bluuebunny/crossref_metadata_2025_split huggingface dataset:
A microstrip‐line‐fed isosceles‐trapezoidal dielectric resonator antenna with slotted ground plane for 2.4 GHz WLAN operation
Authors: Gopakumar C. , Mathew K. T. 
Published: January 2011

AbstractA novel microstrip‐line‐fed isosceles trapezoidal dielectric resonator antenna (ITDRA) with a slotted ground plane is introduced. It is proved by simulation and experiment that the antenna's resonant frequency can be lowered, and the bandwidth can be increased considerably by introducing slots and optimizing their position and dimensions in the ground plane. The proposed antenna is a wideband antenna with a 2:1 VSWR bandwidth of 21.3% centered at 2.43 GHz and exhibits good radiation characteristics and moderate gain in the entire operating band. The antenna covers important application bands viz. ISM: Bluetooth/WLAN 2.4/Wibree (802.11 b/g/n)/ZigBee, WiBro, and DMB. Lowering of the antenna's fundamental resonant frequency can be easily tuned by varying the length of either the slots or strip line. Reduced antenna size (≈28% less) at a fixed frequency can thus be achieved for the proposed design. Details of the design along with experimental and simulation results are presented and discussed. © 2011 Wiley Periodicals, Inc. Microwave Opt Technol Lett 53:553–557, 2011; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.25773
High‐impedance surface‐based square loop antenna with RF‐absorber
Authors: Deo Prafulla , Mehta Amit , Mirshekar‐Syahkal Dariush , Massey Peter J. , Nakano Hisamatsu 
Published: January 2011

AbstractA beam steerable square loop antenna is presented over a high impedance surface with RF‐absorber. For a test frequency of 5.0 GHz, the proposed antenna is 4.69‐mm thick and has an impedance bandwidth of 700 MHz and a gain of 7.93 dB. When compared with a recent published steerable square loop antenna over hybrid high impedance surface, the new antenna offers near equivalent performance but with a much simpler design and a cheaper fabrication process. The absorber's permittivity is found to control the antenna's beam tilt and sidelobe level. © 2011 Wiley Periodicals, Inc. Microwave Opt Technol Lett 53:481–485, 2011; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.25777
Design of aircraft on‐glass antennas for FM radio communications
Authors: Byun Gangil , Kang Woojoon , Kim Younggi , Choo Hosung 
Published: January 2011

AbstractThis letter proposes an on‐glass antenna for FM radio communications on the aircraft. We apply a multiloop structure to obtain a high‐radiation gain with broad matching characteristics. The proposed antenna is designed to imitate the shape of the window frame to minimize disruption to the pilot's visual field. The measurement shows an average bore‐sight gain of −13.4 dBi and a half‐power matching bandwidth of 52% in the FM radio band. © 2011 Wiley Periodicals, Inc. Microwave Opt Technol Lett 53:588–590, 2011; View this article at wileyonlinelibrary.com. DOI 10.1002/mop.25779
Dual‐mode dual‐passband microstrip bandpass filter with a high selective performance
Authors: Wang Yunxiu 
Published: January 2011

AbstractA dual‐mode bandpass filter with a high selective performance for dual‐band application is presented in this article.The filter is designed with square loop resonator with tree‐shaped patches attached to the four inner corners of the loop, which equivalents to load capacitors in the inner of loop resonator. This loading can reduce the size of filter. The input/output feed lines located along a straight line. Such a feed arrangement is physically suitable for certain microwave networks. A demonstrated filter with the dual‐band operating at 1.6 and 2.08 GHz was designed. Simulated and measured results indicate that a high selective dual‐mode dual‐band filter with wide harmonic responses has been achieved. © 2011 Wiley Periodicals, Inc. Microwave Opt Technol Lett 53:666–669, 2011; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.25784
System model for characterizing and reducing the mutual coupling in multiple‐input multiple‐output antennas
Authors: Duroc Yvan , Najam Ali Imran , Siragusa Romain 
Published: January 2011

AbstractA new approach for modeling the mutual coupling in multiple‐input multiple‐output antennas is introduced.The effects of the mutual coupling are described by a linear time invariant model. The introduced technique offers several advantages: first, an analytical model is achieved, and, from this description, a method for reducing the mutual coupling is proposed. © 2011 Wiley Periodicals, Inc. Microwave Opt Technol Lett 53:597–601, 2011; View this article at wileyonlinelibrary.com. DOI 10.1002/mop.25787
Planar compact inverted U‐shaped patch antenna with high‐gain operation for Wi‐Fi access point
Authors: Lu Jui‐Han , Hong Ruei‐Yun 
Published: January 2011

AbstractA planar compact inverted U‐shaped patch antenna with high‐gain operation for Wi‐Fi system has been proposed and investigated.It provides relatively wider impedance bandwidth of 162 MHz covering the 2.45 GHz band (2400–2484 MHz). The proposed planar compact patch antenna also provides the directional radiation patterns with maximum peak antenna gain and efficiency of 7.5 dBi and 87% across the operating band, respectively. © 2011 Wiley Periodicals, Inc. Microwave Opt Technol Lett 53:567–569, 2011; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.25788
Twin‐core fiber fabrication for exciting and detecting signals easily
Authors: Fan Linyong , Jiang Weiwei , Zhao Ruifeng , Pei Li , Jian Shuisheng 
Published: January 2011

AbstractA twin‐core fiber (TCF) with noncircular cross section has been fabricated.The two cores of the TCF can be easily identified. It has been demonstrated that signals can be easily excited and detected in this TCF, by splicing a single‐mode fiber to either of the TCF cores. The splice loss below 1 dB has been repeatedly obtained. Mutual splicing of these TCFs with low splice loss, by using a commercial fusion splicer, has also been demonstrated. The splice loss below 1.5 dB has been repeatedly obtained. Optical devices based on this TCF may be easily inserted into a standard SMF. © 2011 Wiley Periodicals, Inc. Microwave Opt Technol Lett 53:499–502, 2011; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.25792
Near‐field slit probe incorporating a micromachined silicon chip for millimeter‐wave microscopy
Authors: Nozokido Tatsuo , Miyasaka Noriyuki , Bae Jongsuck 
Published: January 2011

AbstractA novel type of slit probe incorporating a micromachined silicon (Si) chip for millimeter‐wave scanning near‐field microscopy is proposed.To improve the spatial resolution and image contrast attainable in millimeter‐wave microscopy, a metal‐coated Si chip with a microslit aperture fabricated using a bulk micromachining technique was attached to the tip of an ordinary slit‐type probe at the end of a tapered rectangular waveguide. The design and fabrication of the Si chip are described, and the results from experiments performed at U‐band (40–60 GHz) frequencies to demonstrate the feasibility of this new probe configuration are presented. © 2011 Wiley Periodicals, Inc. Microwave Opt Technol Lett 53:660–664, 2011; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.25793
Waveguide endwall coupler‐fed microstrip patch array antenna
Authors: Choi Se‐Hwan , Lee Jae‐Young 
Published: January 2011

AbstractIn this letter, we present the 2 by 1 and 2 by 2 array microstrip patch antennas using the waveguide endwall coupler at 24 GHz. These antennas consist of a waveguide feed and two or four patches that are excited by the endwall coupler. As the measured results, the 2 by 2 array antenna has the gain of 10.7 dBi and the bandwidth of 1.3 GHz, and half power beamwidth is 31° on the E‐plane and 35° on the H‐plane. Because this transition technique is very simple and easy to fabricate, it can be used for low cost and high volume production for commercial millimeter‐wave applications. © 2011 Wiley Periodicals, Inc. Microwave Opt Technol Lett 53:630–633, 2011; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.25794
A compact hexagonal dual‐band substrate integrated waveguide filter based on extracted‐pole technique
Authors: Chen Jia , Wu Bian , Jiang Li‐wei , Liang Chang‐hong 
Published: January 2011

AbstractIn this article, a novel hexagon substrate integrated waveguide (SIW) dual‐band filter is presented.First, the formula for calculating the resonant frequency of the dominant mode in triangle SIW cavity is given, then the triangle SIW cavity is used to construct a novel hexagon filter, which reduces the size effectively. According to the extracted‐pole technique using a parallel resonant circuit at the input and output resonator, a dual‐band filter with two passbands at 9.6–9.85 and 10.15–10.4 GHz has been designed and fabricated. © 2011 Wiley Periodicals, Inc. Microwave Opt Technol Lett 53:562–565, 2011; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.25799
Orthogonal rectangular ring‐shaped monopole antenna with double step
Authors: Kim Byeong Hoon , Choi Hak Keun , Park Jae Hyun 
Published: January 2011

AbstractIn this article, a novel wideband crossed planar monopole antenna formed by two orthogonal rectangular rings with double step is studied. The antenna design parameters that achieve wideband property are experimentally investigated. Parametric studies have been performed to optimize the impedance bandwidth of the proposed antenna. From the obtained results, the proposed antenna provides a wide bandwidth with isotropic pattern in the H‐plane and directional pattern in the E‐plane. The measured −14 dB impedance bandwidth for return loss is 0.82–2.7 GHz, which can cover various kinds of wireless services such as Cellular (0.824–0.894 GHz), PCS (1.75–1.87 GHz), WCDMA (1.885–2.17 GHz), WiBro (2.3–2.39 GHz), and S‐DMB (2.605–2.655 GHz). © 2011 Wiley Periodicals, Inc. Microwave Opt Technol Lett 53:572–575, 2011; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.25801
A miniature multibranch inverted‐F antenna to be embedded in the laptop computer for WWAN applications
Authors: Hu Chuan‐Ling , Liu Hsien‐Wen , Yang Chang‐Fa , Lin Shun‐Tian 
Published: January 2011

AbstractA novel miniature multibranch inverted‐F antenna (IFA) suitable for penta‐band Wireless Wide Area Network (WWAN) applications is presented. The antenna is fabricated on a direct bond copper substrate and consists of multibranch strips, which occupies a very small size of 83(L)× 7(W) × 0.5(H) mm3 to be easily embedded inside the laptop computer as an internal antenna. By properly designing the antenna operated as an inverted‐F antenna, two frequency bands covering 813–993 and 1703–2196 MHz for the GSM850/900 and DCS/PCS/UMTS operations are achieved with good radiation efficiencies. Compared with other studies, the proposed antenna with a compact size is suitable to be installed in the laptop computer for the WWAN applications. © 2011 Wiley Periodicals, Inc. Microwave Opt Technol Lett 53:547–550, 2011; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.25802
Cross‐phase modulation impact on coherent optical 16 QAM–WDM transmission systems
Authors: Reis Jacklyn D. , Teixeira António L. 
Published: January 2011

AbstractThis article investigates the impact of fiber nonlinear crosstalk on ultradense 32 × 16 QAM–WDM with coherent detection using Volterra series.The method is validated using Error Vector Magnitude measures against Split‐Step Fourier simulations. The cross‐phase modulation crosstalk contribution is derived and compared to four‐wave mixing and the overall system performance. © 2011 Wiley Periodicals, Inc. Microwave Opt Technol Lett 53:633–636, 2011; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.25805
Wideband thick‐arm spiral antenna for ingestible capsules
Authors: Lee Sang Heun , Lee Jaebok , Yoon Young Joong 
Published: January 2011

AbstractIn this article, a new antenna is introduced for ingestible capsule endoscope systems. As capsule endoscope systems are supposed to operate in the human body and they transmit internal image data with high resolution to external receivers, a wideband small antenna is required. To obtain these properties, the proposed antenna is designed in the form of thick‐arm spiral structure. The total height of the antenna is 5 mm and the diameter is 10 mm. The fractional bandwidth of the proposed antenna is 21% with VSWR < 2, which is wide enough for WBAN in body communication and it has the isotropic radiation pattern. © 2011 Wiley Periodicals, Inc. Microwave Opt Technol Lett 53:529–532, 2011; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.25808
Model‐based phase retrieval in two‐port microwave network measurements
Authors: Fang W. , McNamara D. A. 
Published: January 2011

AbstractA method is proposed for the retrieval of phase‐related quantities from magnitude‐only measurements on microwave networks that are to be manufactured and tested in large quantities. A reduced‐order model is developed using the prototype of such a system and then used to retrieve the phase of nonprototype devices under test. © 2011 Wiley Periodicals, Inc. Microwave Opt Technol Lett 53:495–499, 2011; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.25809
Evaluations and measurements of indoor wireless systems with optical orthogonal frequency division multiplexing lines
Authors: Kim Ajung , Nahm S. 
Published: January 2011

AbstractAn indoor wireless millimeter wave system with an optical orthogonal frequency division multiplexing (OFDM) signal link was developed. Channel modeling for the multipath system was proposed, and the channels in a 60 GHz band were measured. Based on the model, system parameters were evaluated for various subcarrier modulations in OFDM systems. Link performance in a typical office environment under the line‐of‐sight channel condition and with a 30 km optical OFDM link was measured. © 2011 Wiley Periodicals, Inc. Microwave Opt Technol Lett 53:491–495, 2011; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.25810
Integrated, dual‐band three‐dipole‐antenna system for single‐radio, access‐point applications
Authors: Hong Tzi‐Chieh , Su Saou‐Wen 
Published: January 2011

AbstractA printed, dual‐band three‐dipole‐antenna system suited to installation inside a wireless access point (AP) and integrated with the system circuit board as an efficient reflector for dipoles is presented.The multi‐antenna design comprises three dual‐wireless local area network (WLAN)‐band dipole antennas printed on the same layer of a FR4 substrate, and each antenna occupies a moderate area of 13.5 mm × 36.5 mm. The dipoles are set in a sequential, rotating arrangement on the antenna substrate with an equal inclination angle of 120° to form a symmetrical multi‐antenna structure. The three antennas are stacked above the system circuit board of the AP by a small distance. The design, in this case, integrates the system circuit board into an internal multi‐antenna solution. The results show that good port isolation can be obtained with high‐gain, directional radiation characteristics over the 2.4 and 5 GHz bands. Details of a design prototype are described and discussed in the article. © 2011 Wiley Periodicals, Inc. Microwave Opt Technol Lett 53:688–692, 2011; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.25811
A novel compact dual‐mode bandpass filter
Authors: Keshvari M. , Tayarani M. 
Published: January 2011

AbstractUsing slow‐wave transmission line ring resonator and square‐patch element, a novel compact dual‐mode microstrip bandpass filter is developed in this article. A filter having a 3% bandwidth at 2 GHz is designed, fabricated, and measured. The design procedure is given, and the mode‐splitting characteristic and impact of the patch element on the performance of the filter is investigated. The proposed filter has a smaller size compared with conventional dual‐mode bandpass filters at the same central frequency. This compactness is about 35% for the fabricated sample. © 2011 Wiley Periodicals, Inc. Microwave Opt Technol Lett 53:656–659, 2011; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.25812
Dynamic gain equalization for erbium doped fiber amplifiers based on optoceramic sinusoidal filter cascade
Authors: Nascimento Vitor V. , de Oliveira Júlio C. R. F. , Ribeiro Vitor B. , Bordonalli Aldário C. 
Published: January 2011

AbstractThis article presents an experimental demonstration and a systemic analysis of a dynamic gain equalizer for erbium doped fiber amplifier based on a cascade of sinusoidal optoceramic filters controlled by voltage with temperature control. A power imbalance reduction up to 86% is experimentally demonstrated and, based on simulations, optimal device allocation is analyzed. © 2011 Wiley Periodicals, Inc. Microwave Opt Technol Lett 53:623–626, 2011; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.25813
Computationally efficient design optimization of wideband planar antennas using Cauchy approximation and space mapping
Authors: Koziel Slawomir , Ogurtsov Stanislav , Bakr Mohamed H. 
Published: January 2011

AbstractComputationally efficient simulation‐driven design of ultra‐wideband planar antennas is presented using Cauchy‐based surrogate models of the coarsely‐discretized antenna electromagnetic models.Verification of the proposed methodology is performed with satisfactory designs obtained at a computational cost of a few evaluations of high‐fidelity antenna models. © 2011 Wiley Periodicals, Inc. Microwave Opt Technol Lett 53:618–622, 2011; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.25814
Improved diagnostic accuracy of breast MRI through combined apparent diffusion coefficients and dynamic contrast‐enhanced kinetics
Authors: Partridge S. C. , Rahbar H. , Murthy R. , Chai X. , Kurland B. F. , DeMartini W. B. , Lehman C. D. 
Published: January 2011

AbstractThis study investigated the relationship between apparent diffusion coefficient (ADC) measures and dynamic contrast‐enhanced magnetic resonance imaging (MRI) kinetics in breast lesions and evaluated the relative diagnostic value of each quantitative parameter. Seventy‐seven women with 100 breast lesions (27 malignant and 73 benign) underwent both dynamic contrast‐enhanced MRI and diffusion weighted MRI. Dynamic contrast‐enhanced MRI kinetic parameters included peak initial enhancement, predominant delayed kinetic curve type (persistent, plateau, or washout), and worst delayed kinetic curve type (washout > plateau > persistent). Associations between ADC and dynamic contrast‐enhanced MRI kinetic parameters and predictions of malignancy were evaluated. Results showed that ADC was significantly associated with predominant curve type (ADC was higher for lesions exhibiting predominantly persistent enhancement compared with those exhibiting predominantly washout or plateau, P = 0.006), but was not significantly associated with peak initial enhancement or worst curve type (P > 0.05). Univariate analysis showed significant differences between benign and malignant lesions in both ADC (P < 0.001) and worst curve (P = 0.003). In multivariate analysis, worst curve type and ADC were significant independent predictors of benign versus malignant outcome and in combination produced the highest area under the receiver operating characteristic curve (0.85 and 0.78 with 5‐fold cross validation). Magn Reson Med, 2011. © 2011 Wiley‐Liss, Inc.
3D GRASE PROPELLER: Improved image acquisition technique for arterial spin labeling perfusion imaging
Authors: Tan Huan , Hoge W. Scott , Hamilton Craig A. , Günther Matthias , Kraft Robert A. 
Published: January 2011

AbstractArterial spin labeling is a noninvasive technique that can quantitatively measure cerebral blood flow. While traditionally arterial spin labeling employs 2D echo planar imaging or spiral acquisition trajectories, single‐shot 3D gradient echo and spin echo (GRASE) is gaining popularity in arterial spin labeling due to inherent signal‐to‐noise ratio advantage and spatial coverage. However, a major limitation of 3D GRASE is through‐plane blurring caused by T2 decay. A novel technique combining 3D GRASE and a periodically rotated overlapping parallel lines with enhanced reconstruction trajectory (PROPELLER) is presented to minimize through‐plane blurring without sacrificing perfusion sensitivity or increasing total scan time. Full brain perfusion images were acquired at a 3 × 3 × 5 mm3 nominal voxel size with pulsed arterial spin labeling preparation sequence. Data from five healthy subjects was acquired on a GE 1.5T scanner in less than 4 minutes per subject. While showing good agreement in cerebral blood flow quantification with 3D gradient echo and spin echo, 3D GRASE PROPELLER demonstrated reduced through‐plane blurring, improved anatomical details, high repeatability and robustness against motion, making it suitable for routine clinical use. Magn Reson Med, 2011. © 2011 Wiley‐Liss, Inc.
In vivo detection of MRI‐PARACEST agents in mouse brain tumors at 9.4 T
Authors: Li Alex X. , Suchy Mojmir , Li Chunhui , Gati Joseph S. , Meakin Susan , Hudson Robert H. E. , Menon Ravi S. , Bartha Robert 
Published: January 2011

AbstractParamagnetic chemical exchange saturation transfer (PARACEST) contrast agents are under development for biological target identification by magnetic resonance imaging. Image contrast associated with PARACEST agents can be generated by radiofrequency irradiation of the chemically shifted protons bound to a PARACEST contrast agent molecule or by direct irradiation of the on‐resonance bulk water protons. The observed signal change in a magnetic resonance image after the administration of a PARACEST contrast agent is due to both altered relaxation time constants and the CEST effect. Despite high sensitivity in vitro, PARACEST agents have had limited success in vivo where sensitivity is reduced by the magnetization transfer effect from endogenous macromolecules. The purpose of this study was to demonstrate the in vivo detection of a PARACEST contrast agent using the on‐resonance paramagnetic chemical exchange effect (OPARACHEE) in a mouse glioblastoma multiforme tumor model and to isolate the OPARACHEE effect from the changes in relaxation induced by the PARACEST agent. Three mice with tumors were imaged on a 9.4 T MRI scanner following tail vein injection of 150 μL 50 mM Tm3+‐DOTAM‐glycine‐lysine. A fast low angle shot pulse sequence with a low power radiofrequency pulse train (WALTZ‐16) as the preparation pulse was used to generate OPARACHEE contrast. To study the dynamics of agent uptake, reference images (without the preparation pulse) and OPARACHEE images were acquired continuously in an alternating fashion before, during and after agent injection. Signal intensity decreased by more than 10% in tumor in the control images after agent administration. Despite these changes, a clear OPARACHEE contrast of 1–5% was also observed in brain tumors after contrast agent injection and maintained in the hour following injection. This result is the first in vivo observation of OPARACHEE contrast in brain tumors with correction of T1 and T2 relaxation effects. Magn Reson Med, 2011. © 2011 Wiley‐Liss, Inc.