain. In contrast to previous work, the focus here is on development of an efficient and robust numerical algorithm and in particular, the study of an augmented Lagrangian method with a multigrid solver. The paper demonstrates that this combination yields an almost optimal solver (i.e. linear time) for the problem. Copyright © 2010 John Wiley & Sons, Ltd.
Time‐continuous modeling of microstructures in single‐slip finite elasto‐plasticity based on energy relaxation
Authors: Kochmann Dennis M. , Hackl Klaus 
Published: March 2010

AbstractThe non‐(quasi)convexity of the free energy of single crystals in finite elasto‐plasticity gives rise to the formation of fine‐scale fluctuations of the displacement field, which can be interpreted as material microstructures. We outline a numerical procedure to model the origin and subsequent evolution of laminate microstructures. This approach incrementally solves the evolution equations by employing relaxed energy potentials. (© 2009 Wiley‐VCH Verlag GmbH & Co. KGaA, Weinheim)
FE2‐Simulations in Elasto‐Plasticity using Statistically Similar Representative Volume Elements
Authors: Balzani Daniel , Schröder Jörg , Brands Dominik , Carstensen Carsten 
Published: March 2010

AbstractIn the field of direct homogenization methods large representative volume elements (RVE's) cause a high computational cost, which is indicated by a large number of history variables allocating a large amount of memory. Additionally, a high computation time is necessary to solve the systems of equations on the micro‐scale as well as on the macro‐scale. In this contribution we focus on random microstructures consisting of a continuous matrix phase with a high number of embedded inclusions with arbitrary morphology. We present a method for the construction of statistically similar representative volume elements (SSRVE's) which are characterized by a much less complexity than usual RVE's in order to obtain an efficient simulation tool. The basic goal of the underlying procedure is to find a SSRVE, where some selected statistical measures describing the inclusion morphology are as close as possible to the ones of the original arbitrary microstructure. (© 2009 Wiley‐VCH Verlag GmbH & Co. KGaA, Weinheim)
A Model for the Evolution of Laminates
Authors: Hackl Klaus , Heinz Sebastian , Mielke Alexander 
Published: March 2010

AbstractWe study the time evolution of a generalized standard material in elastoplasticity. Of our particular interest are the formation and the evolution of microstructure. Our aim is to prove the existence of solutions. This is a challenging task, since the presence of microstructure comes along with a lack of convexity and, hence, compactness arguments cannot be applied to prove the existence of solutions. In order to overcome this problem, we will incorporate information on the microstructure into the internal variable, which is still compatible with the notion of generalized standard materials. More precisely, we shall allow such forms of microstructure that are given by simple laminates. We will consider a model for the evolution of these laminates and we will state a result on the existence of solutions to the time‐incremental minimization problem. (© 2009 Wiley‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Numerical investigations on autogenous shrinkage of cement paste and mortar
Authors: Leusmann Thorsten , Nothnagel Reinhard 
Published: March 2010

AbstractAutogenous shrinkage of cement paste and concrete is defined as the macroscopic length change occurring with no moisture transferred to the exterior surrounding environment. It is a result of chemical shrinkage affiliated with the hydration of cement particles and the ongoing process of self‐desiccation. The process of self‐desiccation can be modeled starting from the formation of the capillary pore space during hydration in the cement paste. In this proposal a working model will be introduced explaining the difficulties to obtain the autogenous shrinkage strains directly from a simulated or measured microstructure of cement paste. In a second step the autogenous shrinkage of a hardening cement mortar was described on a mesoscopic level. It based on measurements on cement paste. The mortar simply consists of cement paste and a defined fraction of spherical aggregates with a known modulus of elasticity. Furthermore the influence of the interfacial transition zone (ITZ) is studied in numerical simulations. The results of these finite‐element‐calculations are introduced and compared with testing results of the autogenous shrinkage of hardening mortar samples. (© 2009 Wiley‐VCH Verlag GmbH & Co. KGaA, Weinheim)
3D modelling of arterial growth for adaptation to hypertension — the influence of transmural changes in the mechanical environment
Authors: Schmid Holger , Watton Paul , Röhrle Oliver , Wang Yikun , Itskov Mikhail 
Published: March 2010

AbstractMany phenomenological models of cerebral aneurysm formation have been proposed. Such studies have focused on modeling the structural adaption of the arterial wall. However, further development is required to accurately represent the underlying mechanobiology during growth and remodeling processes. Here, we present a 3D computational model that incorporates transmurally heterogeneous material concentrations. This is a critical step toward more realistic models for growth and adaptation. (© 2009 Wiley‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Numerical Simulations of Arterial Walls Based on IVUS‐Data
Authors: Brands Dominik , Schröder Jörg , Klawonn Axel , Rheinbach Oliver , Böse Dirk , Erbel Raimund 
Published: March 2010

AbstractAtherosclerosis has become one of the most frequent causes of death in the last decades. So the analysis and improvement of corresponding medical treatments, e.g., balloon‐angioplasty or stenting, are significant tasks in the fields of biomechanics and biomedical engineering. One important component of the simulation of arterial walls, especially of atherosclerotically degenerated ones, is the knowledge of their anatomical and physiological composition. The intravascular ultrasound and the interpretation by the Virtual Histology provide cross‐sectional images of the diseased arterial walls where the different components are characterized by color‐coding. The topic of this contribution is the 3D reconstruction and discretization of the artery using these color‐coded images and the biplane angiography. (© 2009 Wiley‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Time‐domain analysis of wave propagation in unbounded domains based on the scaled boundary finite element method
Authors: Birk Carolin 
Published: March 2010

AbstractTransient wave propagation in unbounded domains is considered in this paper. The scaled boundary finite element method is used to model the far field. This technique is originally formulated in the frequency‐domain. Two extensions of the method which lead to a direct description of the unbounded medium in the time‐domain are described, that is the rational approximation and the continued‐fraction expansion of the dynamic stiffness. (© 2009 Wiley‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Large Scale Simulation with Scaled Boundary Finite Element Method
Authors: Schauer Marco , Lehmann Lutz 
Published: March 2010

AbstractNowadays scientific and engineering applications often require wave propagation in infinite or unbounded domains. In order to model such applications we separate our model into near‐field and far‐field. The near‐field is represented by the well‐known finite element method (FEM), whereas the far‐field is mapped by a scaled boundary finite element (SBFE) approach. This latter approach allows wave propagation in infinite domains and suppresses the reflection of waves at the boundary, thus being a suitable method to model wave propagation to infinity. It is non‐local in time and space. From a computational point of view, those characteristics are a drawback because they lead to storage consuming calculations with high computational time‐effort. The non‐locality in space causes fully populated unit‐impulse acceleration influence matrices for each time step, leading to immense storage consumption for problems with a large number of degrees of freedom. Additionally, a different influence matrix has to be assembled for each time step which yields unacceptable storage requirements for long simulation times. For long slender domains, where many nodes are rather far from each other and where the influence of the degrees of freedom of those distant nodes is neglectable, substructuring represents an efficient method to reduce storage requirements and computational effort. The presented simulation with substructuring still yields satisfactory results. (© 2009 Wiley‐VCH Verlag GmbH & Co. KGaA, Weinheim)