bluuebunny/crossref_metadata_2025_split huggingface dataset:
Dendronized Polymers: Recent Progress in Synthesis
Authors: Zhang Afang , Shu Lijin , Bo Zhishan , Schlüter A. Dieter 
Published: February 2003

AbstractThis article divides the synthetic routes leading to dendronized polymers into two main categories (attach‐to and macromonomer) and compares their respective advantages and disadvantages. It gives a comprehensive overview on the kind of structures presently available and also spans the bridge between both polymers and molecular objects, decorated with only a few dendrons, and the structurally related, but less well defined polymers with hyperbranched side chains.
A coiled polymer backbone's stretching through the attachment of increasingly sterically demanding dendrons: a) no dendrons; b) dendrons of the first generation; c) second generation; d) third generation.magnified imageA coiled polymer backbone's stretching through the attachment of increasingly sterically demanding dendrons: a) no dendrons; b) dendrons of the first generation; c) second generation; d) third generation.
T‐probe proximity‐fed short‐circuited patch antenna
Authors: Guo Yong‐Xin , Luk Kwai‐Man , Lee Kai‐Fong 
Published: February 2003

AbstractA broadband T‐probe proximity‐fed short‐circuited quarter‐wavelength rectangular patch antenna is proposed as one possible candidate for mobile communication applications. Using a foam layer of thickness ∼0.09λ0 as a supported substrate, an impedance bandwidth of 59% and a gain of over 4.5 dBi have been obtained. The far‐field patterns are stable across the passband. Experimental and computed results based on the finite‐difference time‐domain (FDTD) method are provided. © 2003 Wiley Periodicals, Inc. Microwave Opt Technol Lett 37: 1–2, 2003; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.10805
A low‐cost surface‐mount monopole antenna for GSM/DCS operation
Authors: Lee Gwo‐Yun , Chen Hong‐Twu , Wong Kin‐Lu 
Published: February 2003

AbstractBy folding a metallic strip onto a foam base, a low‐cost surface‐mount monopole antenna suitable for GSM/DCS dual‐band operation is presented. The antenna has a compact size of 33 × 7.5 × 7.5 mm3 and requires no isolation distance to the system ground plane when surface‐mounted to the system circuit board of a communication device. Experimental results of a constructed prototype covering the operating bandwidths of the GSM (890–960 MHz) and DCS (1710–1880 MHz) systems are presented. © 2003 Wiley Periodicals, Inc. Microwave Opt Technol Lett 37: 2–4, 2003; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.10806
Wave propagation, refraction, and focusing phenomena in Lorentzian double‐negative materials: A theoretical and numerical study
Authors: Kärkkäinen M. K. , Maslovski S. I. 
Published: February 2003

AbstractElectromagnetic effects in double‐negative (DNG) materials are considered from the theoretical and numerical points of view. Special attention is given to the causality aspects. The refracton of a cylindrical wave excited by a line source placed above a plane DNG slab and the wave propagation through the slab are studied. The DNG material response is modelled by the resonant constitutive parameters of the Lorentzian form. A novel technique for discretization of the constitutive equations is proposed. The negative refraction and slab focusing phenomena are clearly seen from the simulations. © 2003 Wiley Periodicals, Inc. Microwave Opt Technol Lett 37: 4–7, 2003; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.10807
Development of a higher‐order ADI‐FDTD method
Authors: Wang Zhu , Chen Ji , Chen Yinchao 
Published: February 2003

AbstractIn this paper, a higher‐order alternative‐direction‐implicit (ADI) finite‐difference time‐domain (FDTD) method is presented. The dispersion analysis is performed and the results are compared with those derived from the regular ADI‐FDTD method. Based on the dispersion analysis, a guideline for choosing an appropriate time step in the ADI‐FDTD implementation is also developed. Both numerical simulation and dispersion analysis demonstrate the advantage of this higher order ADI‐FDTD method for improving accuracy. © 2003 Wiley Periodicals, Inc. Microwave Opt Technol Lett 37: 8–12, 2003; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.10808
A linear approximation of the coupling coefficient in the WDM coupler
Authors: Chen Ye , Joines William T. 
Published: February 2003

AbstractA linear approximation of the coupling coefficient for the wavelength division multiplexing (WDM) coupler is presented. Our aim is to better understand and to simplify the design of couplers used in optical communications. The theoretical calculation and the derivation of the linear coupling coefficient were obtained based on coupled mode theory and a simplified equation pertaining to rectangular and circular waveguide couplers. © 2003 Wiley Periodicals, Inc. Microwave Opt Technol Lett 37: 12–15, 2003; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.10809
A simple fiber‐Bragg‐grating sensor system based on a linear‐cavity fiber laser
Authors: Peng Peng‐Chun , Tseng Hong‐Yih , Chi Sien 
Published: February 2003

AbstractA simple fiber‐Bragg‐grating (FBG) sensor system based on a linear‐cavity fiber laser is proposed and experimentally demonstrated. The lasing wavelength shift resulting from the temperature variation on this sensing element is discriminated by two FBGs. These two FBGs, acting as wavelength discriminators, are used to increase the real‐time measurement range for monitoring the temperature variation. © 2003 Wiley Periodicals, Inc. Microwave Opt Technol Lett 37: 15–17, 2003; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.10810
Direction‐of‐arrival estimation for ultra‐wideband EM pulses with an interferometry
Authors: Morimoto T. , Hirata A. , Kawasaki Z. , Shiozawa T. 
Published: February 2003

AbstractIn this paper, we present an interferometry for the direction‐of‐arrival estimation of ultra‐wideband electromagnetic waves. The interaction between the antennas composing the interferometer is calculated by using the finite‐difference time‐domain (FDTD) method, and taken into account in the analysis. We propose a new signal processing scheme for wideband pulses, and demonstrate its effectiveness using a typical wideband pulse. © 2003 Wiley Periodicals, Inc. Microwave Opt Technol Lett 37: 17–18, 2003; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.10811
Investigation of printed reflectarrays as permanent scatterers in SAR interferometry
Authors: Venneri Francesca , Costanzo Sandra , Di Massa Giuseppe , Angiulli Giovanni 
Published: February 2003

AbstractThe use of printed reflectarrays as permanent scatterers in SAR interferometry is investigated. The required feature of a backscattered field in a fixed direction of incidence is obtained as in the usually employed corner‐reflectors, with a more stable and flat structure. A 10‐GHz prototype has been successfully designed and tested. © 2003 Wiley Periodicals, Inc. Microwave Opt Technol Lett 37: 18–20, 2003; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.10812
Extension of forward‐backward method with a DFT‐based acceleration algorithm for efficient analysis of radiation/scattering from large finite‐printed dipole arrays
Authors: Çivi Özlem Aydın 
Published: February 2003

AbstractA discrete‐Fourier‐transform (DFT) based forward‐backward (FB) algorithm has been developed for the fast and accurate analysis of electrically large freestanding dipole arrays [1]. In this paper, an extension of the FB method (FBM) with a DFT‐based acceleration approach is presented to provide a relatively efficient analysis of EM radiation/scattering from an electrically large, planar, periodic, finite dipole array printed on a grounded dielectric substrate. Computational complexity of this new approach is O(Ntot), where Ntot is the number of unknowns. Numerical results are presented to validate the efficiency and accuracy of the method. © 2003 Wiley Periodicals, Inc. Microwave Opt Technol Lett 37: 20–26, 2003; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.10813
A distributed network model of SOI MOSFET for microwave frequency applications
Authors: Kapoor Nirupama , Haldar Subhasis , Gupta Mridula , Gupta R. S. 
Published: February 2003

AbstractIn this paper, a small signal model of SOI MOSFET operating in the inversion region is developed, taking into account the distributed nature of the gate structure. Because the width of the device is large compared to its length, it is essential to consider it as a transmission line. The y and s parameters have been evaluated to obtain various gains, which otherwise cannot be predicted using lumped analysis. This model is useful in predicting the device's high‐frequency performance. © 2003 Wiley Periodicals, Inc. Microwave Opt Technol Lett 37: 26–31, 2003; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.10814
A wideband rectangular microstrip antenna using an asymmetric T‐shaped feed
Authors: Lethakumary B. , Menon Sreedevi K. , Aanandan C. K. , Mohanan P. 
Published: February 2003

AbstractAn electromagnetically coupled T‐shaped microstrip feed used to enhance the impedance bandwidth of a rectangular microstrip antenna is reported. The proposed antenna offers a 2:1 VSWR bandwidth of ∼36% with an increase in gain of 0.8 dB. © 2003 Wiley Periodicals, Inc. Microwave Opt Technol Lett 37: 31–32, 2003; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.10815
Pulse wave propagating in coplanar waveguides (CPWS) on LTCC substrates
Authors: Yin W. Y. , Guo B. , Dong X. T. 
Published: February 2003

AbstractThe propagation of pulse waves in coplanar waveguides (CPWs) is investigated, and these CPWs are assumed to be fabricated on a single‐layer low‐temperature co‐fired ceramic (LTCC) substrate. The input pulse wave can be a Gaussian pulse or a sinusoidally modulated Gaussian pulse. Based on the standard Galerkin's method in the spectral domain, combined with fast Fourier transform (FFT), the pulse waveform and delay in CPWs are demonstrated and compared for LTCCs with different permittivities. © 2003 Wiley Periodicals, Inc. Microwave Opt Technol Lett 37: 32–34, 2003; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.10816
A tunable‐output wavelength converter based on a self‐seeded Fabry‐Perot laser diode with a chirped fiber grating
Authors: Lee Kwang‐Hyun , Cho Yong‐Sang , Kim Sangin , Choi Woo‐Young 
Published: February 2003

AbstractWe report a new all‐optical wavelength conversion scheme based on a self‐seeded Fabry–Perot laser diode with a chirped fiber grating as the external cavity. This converter can convert the wavelength of input optical signals into 14 discrete wavelengths with external RF modulation. We successfully demonstrate all‐optical wavelength conversion at 10 Mbps. © 2003 Wiley Periodicals, Inc. Microwave Opt Technol Lett 37: 35–36, 2003; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.10817
On radiation from canonical source configurations embedded in structurally chiral materials
Authors: Lakhtakia Akhlesh 
Published: February 2003

AbstractRadiation due to six canonical configurations for the source current density embedded in a structurally chiral medium is analyzed theoretically. The radiation spectrum is highly dependent on whether its source is co‐chiral or cross‐chiral, and is localized either in or on the edges of the Bragg regime. The obtained conclusions hold for both chiral liquid crystals and chiral sculptured thin films doped with fluorescent dyes, etc. © 2003 Wiley Periodicals, Inc. Microwave Opt Technol Lett 37: 37–40, 2003; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.10818
The generalized Foster theorem and network‐Q
Authors: Liang Changhong , Su Tao 
Published: February 2003

AbstractThis paper proves the generalized Foster theorem, which can be applied to any lossy situation, while the original Foster theorem [1] only applied to reactive termination. Furthermore, the formula of Q with network parameters is described. One example, the quality factor Q of a pass‐through resonant cavity, is given here. It is clearly seen that the slope of the reactance function may be negative in a lossy situation. © 2003 Wiley Periodicals, Inc. Microwave Opt Technol Lett 37: 40–45, 2003; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.10819
Design of long‐period gratings: Necessity of a three‐layer fiber geometry for cladding mode characteristics
Authors: Singh Rashmi , Kumar Harish , Sharma Enakshi Khular 
Published: February 2003

AbstractIn this paper, we show that a complete three‐layer analysis is necessary to characterise the cladding modes in order to obtain grating period, resonances, and coupling length in the design of long‐period gratings (LPGs), and that the simplified two‐layer fiber geometry used by many authors leads to incorrect designs. This is illustrated by design calculations corresponding to actual applications of long‐period gratings as sensors and gain equalisation filters for EDFA. © 2003 Wiley Periodicals, Inc. Microwave Opt Technol Lett 37: 45–49, 2003; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.10820
High performance RF integrated passive devices on thick oxide substrate using Cu‐BCB process
Authors: Jeong Inho , Kim Ki‐Joong , Kong Tong‐Ook , Kim Jun‐Seok , Choi Hyung‐Kyu , Nam Choong‐Mo , Kim Dong‐Wook , Kwon Young‐Se 
Published: February 2003

AbstractIn this paper, we develop a low‐cost manufacturing technology for RF substrate and a high‐performance process technology for integrated passive devices by electrochemically forming thick oxide on Si wafer and processing Cu thick metal and BCB. Several integrated passive devices such as LPF, BPF, and balun are fabricated using this technology and they show good RF performance in spite of their small chip size. © 2003 Wiley Periodicals, Inc. Microwave Opt Technol Lett 37: 49–52, 2003; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.10821
Non‐linear modeling of 0.18‐μM CMOS using neural network
Authors: Alam M. S. , Armstrong G. A. , Toner B. , Fusco V. F. 
Published: February 2003

AbstractThis paper describes an artificial‐neural‐network (ANN) based non‐linear modeling of deep‐submicron CMOS for RF applications. The neural network model is concise when compared to the conventional modeling approach based on empirical equations and can demonstrate comparable accuracy. The non‐linear voltage dependence of drain current, transconductance, and inter electrode capacitance can be characterized by a 3‐layered neural network, whose inputs are the gate‐to‐source bias voltage Vgs and drain‐to‐source bias Vds. The corresponding “well‐trained” neutral network has been found to be in excellent agreement with all intrinsic parameters and the drain current with measured data exhibits good extrapolation characteristics. This model has been implemented in an Agilent ADS simulation environment and tested on a 0.18‐μm CMOS technology operating at 2.4 GHz. © 2003 Wiley Periodicals, Inc. Microwave Opt Technol Lett 37: 53–56, 2003; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.10822
Combination of genetic algorithm (GA) and fast fourier transform (FFT) for synthesis of arrays
Authors: Wang L. L. , Fang D. G. , Sheng W. X. 
Published: February 2003

AbstractA novel method based on a combination of genetic algorithm (GA) and fast Fourier transform (FFT) is developed to synthesize antenna arrays. Compared with the synthesis method using GA in an angle domain, it can calculate more quickly while maintaining the same precision. Simulation results show this method is applicable. © 2003 Wiley Periodicals, Inc. Microwave Opt Technol Lett 37: 56–59, 2003; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.10823
A circular microstrip‐fed single‐layer single‐slot antenna for multi‐band mobile communications
Authors: Jang Yong‐Woong 
Published: February 2003

AbstractIn this paper, we study a circular microstripline‐fed single‐layer single‐slot antenna. In this case, a modified circular microstrip feedline leads to good impedance matching in a wide dual band. The 10‐dB return loss impedance bandwidth is 50.8% for cellular (0.824–0.96 GHz) and GSM (0.86–0.88 GHz) operations, and is 37.1% for DCS (1.71–1.88 GHz), PCS (1.85–1.99 GHz), and IMT‐2000 (1.90–2.20 GHz) operations. We obtain the result for the return loss of exhibited multi‐band characteristics. The peak antenna gain is 4.61 dBi and 3.80 dBi for the lower (cellular and GSM) and upper (DCS, PCS, and IMT‐2000) bands, respectively. © 2003 Wiley Periodicals, Inc. Microwave Opt Technol Lett 37: 59–62, 2003; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.10824
A two‐layer compact electromagnetic bandgap (EBG) structure and its applications in microstrip filter design
Authors: Yang Ning , Chen Zhi Ning , Wang Yun Yi , Chia M. Y. W. 
Published: February 2003

AbstractThis paper presents a compact electromagnetic bandgap (EBG) structure and its applications in microstrip bandstop filter designs in the S band. The proposed EBG cell is constructed in a two‐layer dielectric substrate, which saves the lateral sizes due to a multi‐layer topology. A lumped‐LC equivalent circuit is extracted from EM simulation. By adjusting the patch dimensions and positions of the shorting pins, the center frequency and equivalent L, C parameters can meet design requirements. Based on the proposed structure and its equivalent circuit, a wideband 3‐pole notch filter is designed. The simulation and measurement show its promising applications in microwave and RF systems. © 2003 Wiley Periodicals, Inc. Microwave Opt Technol Lett 37: 62–64, 2003; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.10825
Correct analysis of Gires–Tournois absorbing interferometer by the method of single expression
Authors: Baghdasaryan Hovik V. , Knyazyan Tamara M. , Berberyan Suren S. , Mankulov Albert A. 
Published: February 2003

AbstractA unidirectional reflective Gires–Tournois interferometer consisting of a highly reflective metallic mirror, an absorbing semitransparent metallic layer, and a dielectric layer between them, is correctly analyzed using the method of single expression (MSE). The interferometer's spectral characteristics versus the distance between the mirrors for different values of semitransparent metallic layer thickness are obtained. Optimal parameters of the interferometer for maximal reflection and maximal absorption of light are defined. Electric‐field and power‐flow density distributions within the whole structure of the interferometer for maximal reflection and absorption are obtained. © 2003 Wiley Periodicals, Inc. Microwave Opt Technol Lett 37: 64–67, 2003; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.10826
A broadband self‐biased monolithic frequency doubler for X‐band application
Authors: Giannini F. , Limiti E. , Serino A. 
Published: February 2003

AbstractA broadband monolithic single‐ended active frequency doubler fed by a single positive DC power supply is presented. The effects of the self‐bias approach on the doubler performances are investigated and a design method is proposed. Measured performances demonstrate the competitiveness of the proposed circuit with respect to more traditional doublers. © 2003 Wiley Periodicals, Inc. Microwave Opt Technol Lett 37: 67–69, 2003; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.10827
A theoretical analysis of the propagation characteristics of an annular circular waveguide with a helical winding as the inner cladding
Authors: Kumar N. , Srivastava S. K. , Ojha S. P. 
Published: February 2003

AbstractIn this paper, we present a fairly rigorous analysis of a helically inner‐cladded annular step‐index waveguide. Using the sheath‐helix boundary conditions on the inner core‐cladding boundary and simple step‐index boundary conditions on the outer core‐cladding boundary, the modal characteristic equation of the waveguide is derived by taking a vector approach and dispersion curves are drawn. We observe the effect of the pitch angle of the helical windings on the modal dispersion characteristics of the proposed waveguide. The main feature of the waveguide is the occurrence of negative dispersion and band gap. This property may be attributed to the periodicity of the inner helical cladding. The width of the forbidden region increases with the pitch angle and thereafter at the pitch angle ≈90° the region is not found. It is also observed that the lowest cutoff value for the usual curves slightly decreases with the increase in the pitch angle. Thus the pitch angle acts as the controlling factor for the negative dispersion and photonic band gap. © 2003 Wiley Periodicals, Inc. Microwave Opt Technol Lett 37: 69–74, 2003; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.10828
Design of a double‐looped monopole array antenna for a DSRC system roadside base station
Authors: Kim Yongjin , Song Choongho , Koo Inmo , Choi Hyungjin , Lee Sangseol 
Published: February 2003

AbstractThe antenna system for a dedicated short‐range communication (DSRC) system must have pattern characteristics that satisfy the system's specifications. Also, the antenna system needs to have good space efficiency for mounting on a roadside base station. The proposed antenna has the traveling‐wave structure of a double‐looped monopole array. The Wilkinson power divider is used for the in‐phase feeding of the array. The designed antenna system's performance is suitable for the DSRC system. © 2003 Wiley Periodicals, Inc. Microwave Opt Technol Lett 37: 74–77, 2003; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.10829
The boundary contour method for piezoelectric media with linear boundary elements
Authors: Wang Qing , Wang Guoqing , Liu Zhengxing , Ding Haojiang 
Published: February 2003

AbstractThis paper presents a development of the boundary contour method (BCM) for piezoelectric media. First, the divergence‐free property of the integrand of the piezoelectric boundary element is proved. Secondly, the boundary contour method formulation is derived and potential functions are obtained by introducing linear shape functions and Green's functions (Computer Methods in Applied Mechanics and Engineering 1998; 158: 65) for piezoelectric media. The BCM is applied to the problem of piezoelectric media. Finally, numerical solutions for illustrative examples are compared with exact ones and those of the conventional boundary element method (BEM). The numerical results of the BCM coincide very well with the exact solution, and the feasibility and efficiency of the method are verified. Copyright © 2003 John Wiley & Sons, Ltd.
Implicit solid, flow and flow–solid finite element approaches in blade forging simulation
Authors: Soltani B. , Mattiasson K. , Samuelsson A. 
Published: February 2003

AbstractA comparative theoretical and numerical study of the flow (rigid‐plastic) and solid (elasto‐plastic, in rate form) simulation approaches applied to the isothermal blade forging process for closing and opening of the dies is presented. In the rigid‐plastic approach the solution is followed by an elasto‐plastic solution in unloading (opening of the dies). The deformation of the billet, effective plastic strains and stresses were compared between the two solutions in the closing of the dies and when the dies were opened. Furthermore, the flow–solid approach was used in simulating the process and then the results, including the time–load and time–volume curves, were compared with previous results. The cost was lower and the efficiency was superior in the suggested flow–solid approach. Copyright © 2003 John Wiley & Sons, Ltd.