bluuebunny/crossref_metadata_2025_split huggingface dataset:
Synergistic digital predistorter based on a low memory power amplifier for wideband linearization
Authors: Kim Jangheon , Moon Junghwan , Kim Ildu , Kim Jungjoon , Kim Bumman 
Published: March 2009

AbstractWe investigate on linearization performance of a digital predistortion (DPD) linearization technique based on the low memory power amplifier (PA) for wideband signals. The low memory PA is implemented using a 90W PEP LDMOSFET at 2.14 GHz, and an envelope short matching topology is applied at the active ports to minimize memory effects. To explore memory effects of the implemented amplifier, the amplifier is tested through two‐tone signals (up to 20 MHz tone spacing). The proposed DPD technique is compared with DPD technique based on a PA exhibiting serious memory effects for a forward‐link WCDMA 3FA signal with 15‐MHz bandwidth. The experimental result shows that the proposed DPD scheme has better linearization performance than the conventional digital predistorter and lower computational complexity over the conventional wideband digital predistorters. © 2009 Wiley Periodicals, Inc. Microwave Opt Technol Lett 51: 1548–1552, 2009; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.24357
A comparison of single mode and multimode fiber links for use in wireless‐over‐fiber systems
Authors: Sittakul V. , Cryan M. J. 
Published: March 2009

AbstractThis article compares the performance of standard single mode fiber (SMF) with 62.5/125 μm multimode fiber (MMF) for radio‐over‐fiber links using 850 nm multimode vertical cavity surface emitting lasers. The results show SMF links suffer from a coupling loss of 15.3 dB which is compensated by the low loss of SMF compared to MMF in the 2.4–5 GHz radio band. Standard SMF is not single moded at 850 nm and mode filters are employed to obtain a smooth modulation response. © 2009 Wiley Periodicals, Inc. Microwave Opt Technol Lett 51: 1445–1449, 2009; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.24362
Implementation of dynamic Hadamard diffuser as a frequency selective surface for W‐band active millimeter wave imaging
Authors: Islam Saiful , Stiens Johan , Jaeger Irina , Poesen Gert , Vounckx Roger 
Published: March 2009

AbstractWe present the design, construction and testing of dynamic 2 × 2 Hadamard diffuser used to reduce speckle, produced by coherent millimeter‐wave sources in active imaging. The 1's and −1's binary entities of the Hadamard matrix constitute the inputs for the construction of sets of orthogonal matrix pattern, corresponding to illumination patterns. The sequence of orthogonal phase patterns was obtained by changing the frequency of the incident beam. Hadamard phase cells were designed on a single wafer considering three grounded sub‐arrays of different slot lengths for the first three quadrants and the artificial magnetic conductor for the last quadrant. We designed the FSS arrays with the finite integral technique, fabricated with etching techniques, and characterized the vector S‐parameters with a free space network analyzer. © 2009 Wiley Periodicals, Inc. Microwave Opt Technol Lett 51: 1440–1445, 2009; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.24363
An extremely miniaturized microstrip branch‐line coupler
Authors: Nosrati Mehdi 
Published: March 2009

AbstractIn this letter, an extremely miniaturized branch‐line coupler (BLC) operating at 0.9 GHz is analyzed, designed, and introduced to enhance the bandwidth accompanied by highly size reduction without via‐holes, multilayered technique, and air‐bridged. A combination of a simple low‐pass and band‐stop filters is proposed to increase isolation between BLC's ports. This model is equaled by a quarter‐wavelength line and necessary equations are obtained using even and odd modes analysis. A compact BLC is designed and tested using this technique. It is shown that the proposed BLC works as well as conventional ones though with size reduction of about 74% and 4.5% enhancement in bandwidth in analogy with recent branch‐line coupler. The measurement results are in good agreement with the theoretical. © 2009 Wiley Periodicals, Inc. Microwave Opt Technol Lett 51: 1403–1406, 2009; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.24365
End‐coupled microstrip slow‐wave resonator filtlers using high‐permittivity ceramic substrate
Authors: Huang Cheng‐Liang , Liu Shih‐Sheng 
Published: March 2009

AbstractThe miniaturization of end‐coupled microstrip slow‐wave resonator filters using two high‐permittivity ceramic substrates (with respective dielectric constants of 9.7 and 25.45) were investigated. The designed end‐coupled structures were simulated using an IE3D simulator. The responses of the fabricated filters using Al2O3 (εr = 9.7, tan δ = 0.000036) and newly developed 0.85MgTiO3‐0.15Ca0.6La0.8/3TiO3 (εr = 25.45, tan δ = 0.00002) ceramic substrates were designed to have a center frequency of 1.8 GHz. The proposed filter showed not only a tremendous reduction in the insertion loss but also demonstrates a marvelous cut in its size. © 2009 Wiley Periodicals, Inc. Microwave Opt Technol Lett 51: 1613–1615, 2009; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.24366
Printed ultra‐wide band microstrip‐line fed slot antenna with a band‐notched function
Authors: Gao Guo‐Ping , Zhang Jin‐Sheng , Jin Tian 
Published: March 2009

AbstractA novel printed ultra‐wide band microstrip‐line fed slot antenna with a band‐notched function suitable for ultra‐wide band application is presented and investigated in this article. The band‐notched characteristic is achieved by inserting a circular arc slot on the circular patch. Experimental results show that the proposed antenna meets the requirement of wide working bandwidth of 3.1–10.6 GHz with VSWR <2, while avoiding the interference with the 5‐GHz wireless local area network band. The magnitude and phase of S21 and group delay are also measured and discussed in this article. © 2009 Wiley Periodicals, Inc. Microwave Opt Technol Lett 51: 1573–1576, 2009; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.24368
All‐optical frequency converter based on fiber four‐wave mixing for bidirectional radio‐over‐fiber systems
Authors: Gao Ying , Gao Shiming , Ou Haiyan 
Published: March 2009

AbstractA frequency up/down‐converter is proposed based on fiber four‐wave‐mixing (FWM) between the output of a dual‐wavelength fiber laser and the modulated optical carrier for bidirection radio‐over‐fiber (RoF) systems. Frequency up‐conversion from 1.50 to 11.08 GHz and down‐conversion from 10.60 to 1.02 GHz are successfully demonstrated and a small efficiency difference between up‐ and down‐conversions has been achieved. A proposal of setting up a bidirectional RoF system based on fiber FWM frequency converter is presented. © 2009 Wiley Periodicals, Inc. Microwave Opt Technol Lett 51: 1542–1545, 2009; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.24370
Dual‐band chip antenna design using intercoupling capacitance
Authors: Choi Hyengcheul , Kim Hyeongdong 
Published: March 2009

AbstractFor the dual‐band (GSM/DCS) operation, the second‐order resonance is used to operate in the high frequency range. To control the bandwidth characteristics in each band, an intercoupling capacitance between the radiating elements is utilized to satisfy the bandwidth requirements of GSM (890–960 MHz) and DCS (1710–1880 MHz) cellular communications systems. © 2009 Wiley Periodicals, Inc. Microwave Opt Technol Lett 51: 1467–1470, 2009; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.24374
A novel compact band‐notched planar monopole antenna from 3 to 40 GHz
Authors: Zhang F. , Zhang F. S. , Zhao G. , Lin C. , Jiao Y. C. 
Published: March 2009

AbstractA novel and compact ultra‐wideband (UWB) microstrip‐fed monopole antenna with frequency band notch function is presented in this study. Different from the conventional methods, a new method of inserting a lune‐shaped disk into the annular structure to achieve a notched band is proposed in this letter. The center frequency of the notched band can be adjusted with ease by tuning the length of the lune‐shaped disk. The designed antenna satisfies the voltage standing wave ratio (VSWR) requirement of less than 2.5 in the frequency between 3 and 40 GHz while showing the band rejection performance in the frequency band of 4.65 to 5.81 GHz. © 2009 Wiley Periodicals, Inc. Microwave Opt Technol Lett 51: 1401–1403, 2009; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.24377
Analysis of wideband multilayer patch antenna with two parasitic elements
Authors: Ansari J. A. , Singh Prabhakar , Yadav Nagendra P. 
Published: March 2009

AbstractThe analysis of stacked patch antenna with two parasitic elements is presented. The antenna shows improved radiation and directivity by 6.57 dB when compared with single layer patch antenna. The bandwidth of the antenna is found to be dependent on various parameters such as h1, h2, and s. The proposed results are compared with the IE3D simulation and reported experimental results. © 2009 Wiley Periodicals, Inc. Microwave Opt Technol Lett 51: 1397–1401, 2009; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.24378
A circular‐disc monopole antenna with band‐rejection function for ultrawideband application
Authors: Sim Chow‐Yen‐Desmond , Chung Wen‐Tsan , Lee Ching‐Her 
Published: March 2009

AbstractThe numerical design method for a microstrip‐fed circular‐disc monopole (CDM) antenna operating within the ultrawideband (UWB) from 3.1 to 10.6 GHz is initially studied. By simply embedding a pair of U‐shaped slots into the ground plane, a band‐rejection (band‐notch) function at around 5 GHz is achieved. For impedance matching and fine tuning of this proposed antenna, a small rectangular slit is inserted at the top centre of the ground plane. Except within the rejection band, the gain and time‐domain characteristics of this antenna has successfully demonstrated that it is applicable to any high data rate short‐range wireless communication system that requires a stable signal transmission in the UWB application. The performances of a common UWB CDM antenna without band‐rejection function and a similar one with a slot loaded in the radiating circular patch are also investigated and compared with the proposed antenna. © 2009 Wiley Periodicals, Inc. Microwave Opt Technol Lett 51: 1607–1613, 2009; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.24379
A novel triple‐band microstrip bandpass filter for wireless communication
Authors: Guan Xuehui , Ma Zhewang , Cai Peng 
Published: March 2009

AbstractA novel triple‐band microstrip bandpass filter is proposed in this article. The first and the third passbands of the filter are realized by the parallel coupled microstrip line, and the second passband is realized by using an end‐coupled microstrip line. Then the resonators are coupled to the same input and output ports. A transmission zero is obtained by using antiparallel microstrip line structure. The measured frequency responses of the fabricated filter agree well with simulated results. © 2009 Wiley Periodicals, Inc. Microwave Opt Technol Lett 51: 1568–1569, 2009; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.24382
High‐performance rat‐race hybrid ring for RF communication using MEBE‐on‐microstrip technology
Authors: Zhang Fei 
Published: March 2009

AbstractThis article presents a planar rat‐race hybrid coupler incorporating a novel technique, which is served by a microstrip electromagnetic band‐gap element (MEBE) on microstrip itself for harmonic suppression and size reduction. The MEBE structure can be easily implemented and utilized in PCB process with no additional/rigorous process and no lumped elements and free ground suspend. Based on the measured results, insertion losses of less than 3.5 dB, return loss of 20 dB, isolation of 25 dB, 25 dB suppression for the 2nd harmonic, and 19 dB suppression for the 3rd harmonic are obtained. In addition, without sacrificing the performance, compact rat‐race coupler with 35.38% area relative to conventional design has been successfully realized. © 2009 Wiley Periodicals, Inc. Microwave Opt Technol Lett 51: 1539–1542, 2009; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.24383
Investigation of polarization‐dependent loss for a macrobending loss sensitive single‐mode fiber
Authors: Wang Pengfei , Farrell Gerald , Semenova Yuliya , Rajan Ginu 
Published: March 2009

AbstractAn investigation of the polarization dependent loss (PDL) of macrobending loss sensitive single fiber (1060XP) is presented theoretically and experimentally. The experimental results are in good agreement with the modeling outcomes. Through the comparison of experimental results of PDL between 1060XP fiber with coatings and bare 1060XP fiber, it is shown that the fiber coating has significant impact on the PDL of bend loss sensitive single‐mode fiber. © 2009 Wiley Periodicals, Inc. Microwave Opt Technol Lett 51: 1460–1464, 2009; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.24388
Bulk and patch ferrite resonator antennas based on the ceramic matrix composite: GdIGx YIG1‐x
Authors: Fechine P. B. A. , Almeida A. F. L. , de Oliveira R. S. , Moretzsohn R. S. T. , Silva R. R. , Sombra A. S. B. 
Published: March 2009

AbstractIn this study, the dielectric properties of the GdIGXYIG1–X ferrite composite material at radio frequency (RF) and microwave frequency bands were studied. These measurements were carried out in different sample geometries: thick films and cylindrical ceramic bulk ferrite resonator. In the RF range, we observed that the material is rather stable because of its short changes as a function of temperature and frequency range. The temperature capacitance coefficient values for all the samples (thick films and cylindrical ceramic bulk samples) presented short positive values at the RF range. The GdIG0.5YIG0.5 thick film was used as a substrate for the microstrip antenna device, where the upper Ag electrode served as a circular patch antenna and a microstrip line was used as a feed line. The microstrip antenna operates in this configuration at 8.185 GHz. In the study of the dielectric properties of the composites antenna geometry, with the same ferrite composite, a bulk cylindrical geometry was investigated. A numerical study, together with the experimental, was done, and the dielectric characteristics of the composite like ϵr, tgδE, and μr were obtained. © 2009 Wiley Periodicals, Inc. Microwave Opt Technol Lett 51: 1595–1602, 2009; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.24395
2‐Gb/s all‐optical serial digital‐to‐analog converter
Authors: Gehl M. , Dapkus C. , Granieri S. , Siahmakoun A. 
Published: March 2009

AbstractA fiber‐optic combined serial‐to‐parallel and digital‐to‐analog converter is proposed and demonstrated. The system is based on bit interleaving and cross‐gain modulation in a semiconductor optical amplifier. The demonstrated 3‐bit digital converter operates at 2 Gb/s, however, the proposed architecture could be easily modified to operate at higher bit‐rates. © 2009 Wiley Periodicals, Inc. Microwave Opt Technol Lett 51: 1561–1565, 2009; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.24397
Efficient tensor based FDTD scheme for modeling sloped interfaces in lossy media
Authors: Singh Gurpreet , Leong Tan Eng , Ning Chen Zhi 
Published: March 2009

AbstractThis article presents an efficient tensor based finite‐difference time‐domain (FDTD) scheme for modeling sloped interfaces in lossy media. The formulated scheme achieves its improved efficiency by implicitly solving the internal fields affected by an interface. This permits the reduction of updating coefficients in the scheme. FDTD simulations that are generally used to compute scattering parameters or radar cross sections gain from this implicit computation. The scheme is formulated without assuming any single frequency approximation, previously assumed in the literature. This permits FDTD simulation results over a wide frequency bandwidth in a single FDTD simulation run. To allow a more accurate and conformal approximation, the scheme extends the use of cell filling ratio to lossy media. © 2009 Wiley Periodicals, Inc. Microwave Opt Technol Lett 51: 1530–1537, 2009; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.24398
Wideband coplanar waveguide‐fed dual meandered‐strip monopole antenna
Authors: Liu Wen‐Chung , Ko Hong‐Lun 
Published: March 2009

AbstractA wideband coplanar waveguide (CPW)‐fed monopole antenna is presented, which is derived from a dual folded‐strip antenna. By meandering the folded strips, good antenna performances such as wideband with 4.07 GHz, defined from −10 dB return loss, average gain of ≥4.5 dBi, and stable monopole‐like radiation patterns across the matching band are obtained. The proposed antenna is low‐profile and has a compact size, with, including ground plane, only 15 mm × 20 mm × 1.6 mm, suitable for wideband communication application. © 2009 Wiley Periodicals, Inc. Microwave Opt Technol Lett 51: 1458–1460, 2009; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.24401
Neuroimaging of traumatic brain injury
Authors: Le Tuong H. , Gean Alisa D. 
Published: March 2009

AbstractIn this article, the neuroradiological evaluation of traumatic brain injury is reviewed. Different imaging strategies in the assessment of traumatic brain injury are initially discussed, and this is followed by a review of the imaging characteristics of both primary and secondary brain injuries. Computed tomography remains the modality of choice for the initial assessment of acute head injury because it is fast, widely available, and highly accurate in the detection of skull fractures and acute intracranial hemorrhage. Magnetic resonance imaging is recommended for patients with acute traumatic brain injury when the neurological findings are unexplained by computed tomography. Magnetic resonance imaging is also the modality of choice for the evaluation of subacute or chronic traumatic brain injury. Mild traumatic brain injury continues to be difficult to diagnose with current imaging technology. Advanced magnetic resonance techniques, such as diffusion‐weighted imaging, magnetic resonance spectroscopy, and magnetization transfer imaging, can improve the identification of traumatic brain injury, especially in the case of mild traumatic brain injury. Further research is needed for other advanced imaging methods such as magnetic source imaging, single photon emission tomography, and positron emission tomography. Mt Sinai J Med 76:145–162, 2009. © 2009 Mount Sinai School of Medicine
Pathophysiology of traumatic brain injury
Authors: Greve Mark W. , Zink Brian J. 
Published: March 2009

AbstractTraumatic brain injury is a major source of death and disability worldwide. Significant success has been achieved in improving short‐term outcomes in severe traumatic brain injury victims; however, there are still great limitations in our ability to return severe traumatic brain injury victims to high levels of functioning. Primary brain injury, due to initial injury forces, causes tissue distortion and destruction in the early postinjury period. Clinical outcomes depend in large part on mediating the bimolecular and cellular changes that occur after the initial injury. These secondary injuries from traumatic brain injury lead to alterations in cell function and propagation of injury through processes such as depolarization, excitotoxicity, disruption of calcium homeostasis, free‐radical generation, blood‐brain barrier disruption, ischemic injury, edema formation, and intracranial hypertension. The best hope for improving outcome in traumatic brain injury patients is a better understanding of these processes and the development of therapies that can limit secondary brain injury. Mt Sinai J Med 76:97–104, 2009. © 2009 Mount Sinai School of Medicine
Severe traumatic brain injury: maximizing outcomes
Authors: Tang Mary E. , Lobel Darlene A. 
Published: March 2009

AbstractSevere traumatic brain injury is one of the leading causes of death and disability in the United States. The initial management of traumatic brain injury involves early resuscitation, computed tomography scanning, and surgical evacuation of mass lesions, when indicated. Recent research suggests that the prevention and treatment of secondary brain injury decrease mortality and improve outcomes. Specifically, treatment should address not only cerebral protection but also prevention of injury to other organ systems. To achieve the best outcomes, attention must be focused on optimizing blood pressure and brain tissue oxygenation, maintaining adequate cerebral perfusion pressures, and preventing seizures. In addition, maximizing good outcomes depends on proactively addressing the risk of common sequelae of brain injury, including infection, deep venous thrombosis, and inadequate nutrition. Guidelines developed for the management of severe traumatic brain injury have dramatically improved functional neurological outcomes. Mt Sinai J Med 76:119–128, 2009. © 2009 Mount Sinai School of Medicine
Persistent reduction of conduction velocity and myelinated axon damage in vibrated rat tail nerves
Authors: Loffredo Michael A. , Yan Ji‐Geng , Kao Dennis , Zhang Lin Ling , Matloub Hani S. , Riley Danny A. 
Published: March 2009

AbstractProlonged hand‐transmitted vibration exposure in the workplace has been recognized for almost a century to cause neurodegenerative and vasospastic disease. Persistence of the diseased state for years after cessation of tool use is of grave concern. To understand persistence of vibration injury, the present study examined recovery of nerve conduction velocity and structural damage of myelinated axons in a rat tail vibration model. Both 7 and 14 days of vibration (4 h/day) decreased conduction velocity. The decrease correlated directly with the increased percentage of disrupted myelinated axons. The total number of myelinated axons was unchanged. During 2 months of recovery, conduction velocity returned to control level after 7‐day vibration but remained decreased after 14‐day vibration. The rat tail model provides insight into understanding the persistence of neural deficits in hand–arm vibration syndrome. Muscle Nerve, 2009
Time–frequency analysis of rhythmic masticatory muscle activity
Authors: Farella Mauro , Palla Sandro , Gallo Luigi Maria 
Published: March 2009

AbstractThe aim of this study was to develop and validate under laboratory conditions an algorithm for a time–frequency analysis of rhythmic masticatory muscle activity (RMMA). The algorithm baseband demodulated the electromyographic (EMG) signal to provide a frequency versus time representation. Using appropriate thresholds for frequency and power parameters, it was possible to automatically assess the features of RMMA without examiner interaction. The algorithm was first tested using synthetic EMG signals and then using real EMG signals obtained from the masticatory muscles of 11 human subjects who underwent well‐defined rhythmic, static, and possible confounding oral tasks. The accuracy of detection was quantified by receiver operating characteristics (ROC) curves. Sensitivity and specificity values were ≥90% and ≥96%, respectively. The areas under the ROC curves were ≥95% (standard error ±0.1%). The proposed approach represents a promising tool to effectively investigate rhythmical contractions of the masticatory muscles. Muscle Nerve, 2009