bluuebunny/crossref_metadata_2025_split huggingface dataset:
Retrofittable antireflection coatings for T‐rays
Authors: Withayachumnankul Withawat , Fischer Bernd M. , Mickan Samuel P. , Abbott Derek 
Published: June 2007

AbstractT‐ray reflection loss at a window's surface is reduced by means of a quarter‐wave antireflection coating. Because T‐ray wavelengths are much longer than visible wavelengths, the antireflection layer for T‐rays is much larger than the layers typically used in optics. This creates an interesting opportunity for retrofittable antireflection layers. In the experiment, an antireflection coating made from ordinary polyethylene sheets is pressed onto the surfaces of a silicon window in the way that rapid replacement of the rettrofittable coating is possible. Measured by terahertz time‐domain spectroscopy (THz‐TDS), the coated window shows enhancement of the transmittance within a range of T‐ray frequencies. © 2007 Wiley Periodicals, Inc. Microwave Opt Technol Lett 49: 2267–2270, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.22664
Design of dual‐band filter using defected split‐ring resonator combined with interdigital capacitor
Authors: Wu B. , Fan J. W. , Zhao L. P. , Liang C. H. 
Published: June 2007

AbstractA novel type of dual‐band microstrip structure and its equivalent circuit are investigated, which is composed of defected split‐ring resonator and interdigital capacitor. The influence of design parameters on the frequency characteristics is discussed, then a dual‐band microstrip filter, which has two passbands of 1.8–2.5 GHz and 5.5–5.9 GHz with a transmission zero, is designed and fabricated. © 2007 Wiley Periodicals, Inc. Microwave Opt Technol Lett 49: 2104–2106, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.22673
Design of ultra wideband 3DB quadrature microstrip/slot coupler
Authors: Abbosh A. M. , Bialkowski M. E. 
Published: June 2007

AbstractThis article presents the configuration and design method of a compact ultra wideband 3dB quadrature coupler employing a microstrip/slot technology. The proposed device uses two substrates with a common ground plane. It is formed by two identical multisection elliptical conducting strips, which are broadside coupled through a multisection elliptical slot in the ground plane. Results of simulation and measurements show that the coupler exhibits a coupling equal to 3 ± 1 dB for the band 2.3–12.3 GHz. The isolation and return loss are better than 23 dB across that band. © 2007 Wiley Periodicals, Inc. Microwave Opt Technol Lett 49: 2101–2103, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.22674
Continuous measurements of granular materials permittivities in microwave range
Authors: Li Yue‐e , Ding Guangze , Xu Fuyong 
Published: June 2007

AbstractMost of numerous available measurement techniques of microwave dielectric property are static measurement, and their specimen preparations are complex and tedious. In this article, a novel trapezoidal groove guide sensor for achieving continuous measurement is designed, and has been applied in measuring the moisture of the granular materials. Rigid theoretical formulas have been educed. The measured experimental cures are in good agreement with the theoretical curves. © 2007 Wiley Periodicals, Inc. Microwave Opt Technol Lett 49: 2234–2236, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.22677
A new phenomenon in GaAs photoconductive semiconductor switches triggered by laser diode
Authors: Sun Yanling , Shi Shunxiang , Zhu Yanwu , Wu Xin 
Published: June 2007

AbstractA new phenomenon in GaAs photoconductive semiconductor switches triggered by laser diodes is reported. It occurs when the switch is biased under the threshold and triggered by serial laser pulses. This phenomenon reflects the carrier accumulation effect when the switch operates at the nonlinear mode. The effects of bias voltage and optical pulse energy on the carrier accumulation are investigated. The results indicate that number of carrier can be controlled by adjusting bias voltage and optical pulse energy. © 2007 Wiley Periodicals, Inc. Microwave Opt Technol Lett 49: 2232–2234, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.22678
CAD formulas for patch dimensions of rectangular microstrip antennas with various substrate thicknesses
Authors: Akdagli Ali 
Published: June 2007

AbstractThis letter presents the closed‐from formulas for determining the patch dimensions of electrically thin and thick rectangular microstrip antennas. The presented formulas constructed by utilizing a differential evolution algorithm become very useful as computer‐aided design (CAD) models for patch antenna design. A comparison between the calculated and experimental results derived from 33 patch antennas demonstrates that the proposed CAD formulas provide <0.16% and 0.22% errors on average for the patch length and patch width, respectively. The results obtained by using the formulas given here are found to be closer to the experimental values, as compared with previous results presented by several researchers. © 2007 Wiley Periodicals, Inc. Microwave Opt Technol Lett 49: 2197–2201, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.22679
A high temperature superconducting group‐delay equalizer
Authors: Zuo Tao , Fang Lan , Yan Shaolin , Zhao Xinjie , Zhou Tiege , Ji Lu , Zhang Xu , Xie Qinglian , Wu Zhizhen 
Published: June 2007

AbstractA planar structure of group‐delay equalizer, which is built on high temperature superconducting (HTS) films, is proposed in this article. The HTS equalizer consists of one microstrip 3‐dB hybrid and two identical 1‐port coupled‐resonator filters. Compared with the traditional equalizers composed of cavity or coaxial resonators, the HTS equalizer has the advantages of smaller insertion loss and smaller size. As an example, a 3‐pole HTS equalizer is designed to equalize a 6‐pole HTS filter and good performance is achieved. © 2007 Wiley Periodicals, Inc. Microwave Opt Technol Lett 49: 2163–2165, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.22681
Dual and triple‐band PIFA design for WLAN applications
Authors: Sim Chow‐Yen‐Desmond 
Published: June 2007

AbstractThe design of a dual and triple‐band planar inverted‐F antenna (PIFA) is proposed for WLAN 802.11 a/b/g applications. Dual‐band operation is achieved by simply truncating one of the top rectangular radiating plate's corners, and wide bandwidth for the upper‐band is obtained by applying an additional small rectangular slit. By further extending the slit length, a triple‐band operation can also be achieved with a maximum gain of around 5 dBi. Simulated results are provided to validate the measured results. © 2007 Wiley Periodicals, Inc. Microwave Opt Technol Lett 49: 2159–2162, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.22682
Triangular slot antenna with a double‐T‐shaped tuning stub for wideband operation
Authors: Yoon JoongHan 
Published: June 2007

AbstractIn this study, a triangular slot antenna fed by a double‐T‐shaped tuning stub for wide bandwidth is proposed and experimentally studied. The prototype consists of a triangular slot model and double‐T‐shaped tuning stub. The effect of various parameters of the double‐T‐shaped tuning stub on wideband operation is investigated. From the experimental results, the measured impedance bandwidth, defied by VSWR 1:2, was found capable of reaching an operating bandwidth of 3.384 GHz, or 83.19%. The antenna radiation patterns and gains within the operating band were also measured and studied. © 2007 Wiley Periodicals, Inc. Microwave Opt Technol Lett 49: 2123–2128, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.22684
Geometrically based power azimuth spectrum models for mobile communication systems
Authors: Jiang Lei , Tan Soon Yim 
Published: June 2007

AbstractA geometrically base single bounce power azimuth spectrum model for mobile communication systems is proposed in this article. The scatterers are assumed to distribute around the transmitting antenna within a circular region. The distribution of the scatterers can be arbitrary, e.g., Rayleigh, exponential etc. Power azimuth spectrums are derived for these propagation environments. Comparisons between our theoretical calculations and the empirical results as well as the measurement data reported in the literature show that the Rayleigh distribution scatterer models is applicable for the outdoor microcell propagation environment, while the exponential distribution scatterer model is accurate for the indoor office/laboratory propagation environment. © 2007 Wiley Periodicals, Inc. Microwave Opt Technol Lett 49: 2093–2097, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.22686
All‐fiber actively Q‐switched Er3+/Yb3+ co‐doped ring laser
Authors: Zhang Shu‐Min , Lu Fu‐Yun , Wang Jian 
Published: June 2007

AbstractWe report on a all‐fiber actively Q‐switched laser based on a Mach‐Zehnder interferometer (MZI). One of the arms of the MZI is bonded on a piezoelectric transducer (PZT). The path length difference between those two arms will change when a RF electric signal is applied drives the PZT, allowing control of the Q‐factor of the cavity and, thus, performing active Q‐switching. Using Er3+/Yb3+ co‐doped fiber (EYDF) and a maximum pump power of 712 mW, Q‐switch pulses with peak power of 2.2 W and pulse width of 1.2 μs were obtained. Furthermore, our result also shows that, to generate stable Q‐switched‐pulses, with different pump power, one must select different modulation frequency, this phenomenon is experimentally proved for the first time to our knowledge. The pulse repetition rate of the laser can be adjusted from few Hz up to 25 kHz. © 2007 Wiley Periodicals, Inc. Microwave Opt Technol Lett 49: 2183–2186, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.22692
Wide coverage area of UHF‐band RFID system using a pattern reconfigurable antenna
Authors: Rhyu Hanphil , Harackiewicz Frances J. , Lee Byungje 
Published: June 2007

AbstractA new type of a reader antenna for a UHF‐band RFID system is proposed to cover a wider area. The proposed antenna consists of a circular polarized patch element, an omnidirectional electrical loop element, and a feeding network. By combining two antenna elements whose radiation patterns and half‐power beamwidths (HPBW) are different from each other, the coverage area of the RFID system is increased. The experimental results show the proposed antenna has a HPBW of more than 120° and works well in the UHF band RFID system. © 2007 Wiley Periodicals, Inc. Microwave Opt Technol Lett 49: 2154–2157, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.22694
Electromagnetically coupled microstrip square/circular ring resonators: Inset/offset feed variation effects on resonance frequency
Authors: Ghanbari Hossein , Karekar Ravi N. , Aiyer Rohini C. 
Published: June 2007

AbstractInset/offset feed‐dependent variation of electromagnetically coupled microstrip square and circular ring resonators (MSRR/MCRR) over a wide range indicate overall increase and decrease in resonant frequency (fr) respectively. On the basis of the experimental results, equations are suggested to determine fr as a function of the normalized inset and offset feed positions. Equations are validated for a limited range. High values of quality factor Q = 618 are obtained with MSRR as compared with MCRR (Q = 375) at two offset points near the ring edge with VSWR ≈ 1. This advantage can be used for applications such as frequency‐selective circuits and sensors. © 2007 Wiley Periodicals, Inc. Microwave Opt Technol Lett 49: 2118–2121, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.22696
Synthesis of a three‐dimensional triband (L1L2 GPS and Wi‐Fi) prefractal tree antenna
Authors: Azaro Renzo , Zeni Edoardo , Gazzini Tommaso , Dallapiccola Ramona , Massa Andrea 
Published: June 2007

AbstractIn this article, the synthesis process of a 3D wire antenna with a tree‐like shape and operating at three different frequency bands (L1–L2 GPS bands and Wi‐Fi) is described. By exploiting the degrees of freedom of the reference tree geometry, the electrical project constraints are fitted by optimizing the antenna shape through a particle swarm‐based optimization procedure. Both numerical and experimental assessments confirm effectiveness of the synthesis procedure. © 2007 Wiley Periodicals, Inc. Microwave Opt Technol Lett 49: 2114–2118, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.22699
Surface‐mount loop antenna for AMPS/GSM/DCS/PCS operation in the PDA phone
Authors: Li Wei‐Yu , Wong Kin‐Lu 
Published: June 2007

AbstractA surface‐mount loop antenna very suitable for application in the mobile devices such as the PDA (Personal Digital Assistant) phone for quad‐band operation is presented. The antenna comprises of a loop metal pattern for generating two wideband resonant modes at about 900 and 1800 MHz to cover the AMPS/GSM/DCS/PCS bands and a central coupling stub as the feed structure. Although quad‐band operation is obtained, the antenna occupies a small volume of 7 × 8 × 60 mm3or about 3.4 cm3only and is easy to be embedded inside the PDA phone as an internal antenna. Details of the proposed surface‐mount loop antenna are presented and discussed. © 2007 Wiley Periodicals, Inc. Microwave Opt Technol Lett 49: 2250–2254, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.22700
A high‐power MMIC VCO utilizing metamorphic HEMT technology
Authors: Jun Dong‐Hwan , Kim Sung‐Won , Seo Kwang‐Seok , Jang Jae‐Hyung , Song Jong‐In 
Published: June 2007

AbstractA high‐power monolithic microwave integrated circuit voltage controlled oscillator (MMIC VCO) that can drive optical devices such as an electro‐absorption and an electro‐optic modulators is presented. A common‐gate metamorphic HEMT (MHEMT) with 0.2 mm of gate width in conjunction with inductive feedback was used to generate negative resistance. The low‐loss coplanar waveguide transmission line on the 650 μm‐thick metamorphic GaAs substrate was utilized to minimize loss. The maximum generated output power of the MHEMT VCO was 40.1 mW at 24.1 GHz when biased atVds= 3.8 V andVgs= −0.44 V. Phase noise and frequency tuning range were estimated to be −93.4 dBc/Hz at 1 M Hz offset and 1 GHz, respectively. Experimental results show great promise for the MHEMT MMIC VCO to be used in future high‐power microwave source applications especially for driving optical devices. © 2007 Wiley Periodicals, Inc. Microwave Opt Technol Lett 49: 2221–2224, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.22702
Radiation performance of purely metallic waveguide‐fed compact Fabry–Perot antennas for space applications
Authors: Roncière O. , Arcos B. A. , Sauleau R. , Mahdjoubi K. , Legay H. 
Published: June 2007

AbstractMetallic electromagnetic bandgap resonator antennas are highly attractive to design very efficient primary feeds of focal array fed reflector antennas for space Tx applications. The antennas analayzed in this work consists of purely metallic Fabry–Perot (FP) cavities with a single partially reflecting surface (PRS) and four perfect electrical conductor (PEC) walls on the sides. They are excited by a standard metallic waveguide. In contrast to prior work, we focus our attention on compact FP resonators whose size is in the order of a few wavelengths in free space. Their radiation characteristics (namely, their resonant frequency, maximum directivity, aperture efficiency, and radiation bandwidth) are investigated numerically in X‐band with the finite‐difference time‐domain method. The extensive study of their radiation performance as a function of their size and grid reflectivity of the PRS, as well as the comparison with the well‐known characteristics of large FP antennas, highlight three main features that must be taken into account for an optimum design: (1) for a given grid reflectivity, the resonant frequency increases while reducing the size of the shielded resonator, (2) for a given size of the antenna there exists an optimum reflectivity maximizing the aperture efficiency, (3) at resonance, the beam radiated by a square cavity is not circularly symmetric. In particular, we have shown that, for a 2 ×λocavity, it is possible to reach a high‐aperture efficiency (ηs= 80%) over a 2.8% (−1 dB radiation) bandwidth. © 2007 Wiley Periodicals, Inc. Microwave Opt Technol Lett 49: 2216–2221, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.22703
Fast simulation of periodic guided‐wave structures based on commercial software
Authors: Xu F. , Patrovsky A. , Wu K. 
Published: June 2007

AbstractThe new forms of periodic electromagnetic field variables, which can be resolved from the Maxwell's equations, are shown. As a result, periodic guided‐wave problems can be converted into equivalent resonator problems and the eigen‐frequency algorithms of resonators can be used to extract the complex propagation constants of periodic structures. © 2007 Wiley Periodicals, Inc. Microwave Opt Technol Lett 49: 2180–2182, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.22704
Implementation of wave digital model in analysis of arbitrary nonuniform transmission lines
Authors: Stošić Biljana P. , Gmitrović Miodrag V. 
Published: June 2007

AbstractAn efficient method of analysis of nonuniform transmission lines (NTL), based on wave digital model composed of cascaded unit elements and two‐port adaptors, is described. The proposed technique treats NTL as a cascade connection of equal‐length or equal‐delay uniform transmission lines. A simple algorithm for calculating transmission and input reflection coefficients is derived. Two application examples, proving the efficiency and response accuracy of the new technique, are given. © 2007 Wiley Periodicals, Inc. Microwave Opt Technol Lett 49: 2150–2153, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.22706
Optimization of optical modulator chirp measurement technique using differential frequency beating
Authors: Abdul‐Rashid H. A. , Al‐Qdah M. T. , Chuah H. T. , Tayahi M. , Abdullah M. K. 
Published: June 2007

AbstractOptimization of the optical modulator chirp measurement technique using differential frequency beating is presented in this paper. The performance of the chirp measurement technique is studied in terms of the measurement range, sensitivity, and resonant frequency as the accumulated chromatic dispersion (CD) in the fiber is varied. Based on the mathematical model and experimental and simulation results, the technique's measurement range and sensitivity increase with reduced accumulated CD in the fiber. However, the resonant frequencies increase with reduced accumulated CD. The chirp measurement technique is optimized at an accumulated CD of ∼600 ps/nm, with a measurement range of ±4.75, maximum sensitivity of 3.3 GHz, and maximum resonant frequency of 14.28 GHz. © 2007 Wiley Periodicals, Inc. Microwave Opt Technol Lett 49: 2306–2309, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.22718
60 GHz multi‐chip module based on cost effective hybrid multilayer PWB
Authors: Choi Sung Tae , Hamaguchi Kiyoshi , Ogawa Hiroyo , Tokuda Kiyohito , Kim Yong Hoon 
Published: June 2007

AbstractA novel cost‐effective 60‐GHz multi‐chip module (MCM) is proposed and demonstrated. It is based on a low‐cost multilayer printed wiring board (PWB) with a novel vertical transition and a single layer waveguide transition which enables the use of low‐cost substrates with high dielectric loss for millimeter wave applications. The proposed MCM technology has been successfully applied to the packaging of a 60‐GHz self‐heterodyne mixer, and no substantial difference in the RF performance is observed with the packaging. © 2007 Wiley Periodicals, Inc. Microwave Opt Technol Lett 49: 2303–2305, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.22719
Compact‐planar monopole loop antennas for 802.11b/g WLAN systems
Authors: Bledowski Mariusz , Kitlinski Marek 
Published: June 2007

AbstractTwo monopole antennas using Koch loop and Minkowski loop radiators fed by microstrip line are proposed for WLAN applications in the 2.45/5.25 bands. To achieve the desired resonances, new configurations of impedance transformer with transmission line length close to λ/12 were designed. The prototypes have been examined, fabricated, and experimentally tested and found to fulfill with excess WLAN system requirements. © 2007 Wiley Periodicals, Inc. Microwave Opt Technol Lett 49: 2299–2303, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.22720
State of the art of where we are at using stem cells for stress urinary incontinence
Authors: Furuta Akira , Jankowski Ron J. , Honda Masashi , Pruchnic Ryan , Yoshimura Naoki , Chancellor Michael B. 
Published: June 2007

AbstractAimsThis review aims to discuss: 1) the neurophysiology, highlighting the importance of the middle urethra, and treatment of stress urinary incontinence (SUI); 2) current injectable cell sources for minimally‐invasive treatment; and 3) the potential of muscle‐derived stem cells (MDSCs) for the delivery of neurotrophic factors.MethodsA PUB‐MED search was conducted using combinations of heading terms: urinary incontinence, urethral sphincter, stem cells, muscle, adipose, neurotrophins. In addition, we will update the recent work from our laboratory.ResultsIn anatomical and functional studies of human and animal urethra, the middle urethra containing rhabdosphincter, is critical for maintaining continence. Cell‐based therapies are most often associated with the use of autologous multipotent stem cells, such as the bone marrow stromal cells. However, harvesting bone marrow stromal stem cells is difficult, painful, and may yield low numbers of stem cells upon processing. In contrast, alternative autologous adult stem cells such as MDSCs and adipose‐derived stem cells can be easily obtained in large quantities and with minimal discomfort. Not all cellular therapies are the same, as demonstrated by the differences in safety and efficacy from muscle‐sourced MDSCs versus myoblasts versus fibroblasts.ConclusionsTransplanted stem cells may have the ability to undergo self‐renewal and multipotent differentiation, leading to sphincter regeneration. In addition, such cells may release, or be engineered to release, neurotrophins with subsequent paracrine recruitment of endogenous host cells to concomitantly promote a regenerative response of nerve‐integrated muscle. The dawn of a new paradigm in the treatment of SUI may be near. Neurourol. Urodynam. 26:966–971, 2007. © 2007 Wiley‐Liss, Inc.