bluuebunny/crossref_metadata_2025_split huggingface dataset:
Quantitative analysis of gemcitabine triphosphate in human peripheral blood mononuclear cells using weak anion‐exchange liquid chromatography coupled with tandem mass spectrometry
Authors: Veltkamp S. A. , Hillebrand M. J. X. , Rosing H. , Jansen R. S. , Wickremsinhe E. R. , Perkins E. J. , Schellens J. H. M. , Beijnen J. H. 
Published: November 2006

AbstractGemcitabine triphosphate (dFdCTP) is a highly active metabolite of gemcitabine. It is formed intra‐cellularly via the phosphorylation of gemcitabine by deoxycytidine kinase. The monitoring of dFdCTP in human peripheral blood mononuclear cells (PBMCs), in addition to plasma concentrations of gemcitabine and its metabolite 2′,2′‐difluorodeoxyuridine, is considered very useful in determining pharmacokinetic–pharmacodynamic relationships.We describe a novel sensitive assay for the quantification of dFdCTP in human PBMCs. The method is based on weak anion‐exchange liquid chromatography and detection with tandem mass spectrometry (LC‐MS/MS). The assay has been validated from 1 ng/ml (lower limit of quantification, LLOQ) to 25 ng/ml (upper limit of quantification, ULOQ) using 180 µl aliquots of PBMC extracts containing ∼0.648 mg protein or 3.8 × 106 lysed PBMCs. The LLOQ is equivalent to 94 fmol/106 cells (1 ng/ml = 0.18 ng/180 µl or 0.18 ng/0.648 mg protein = 0.047 ng/106 cells or 94 fmol/106 cells). This highly sensitive assay is capable of quantifying about 200‐fold lower concentrations of dFdCTP in human PBMCs than currently available methods. Copyright © 2006 John Wiley & Sons, Ltd.
A novel low‐dispersive (2,2) collocated FDTD scheme
Authors: Bommaraju Chakrapani , Marklein Rene , Schuhmann Rolf , Weiland Thomas 
Published: November 2006

AbstractThe dispersion relation and the convergence of a modified finite‐difference time‐domain scheme (MFDTD), which has fourth‐order convergence and excellent broadband characteristics, are presented. The accuracy of several low‐dispersion finite‐difference time‐domain schemes in 2‐D is compared with that of the MFDTD, via direct evaluation of the dispersion relation. Convergence of the FDTD and the MFDTD in 2‐D are also examined. Copyright © 2006 John Wiley & Sons, Ltd.
Accuracy improved ADI‐FDTD methods
Authors: Ahmed Iftikhar , Chen Zhizhang (David) 
Published: November 2006

AbstractFDTD method plays an important role for simulation of different structures in various fields of engineering, such as RF/microwaves, photonics and VLSI. However, due to the CFL stability constraint, the FDTD time step is still small and the related CPU time is still large for modelling fine geometry where small cell sizes are required to resolve fields. As a result, the unconditionally stable CFL‐condition‐free ADI‐FDTD method is becoming a popular alternative to the FDTD method. The ADI‐FDTD method allows the use of larger time steps; however, it comes at the cost of larger errors. To mitigate the problem of these larger errors, in this paper we propose to modify the conventional ADI‐FDTD algorithm. The modifications are based on the fact that because the ADI‐FDTD is a truncated form of the Crank–Nicolson (CN) method, the truncated terms can be re‐introduced approximately into the ADI algorithms to improve accuracy. Two accuracy‐improved ADI‐FDTD algorithms are derived and then validated for two‐dimensional cases. Unfortunately, in the three‐dimensional case the proposed methods are not found to be unconditionally stable. Copyright © 2006 John Wiley & Sons, Ltd.
PML termination of conducting media in the finite difference time domain method for bodies of revolution (BORs)
Authors: Carrión José , Farahat Nader 
Published: November 2006

AbstractIn this paper we discuss the use of perfectly matched layers (PMLs) for the termination of conducting media in the body of revolution finite difference time domain (BOR–FDTD) algorithm. This type of termination enables us, to accurately and efficiently model long conductors possessing rotational symmetry. The formulation is validated by investigating the propagation characteristics of two practical guiding wave structures, viz., a coaxial cable (RG‐142) and a circular waveguide operating in the TE11mode. Both the conductors as well as dielectrics are extended into the PML region in order to simulate infinitely long guides. Copyright © 2006 John Wiley & Sons, Ltd.
System identification and model order reduction for TLM analysis
Authors: Lukashevich D. , Coccetti F. , Russer P. 
Published: November 2006

AbstractA system identification (SI) and Prony's model based algorithm for modelling and prediction of a time‐domain transient response is introduced and applied to time‐domain transmission line matrix (TLM) transient responses in order to extrapolate parameters of microwave circuits and accelerate the simulation process.Application of moment matching model order reduction (MOR) techniques to the TLM method is presented with emphasis placed on Krylov subspace methods based on the Lanczos process and its modifications. The Krylov subspace methods are attractive for MOR in the TLM framework because the construction of orthonormal and biorthogonal bases for correspondent Krylov subspaces can be carried out through a direct application of the implicit TLM solver. MOR applied to TLM allows one to generate a compact macromodel of a TLM‐system and significantly reduce the computational time.The efficiency and advantages of the SI and MOR techniques are demonstrated through their applications to the full‐wave analysis of different electromagnetic structures. In addition, a brief comparison of SI and MOR involved for modelling of a planar patch antenna is provided. Copyright © 2006 John Wiley & Sons, Ltd.
A predator–prey model with disease in the prey species only
Authors: Greenhalgh David , Haque Mainul 
Published: November 2006

AbstractA predator–prey model with transmissible disease in the prey species is proposed and analysed. The essential mathematical features are analysed with the help of equilibrium, local and global stability analyses and bifurcation theory. We find four possible equilibria. One is where the populations are extinct. Another is where the disease and predator populations are extinct and we find conditions for global stability of this. A third is where both types of prey exist but no predators. The fourth has all three types of individuals present and we find conditions for limit cycles to arise by Hopf bifurcation. Experimental data simulation and brief discussion conclude the paper. Copyright © 2006 John Wiley & Sons, Ltd.
Modeling absorption of rough interface between dielectric and conductive medium
Authors: Gu Xiaoxiong , Tsang Leung , Braunisch Henning , Xu Peng 
Published: November 2006

AbstractThe effects of a random rough surface between dielectric and lossy conductive medium on power absorption are analyzed by considering incident plane waves impinging on the interface. We use two methods to formulate and solve the 2‐D problem: the two‐media small perturbation method to second order (SPM2) and the numerical system transfer operator matrix method, referred to as T‐matrix method. The two methods are in agreement within the regimes of validity. The results show significant difference between absorption of a rough surface and that of a smooth surface. Surface fields are further examined numerically. © 2006 Wiley Periodicals, Inc. Microwave Opt Technol Lett 49: 7–13, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.22023
Analysis of an E‐shaped patch antenna
Authors: Pandey Vijay K. , Vishvakarma Babau R. 
Published: November 2006

AbstractThis paper presents the theoretical and simulation investigations of an E‐shaped patch antenna applicable in modern mobile communications. It shows marked improvement in the bandwidth when compared with rectangular patch antenna with acceptable radiation pattern. Further, the bandwidth is optimized with respect to notch length, width, and position. Typically, the antenna shows an enhanced impedance bandwidth of 32.5%. © 2006 Wiley Periodicals, Inc. Microwave Opt Technol Lett 49: 4–7, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.22024
Transmission characteristics of dielectric loaded double trapezoidal‐ridge waveguide
Authors: Lu Mai , Persson Mikael 
Published: November 2006

AbstractAs a new kind of broadband microwave component, transmission characteristics of dielectric loaded double trapezoidal‐ridge waveguide have been analysed by edge element method. Variations of the cutoff wavelength, single‐mode bandwidth and field patterns with the ridge dimensions for different values of dielectric constant have been investigated in details. Numerical results in this article provide an extension to the existing design data for ridge waveguides and are considered helpful in practical applications. © 2006 Wiley Periodicals, Inc. Microwave Opt Technol Lett 49: 1–4, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.22025
Broadband CMOS mixer cell for UWB applications
Authors: Chen W. L. , Huang G. W. , Chang S. F. 
Published: November 2006

AbstractA broadband mixer cell with active matching network was developed using commercial 0.25‐μm CMOS technology. From experimental results, the down‐converter with the proposed mixer cell achieves a RF input return loss greater than 10 dB from 3.1 to 23.3 GHz. For UWB low‐band application, it achieves a conversion gain of −9.2 dB and an input P1dB greater than −3 dBm at the moderate LO power level of 4 dBm. © 2006 Wiley Periodicals, Inc. Microwave Opt Technol Lett 49: 127–128, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.22026
Improving the performance of a 10 Gbit/s optical communication system with a thermally actuated chromatic dispersion compensator based on chirped fiber Bragg gratings
Authors: Neto B. , André P. 
Published: November 2006

AbstractIn this letter we describe the use of tunable chromatic dispersion compensator based on chirped fiber Bragg grating to improve the performance of a 10 Gbit/s optical fiber communication system. Tunable compensation is achieved by applying temperature gradients along the grating longitudinal axis. It is demonstrated that thermal gradients comprised between −40 and 40°C were able to change the grating dispersion from −84.88 to −218.30 ps/nm. Previously developed model that issued a BER variation on the system from 1.82 × 10−12to 1.62 × 10−9are consistent with the experimental evidences reported here. © 2006 Wiley Periodicals, Inc. Microwave Opt Technol Lett 49: 124–127, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.22027
A small‐size semilumped three‐port tunable power divider
Authors: Perrier A.‐L. , Duchamp J.‐M. , Ferrari P. 
Published: November 2006

AbstractIn this paper, a small‐size semi‐lumped three‐port power divider with both power and frequency tune is designed and measured. The proposed topology uses complex impedance transformers in each output branch. A 3D CPW prototype is realized with varactor diodes. It exhibits a wide tunable power, from −1.3 to −17 dB, and a wide working frequency tune, from 0.8 to 1.4 GHz. © 2006 Wiley Periodicals, Inc. Microwave Opt Technol Lett 49: 90–94, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.22029
UMTS diplexer design using dual‐mode ring resonators
Authors: Ho Min‐Hua , Xu Wei‐Qin , Chen Yu‐Wei 
Published: November 2006

AbstractIn this letter, we propose a novel design of a UMTS diplexer using dual‐mode rectangular ring‐resonators. The diplexer is composed of two rectangular rings, which termed as the Tx‐ and Rx‐ring, with each ring its input and output ports separated from each other by a quarter‐wavelength to create the degenerate‐mode resonance. The ratio of the long‐ and short‐side dimension of rectangular ring can be used to fine tune the passband's bandwidth and the ratio is properly chosen to achieve sufficient bandwidth required by the UMTS diplexer applications. An enhanced parallel‐coupled structure is introduced in the circuit to replace the conventional end‐gap coupling for reducing the insertion losses in the passband. The effect of the coupling‐line length is also simulated and the resulting data are used to precisely tune the positions of the zeros. In the zero assignment, one of the zeros possessed by each ring filter is managed to be implanted in the passband of its counterpart filter for increasing the isolation between the Rx‐ and Tx‐port. © 2006 Wiley Periodicals, Inc. Microwave Opt Technol Lett 49: 63–65, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.22030
Performance of duo‐stage SOA based all‐optical multicasting switching matrix for future grid networking
Authors: Lee Bernard H. L. , Shahril S. M. , Mohamad R. , Kaharudin D. 
Published: November 2006

AbstractThis paper presents the performance evaluation of a duo‐stage SOA based All‐Optical Multicasting capable Switch architecture suitable for the requirements of Grid Networking. SOAs based devices are located at the input and the output ports of the switch. The SOAs located at the input port serves as a multicasting and routing device feeding the signals into an N × N arrayed waveguide gratings and the SOAs at the output are regenerators to restore the quality of the signals before sending them into the network. This design uses the non‐linearity processes in SOA such as Cross Gain Modulation and Cross Phase Modulation to achieve a maximum of 1–16 multicast at a bit‐rate of 10 Gbps within the all‐optical switch. © 2006 Wiley Periodicals, Inc. Microwave Opt Technol Lett 49: 59–62, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.22031
Improved spiral compact microstrip resonance cell low‐pass filter with wide stopband characteristics
Authors: Che Wenquan , Deng Kuan , Xu Lei , Wang Dapeng , Geng Liang 
Published: November 2006

AbstractAn improved spiral compact microstrip resonance cell (SCMRC) structure is proposed in this article. Good low pass performance and wide stopband characteristics can be achieved with a simple single cell, two transmission zeros are introduced within the stopband and thus improve the bandwidth significantly. The measured results of the prototype show that the insertion loss is less than 0.55 dB in the passband, and the bandwidth of the stopband is about 90%, nearly two times of the original SCMRC structure. © 2006 Wiley Periodicals, Inc. Microwave Opt Technol Lett 49: 121–124, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.22032
A CMOS multiphase shifting network with RC‐CR filter and bias‐level‐scaled active interpolator
Authors: Lee Mi‐Young , Yoo Changsik 
Published: November 2006

AbstractA CMOS multiphase shifting network is described, which is developed for the use in a subharmonic mixing based direct‐conversion receiver of 5–6 GHz wireless LAN. Accurate phase shift and amplitude matching are simultaneously achieved with a third‐order RC–CR filter followed by the active interpolators whose bias levels are scaled for accurate phase shift. Implemented in a 0.18 μm CMOS process, the phase shifting network provides octa‐phase local oscillator (LO) signals spaced by 45°. The measured accuracy of the phase shift and amplitude matching are better than 0.8° and 0.4%, respectively. The phase shifting network excluding LO buffers dissipates 13 mW from a 1.8 V supply voltage. © 2006 Wiley Periodicals, Inc. Microwave Opt Technol Lett 49: 118–121, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.22033
Double negative media using interconnected ω‐type metallic particles
Authors: Lheurette É. , Vanbésien O. , Lippens D. 
Published: November 2006

AbstractWe report on broadband low‐loss properties of Ω‐based metamaterials. It is shown that interconnecting elementary current‐loops via their arms can yield to a relative bandwidth of around 70% for infinite arrays. Combining interconnected and disconnected sections permits one to engineer the left‐handed and right‐handed dispersion branches with the prospect of composite artificial media such as those initially proposed by Itoh and coworkers (IEEE Microwave Mag 34 (2004) 34–50) in the context of transmission lines. This typical behavior is interpreted through a lumped element model. At last, some guidelines to optimize the transmission properties of Ω‐shaped arrays are presented. These results are discussed on the basis of recently published data concerning Ω‐shaped and C‐shaped particles. © 2006 Wiley Periodicals, Inc. Microwave Opt Technol Lett 49: 84–90, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.22034
Exploring the possibility of enhancing the bandwidth of μ‐negative metamaterials by employing tunable varactors
Authors: Alù Andrea , Bilotti Filiberto , Vegni Lucio 
Published: November 2006

AbstractWe analyze here the performance of μ‐negative metamaterials in different configurations at microwave and optical frequencies that employ variable values of capacitances or tunable varactors, with the purpose of increasing their bandwidth of operation. The proposed method shows moderately good results both in resonant‐like and in transmission‐line configurations. © 2006 Wiley Periodicals, Inc. Microwave Opt Technol Lett 49: 55–59, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.22036
Wide stopband EBG structure design based on 2D nonlinearly tapered slot array
Authors: Wu Jack , Qiu S. N. , Qiu C. X. , Shih I. 
Published: November 2006

AbstractElectromagnetic bandgap structures are well known for their stopband features and can be applied at microwave frequencies. In this work, a wide stopband electromagnetic band‐gap (EBG) structure design based on 2D tapered slot array is presented. Each tapered slot length is designed to provide stopband at a specific frequency to maximize the attenuation level. The tapered slot array is positioned in the ground plane of a microstrip transmission line structure. Thus, the overall 9‐slot nonlinearly tapered array produces a wide stopband from 9.3 to 20 GHz with attenuation better than 25 dB, which is observed in both simulation and actual measurements. The nonlinearly tapered EBG structure can be applied as an efficient lowpass filter. © 2006 Wiley Periodicals, Inc. Microwave Opt Technol Lett 49: 31–34, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.22038
Characteristics of low K thin film microstrip line on standard lossy silicon substrate for radio frequency integrated circuits
Authors: Wu Hung‐Wei , Weng Min‐Hang , Su Yan‐Kuin , Yang Ru‐Yuan 
Published: November 2006

AbstractIn this paper, effective dielectric constant, line attenuation, and characteristic impedance of thin film microstrip line (TFML) on polyimide dielectric as interconnection for radio frequency integrated circuits is investigated. The TFML is fabricated on low cost low resistivity silicon substrate (ρ≤10 Ω cm) by incorporating a spin‐on dielectric polyimide and sputtering of aluminum. An accurate on‐wafer‐procedure for extracting the microwave characteristics of TFML up to 50 GHz is described and the method is successfully applied to low‐K polyimide deposited on the silicon. © 2006 Wiley Periodicals, Inc. Microwave Opt Technol Lett 49: 79–83, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.22052
A 6 GHz low power differential VCO
Authors: Jang Sheng‐Lyang , Lee Shao‐hua , Chiu Chung‐Ching , Chuang Yun‐Hsueh 
Published: November 2006

AbstractThis paper presents a new differential CMOS voltage controlled oscillator (VCO). The topology of the proposed differential VCO is a combination of Colpitts CMOS VCO and cross‐coupled lateral BJT VCO. A symmetric transformer and differential differentially tuned MOS varactors are used to reduce phase noise. The VCO has been fabricated with the 0.18‐μm CMOS process. At the 1.2‐V supply voltage, the output frequency of VCO is from 5.99 to 6.43 GHz with 441 MHz tuning range and a phase noise of −118.5 dBc/Hz at the 1 MHz offset from the center frequency of 6.43 GHz. Its core current consumption is 2.8 mA and the core power consumption is 3.36 mW. The total power consumption of this VCO is 9.12 mW. The figure of merit (FOM) of this differential VCO is −189.4 dBc/Hz. © 2006 Wiley Periodicals, Inc. Microwave Opt Technol Lett 49: 76–79, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.22043
Planar branched monopole antenna for UWB applications
Authors: Jacob K. Francis , Suma M. N. , Raj Rohith K. , Joseph Manoj , Mohanan P. 
Published: November 2006

AbstractDevelopment of a compact microstrip‐fed, branched monopole antenna for ultra wide band (UWB) applications is presented. By suitably embedding branches on the top edge of the strip monopole, an UWB response can be easily achieved by merging different resonances. The simulated and experimental results demonstrate that the proposed antenna achieves more than 3:1 impedance bandwidth for 2:1 VSWR criteria. The antenna exhibits nearly omni directional radiation characteristics and moderate gain in the entire band. The proposed antenna is printed on a FR4 substrate of εr = 4.4 and thickness h = 1.6 mm and having an overall dimension of 65 × 35 mm2 including the ground plane. The parameters that affect the performance of the antenna are presented and discussed. © 2006 Wiley Periodicals, Inc. Microwave Opt Technol Lett 49: 45–47, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.22045
Study of the Bluetooth headset antenna with the user's head
Authors: Wong Kin‐Lu , Hsu Ming‐Ren , Li Wei‐Yu , Su Saou‐Wen , Chen Austin 
Published: November 2006

AbstractA promising planar inverted‐F metal‐strip antenna suitable for Bluetooth headset application is studied. The antenna has a low‐profile appearance and can be embedded inside the housing of the Bluetooth headset to operate as an internal antenna. The antenna is to be mounted along the side edge of the system circuit board of the headset, almost not occupying the valuable board space. Results have indicated that, when the antenna is mounted at either end of the side edge, a large bandwidth (>250 MHz) centered at about 2442 MHz can be achieved, making the antenna easily cover the Bluetooth operation in the 2400–2484 MHz band. Performances of the studied antenna attached to the user's head are also studied. Large distortion in the antenna's radiation pattern is observed. However, the antenna's radiation efficiency is still larger than about 70% over the operating band, which is acceptable for practical applications. Details of the obtained experimental and simulation results are presented and discussed. © 2006 Wiley Periodicals, Inc. Microwave Opt Technol Lett 49: 19–23, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.22047
Transmission peak at low frequencies by a fractal distribution of metamaterials layers in free space
Authors: Saleh A. S. , Raveu N. 
Published: November 2006

AbstractA periodic distribution of metamaterials layers in free space generates wide forbidden bands. This work investigates the Cantor bar distribution of metamaterials slabs in free space. This distribution provides narrow transmission peaks in the forbidden bands. A design of narrow bandpass filter with a signification gain of dimension is proposed. © 2006 Wiley Periodicals, Inc. Microwave Opt Technol Lett 49: 105–109, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.22048