bluuebunny/crossref_metadata_2025_split huggingface dataset:
Wideband and low‐loss triangular patch dual‐mode bandpass filter using quasi‐fork recessed tapped I/O
Authors: Chen Han‐Jan , Weng Min‐Hung , Horng Jui‐Hong , Houng Mau‐Phou , Wang Yeong‐Her 
Published: August 2004

AbstractA microstrip triangular‐patch dual‐mode filter using quasi‐fork recessed tapped I/O is designed and fabricated. The proposed filter uses quasi‐fork recessed tapped I/O for enhanced coupling and dual‐mode excitation. The filter characteristics, which are influenced by the recessed depth and gap size between the feed line and the triangular‐patch resonator, is studied. The central frequency of 4.19 GHz, insertion loss S21 of −1.26 dB, and 3‐dB bandwidth of 26.5% are measured, and the three attenuation poles have deep insertion losses of −36.8 dB at 2.72 GHz, −44.6 dB at 3.06 GHz, and −49 dB at 5.56 GHz, respectively. The proposed filters demonstrate good agreement between the experiment and simulation. © 2004 Wiley Periodicals, Inc. Microwave Opt Technol Lett 43: 99–101, 2004; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.20388
Fabry–Perot‐based approach for the measurement of complex permittivity of samples inserted in resonant cavities
Authors: André P. S. , Costa L. C. , Devesa S. 
Published: August 2004

AbstractA new approach to measure the complex dielectric permittivity of materials placed inside a microwave resonant cavity is presented. We exploit the similarity between the microwave cavity and an optical cavity to develop a new measurement technique, which is used to obtain the complex permittivity of a polybutylene terephtalate (PBT). © 2004 Wiley Periodicals, Inc. Microwave Opt Technol Lett 43: 106–108, 2004; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.20390
Lossy transmission line metamaterials
Authors: Caloz Christophe , Itoh Tatsuo 
Published: August 2004

AbstractLossy purely LH and generalized CRLH TL metamaterials are analyzed using both an ideal approach, assuming perfectly homogeneous media, and a lumped‐element approach, taking into account the real periodic LC configuration of artificial metastructures. The effects of losses are identified and discussed. A CRLH TL metamaterial with small losses is shown to exhibit propagation characteristics identical to that of a lossless metamaterial. © 2004 Wiley Periodicals, Inc. Microwave Opt Technol Lett 43: 112–114, 2004; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.20392
A compact very‐high‐permittivity dielectric‐eye resonator antenna for multiband wireless applications
Authors: Paul Binu , Mridula S. , Mohanan P. , Bijumon P. V. , Sebastian M. T. 
Published: August 2004

AbstractA very‐high‐permittivity (εr = 100) multiband dielectric‐eye resonator antenna is presented. The compact antenna, excited by a microstrip line, resonates at two frequencies centered around the 1.9‐GHz and 2.4‐GHz bands with identical polarization. The behavior of the antenna at different positions along the feed line is studied and optimized. Multiple resonances with the same polarization and broad radiation patterns suggest the suitability of the antenna for multiband wireless applications. © 2004 Wiley Periodicals, Inc. Microwave Opt Technol Lett 43: 118–121, 2004; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.20394
A broadband slope‐strip‐fed microstrip patch antenna
Authors: Wang Wei , Chen Sheng‐Bing , Zhong Shun‐Shi 
Published: August 2004

AbstractA novel slope‐strip feeding technique for a microstrip antenna is presented in order to achieve a broad bandwidth. The experimental results show that the optimal bandwidth attained is 53.4% for less than −10‐dB return loss. © 2004 Wiley Periodicals, Inc. Microwave Opt Technol Lett 43: 121–123, 2004; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.20395
An improved substrate‐loss model to determine MOSFET drain, source and substrate elements
Authors: Torres‐Torres Reydezel , Murphy‐Arteaga Roberto , Torres‐Jacome Alfonso 
Published: August 2004

AbstractAn improved model to account for the substrate‐loss effects in RF‐MOSFETs, which includes its associated parameter extraction, is presented in this paper. This model considers the source‐to‐bulk capacitance, which allows the proper modeling of MOSFETs output admittance at high frequencies, thus obtaining an excellent agreement between simulated and experimental data up to 21 GHz. The proposed model also allows the determination of the source and drain resistances at a given gate bias, independent of frequency. © 2004 Wiley Periodicals, Inc. Microwave Opt Technol Lett 43: 126–130, 2004; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.20397
One‐dimensional reconstruction of a defect profile based on millimeter‐wave nondestructive techniques
Authors: Maazi M. , Glay D. , Lasri T. 
Published: August 2004

AbstractThis paper describes a procedure for the characterization of defects inside dielectric materials. This nondestructive technique is supported by the development of a system that operates at 35 GHz. The reconstruction of the defect profile is performed by considering that the measured data are the result of a convolution of the true data with a point‐spread function (PSF). © 2004 Wiley Periodicals, Inc. Microwave Opt Technol Lett 43: 133–138, 2004; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.20399
Numerical validation of dispersion relations using a cylindrical wave for 2D FDTD methods
Authors: Sun Guilin , Trueman Christopher W. 
Published: August 2004

AbstractThe numerical dispersion of a proposed new FDTD scheme is often evaluated and compared with that of well‐established FDTD methods. Because there may be a theoretical deficiency in the dispersion analysis, numerical experimentation is often used to validate the dispersion relation. This paper describes the “matching method” for validation using a cylindrical wave in the two‐dimensional (2D) case. The matching method is demonstrated by evaluating the numerical dispersion of Yee's FDTD and ADI‐FDTD. The result is compared with the analytical numerical dispersion relation, and excellent agreement is obtained. The difference between the theoretical value for the numerical dispersion and that from numerical experiments using the matching method is 10−5 for Yee's FDTD and 10−4–10−5 for ADI‐FDTD. The numerical velocity obtained from the matching method satisfies the theoretical dispersion relation with residual errors to the order of 10−6. Such accuracy is sufficient to conclude that a numerical dispersion relation is correct. Although the matching method uses a cylindrical wave to test the numerical dispersion relation, the cylindrical wave is not a solution of the difference equations, thus it cannot be used to derive a theoretical dispersion relation. © 2004 Wiley Periodicals, Inc. Microwave Opt Technol Lett 43: 138–142, 2004; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.20400
Novel compact photonic band‐gap structures using rectangular increasing‐distance spiral slots
Authors: Fuqi Shan , Baoxin Gao 
Published: August 2004

AbstractA novel, compact, rectangular increasing‐distance spiral‐slot (RIDSS) structure is proposed for photonic band‐gap (PBG) applications. The dimension of the RIDSS structure is only about 1/8λ at the cutoff frequency. Only three cells of the RIDSS‐PBG are sufficient for the measured beyond the 20‐dB stopband from 1470 to 2034 MHz, thus rendering the whole structure super‐compact. © 2004 Wiley Periodicals, Inc. Microwave Opt Technol Lett 43: 144–146, 2004; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.20402
A broadband CPW‐fed nonuniform folded‐slot antenna with a pair of matching slots
Authors: Deng S. M. , Chiu C. W. , Lai T. M. , Chen T. W. 
Published: August 2004

AbstractIn this paper, we describe a variation of a folded slot antenna that is formed by a nonuniform‐width slot. The antenna is fed by a coplanar waveguide on which a pair of small slits are located on both sides for broadband matching. The simulated results and measured data reveal that it enjoys a relatively wide bandwidth of 37.4%. © 2004 Wiley Periodicals, Inc. Microwave Opt Technol Lett 43: 147–148, 2004; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.20403
High‐performance bulk and thin‐film microstrip transmission lines on VLSI‐standard Si substrates
Authors: Chen C. C. , Hung B. F. , Chin Albert , McAlister S. P. 
Published: August 2004

AbstractMicrostrip transmission lines with very low power loss of 0.4 dB/mm at 50 GHz have been fabricated on Si substrates using an optimized ion‐implantation process. These devices have the inherent advantages of smaller chip size and better power performance than CPW lines. Using the same approach, high‐performance thin‐film microstrip lines are also developed, showing a loss of 0.9 dB/mm at 20 GHz. This approach is compatible with existing VLSI backend layout technology. © 2004 Wiley Periodicals, Inc. Microwave Opt Technol Lett 43: 148–151, 2004; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.20404
Characterization of resistive‐loaded wire loop in UWB (impulse) radio
Authors: Li Hui Feng , Chen Zhi Ning , Li Le‐Wei 
Published: August 2004

AbstractThis paper discusses the applicability of loaded circular‐loop antennas for impulse radio systems using a time‐domain integral‐equation (TDIE) method. The circular loops loaded with lumped and distributed resistances are characterized for pulse radiation and reception. The effects of the loads on the current distributions are investigated. The performance of the system comprising two identical loop antennas is examined and validated by measurement for ultra‐wideband applications. © 2004 Wiley Periodicals, Inc. Microwave Opt Technol Lett 43: 151–156, 2004; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.20405
Some properties of an open‐ended circular waveguide with one‐ and two‐sided ideal hard walls
Authors: Skobelev Sergei , Kildal Per‐Simon 
Published: August 2004

AbstractThe problem of radiation from a hard open‐ended circular waveguide excited in the dominant TEM mode is solved. The cases of one‐sided and two‐sided hard‐wall surfaces are considered. The rigorous solution obtained shows that the reflected TEM mode field in the latter case, unlike that in the former case, is completely concentrated at the surface outside the waveguide. © 2004 Wiley Periodicals, Inc. Microwave Opt Technol Lett 43: 160–164, 2004; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.20407
A compact hairpin bandpass filter on high‐permittivity dielectrics using a tape‐casting technique
Authors: Chen Lih‐Shan , Weng Min‐Hung , Huang Tsung‐Hui , Chen Han‐Jan , Hsi Yi‐Chang , Houng Mau‐Phon 
Published: August 2004

AbstractBy using high‐permittivity dielectrics, bandpass filters can be miniaturized. A hairpin‐line filter based on high‐permittivity dielectrics is proposed in this study. Ba2Ti9O20, with high dielectric constant, low loss, and stable temperature is available for the dielectric resonator and is adopted as a material in the fabrication of high‐permittivity ceramic substrates. A tape‐casting technique is employed to produce thin and flat Ba2Ti9O20‐based ceramic substrates. The center frequency of the fabricated bandpass filter is 5.75 GHz and the bandwidth is 742 MHz. The measured insertion and return losses of the filter are −1.34 and −12 dB, respectively. The measured response of the fabricated filter is in agreement with the simulated results. © 2004 Wiley Periodicals, Inc. Microwave Opt Technol Lett 43: 164–166, 2004; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.20408
Gain clamped double‐pass L‐band EDFA with incorporation of FBG at the input end of the optical amplifier
Authors: Harun S. W. , Ahmad H. 
Published: August 2004

AbstractA gain‐clamping technique in two‐stage double‐pass L‐band EDFA is demonstrated using a single fiber Bragg grating (FBG). Two types of FBGs, broadband and narrowband, have been used in the gain‐clamped system. The gain is clamped at 18.7 and 17.5 dB for the design with narrowband and broadband FBGs, respectively. The measured gain variation in both designs is below ±0.15 dB. The maximum input‐signal‐power level for which the gain remains clamped for the narrowband and broadband FBG systems is about −15 and −10 dBm, respectively. However, the existence of a strong laser in the cavity severely reduces the population inversion at the input part of the amplifiers. This causes the noise figure of both designs to increase by 6.4 dB and 3.5 dB for narrowband and broadband FBG system, compared to that of unclamped amplifier, at small signal power. These results show that gain clamping can be achieved in a double‐pass amplifier by simply adding a single FBG, whereby the broadband system shows a better performance than the narrowband system in terms of input‐signal‐power dynamics range and noise figure. © 2004 Wiley Periodicals, Inc. Microwave Opt Technol Lett 43: 166–168, 2004; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.20409
A dual‐mode bandpass filter with a wide stopband
Authors: Weng Min‐Hung , Yang Ru‐Yuan , Hung Cheng‐Yuan , Wu Hung‐Wei , Chen Wu‐Nan , Houng Mau‐Phon 
Published: August 2004

AbstractA novel dual‐mode band‐pass filter with a cross‐shaped resonator and three ring resonators has been designed and implemented. The proposed structure is different from the conventional dual‐mode band‐pass filter. The designed dual‐mode band‐pass filter has a very sharp attenuation rate by two transmission zeros, and high spurious suppression by the band‐stop effect of the three ring resonators. The experiments show good agreement with the simulations. © 2004 Wiley Periodicals, Inc. Microwave Opt Technol Lett 43: 177–179, 2004; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.20412
Clinical features and pathophysiological basis of sensory neuronopathies (ganglionopathies)
Authors: Kuntzer Thierry , Antoine Jean‐Christophe , Steck Andreas J. 
Published: August 2004

AbstractSensory ganglionopathies have a frequent association with neoplastic disorders (paraneoplastic subacute sensory neuronopathy, or SSN) or dysimmune disorders (Sjögren's syndrome, SS; Miller Fisher syndrome; and Bickerstaff's brainstem encephalitis, BBE), with drugs, such as cisplatin or pyridoxine, and with inherited disorders with degeneration of dorsal root ganglion cells. Unsteady gait and pseudoathetoid movements of the hand are the distinctive signs encountered in these disorders. The chronic disorders are characterized by non–length‐dependent abnormalities of sensory nerve action potentials (SNAPs) and differ from other sensory neuropathies in showing a global, rather than distal, decrease in SNAP amplitudes. This review focuses on recent advances in defining the mechanisms involved in sensory ganglionopathies. Specific topics include a summary of their clinical features, pathological findings, and immunopathology. In SSN, early diagnosis by the detection of anti‐Hu antibodies and early treatment of the cancer gives the best chance of stabilizing the disorder. In SS sensory ganglionitis, response to treatment has been disappointing, but immunomodulating treatments are emerging. The immunological profile common to BBE and Fisher syndrome supports a common pathogenesis. In toxic sensory neuronopathy, no treatment is available. The differential diagnosis involves separating sensory ganglionopathies from other ataxic polyneuropathies, such as infectious neuropathies, sensory neuropathies with various autoantibodies, and the neuropathies seen in celiac disease. Muscle Nerve 30:255–268, 2004
Porphyric neuropathy
Authors: Albers James W. , Fink John K. 
Published: August 2004

AbstractThe hepatic porphyrias are a group of rare metabolic disorders characterized by enzymatic defects in the biosynthesis of heme, a metalloporphyrin that is the principal product of porphyrin metabolism. The hepatic porphyrias are genetically transmitted as autosomal‐dominant disorders with variable expression that produce a particularly severe form of neuropathy. Most medical students readily recognize acute attacks of porphyria when the classic triad of abdominal pain, psychosis, and neuropathy is present. Yet, porphyric neuropathy is a source of confusion in practice, and patients with porphyria rarely receive the correct diagnosis early in the course of the illness. Porphyric neuropathy is manifest by symptoms, signs, and cerebrospinal fluid abnormalities resembling acute Guillain–Barré syndrome. However, accompanying psychological features, a proximal predilection of asymmetric weakness, and electrodiagnostic findings indicative of an axonal polyradiculopathy or neuronopathy all suggest the diagnosis of porphyria. Confirmation of the diagnosis depends on use of appropriate laboratory studies. The underlying pathophysiology of porphyric neuropathy has not been established, but it may be related to direct neurotoxicity of elevated levels of δ‐aminolevulinic acid. The severity of the neuropathy and the availability of potential treatments, including avoidance of provocative factors, make identification important. Muscle Nerve 30: 410–422, 2004
A mesh‐free approach to solving the axisymmetric Poisson's equation
Authors: Chen C. S. , Muleshkov A. S. , Golberg M. A. , Mattheij R. M. M. 
Published: August 2004

AbstractIn this article, we extend previous work of Karageorghis and Fairweather (Int J Numer Methods Engng 44 (199), 1653–1669) on the method of fundamental solutions (MFS) for solving Laplace's equation in axisymmetric geometry to the case of Poisson's equation. When the boundary condition and source term are axisymmetric, the problem reduces to solving the Poisson's equation in cylindrical coordinates in the two‐dimensional (r, z) region of the original three‐dimensional domainS.Hence, the original boundary value problem is reduced to a two‐dimensional one. To make use of the MFS, it is necessary to calculate a particular solution, which can be subtracted off, so that the MFS can be used to solve the resulting Laplace problem. This presents a novel problem, since the axisymmetric Poisson operator does not have constant coefficients, so previous methods based on radial basis functions cannot be used. To overcome this, the source term is approximated by a two‐dimensional polynomial inrandzas in Goldberg et al. (Numer Methods Partial Differential Eq 19 (2003), 112–133). One can then obtain polynomial particular solutions by the method of undetermined coefficients. The resulting Laplace equation is then solved by the axisymmetric MFS. Numerical results are given to show the accuracy and efficiency of the proposed numerical method. © 2004 Wiley Periodicals, Inc. Numer Methods Partial Differential Eq, 2005
On the structure and growth rate of unstable modes to the Rossby‐Haurwitz wave
Authors: Skiba Yuri N. , Pérez‐García Ismael 
Published: August 2004

AbstractThe normal mode instability study of a steady Rossby‐Haurwitz wave is considered both theoretically and numerically. This wave is exact solution of the nonlinear barotropic vorticity equation describing the dynamics of an ideal fluid on a rotating sphere, as well as the large‐scale barotropic dynamics of the atmosphere. In this connection, the stability of the Rossby‐Haurwitz wave is of considerable mathematical and meteorological interest. The structure of the spectrum of the linearized operator in case of an ideal fluid is studied. A conservation law for perturbations to the Rossby‐Haurwitz wave is obtained and used to get a necessary condition for its exponential instability. The maximum growth rate of unstable modes is estimated. The orthogonality of the amplitude of a non‐neutral or non‐stationary mode to the Rossby‐Haurwitz wave is shown in two different inner products. The analytical results obtained are used to test and discuss the accuracy of a numerical spectral method used for the normal mode stability study of arbitrary flow on a sphere. The comparison of the numerical and theoretical results shows that the numerical instability study method works well in case of such smooth solutions as the zonal flows and Rossby‐Haurwitz waves. © 2004 Wiley Periodicals, Inc. Numer Methods Partial Differential Eq, 2005
First‐trimester diagnosis of hydrolethalus syndrome in a Chinese family
Authors: Chan Ben Chong Pun , Shek Tony Wai Hung , Lee Chin Peng 
Published: August 2004

AbstractWe report a case resembling hydrolethalus syndrome in a Chinese family. Fetal polydactyly, syndactyly, encephalocele and cardiac malformation were detected on ultrasound examination at 12 weeks' gestation. Termination of pregnancy was performed, and postmortem examination confirmed the findings. This is the first report of a first‐trimester prenatal diagnosis of hydrolethalus syndrome in the Chinese population. Copyright © 2004 John Wiley & Sons, Ltd.
The impact of fetal renal pelvic diameter on postnatal outcome
Authors: John Ulrike , Kähler Christiane , Schulz Sven , Mentzel Hans Joachim , Vogt Susanna , Misselwitz Joachim 
Published: August 2004

AbstractObjectivesTo determine thresholds for the fetal renal pelvic anterior–posterior diameter (APD) predicting postnatal clinically relevant pelvicaliceal dilatation.MethodsOne hundred and forty‐eight infants whose prenatal sonography had identified an isolated uni‐ or bilateral fetal APD of ≥4 mm before 33 and/or ≥7 mm after 33 weeks' gestational age were investigated postnatally. On the basis of postnatal ultrasound examination, these infants were grouped according to the Society for Fetal Urology Grading System: no pelvic dilatation (n = 38); only pelvic dilatation (n = 59); pelvicaliceal dilatation (n = 33); pelvicaliceal and ureter dilatation (n = 18).ResultsFetal pyelectasis of 7 mm was 89.3% sensitive and 78.9% specific <33 weeks, and ≥33 weeks pyelectasis of 10 mm was 88.4% and 78.6% in predicting subsequent postnatal pelvicaliectasis, respectively. Using a threshold of 4 mm <33 weeks and 7 mm ≥33 weeks yielded a sensitivity of 100% and a specificity of 18.7% and 47.8%, respectively. The median APD (range) at ≥33 weeks was 19 mm (9–36 mm) in patients requiring surgery and 13 mm (7–21 mm) in conservatively treated patients (p = 0.001). Thirteen of fourteen patients with APD ≥ 19 mm underwent surgery.ConclusionWomen with ultrasonographically detected prenatal fetal pelvic dilatation of ≥4 mm before 33 weeks and of ≥7 mm from 33 weeks onwards of gestation should have repeated prenatal ultrasound scans and a detailed postnatal evaluation. The dilatations of an APD >4 mm before 33 weeks, which have disappeared at the post‐33‐week scan need no further investigation in the postnatal period. Copyright © 2004 John Wiley & Sons, Ltd.