bluuebunny/crossref_metadata_2025_split huggingface dataset:
Tri‐section stepped‐impedance bandpass filter with wide stopband performance
Authors: Wang Yunxiu , Wang Bing‐Zhong , Wang Jianpeng , Gao Shanshan , Xiao Shaoqiu 
Published: February 2007

AbstractIn this paper, a compact microstrip bandpass filter with wide stopband performance is presented. Wide stopband performance is achieved by introducing both stepped‐impedance resonator and over‐coupling technique. With the new structure, the filter has not only wide upper stopband performance with harmonic frequency outside 5f0but also compact size. © 2007 Wiley Periodicals, Inc. Microwave Opt Technol Lett 49: 870–872, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI.10.1002/mop.22255
C‐band fully integrated SiGe HBT superharmonic QVCO
Authors: Tseng S. C. , Meng C. C. , Chang Y. W. , Huang G. W. 
Published: February 2007

AbstractThis paper demonstrates a 4‐GHz monolithic SiGe heterojunction bipolar transistor quadrature voltage‐controlled oscillator (QVCO) using superharmonic coupling topology. The QVCO at 4.17 GHz has phase noise of −116 dBc/Hz at 1 MHz offset frequency, output power of −6 dBm, and the figure of merit −179 dBc/Hz. The core current consumption is 3.2 mA at 3 V supply voltage. The die size is about 1.4 mm × 1.2 mm. © 2007 Wiley Periodicals, Inc. Microwave Opt Technol Lett 49: 867–869, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI.10.1002/mop.22256
Shaped beam printed antenna with waveguide power divider for synthetic aperture radar applications
Authors: Sharma S. B. , Kulshrestha Sanjeev , Pandey B. K. , Sharma D. K. , Jyoti Rajeev , Chakrabarty S. B. 
Published: February 2007

AbstractThis paper presents design and development of X band 8 × 32 element planar array, with center frequency at 9.65 GHz. Stacked microstrip patch antenna where the lower patch is directly fed by microstrip line has been used as a single radiating element. The complex excitation coefficients have been computed using null perturbation technique, so as to provide shaped beam pattern in elevation plane and pencil beam pattern in the azimuth plane. Eight elements have been used to form shaped pattern. Different sets of coefficients were computed. The set of excitation coefficient that results in minimum current taper ratio has been selected to realize the antenna. H plane septum power divider has been used for high‐power requirement, along with tapered transition from waveguide to microstrip. The simulated and measured data on return loss and radiation patterns have been presented. © 2007 Wiley Periodicals, Inc. Microwave Opt Technol Lett 49: 832–835, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.22257
Multicenter perfectly matched layer implementation for finite element mesh truncation
Authors: Ozgun Ozlem , Kuzuoglu Mustafa 
Published: February 2007

AbstractWe present the multicenter perfectly matched layer (PML) technique, which is an easy and practical conformal PML implementation, obtained by the complex coordinate stretching, to the problem of mesh truncation in the finite element method. After developing the analytical background of this method, we demonstrate its performance in electromagnetic radiation/scattering problems. © 2007 Wiley Periodicals, Inc. Microwave Opt Technol Lett 49: 827–832, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.22258
A simple method to design a compact and high performance wideband filter
Authors: Hung Cheng‐Yuan , Weng Min‐Hang , Su Yan‐Kuin , Yang Ru‐Yuan 
Published: February 2007

AbstractIn this letter, a simple method to design a compact and high performance dual hooks wideband filter with open stubs is presented. By combining the coupled line section with two tapped open stubs, a wideband filter with wide stopband and very high passband selectivity is realized. This filter at center frequency f0 of 5.3 GHz has presented very good measured characteristics, including 3‐dB fractional bandwidth of 85%, very low insertion loss of −0.5 ± 0.3 dB, wide stopband from 8 to 15 GHz, and very high selectivity near the passband edge. © 2007 Wiley Periodicals, Inc. Microwave Opt Technol Lett 49: 822–824, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.22268
Generation of dark RZ signals by using one delayed line Mach‐Zehnder interferometer along with one phase modulator
Authors: Shao Yufeng , Chen Lin , Wen Shuangchun 
Published: February 2007

AbstractWe propose and experimentally demonstrate a simple and novel optical transmitter for 10‐Gbit/s dark RZ signals. The proposed transmitter comprises a phase modulator and a delayed line Mach‐Zehnder (DL‐MZ) interferometer. Different duty cycle and extinction ratio of dark RZ signals can be generated by adjusting the time delayed line of the DL‐MZ interferometer. Dark RZ signals show higher optical spectra efficiency. © 2007 Wiley Periodicals, Inc. Microwave Opt Technol Lett 49: 755–759, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.22272
Tunable erbium‐doped fiber ring laser based on coupling between side‐polished fiber and sliding tapered planar waveguide
Authors: Lee Dong‐Ho , Kwon Kwang‐Hee , Song Jae‐Won , Kim Kwang‐Taek 
Published: February 2007

AbstractA tunable erbium‐doped fiber ring laser was made using a tunable side‐polished fiber (SPF) filter with a tapered planar waveguide (PWG). The thickness of the tapered PWG varied because it slides laterally on the side‐polished region. The proposed SPF filter does not need additional physical energy after resonant wavelength selected. Tuning direction of SPF filter is not limited. In addition, the proposed SPF filter can change the tuning resolution by changing the tapered angle of PWG. © 2007 Wiley Periodicals, Inc. Microwave Opt Technol Lett 49: 887–889, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.22273
A closed‐form solution to the asymptotic part of the MOM impedance matrix and the MOM excitation vector for printed structures on planar grounded dielectric slabs
Authors: Bakýr O. , Ertürk V. B. 
Published: February 2007

AbstractIn the spectral domain method of moments (MoM) solution of printed structures on planar grounded dielectric slabs, the infinite double integrals which appear in the asymptotic parts of the MoM impedance matrix and the MoM excitation vector elements, have been previously transformed to one‐dimensional finite integrals, which have been numerically computed using the highly specialized “International Mathematics and Statistics Library” subroutines. In this paper, these one‐dimensional integrals are evaluated in closed‐form, resulting in an improved efficiency and accuracy for the rigorous investigation of printed antennas and complex millimeter and microwave integrated circuits. Numerical results in the form of mutual impedance between two expansion functions and input impedance of various microstrip antennas are presented to assess the accuracy of these closed‐form expressions. © 2007 Wiley Periodicals, Inc. Microwave Opt Technol Lett 49: 882–886, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.22274
Noise modeling of heterojunction bipolar transistors using neural network approach
Authors: Marković V. , Prasad S. , Stoǐć A. 
Published: February 2007

AbstractThe advantages of heterojunction bipolar transistors (HBTs) make them very promising for modern RF communication systems and therefore their noise performance becomes an important issue as well. A procedure for HBT noise modeling based on the neural network approach is presented in this paper. The proposed models are characterized by high accuracy and efficiency commonly requested for today's CAD techniques. © 2007 Wiley Periodicals, Inc. Microwave Opt Technol Lett 49: 852–854, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI.10.1002/mop.22275
Expressions of radiation field and input resonance resistance of coaxial and microstrip line fed rectangular microstrip antennas
Authors: Şimşek Serkan , Işık Cevdet , Tezel Necmi Serkan , Akkaya İnci 
Published: February 2007

AbstractIn this paper, the radiation field of a rectangular microstrip antenna is calculated considering four edges of the antenna. The present method is based on expressing the radiated field, the radiation power, and the power losses in terms of the feeding voltage, and then developing an expression for the input resonance resistance of the antenna at resonance. © 2007 Wiley Periodicals, Inc. Microwave Opt Technol Lett 49: 817–822, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.22277
Wideband and low noise CMOS amplifier for UWB receivers
Authors: Jung Jihak , Yun Taeyeoul , Choi Jaehoon , Kim Hoontae 
Published: February 2007

AbstractAn ultra‐wideband (UWB) low noise amplifier (LNA) that consists of two common‐source and shunt‐feedback stages is presented. Measurement results show the maximum gain (S21) of 13.5 dB with the 3‐dB band from 1.85 to 10.2 GHz and return losses (S11, S22) of less than −10 dB from 3 to 11 GHz. In addition, the fabricated LNA achieves the average noise figure (NF) of 4.5 dB from 1.85 to 10.2 GHz. To our knowledge, these are the best measured data up to date for the CMOS LNA. The input‐referred third‐order intercept point (IIP3) and the input‐referred 1‐dB compression point (P1dB) are obtained as −1 dBm and −9 dBm, respectively, while consuming 13 mW in 0.18 μm RF CMOS process. © 2007 Wiley Periodicals, Inc. Microwave Opt Technol Lett 49: 749–752, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.22282
Design and implementation of a 1.5‐ to 17‐GHz SiGe UWB LNA utilizing multiple‐feedback loops and inductive peaking technique
Authors: Yen Shu‐Hui , Lin Yo‐Sheng , Chen Chi‐Chen 
Published: February 2007

AbstractIn this paper, we demonstrate a 1.5‐ to 17‐GHz ultra‐wideband (UWB) low‐noise amplifier (LNA) with small‐inductance input inductor and multiple‐feedback loops implemented in a 0.35 μm SiGe BiCMOS technology. A method named inductive peaking, which adds an inductor in series with the base‐terminal of the second‐stage amplifier to enhance the frequency of the dominant pole, was adopted to improve gain and bandwidth of the LNA. The measurement results show that very flat gain (S21) of 8 ± 0.5 dB was achieved for frequencies between 2 and 15 GHz. In addition, reverse isolation (S12) lower than −27 dB, input return loss (S11) and output return loss (S22lower than −9 dB, and noise figure lower than 5.5 dB was achieved in the 3.1–10.6 GHz UWB band. The chip area was 775 × 710 μm2, excluding the test pads. This LNA drains 7 mA current at supply voltage of 3 V, i.e. it only consumes 21 mW power. © 2007 Wiley Periodicals, Inc. Microwave Opt Technol Lett 49: 876–879, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI.10.1002/mop.22284
Photo‐induced millimeter wave losses in coplanar waveguide on high resistivity silicon
Authors: Poesen G. , Koers G. , Stiens J. , Carchon G. , De Raedt W. , Vounckx R. 
Published: February 2007

AbstractWe report on a multifunctional optoelectronic radio frequency attenuator for millimeter wave applications, designed in a multilayer thin‐film multichip module technology on high resistive silicon. Insertion loss of measurements and electromagnetic simulations of a coplanar waveguide line under illumination demonstrate a contrast of 40 dB at 100 GHz. © 2007 Wiley Periodicals, Inc. Microwave Opt Technol Lett 49: 808–810, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.22288
Photonic crystal optical fibers for dispersion compensation and Raman amplification: Design and experiment
Authors: Digweed‐Lyytikainen K. , De Francisco C. A. , Spadoti D. , Juriollo A. A. , Rosolem J. B. , Ayres Neto J. B. M. , Borges B. V. , Canning J. , Romero M. A. 
Published: February 2007

AbstractAn optimal design of photonic crystal optical fibers for simultaneous dispersion compensation and Raman amplification is investigated by numerical simulation using the finite‐difference simultaneous over‐relaxation method. The proposed fiber was fabricated and experimental characterization results are presented. © 2007 Wiley Periodicals, Inc. Microwave Opt Technol Lett 49: 872–874, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI.10.1002/mop.22294
An explicit fourth‐order accurate FDTD method based on the staggered ADAMS‐bashforth time integrator
Authors: Xiao Fei , Tang Xiaohong , Wang Ling 
Published: February 2007

AbstractThis article presents an explicit fourth‐order accurate Finite Difference Time Domain (FDTD) method, in which the fourth‐order accurate staggered Adams‐Bashforth time integrator is used for temporal discretization and the fourth‐order accurate Taylor Central Finite Difference scheme for spatial discretization. The analysis shows that the numerical dispersion of the new FDTD method is much lower than that of the Fang‐FDTD method and the stability restraint of the new FDTD methods is relaxed in comparison with that of the FDTD method using the Staggered Backward Differentiation time integrator. © 2007 Wiley Periodicals, Inc. Microwave Opt Technol Lett 49: 910–912, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.22303
A valid and convenient method of using mode charts and quality factor charts in DR cavity filter designs
Authors: Sun Xiaoguang 
Published: February 2007

AbstractMode charts and Quality factor charts are computed using the mode matching method in the article. To get accurate Q factors, perturbation theory is applied. Using the charts, a six‐cavity DR filter is designed and fabricated. And the validity of the method is verified by experiment. © 2007 Wiley Periodicals, Inc. Microwave Opt Technol Lett 49: 960–963, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.22310
Study of ground plane of dual‐band patch antenna on SAR
Authors: Chan K. H. , Tang C. K. , Wong K. H. , Fung L. C. , Leung S. W. 
Published: February 2007

AbstractThis paper investigates the effects of different ground plane configurations of a typical GSM900/1800 dual‐band internal planar inverted‐F patch antenna (PIFA) on specific absorption rate (SAR) and corresponding antenna performance. The effect of the length and width of the ground plane and the addition of vertical sidewall on the ground plane are presented. Results have shown that when the length and width of the antenna ground plane is increased, the SAR value could be reduced while radiation efficiency is not significantly affected, the antenna gain is reduced by 3.5 dB at 930 MHz, and the envelope of far‐field antenna pattern is mainly affected in the human head direction. The addition of vertical sidewall at four sides of the ground plane with a height of 7 mm could provide a SAR reduction at 1.75 GHz by 63% without significantly affecting the performance of the PIFA antenna. © 2007 Wiley Periodicals, Inc. Microwave Opt Technol Lett 49: 949–953, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.22316
Refractive index sensor based on fiber laser
Authors: Yang Xiufeng , Luo Shaojun , Chen Zhihao , Ng Jun Hong 
Published: February 2007

AbstractA refractive index sensor based on the transient behavior of the fiber laser is presented. The refractive index was measured by monitoring the delay time of the lasing from the pump excitation time. High refractive index sensitivity of 10−6 can be obtained. © 2007 Wiley Periodicals, Inc. Microwave Opt Technol Lett 49: 916–918, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.22318
Surface‐wave bandgap of polarization dependent electromagnetic bandgap structures
Authors: Fu Yunqi , Yuan Naichang 
Published: February 2007

AbstractPolarization‐dependent reflection‐phase feature could be realized by using a rectangular patch in mushroom‐like electromagnetic bandgap (EBG) structures. The surface‐wave bandgap of this polarization‐dependent EBG structure have been investigated in this article. It has been shown that the surface‐wave bandgap along two periodic directions almost overlaps and compactness in one direction could be achieved by increase the length of the other. One compact EBG microstrip line has been presented. © 2007 Wiley Periodicals, Inc. Microwave Opt Technol Lett 49: 949–949, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.22321
Novel bandpass filter with size reduction and harmonic suppression
Authors: Zhang Xiu‐Yin , Xue Quan , Hu Bin‐Jie 
Published: February 2007

AbstractA novel microstrip bandpass filter with size reduction and harmonic suppression is proposed in this article. The filter is based on microstrip open loop resonators with coupled open stubs. By adding coupled open stubs to open loop resonator, extra controllable transmission zero can be obtained. The extra transmission zero can be tuned at the second harmonic frequency to suppress spurious response. When compared with the conventional microstrip open‐loop bandpass filter, this filter could achieve size reduction and spurious responses suppression simultaneously. A demonstration filter was designed, fabricated, and measured. Theoretical and experimental results are presented and show good agreement. © 2007 Wiley Periodicals, Inc. Microwave Opt Technol Lett 49: 914–916, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.22323
Language and communication development in down syndrome
Authors: Roberts Joanne E. , Price Johanna , Malkin Cheryl 
Published: February 2007

AbstractAlthough there is considerable variability, most individuals with Down syndrome have mental retardation and speech and language deficits, particularly in language production and syntax and poor speech intelligibility. This article describes research findings in the language and communication development of individuals with Down syndrome, first briefly describing the physical and cognitive phenotype of Down syndrome, and two communication related domains—hearing and oral motor skills. Next, we describe language development in Down syndrome, focusing on communication behaviors in the prelinguistic period, then the development of language in children and adolescents, and finally language development in adults and the aging period. We describe language development in individuals with Down syndrome across four domains: phonology, semantics, syntax, and pragmatics. Wethen suggest strategies for intervention and directions for research relating to individuals with Down syndrome. © 2007 Wiley‐Liss, Inc. MRDD Research Reviews 2007;13:26–35.
Language and communicative development in Williams syndrome
Authors: Mervis Carolyn B. , Becerra Angela M. 
Published: February 2007

AbstractWilliams syndrome, a genetic disorder caused by a microdeletion of ∼25 genes on chromosome 7q11.23, is associated with mild to moderate intellectual disability or learning difficulties. Most individuals with Williams syndrome evidence a cognitive profile including relative strengths in verbal short‐term memory and language, and considerable weakness in visuospatial construction. The syndrome has often been argued to provide strong evidence for the independence of language from other aspects of cognition. We provide a brief history of early research on the language abilities of individuals with Williams syndrome and then review contemporary studies of language and cognition in Williams syndrome, beginning with a consideration of performance on standardized assessments. In the remainder of the article, we first consider early language acquisition, with a focus on speech production and perception, vocabulary acquisition, and communicative/pragmatic development and then consider the language abilities of school‐age children and adolescents, focusing on semantics, grammar, and pragmatics. We argue that rather than being the paradigm case for the independence of language from cognition, Williams syndrome provides strong evidence of the interdependence of many aspects of language and cognition. © 2007 Wiley‐Liss, Inc. MRDD Research Reviews 2007;13:3–15.
The study of autism as a distributed disorder
Authors: Müller Ralph‐Axel 
Published: February 2007

AbstractPast autism research has often been dedicated to tracing the causes of the disorder to a localized neurological abnormality, a single functional network, or a single cognitive‐behavioral domain. In this review, I argue that autism is a “distributed disorder” on various levels of study (genetic, neuroanatomical, neurofunctional, behavioral). “Localizing” models are therefore not promising. The large array of potential genetic risk factors suggests that multiple (or all) emerging functional brain networks are affected during early development. This is supported by widespread growth abnormalities throughout the brain. Interactions during development between affected functional networks and atypical experiential effects (associated with atypical behavior) in children with autism further complicate the neurological bases of the disorder, resulting in an “exponentially distributed” profile. Promising approaches to a better characterization of neural endophenotypes in autism are provided by techniques investigating white matter and connectivity, such as MR spectroscopy, diffusion‐tensor imaging (DTI), and functional connectivity MRI. According to a recent hypothesis, the autistic brain is generally characterized by “underconnectivity.” However, not all findings are consistent with this view. The concepts and methodology of functional connectivity need to be refined and results need to be corroborated by anatomical studies (such as DTI tractography) before definitive conclusions can be drawn. © 2007 Wiley‐Liss, Inc. MRDD Research Reviews 2007;13:85–95.
Simultaneous B homogenization and specific absorption rate hotspot suppression using a magnetic resonance phased array transmit coil
Authors: Van den Berg Cornelis A. T. , van den Bergen Bob , Van de Kamer Jeroen B. , Raaymakers Bas W. , Kroeze Hugo , Bartels Lambertus W. , Lagendijk Jan J. W. 
Published: February 2007

AbstractIn high‐field MRI severe problems with respect to B uniformity and specific absorption rate (SAR) deposition pose a great challenge to whole‐body imaging. In this study the potential of a phased array transmit coil is investigated to simultaneously reduce B nonuniformity and SAR deposition. This was tested by performing electromagnetic simulations of a phased array TEM coil operating at 128 MHz loaded with two different homogeneous elliptical phantoms and four dielectric patient models. It was shown that the wave interference of a circularly polarized RF field with an ellipse and a pelvis produces largely identical B and electric field patterns. Especially for obese patients, this results in large B nonuniformity and global areas with elevated SAR deposition. It is demonstrated that a phased array transmit coil can reduce these phenomena. The technique was especially successful in suppressing SAR hotspots with a decrease up to 50%. The application of optimized settings for an ellipse to the patient models leads to comparable results as obtained with the patient‐specific optimizations. This suggests that generic phase/amplitude port settings are possible, requiring no preinformation about patient‐specific RF fields. Such a scheme would, due to its simultaneous B homogenization and extra SAR margin, have many benefits for whole‐body imaging at 3 T. Magn Reson Med 57:577–586, 2007. © 2007 Wiley‐Liss, Inc.