bluuebunny/crossref_metadata_2025_split huggingface dataset:
A New Method for the Analysis of the Substitution Pattern of Hydroxyethyl(methyl)‐Celluloses Along the Polysaccharide Chain
Authors: Mischnick Petra , Unterieser Inga , Voiges Kristin , Cuers Julia , Rinken Marian , Adden Roland 
Published: May 2013

AbstractHydroxyethylmethyl celluloses (MSHE 0.15–0.26, DSMe 1.49–1.82) and hydroxyethyl celluloses (MSHE 1.89–3.03) are analyzed with respect to their substituent distribution in the polymer chains. The cellulose ethers are peralkylated and partially hydrolyzed, and are analyzed by electrospray ionization‐ion trap‐mass spectrometry (ESI‐IT‐MS). The randomness of the partial hydrolysis is proven. Quantitative evaluation of their mass spectra becomes possible after labeling the oligosaccharides at the reducing end. Reductive amination with o‐aminobenzoic acid gives better results than hydrazone formation with cationic Girard's T reagent. Syringe pump infusion gives more‐accurate results compared with liquid chromatography (LC)‐ESI‐MS. Profiles of the substituent distribution in the oligosaccharide fractions of DP 2–DP 7 are compared with the theoretical random distribution of glucosyl units in the chain.magnified image
A Compact Broadband Balun on Multilayer Organic Substrate
Authors: Ta Hai Hoang , Pham Anh Vu 
Published: May 2013

ABSTRACTWe present the design and development of a compact, broadband balun based on a quasi‐lumped LC transformer. The balun is constructed on a multilayer liquid crystal polymer substrate. The balun has a wide range of operating frequency from 0.9 to 3.6 GHz. Within this operating band, the balun achieves a measured insertion loss of less than 1 dB, a measured return loss of better than 10 dB, a measured amplitude imbalance of less than 1 dB and a measured phase imbalance less than 7°. This balun has an extremely compact size of 2 × 2.5 mm2. © 2013 Wiley Periodicals, Inc. Microwave Opt Technol Lett 55:1957–1959, 2013
Locally Implicit Discontinuous Galerkin Finite Element Method for Transient Analysis of 3D Layered Structures with Electrically Small Details
Authors: Chen, Jiefu , Tobon, Luis , Huo Liu Qing 
Published: May 2013

ABSTRACTAn efficient locally implicit discontinuous Galerkin finite element method is proposed for time domain analysis of 3D layered problems. The vector mixed finite elements with discontinuous Galerkin method are employed for spatial discretization, and the singly diagonally implicit Runge–Kutta scheme is used for time stepping. The block Thomas algorithm is utilized during time integration to eliminate the subdomain‐based iteration. Numerical examples demonstrate the proposed method is efficient in simulating 3D layered structures containing electrically small components. © 2013 Wiley Periodicals, Inc. Microwave Opt Technol Lett 55:1912–1916, 2013
Changing the Electromagnetic Bandgap and Stopbands in a Multistate Periodic Circuit
Authors: Thalakotuna, Dushmantha N. P. , Esselle Karu P. , Matekovits, Ladislau , Heimlich Michael , Hay Stuart G. 
Published: May 2013

ABSTRACTChanging the electromagnetic bandgaps (EBGs) and hence the stopbands in a multistate periodic microwave circuit is investigated experimentally. The state of the prototype circuit, consisting of 24 unit cells, is changed by closing or opening gaps in selected unit cells. This varies the periodic loading along the circuit and hence the EBG. In most states, the circuit behaves as a bandstop filter, and its stopband width and location are determined by the circuit state. Experimental results confirm that the first stopband width can be as large as 63% (at 4.92 GHz) or can be absent. The EBG leads to excellent isolation around 40 dB in the stopbands. Sharp roll‐off between passbands and stopbands (upto 120 dB/octave) and small length compared to microstrip filters with similar cut‐off and roll‐off characteristics are other advantages of the proposed platform. © 2013 Wiley Periodicals, Inc. Microwave Opt Technol Lett 55:1871–1874, 2013
A Low Cost 8 × 8 W‐Band Substrate Integrated Waveguide Antenna Array Detector on LCP
Authors: Samuel Chieh, Jia‐Chi , Pham Anh‐Vu , Pidwerbetsky, Alex , Kannell George 
Published: May 2013

ABSTRACTThe design and fabrication of a W‐band 64 element slot antenna array based on the substrate integrated waveguide structure is presented in this communication. The prototype antenna array is fabricated on a liquid crystal polymer substrate using standard printed circuit board (PCB) manufacturing processes. Characterization of the unbalanced antenna is accomplished through the use of a millimeter‐wave diode detector circuit, which is integrated onto the antenna array. Measurements show a beamwidth of approximately 13.2°. The maximum sensitivity of the antenna array with the diode detector is 121 mV/mW at 96 GHz. The total size of the antenna array with detector circuit is 4 × 3 cm2. © 2013 Wiley Periodicals, Inc. Microwave Opt Technol Lett 55:1825–1830, 2013
Frequency‐Tunable Monopole Antenna for Wimax Applications
Authors: Sun X. L. , Cheung S. W. , Yuk T. I. 
Published: May 2013

ABSTRACTThis article presents a planar dual‐band monopole antenna with a frequency‐tunable band for use in wireless devices of the 2.4 and 3.4 GHz worldwide interoperability for microwave access (WiMAX) system. The antenna has two radiating branches acting as monopoles and resonating at around 2.4 GHz (lower band) and 3.4 GHz (higher band). A varactor is placed on the radiating branch responsible for the lower band. A very simple DC biasing circuit is designed for reverse‐biasing the varactor. By varying the DC‐bias voltages from 0 to 12 V for the varactor, the lower band of the antenna can be continuously tuned from 2.3 to 2.83 GHz, covering the frequency bands from 2.3 to 2.4 GHz and 2.5 to 2.7 GHz for the WiMAX system. The antenna has a small overall size of 40 × 35 × 0.8 mm3 with a compact radiator of only 14.5 × 8.2 mm2. The antenna performance in terms of reflection coefficient, radiation pattern, peak gain, and efficiency is studied using computer simulation. For verification of simulation results, the antenna is fabricated and measured. The feeding cable used in measurement causes substantial discrepancies between the simulated and measured simulation results. To study the cable effects, a computer simulation model is included for studies. With the cable model, the simulated and measured results agree very well. © 2013 Wiley Periodicals, Inc. Microwave Opt Technol Lett 55:1902–1907, 2013
Wide‐Beam UWB Antenna with A Couch‐Like Reflector for use in an Indoor Home Security Service
Authors: Moon Junyoung , Ha Jaegeun , Choi Jaehoon 
Published: May 2013

ABSTRACTAn impulse radar‐UWB antenna for home security service application is proposed. The antenna consists of a partially elliptical monopole and a couch‐like reflector. The couch‐like reflector creates an antenna beam wide enough to be used for home security service applications. In addition, the antenna can be inconspicuously installed in the upper corner of a room. The dimension of the proposed antenna is 21 × 38 × 20 mm3. The measured H‐plane beam width is wider than 130° over the 10 dB return loss bandwidth of the antenna (6.7–10.33 GHz). The peak gain is greater than 4 dBi in the frequency band of interest. © 2013 Wiley Periodicals, Inc. Microwave Opt Technol Lett 55:1721–1724, 2013
A Miniaturized Branch‐Line Coupler Using Triangular Patch Type Artificial Transmission Line
Authors: Oh Song‐Yi , Hwang Hee‐Yong 
Published: May 2013

ABSTRACTA branch‐line coupler using microstrip artificial transmission lines (ATLs) with slotted triangular patches is proposed. For the ATL, a five‐section stepped‐impedance line (SIL) is compactly folded into a right angle isosceles triangle, and the effect of the slot width between folded lines is analyzed. The designed branch‐line coupler is composed of four ATLs, so that it has a maximally compact rectangular geometry. A further miniaturization by changing patch shape and the performance analysis according to the slot widths between the four ATLs are carried out. The fabricated 3‐dB branch‐line coupler has comparable electrical performance and only 10.9% area compared to the conventional branch‐line coupler at 0.717 GHz, which is one of the smallest couplers among similar studies that have been reported. © 2013 Wiley Periodicals, Inc. Microwave Opt Technol Lett 55:1718–1721, 2013
A CPW‐FED Rectangular Slot Antenna for S and C Band Applications
Authors: Ung Johnny , Karacolak Tutku 
Published: May 2013

ABSTRACTThe main objective of this study is to present a compact coplanar waveguide (CPW)‐fed rectangular slot patch antenna for operation in the S (2–4 GHz) and C bands (4–8 GHz). The proposed antenna has dimensions 20 × 36 × 0.5 mm3. The antenna is fabricated on a thin low loss Rogers RO3203 substrate and tested. Results are then compared with simulations. The simulated and measured −10 dB bandwidths are found to be 104% (2.48–7.86 GHz) and 103% (3.03–9.41 GHz), respectively. The antenna shows an omnidirectional radiation pattern with reasonable gain values over the same frequency band. © 2013 Wiley Periodicals, Inc. Microwave Opt Technol Lett 55:1714–1717, 2013
A Dual‐Band Bandpass Filter Using Capacitively I/O Coupling
Authors: Lee Jahyeon , Lim Yeongseog 
Published: May 2013

ABSTRACTA compact microstrip dual‐band bandpass filter with good frequency selectivity was proposed. The proposed dual‐band bandpass filter is configured with two dual‐mode resonator and skew‐symmetrically coupled capacitively input/output coupling. By using these input/output coupling structure, extra transmission zeros can be generated. The dual‐band bandpass filter is designed for 2.4/5.2 GHz WLAN. Experimental measurements are also presented for the validation of the theory. © 2013 Wiley Periodicals, Inc. Microwave Opt Technol Lett 55:1823–1825, 2013
Design of a Compact Hexa‐Band Coupling Antenna for 4g Mobile Handset Using a Small Element With Two Slots
Authors: Choi, Sunho , Jeong, Gye‐Taek , Kim Woosu 
Published: May 2013

ABSTRACTThis article describes the design, fabrication, and measurement of a compact hexa‐band coupling antenna for 4G mobile handset using a small element with two slots. In order to obtain sufficient bandwidth (LTE700, GSM850, GSM900, GSM1800, GSM1900, UMTS) when Voltage Standing Wave Ratio (VSWR) ≤ 3:1, two slots are inserted in the small element, and coupling patch is used. The measured result of the fabricated antenna provides 410 MHz bandwidth from 0.688 to 1.098 GHz and 643 MHz bandwidth from 1.607 to 2.250 GHz (VSWR ≤ 3:1) with the gain ranging from −0.52 to 6.63 dBi. Also, a good radiation pattern is achieved within the hexa‐band (0.698–0.960 GHz and 1.710–2.170 GHz) range. © 2013 Wiley Periodicals, Inc. Microwave Opt Technol Lett 55:1708–1711, 2013
An Nmos Cross‐Coupled Quadrature Vco using Coupling Common‐Gate Pmosfets
Authors: Jang Sheng‐Lyang , Lin Hsi‐Han , Hsue Ching‐Wen 
Published: May 2013

ABSTRACTThis letter presents a fully integrated cross‐coupled quadrature voltage‐controlled oscillator (QVCO) using common‐gate transistor instead of common‐source transistor as a coupling device. The prototype wide‐tuning X‐band QVCO in 0.18‐μm CMOS process is proposed to generate four output phases and consists of two n‐core cross‐coupled VCOs and four pMOS coupling devices. The proposed QVCO oscillates from 8.52 to 10.56 GHz and the power consumption is 9.76 mW at 0.8 V supply voltage. The measured phase noise is −118.88 dBc/Hz at 1‐MHz offset frequency from the carrier frequency 9.86 GHz. The QVCO occupies a chip area of 0.623 × 1.197 mm2 and provides a figure of merit of −188.86 dBc/Hz. The figure of merit including tuning range, FOMT, of this QVCO is −195.30 dBc/Hz. © 2013 Wiley Periodicals, Inc. Microwave Opt Technol Lett 55:1705–1708, 2013
Analysis of Blockage Effects in a Center‐Fed Reflectarray
Authors: Pan Yu , Zhang Yan 
Published: May 2013

ABSTRACTThree quick methods that account for the blockage effects in a center‐fed reflectarray antenna design are presented. The first method simply adds the radiation pattern of the reflectarray on the passive feed horn antenna. For the second approach, the blockage is incorporated more accurately by introducing shadows on the reflectarray surface according to the location of the obstacles. The third approach places a physical metal sheet at the blocking obstacle on the main reflectarray surface. The radiation pattern of the complete antenna structure is also calculated using a full‐wave solver that also serves as a reference for accuracy comparison. To further validate the results, prototype reflectarray antennas based on two types of radiation elements are fabricated and the measured patterns are compared with predictions. © 2013 Wiley Periodicals, Inc. Microwave Opt Technol Lett 55:1921–1926, 2013
Two New Electric Coupling Structures for Double Folded Substrate Integrated Waveguide Cavity Filters with Transmission Zeros
Authors: Yang Guang , Liu Wei , Liu Falin 
Published: May 2013

ABSTRACTTwo electric coupling structures for double folded substrate integrated waveguide (DFSIW) cavity filters are presented in this article. The coupling strength can be easily tuned, and the coupling mechanism is investigated. With electric coupling realized by the proposed structures in the main path and magnetic coupling by a conventional coupling structure in the cross coupling path, an X‐band cross‐coupled filter is designed, which possesses a transmission zero on either side of the passband. A prototype of the filter is fabricated to validate the predicted frequency response, and the measured results agree with the simulated ones. © 2013 Wiley Periodicals, Inc. Microwave Opt Technol Lett 55:1815–1818, 2013
A Novel Beam Steering of Hybrid Switchable Beam Textile Antenna
Authors: Jais, Mohd I. , Jamlos, M. F. , Jusoh, Muzammil , Sabapathy, Thenna , Kamarudin Muhammad R. 
Published: May 2013

ABSTRACTA novel hybrid switchable beam textile antenna (HSBTA) is proposed in this research. The HSBTA introduced by a coaxial probe technique to feed current flow to center of HSBTA and distribute the current to four circles of radiating elements. This research found that the integration of RF switches and electronic components is successfully embedded into wearable textile antenna using a silver‐conductive epoxy adhesive. The four RF switches are then incorporated at four ideal locations of HSBTA's circle radiating elements to generate the beam steering ability with directivity as high as 6.8 dBi. With the help of particular RF switching scheme, the HSBTA has successfully tailored the beam to four different angles of 0°/360°, 90°, 180°, and 270° at single operating frequency of 2.45 GHz. Dimensionwise, 88 × 88 mm2 could lead the HSBTA to be deployed on smart garment for wireless body area network application. © 2013 Wiley Periodicals, Inc. Microwave Opt Technol Lett 55:1893–1897, 2013
Design of a Microwave Bandpass Filter with Compact Size and Wide Stopband
Authors: Sheen Jyh , Cheng Yang‐Hung , Liu Weihsing 
Published: May 2013

ABSTRACTThis article presents a design of a microstrip bandpass filter (BPF) with a compact size and wide stopband. The wide stopband is achieved by suppressing the first and second harmonic resonance frequencies. The slow‐wave coupling stepped impedance resonator with cross‐coupled structure is adopted to design the BPF. The two‐resonator filter was fabricated with a 2.45‐GHz center frequency and 0.245‐GHz bandwidth using the Roger 4003C substrate. The device was simulated using the ADS design software. This device has shown a compact size and very low insertion loss. © 2013 Wiley Periodicals, Inc. Microwave Opt Technol Lett 55:1860–1863, 2013
Small‐Size Planar LTE/WWAN Antenna and Antenna Array Formed by the Same for Tablet Computer Application
Authors: Wong Kin‐Lu , Jiang Huan‐Jynu , Weng Teng‐Wei 
Published: May 2013

ABSTRACTFor eight‐band LTE/WWAN operation (704–960/1710–2690 MHz) in the Ultrabook or thin‐profile tablet computer, a planar antenna of simple structure and small size is presented. The proposed antenna is obtained by modifying a simple planar inverted‐F antenna and can be printed on one surface of a thin FR4 substrate of size 10 × 45 mm2 only. The antenna's lower band bandwidth is greatly widened by embedding a proper chip capacitor of 2.7 pF at the feeding strip. This chip capacitor combines with the antenna's shorting strip can control the excitation of a parallel resonance to modify the impedance matching of the antenna's lower band such that a widened bandwidth is easily obtained to cover the LTE700/GSM850/900 operation. Conversely, the antenna's upper‐band bandwidth is also greatly enhanced by using a coupled section in the antenna's radiating strip and adding a parasitic shorted strip near the feeding strip, which lead to multiple resonant modes excited to form a wide bandwidth (>1 GHz) to cover the GSM1800/1900/UMTS/LTE2300/2500 operation. Owing to its small size and simple structure, the proposed antenna is very suitable to be applied in achieving an antenna array with high isolation for MIMO or dual talk (dual WWAN) operation. Promising high‐isolation antenna arrays formed by the proposed antennas are presented. The obtained isolation between the antennas in the antenna array is better than 12 dB, and the envelope correlation coefficient is less than 0.15 for frequencies over the LTE/WWAN bands. Details of the proposed antenna and antenna array are presented. © 2013 Wiley Periodicals, Inc. Microwave Opt Technol Lett 55:1928–1934, 2013
Design of A Compact Printed Double‐Sided Dual‐Band Dipole Antenna by Fdtd for Wifi Application
Authors: Huang Jhin‐Fang , Lai Wen‐Cheng 
Published: May 2013

ABSTRACTThis paper presents a novel design of printed doubled‐sided dipole antenna for WiFi application in 2.4 and 5.2 GHz ISM bands. The printed dipole antenna consists of one dipole arranged back to back on both sides of a dielectric substrate and is suitable for integration with monolithic microwave integrated circuit (MMIC) module. A microstrip tapered feed line is designed to match the antenna. Simulator FDTD is used to tune and verify the analysis. Both simulated and measured data are much identical. The printed dual‐band dipole antenna with the dimension of 46 × 36 mm2 achieves a measured gain at 2.4 GHz band to be about 1.7 dBi with a bandwidth of 200 MHz and at 5.2 GHz band to be about 0 dBi with a bandwidth of 400 MHz, respectively. © 2013 Wiley Periodicals, Inc. Microwave Opt Technol Lett 55:1845–1851, 2013
Low Sar Multiband CPW‐Fed Pifa with Independent Resonant Frequency Control for Wireless Communication Applications
Authors: Soliman Ahmed M. , Elsheakh Dalia M. , Abdallah Esmat A. 
Published: May 2013

ABSTRACTLow specific absorption rate (SAR) compact hexaband planar inverted‐F antenna (PIFA) with independent resonant frequency control has been studied in this letter. Two trapezoidal‐shaped slots are etched on the coplanar waveguide‐fed PIFA‐radiating plate to create two independent resonant frequencies as well as the fundamental PIFA itself. Three coupled slots are added within the ground plane to create an additional three independent resonant frequencies with slight effect on the other resonant frequencies. Multiband capabilities with bandwidth enhancement and acceptable SAR values are realized for different wireless communication applications. The SAR in the presence of human head is investigated by using CST 2012 Microwave Studio Hugo Voxil Model. The proposed antennas are fabricated, and there is a good agreement between measured and simulated results. © 2013 Wiley Periodicals, Inc. Microwave Opt Technol Lett 55:1802–1810, 2013
Wireless Interrogation of an Optically Modulated Resonant Tunnelling Diode Oscillator
Authors: Cantú, Horacio I. , Salgado, Henrique , Romeira, Bruno , Kelly, Anthony E. , Ironside, Charles N. , Figueiredo Jose M. L. 
Published: May 2013

ABSTRACTIn this work, a resonant tunnelling diode‐photo‐detector based microwave oscillator is amplitude modulated using an optical signal. The modulated free running oscillator is coupled to an antenna and phase locked by a wireless carrier that allows remote extraction of the information contained in the modulation. An off‐the‐shelf demodulator has been used to recover the envelope of the baseband data originally contained in the optical signal. Data were successfully transmitted at a rate of 1 MSym/s with a bit error rate below 10−6. © 2013 Wiley Periodicals, Inc. Microwave Opt Technol Lett 55:1728–1730, 2013
Pseudo‐Elliptic Function Bandstop Filter with Shunt Foster Sections
Authors: Malherbe Johannes A. G. , Louw Johnnes J. 
Published: May 2013

ABSTRACTFilters with transmission zeros in the stopband have been shown to have superior rates of cutoff. Conventional Cauer filters give excellent performance but are relatively large and not always practically realizable. In this article, the design of a pseudo‐elliptic bandstop filter which employs only shunt Foster sections and unit elements is presented. The filter is of the same size as a Chebyshev filter of the same order, but has a performance comparable to a Cauer filter. © 2013 Wiley Periodicals, Inc. Microwave Opt Technol Lett 55:1758–1762, 2013
Erratum: Efficient Numerical Tool for the Analysis and Design of Reflectarrays Based on Cells with Three Parallel Dipoles
Authors: Florencio, Rafael , Boix Rafael R. , Carrasco Eduardo , Encinar, José A. , Losada Vicente 
Published: May 2013

ABSTRACTOriginally published Microwave Opt Technol Lett 55:1212–1216, 2013. © 2013 Wiley Periodicals, Inc. Microwave Opt Technol Lett 55:1976, 2013; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.27739 (Original article DOI 10.1002/mop.27533)
Electrodiagnosis of ulnar neuropathy at the elbow (Une): A bayesian approach
Authors: Logigian Eric L. , Villanueva Raissa , Twydell Paul T. , Myers Bennett , Downs Marlene , Preston David C. , Kothari Milind J. , Herrmann David N. 
Published: May 2013

ABSTRACTIntroduction: In ulnar neuropathy at the elbow (UNE), we determined how electrodiagnostic cutoffs [across‐elbow ulnar motor conduction velocity slowing (AECV‐slowing), drop in across‐elbow vs. forearm CV (AECV‐drop)] depend on pretest probability (PreTP). Methods: Fifty clinically defined UNE patients and 50 controls underwent ulnar conduction testing recording abductor digiti minimi (ADM) and first dorsal interosseous (FDI), stimulating wrist, below‐elbow, and 6‐, 8‐, and 10‐cm more proximally. For various PreTPs of UNE, the cutoffs required to confirm UNE (defined as posttest probability = 95%) were determined with receiver operator characteristic (ROC) curves and Bayes Theorem. Results: On ROC and Bayesian analyses, the ADM 10‐cm montage was optimal. For PreTP = 0.25, the confirmatory cutoffs were >23 m/s (AECV‐drop), and <38 m/s (AECV‐slowing); for PreTP = 0.75, they were much less conservative: >14 m/s, and <47 m/s, respectively. Conclusions: (1) In UNE, electrodiagnostic cutoffs are critically dependent on PreTP; rigid cutoffs are problematic. (2) AE distances should be standardized and at least 10 cm. Muscle Nerve 49:337–344, 2014