bluuebunny/crossref_metadata_2025_split huggingface dataset:
Design of a new wideband microstrip‐fed circular slot antenna
Authors: Habib Mohamed A. , Denidni Tayeb A. 
Published: March 2006

AbstractIn this paper, a new ultra‐wideband slot antenna with a simplified feeding network is presented. This antenna is composed of a circular slot coupled to a circular patch fed with 50Ω microstrip line. A proper parametric investigation was carried out for optimization of the proposed structure. Simulations and measurements show that a large bandwidth from 2.13 to 11.11 GHz can be achieved, which represents a relative bandwidth of 136.4%. Furthermore, good agreement between simulated and experimental results is obtained. © 2006 Wiley Periodicals, Inc. Microwave Opt Technol Lett 48: 919–923, 2006; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.21519
A double‐spiral resonator structure to realize left‐handed material with lower resonant frequency
Authors: Zhao Hui , Cui Tie Jun 
Published: March 2006

AbstractA double‐spiral resonator (DSR) structure causing negative permeability is proposed in this paper, which combines the characteristics of split‐ring resonator (SRR) and spiral to reduce the resonant frequency. Hence, such a DSR structure has a small unit‐to‐wavelength ratio in realizing the left‐handed property, which behaves more like a material. A quasi‐static analysis is given to make an equivalence of the DSR structure to a left‐handed material (LHM). Simulation results show that such an LHM possesses a small loss. © 2006 Wiley Periodicals, Inc. Microwave Opt Technol Lett 48: 923–926, 2006; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.21520
Reconfigurable printed‐dipole antenna with harmonic trap for wideband applications
Authors: Mirkamali Ali , Hall Peter S. , Soleimani Mohammad 
Published: March 2006

AbstractThis paper presents the concept of using a harmonic trap to design a wideband reconfigurable antenna. The reconfigurable antennas can be used to select one of a number of operating frequency bands. If these bands cover a very wide frequency range, then one of the higher‐frequency bands can be a harmonic of a lower band. When the antenna operates at the lower band, it can have a good match at the high frequency. This paper proposes a technique for designing a wideband reconfigurable printed dipole antenna so as to select only one of the operating frequency bands by using a harmonic trap. The antenna is designed, fabricated, and measured. It is shown that by using switches and harmonic traps, a reconfigurable printed dipole antenna can be designed over a frequency range of 3:1. The antenna is thus suitable for frequency switching in the FCC ultra‐wideband allocation. © 2006 Wiley Periodicals, Inc. Microwave Opt Technol Lett 48: 927–929, 2006; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.21521
Printed collinear two‐antenna element for WLAN access points in a MIMO system
Authors: Wong Kin‐Lu , Chou Jui‐Hung 
Published: March 2006

AbstractA printed collinear two‐antenna element suitable for application in a wireless local area network (WLAN) access point in a multi‐input multi‐output (MIMO) system is presented. The printed element comprises one dipole antenna and one monopole antenna, both printed in a collinear configuration on a narrow FR4 substrate of width 12 mm and length 120 mm and showing good omnidirectional radiation characteristics. It has been found that an antenna system formed by using two proposed elements spaced 75 mm or larger can have good isolation (better than −20 dB) between any two of the four antennas in the two proposed elements. With the comparison to the conventional antenna system formed by four discrete antennas, the antenna system with two proposed elements shows a much smaller lateral length. This characteristic makes the proposed collinear two‐antenna element advantageous for application in a MIMO system. © 2006 Wiley Periodicals, Inc. Microwave Opt Technol Lett 48: 930–933, 2006; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.21522
Switchable patterned centre‐conductor CPW filter using RF MEMS
Authors: Mariani Michael A. , Roy Langis , Tait R. Niall 
Published: March 2006

AbstractA novel switchable coplanar waveguide (CPW) notch filter is developed using a microelectromechanical system (MEMS) switch element to perturb a patterned CPW centre‐conductor line. The switch element is easily integrated with the CPW due to isolation of DC bias from RF signal paths. An equivalent lumped‐element model has been developed for simulation of the electrical response of the filter. The measured notch frequency was shifted from 24.75 to 22.25 GHz, with greater then 20‐dB rejection in both states. © 2006 Wiley Periodicals, Inc. Microwave Opt Technol Lett 48: 935–938, 2006; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.21524
An oscillator with low phase noise and superior harmonic suppression characteristics based on uniplanar compact split ring resonators
Authors: Hwang Cheol Gyu , Myung Noh Hoon 
Published: March 2006

AbstractIn this paper, we describe a novel microwave oscillator incorporating a CPW‐based split‐ring resonator (SRR) as a resonant component of the circuit. The high quality (Q) factor and spurious‐free SRR contribute to phase noise reduction as well as the harmonic tuning of the oscillator circuit in a very small chip area. The fabricated 5.5‐GHz oscillator showed an output power of 2.774 dBm with a 2nd‐harmonic suppression of −43.04 dB and phase noise of −100.8 dBc/Hz at 100‐kHz offset. The proposed oscillator is believed to be the first application of a metamaterial to the performance enhancement of a microwave active device. © 2006 Wiley Periodicals, Inc. Microwave Opt Technol Lett 48: 938–940, 2006; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.21525
Fabrication and measurement of a compact meander‐line‐type microstrip patch antenna with shorting pin for the 5‐GHz band
Authors: Yoon Joong Han 
Published: March 2006

AbstractThis paper investigates the characteristics of the modified meander‐line‐type patch antenna for the 5‐GHz band. Its design was based on a modified meander line width and shorting pin with coaxial feeding. Its maximum measured impedance bandwidth (−10 dB and below) reaches approximately 1.64 GHz (4.765–6.405 GHz). Radiation patterns at different frequencies are also discussed, and the measured gains are about 5.74 to 9.09 dBi. © 2006 Wiley Periodicals, Inc. Microwave Opt Technol Lett 48: 944–947, 2006; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.21527
Design of an internal antenna with wide and multiband characteristic for mobile handset
Authors: Park Hoon , Kang Myoung il , Choi Jaehoon 
Published: March 2006

AbstractThe development of a small electrical antenna plays an important role in the rapidly growing mobile communication market. This paper presents the design of a novel small and wideband planar inverted F‐antenna that simultaneously covers the GSM900/GPS/DCS1800/DCS1900/IMT2000/WLAN/DMB service bands. A very wide impedance‐bandwidth characteristic was achieved by optimizing both the distance between the feed line and short strip and the width of a short strip. The commercial electromagnetic software CST Microwave Studio is used to design the structure. The maximum gains at the frequencies of 915, 1850, 2025, and 2450 MHz were 1.79, 3.56, 3.65, and 1.67 dBi, respectively. The overall radiation pattern is suitable for mobile application. © 2006 Wiley Periodicals, Inc. Microwave Opt Technol Lett 48: 947–950, 2006; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.21528
Equivalent circuit modeling of broadband antennas using a rational function approximation
Authors: Kim Youngwook , Ling Hao 
Published: March 2006

AbstractThis paper describes a technique for synthesizing an equivalent circuit for a broadband antenna. A method is proposed for generating a rational function approximation with real coefficients in order to model the input impedance of the antenna in the frequency domain. An algorithm is then developed to find the best‐fit positive‐real rational function that is realizable by passive circuits. The technique is applied to a planar UWB antenna from 3 to 10 GHz. The results show that a modeling error of 0.59% can be achieved. The Brune's theorem is used to synthesize an equivalent circuit of the antenna. © 2006 Wiley Periodicals, Inc. Microwave Opt Technol Lett 48: 950–953, 2006; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.21529
High‐linear‐power MESFET devices using source‐degeneration inductance and input‐impedance mismatch
Authors: Meng C. C. , Wang W. 
Published: March 2006

AbstractLinearity can be improved drastically by sacrificing power gain with the same output power. GaAs MESFET devices with via‐hole ground and with bond‐wire ground are used to investigate the effect of source‐inductive feedback and input‐impedance mismatch on the effect of linearity. At 2.4 GHz, the device without bond‐wire ground and mismatched input impedance has the highest linearity OIP3= 50 dBm, gain = 13.5 dB gain, andP1dB= 29 dBm, while the device with via‐hole ground and matched input impedance has the lowest linearity OIP3= 40 dBm, 18.3 dB gain, andP1dB= 29 dBm. © 2006 Wiley Periodicals, Inc. Microwave Opt Technol Lett 48: 953–954, 2006; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.21530
Surface plasmon resonance sensors using silica‐on‐silicon optical waveguides
Authors: Chu Yi‐Shin , Hsu Wen‐Hao , Lin Chii‐Wann , Wang Way‐Seen 
Published: March 2006

AbstractSurface plasmon resonance (SPR) sensors made by multimode silica‐on‐silicon channel waveguides are investigated theoretically and experimentally. Promising sensing characteristics, with sensitivity up to 4547 nm/RIU, are observed over a wide detection range without a conventional tuning‐layer design. The Si‐based device‐fabrication process offers great potential for high‐level sensor integration. © 2006 Wiley Periodicals, Inc. Microwave Opt Technol Lett 48: 955–957, 2006; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.21531
PML implementation in the ADI‐FDTD method using bilinear approximation
Authors: Wang Gang , Huang Binke , Liu Xiaolong 
Published: March 2006

AbstractBilinear approximation is employed to implement the perfectly matched layer (PML) absorbing boundary condition in the alternating direction implicit (ADI) finite‐difference time‐domain (FDTD) method. Numerical examples show that this implementation is effective and unconditionally stable. © 2006 Wiley Periodicals, Inc. Microwave Opt Technol Lett 48: 957–960, 2006; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.21532
Piecewise travelling‐wave basis functions for wires
Authors: García‐Tuñón I. , Rodríguez J. L. , Taboada J. M. , Obelleiro F. 
Published: March 2006

AbstractThis paper presents a method of moments (MoM) formulation for large thin‐wire structures. In our approach, a modified version of the well‐known Rao–Wilton–Glisson (RWG) basis functions for wires including a linear phase term is considered. This additional term allows an efficient representation of the travelling‐wave modes on each wire, while it preserves the main advantages of RWG bases for arbitrarily complex wire topologies. The paper contains a detailed description of the algorithm used for the computation of the impedance matrix integrals. Finally, some results for scattering problems are presented to show the agreement with the conventional RWG‐MoM solution. © 2006 Wiley Periodicals, Inc. Microwave Opt Technol Lett 48: 960–966, 2006; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.21533
Beam‐scanning improvement of reflectarrays by reducing the cell size at millimetre waves
Authors: Lanteri J. , Dauvignac J. Y. , Pichot Ch. , Migliaccio C. 
Published: March 2006

AbstractMost reflectarrays use a half‐wavelength cell size. In this paper, we present a new reflector‐antenna configuration that provides beam scanning and gain improvements by reducing the size of the cells. Small reflectarrays with cell sizes λ/2 and λ/4, respectively, have been designed at 94 GHz. The measured λ/4 reflectarray at 94 GHz achieves a beam scanning angle of ±60° with a loss of gain of 1 dB, whereas the λ/2 one exhibits a loss of 3 dB. Numerical simulations show that the improvement does not appear significant below the limit of λ/6. © 2006 Wiley Periodicals, Inc. Microwave Opt Technol Lett 48: 966–968, 2006; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.21534
A compact inverted double‐L antenna
Authors: Zhuang Zhiming , Shen Zhongxiang , Shum Ping 
Published: March 2006

AbstractA compact inverted double‐L antenna (CDLA) fed by a microstrip line and operating at 2.45 GHz is presented in this paper. The linearly polarized CDLA can be constructed using conducting wires mounted on a small PCB board. This antenna maintains a simple structure, low profile, and compact size, which can be very useful for mobile communication systems such as Bluetooth and radio frequency identification (RFID) applications. Simulated and measured results are provided and good agreement between them is observed. © 2006 Wiley Periodicals, Inc. Microwave Opt Technol Lett 48: 968–969, 2006; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.21535
CAD formulas of the capacitance to ground of square‐spiral inductors with one‐ or two‐layer substrate by synthetic asymptote
Authors: Tang Wanchun , Pan Tingshan , He Xiaoxiang , Chow Y. Leonard 
Published: March 2006

AbstractThis paper gives simple CAD formulas of the capacitance to ground of square‐spiral inductors on one‐ or two‐layer substrate by synthetic asymptote. From the derived formula, the equivalent capacitor is a fringe capacitor in parallel with an ideal parallel‐plate capacitor. The average error is less than 2%. © 2006 Wiley Periodicals, Inc. Microwave Opt Technol Lett 48: 972–977, 2006; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.21537.
Wideband patch antenna fed by a modified L‐shaped probe
Authors: Lai Hau Wah , Luk Kwai Man 
Published: March 2006

AbstractThis paper presents a wideband patch antenna fed by a modified L probe. The antenna has impedance bandwidth of 21% (SWR < 2) and cross polarization level of less than −15 dB across the operating bandwidth. The antenna has a gain of 8.5 dBi. Both simulated and experimental results are provided, and they are in good agreement. © 2006 Wiley Periodicals, Inc. Microwave Opt Technol Lett 48: 977–979, 2006; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.21538.
A single‐input single‐chain dual‐band power amplifier for CDMA mobile application
Authors: Kim Ki Young , Kim Ji Hoon , Park Chul Soon 
Published: March 2006

AbstractWe demonstrate a new structure of the single‐input single‐chain power amplifier for cellular (850 MHz)/PCS (1750 MHz) dual‐band operation. The single‐input structure seems adequate for the reconfigurable multiband transmitter and the single‐chain structure can achieve a small chip and module size, thus reducing manufacturing costs. This two‐stage amplifier has a maximum output power of 30 dBm (29 dBm), a power‐added efficiency (PAE) of 42% (37%), and an adjacent channel power ratio (ACPR) of −51 dBc (−48 dBc) at the output power of 28 dBm (28 dBm) under 3.4‐V operation voltage for cellular (PCS) band. © 2006 Wiley Periodicals, Inc. Microwave Opt Technol Lett 48: 981–983, 2006; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.21540
Theoretical investigation of metallic elliptically periodic structures using Mathieu functions
Authors: Denidni T. A. , Boutayeb H. 
Published: March 2006

AbstractIn this paper, an analysis of elliptical periodic structures composed of metallic wires is presented. The transmission and reflection coefficients of elliptical frequency‐selective surfaces (FSSs) are calculated by expressing the scattered field via Mathieu functions and by using an elliptical‐wave multiple reflections model. It is shown that when the elliptical period and the focus are constant, elliptical periodic surfaces have the same transmission and reflection coefficients. This work has potential applications for designing directive antennas. © 2006 Wiley Periodicals, Inc. Microwave Opt Technol Lett 48: 988–992, 2006; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.21543
All‐optical data format conversion from WDM to OTDM based on FWM
Authors: Verdurmen E.J.M. , Khoe G.D. , Koonen A.M.J. , de Waardt H. 
Published: March 2006

AbstractConversion from 2 × 10 Gb/s NRZ WDM signals to a 20‐Gb/s OTDM signal has been experimentally verified based on four‐wave mixing (FWM) in a highly nonlinear fiber (HNLF) without the need of an extra NRZ‐to‐RZ conversion step. 10‐GHz control pulses are generated by the means of super continuum (SC) generation and are therefore synchronized with each other in time. © 2006 Wiley Periodicals, Inc. Microwave Opt Technol Lett 48: 992–994, 2006; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.21544
Optical correlator employing opto‐VLSI processing
Authors: Aljada Muhsen , Zheng Rong , Alameh Kamal , Al‐Begain Khalid 
Published: March 2006

AbstractWe propose a novel optical correlator employing an Opto‐VLSI processor in conjunction with an array of fibre Bragg gratings with different Bragg wavelengths for optical header recognition. The recognition of 5‐bit optical header patterns is experimentally demonstrated at 2.27 Gb/s. © 2006 Wiley Periodicals, Inc. Microwave Opt Technol Lett 48: 995–997, 2006; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.21545
High‐dynamic‐range C+L band variable optical attenuator using a titled angle shutter
Authors: Liaw Shien‐Kuei , Lai Ying‐Tse , Chang Ming‐Hung , Lai Yi‐Gun 
Published: March 2006

AbstractA high‐dynamic‐range variable optical attenuator (VOA) using a movable shutter, which moves in a tilted‐angle direction to the collimate fiber pair, is proposed. The VOA operates in the C+L band with the advantages low cost, high dynamic range of more than 50 dB, low insertion loss of 0.8 dB, low wavelength‐dependent loss (WDL), and low polarization‐dependent loss of ±0.4 dB and 0.4 dB, respectively, with attenuation of 50 dB. A compact size of 5.0 × 1.5 × 1.5 cm is obtained. © 2006 Wiley Periodicals, Inc. Microwave Opt Technol Lett 48: 1000–1002, 2006; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.21547
To extend delivery distance of the optical MM‐wave generated by DSB modulation and vestigial sideband filtering
Authors: Yu Jianguo , Yu Jianjun , Chang Gee Kung 
Published: March 2006

AbstractDue to RF fading effect caused by fiber dispersion in standard single‐mode fiber (SSMF), the maximum delivery distance in SSMF for the optical millimeter (mm)‐wave signals generated by the double‐sideband modulation scheme is shorter than 2 km at a power penalty of 2 dB. We experimentally demonstrate that the maximum transmission distance can be largely extended after using vestigial sideband (VSB) filtering. When we use VSB filtering technique, the transmission distance for the mm‐wave signals is extended more than 40 km at a power penalty of 2 dB. © 2006 Wiley Periodicals, Inc. Microwave Opt Technol Lett 48: 1003–1004, 2006; Published online in Wiley InterScience (www.interscience.wiley.com) DOI 10.1002/mop.21548
Electron spin resonance study of radicals generated in cellulose/N‐methylmorpholine solutions after flash photolysis at 77 K
Authors: Konkin A. , Wendler F. , Roth H.‐K. , Schroedner M. , Bauer R.‐U. , Meister F. , Heinze T. , Aganov A. , Garipov R. 
Published: March 2006

AbstractThe processes of radical formation in N‐methylmorpholine‐N‐oxide monohydrate (NMMO) and cellulose/NMMO solutions were studied by ESR at 77 K under high‐power UV (λ = 248 nm) excimer laser flash photolysis. Radicals mainly generated were attributed to the nitroxide type radicals CH2NO•CH2and CH2NO•CH3 at the first step and methyl •CH3 and formyl •CHO radicals at the second step of the photoreaction. Kinetic studies of these radicals revealed that formation and recombination rates of the radicals depend on the cellulose concentration in cellulose/NMMO solutions and the concentration of additional ingredients, e.g. Fe(II) and propyl gallate. Even at frozen state temperature, acceleration or quenching of radical reaction processes was found. The proposed scheme of UV light‐induced NMMO degradation during irradiation based on ESR data correlates well with independently obtained results based on high‐performance liquid chromatography (HPLC). The analysis of degradation products by HPLC, e.g. aminoethanol and acetaldehyde, supports the assumption concerning a radical‐initiated ring opening of NMMO. Copyright © 2006 John Wiley & Sons, Ltd.
Influence of the spatial position of a trifluoromethyl group on the 13C chemical shifts in the cyclohexane series
Authors: Carcenac Yvan , Diter Patrick , Wakselman Claude , Tordeux Marc 
Published: March 2006

AbstractThe influence of the introduction of a trifluoromethyl group on the 13C chemical shifts in cyclohexane was examined. The two main effects observed are located at the α and γ positions relative to the carbon bearing the fluorine atoms. By comparison of the collected data it was possible to calculate the increments corresponding to the substitution of a hydrogen atom by a CF3 group at axial or equatorial positions on the cyclohexane ring. Copyright © 2006 John Wiley & Sons, Ltd.
Weapon injuries in the 12th century Crusader garrison of Vadum Iacob Castle, Galilee
Authors: Mitchell P. D. , Nagar Y. , Ellenblum R. 
Published: March 2006

AbstractThis project analyses the wounds sustained by those defending the Crusader castle of Vadum Iacob, which is to the north of the Sea of Galilee in Israel. To our knowledge this is the first Crusader castle garrison to be excavated and studied, and consequently gives unique information concerning medieval battle wounds. The Muslim forces of Saladin stormed the castle in August 1179. The skeletal remains of five of the garrison who were killed during the siege and the execution which followed have been studied, providing a vivid portrait of what it must have been like in the last hours as the castle surrendered. Multiple sword and arrow wounds were noted, and arrowheads were still in situ at the time of their deaths. All the soldiers appear to have been stripped of their armour and then dumped together with corpses of horses that died in the battle. We explore the nature and anatomical location of the wounds in the context of medieval Islamic weapons, battlefield tactics and the defensive armour of the Crusaders. Despite the limited number of soldiers discovered, the unique nature of this site makes the findings of great significance. Copyright © 2006 John Wiley & Sons, Ltd.