bluuebunny/crossref_metadata_2025_split huggingface dataset:
Band‐notched ultra‐wideband planar monopole antenna using shunt open‐circuited stub
Authors: Pan Chien‐Yuan , Chiu Kuo‐Yung , Duan Jhih‐Hao , Jan Jen‐Yea 
Published: April 2011

AbstractThis article presents an ultra‐wideband planar monopole antenna with band‐notched characteristics.The proposed antenna consists of a sector monopole and a microstrip feedline with a quarter‐wavelength open‐circuited transmission line (a stub). The open‐circuited stub is connected in parallel with the microstrip feedline in order to achieve band‐notched performance. The measured impedance bandwidth for voltage standing wave ratio (VSWR) ≤ 2 is from 3.01 to 11 GHz, except the notched band of 5.08 to 5.96 GHz for the WLAN system. This design technique is very suitable to develop other planar antennas for band‐notched applications. © 2011 Wiley Periodicals, Inc. Microwave Opt Technol Lett, 2011; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.26054
Band‐notched UWB planar antenna with parasitic spiral strips
Authors: Xia Tengfei , Yang Shiwen , Nie Zaiping 
Published: April 2011

AbstractA novel band‐notched ultra‐wideband (UWB) planar antenna with a pair of parasitic spiral strips is proposed in this article. The antenna composed of a planar monopole and a plane in the same shape of half circle achieves UWB properties, whereas a pair of parasitic spiral strips with small sizes at the monopole plane can be used to reject certain frequency band. The center frequency and bandwidth of the rejected band are both adjustable by partially changing the shape of the parasitic spiral strips. Numerical examples for the cases without rejection, narrow band or wide band rejection are presented for comparison. Simulated and measured results show that the proposed UWB planar antenna with parasitic spiral strips can be used to obtain band‐notched properties at the desired band. © 2011 Wiley Periodicals, Inc. Microwave Opt Technol Lett, 2011; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.26055
Wideband rectangular ring patch antenna with a three‐pointed‐star strip for WLAN/WiMAX applications
Authors: Ren Xueshi , Yin Yingzeng , Zheng Shufeng 
Published: April 2011

AbstractIn this article, a novel wideband rectangular ring patch antenna for WLAN and WiMAX applications is presented. The antenna is composed of a rectangular ring with microstrip feed line, a three‐pointed‐star strip and a partial ground plane. With the three‐pointed‐star strip, the rectangular ring patch antenna can realize wide impedance bandwidth (return loss ≥ 10 dB) of 4162 MHz (2.384–6.546 GHz), which make it easy to cover the required bandwidths for WLAN bands (2.4–2.483, 5.15–5.35, and 5.725–5.825 GHz) and WiMAX bands (2.4–2.6, 3.3–3.8 and 5.25–5.85 GHz) applications. Details of the proposed wideband antenna design are presented and discussed. © 2011 Wiley Periodicals, Inc. Microwave Opt Technol Lett, 2011; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.26061
Analysis of ground layout effect in CMOS concurrent dual‐band LNA
Authors: Liu Yang , Kim Hyeongdong 
Published: April 2011

AbstractGround planes are often used on the integrated circuits.An improperly designed ground plane can be a major source of noise and attenuation to affect the circuit performances. Using a full‐wave simulator HFSS, this article analyzes a ground plane effect in layout of a CMOS concurrent dual‐band low‐noise amplifier (LNA). The concurrent dual‐band LNA that operates at 2.4 and 5.2 GHz is fabricated using 180‐nm CMOS technology. Comparing with the circuit simulation result, the measured result shows a 7‐dB gain reduction at 5.2 GHz. In an attempt to find the cause and solve the problem, a full‐wave simulation that can analyze the layout effects is carried out. On the basis of the full‐wave analysis, we determine that the ground plane potentially produces a parasitic inductive component which deteriorates the gain performance at the higher operating frequency band. A modified ground plane layout for reducing the parasitic inductance is proposed, and the LNA achieves the improved gain and noise performances similar to the circuit simulation. © 2011 Wiley Periodicals, Inc. Microwave Opt Technol Lett, 2011; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.26062
Experimental study of the optical waveguides by scanning near‐field optical microscopy (NSOM)
Authors: Yan Chunsheng 
Published: April 2011

AbstractIn this article, the ordinary optical waveguides are investigated by the near field optical microscopy (NSOM). Three kinds of experimental systems are set up and the corresponding operation modes of NSOM (illumination mode, illumination‐collection mode and collection mode) are realized and analyzed. © 2011 Wiley Periodicals, Inc. Microwave Opt Technol Lett, 2011; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.26068
A broadband suspended substrate stripline filter using dual‐mode resonator
Authors: Kim Jin‐Sup , Lee Kyu‐Bok , Lee Jae‐Young , Shin Hyunchol 
Published: April 2011

AbstractA broadband suspended substrate filter is proposed and implemented using dual‐mode resonator aiming at transmitting the signals in the passband of 10–18 GHz. It is composed of two quarter‐wavelength resonators and inductor. The inductor is a short‐circuited stub. After optimization of this filter, a good bandpass behavior with 10 transmission poles is theoretically realized and experimentally confirmed. Within the whole BPF passband, the return loss is found better than 10 dB, and the insertion loss is less than 1.9 dB. © 2011 Wiley Periodicals, Inc. Microwave Opt Technol Lett, 2011; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.26070
Enhancement of power and frequency in Planar Gunn diodes by introducing extra delta‐doping layers
Authors: Li Chong , Khalid Ata , Caldwell Sonia H.Paluchowski , Pilgrim Neil J. , Holland Martin C. , Dunn Geoffrey M. , Cumming David R. S. 
Published: April 2011

AbstractPlanar Gunn diodes operating above 100 GHz fabricated in GaAs/AlGaAs heterojunction structures with single and double δ‐doping layers on each side of GaAs channel are numerically studied and experimentally demonstrated. The results show enhanced RF power and oscillation frequency when double δ‐doping technique was used. By using a two‐dimensional numerical simulation tool, the conduction band profile, electron concentration in the epitaxy layers and current‐voltage characteristics are investigated. Simulation results indicate that extra δ‐doping layers increase electron confinement in the conducting channel, therefore higher current levels are obtained. Simulated current‐voltage characteristics in both cases agree well with experimental results. © 2011 Wiley Periodicals, Inc. Microwave Opt Technol Lett, 2011; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.26071
Dual‐band push‐push OSC using CRLH transmission line and tunable negative resistance based on pin diode
Authors: Kim Yang‐Hyun , Choi Jaewon , Seo Chulhun 
Published: April 2011

AbstractIn this article, the dual‐band oscillator (OSC) using the composite right/left‐handed (CRLH) transmission ‐line (TL) and the tunable negative resistance based on the pin diode is presented. It is demonstrated that the CRLH TL can lead to metamaterial transmission line with the dual‐band tuning. The dual‐band push‐push oscillator design approach demonstrated in this work enables higher OSC frequency operation, lower noise performance, and smaller size, which is attractive for military radar frequency source applications. The phase noise of OSC is from −110.12 to −111.27 dBc/Hz @ 100 kHz in the tuning range, 4.05–4.11 GHz for the forward bias of the pin diode, whereas that of OSC is from 112.26 to −113.13 dBc/Hz @ 100 kHz in the tuning range, 9.97–10.17 GHz for the reverse bias of the pin diode. © 2011 Wiley Periodicals, Inc. Microwave Opt Technol Lett, 2011; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.26072
A miniature CMOS VCO with symmetric trace differential stacked spiral inductor
Authors: Kim Joonchul , Lee Jaeseok , Nam Byungjae , Kim Hyeongdong 
Published: April 2011

AbstractIn this study, a miniature silicon‐based symmetric trace differential stacked spiral inductor (SDSSI) was used in the design of a voltage controlled oscillator (VCO) using standard 0.18 μm CMOS technology. The SDSSI has a high self‐resonance frequency (fsr) and quality factor (Q) in spite of using the stacking technique, because the parasitic capacitance between the layers is reduced by alternatively locating traces at different positions in each layer. The output power spectrum and phase noise of the designed VCO is −0.79 dBm and 114 dBc/Hz at 1‐MHz offset frequency, respectively. The oscillation frequencies cover from 1.84 GHz to 2.38 GHz with a tuning range of 26%, while the occupied on‐chip area of the VCO is only 350 × 450 μm2. © 2011 Wiley Periodicals, Inc. Microwave Opt Technol Lett, 2011; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.26073
Dual‐band transformer‐coupled quadrature injection‐locked frequency dividers
Authors: Jang Sheng‐Lyang , Yang Ren‐Kai , Chang Chia‐Wei , Juang Miin‐Horng , Liu Cheng‐Chen 
Published: April 2011

AbstractThis letter proposes a dual‐band divide‐by‐2 transformer‐coupled quadrature injection‐locked frequency divider (QILFD).The QILFD is composed of a transformer‐coupled quadrature voltage controlled oscillator and two injection MOSFETs. The CMOS QILFD has been implemented with the Taiwan Semiconductor Manufacture Company (TSMC) 0.18 μm CMOS technology, and the core power consumption is 3.997 mW at the supply voltage of 0.7 V. The tank impedance of the QILFD shows a dual resonance behavior, which leads to a dual‐band locking range at a fixed bias condition. At the injection input power of 3 dBm, the low‐band and high‐band divide‐by‐2 locking ranges are from 6.90 to 8.56 GHz and 9.52 to 12.10 GHz, respectively. © 2011 Wiley Periodicals, Inc. Microwave Opt Technol Lett, 2011; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.26074
Electrically coupled tapered slot ultra wideband antenna with tunable notch
Authors: Yang Xiao Dong , Rahman A. , Abbasi Qammer H. , Hao Y. 
Published: April 2011

AbstractA band notch characteristic using a unequi‐arm H‐shaped conductor element is used for designing a Tapered‐Slot ultra wideband (UWB) antenna that can be useful in rejection of the higher band assigned for wireless local area network, with a targeted application in UWB wireless body area network. Based on the simulation and measurement results, a band notched tapered slot UWB antenna using a unequi‐arm H‐shaped conductor proves to be effective in rejecting unwanted frequency in terms of its selectivity and small real estate. © 2011 Wiley Periodicals, Inc. Microwave Opt Technol Lett, 2011; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.26075
Experimental investigations on line‐of‐sight multiple‐input‐multiple‐output channel characteristics with multi‐polarization antenna arrays
Authors: Zhang Nianzu , Li Linsheng , Hong Wei 
Published: April 2011

AbstractIn this article, the line‐of‐sight (LOS) multiple‐input‐multiple‐output (MIMO) channel characteristics with multiple polarized antenna arrays are experimentally investigated. The channel transmission matrices under different combinations of up to six kinds of antenna polarizations are measured, and then the matrix condition number and channel capacity are studied. It is concluded from the results that we can achieve lower matrix condition number and higher capacity with proper combination and configuration of antenna polarization in LOS environment. Furthermore, the relationship between channel capacity and channel matrix condition number is also analyzed. © 2011 Wiley Periodicals, Inc. Microwave Opt Technol Lett, 2011; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.26078
A compact planar bandpass filter with wide out‐of‐band rejection implemented by substrate‐integrated waveguide and complementary split‐ring resonator
Authors: Deng Kuan , Guo Zengxu , Li Chao , Che Wenquan 
Published: April 2011

AbstractA compact planar bandpass filter is presented in this letter, which is implemented by the combination of three different electromagnetic structures, saying, substrate‐integrated waveguide (SIW), square complementary split‐ring resonators (CSRRs) and dumbbells slot.The resonator is formed by a SIW cavity loaded with some complementary split‐ring resonators (CSRRs) on its top metal plane, causing a stopband with a very sharp rejection. Meanwhile, several dumbbells are etched on the bottom plane of SIW just below each CSRR to enhance the coupling. Double‐sided parallel strip line (DSPSL) is also used to excite the SIW and guarantee good propagation between these two different structures. An X‐band prototype is designed and fabricated for demonstration, good agreement is observed between simulation and measurement, indicating a very wide rejection band ranging from 11 GHz to 23 GHz and quite strong suppression to spurious modes. © 2011 Wiley Periodicals, Inc. Microwave Opt Technol Lett, 2011; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.26079
Analysis of losses in a double‐negative metamaterial composed of magnetodielectric spheres embedded in a matrix
Authors: Liu Jin , Bowler Nicola 
Published: April 2011

AbstractA simple‐cubic lattice of identical, magnetodielectric spheres exhibiting double‐negative (DNG) behavior is analyzed.An analytic expression for the threshold loss angle δth of the spheres, above which DNG behavior is extinguished, is derived by utilizing the Möbius transformation. The formula is valid for either dielectric or magnetic loss exhibited by the particles, and is derived based on the dipole approximation of Mie's theory of scattering by a sphere. For spheres with equal real relative permittivity and permeability, it is shown that δth increases as particle volume fraction increases. It is also shown that the loss angle of the effective medium can be controlled by appropriate choice of frequency. © 2011 Wiley Periodicals, Inc. Microwave Opt Technol Lett, 2011; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.26081
Direct modulation of multimode fiber Bragg grating external cavity lasers
Authors: Xu Qing‐Yang , Yan Minhui , Xu Chang‐Qing , Li Xun 
Published: April 2011

AbstractDirect modulation characteristics have been investigated for a Fabry‐Perot laser diode coupled with a multimode fiber Bragg grating.Large signal modulation at 2.5 Gb/s with none‐return‐to‐zero format has been demonstrated for the 2‐cm long multimode fiber Bragg grating external cavity laser. By using a short external cavity of about 7.5 mm, small‐signal frequency responses larger than 8 GHz are achieved. © 2011 Wiley Periodicals, Inc. Microwave Opt Technol Lett, 2011; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.26083
Step index holey fiber design by genetic algorithm for chromatic dispersion compensation
Authors: da Silva José Patrocínio , Bezerra Diego Souza , Hernández‐Figueroa H.E. 
Published: April 2011

AbstractA new approach to obtain ultra‐flattened‐chromatic‐dispersion‐optical‐fibers by introducing a small airhole at the core of a conventional step‐index‐optical‐fiber is presented. The proposed structure exhibits a simple geometry and has been analyzed through a vectorial finite element method in conjunction with genetic algorithm. The structure parameters are optimized using genetic algorithm to obtain ultra wideband residual dispersion compensation. Numerical results show that the optimized model exhibits flattened negative dispersion over E + S + C + L + U wavelength bands with an average dispersion of −253 ps km−1 nm−1. © 2011 Wiley Periodicals, Inc. Microwave Opt Technol Lett, 2011; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.26084
A compact and small printed monopole antenna for WLAN applications
Authors: Chen Wen‐Shan , Lee Bau‐Yi , Chang Po‐Yuan 
Published: April 2011

AbstractThis article proposes a compact and small printed monopole antenna for wireless local area network (WLAN) applications.The substrate used in this design is an FR4 substrate with a permittivity of 4.4, which is an inexpensive and widely used printed circuit board (PCB). The overall dimensions of the proposed antenna (25 × 20 × 1.6 mm3) can be easily applied in todays portable wireless products. The low‐frequency band centered at 2.4 GHz is resonated by the coupling between the U‐liked ground plane and 50‐ohm microstrip feed‐line. When the rectangular patch A is added on the ground plane, the high‐frequency band centered at 5.48 GHz is obtained. Because of the different polarization direction, the radiation patterns of low‐frequency band in X‐Z plane are similar to that of high‐frequency band in Y‐Z plane. The 10‐dB impedance bandwidths (2.39–2.52 and 4.97–6.07 GHz) meet the WLAN application bands. With the advantages of dimension, cost, and performance, the proposed antenna appears to be a promising candidate for WLAN applications. © 2011 Wiley Periodicals, Inc. Microwave Opt Technol Lett, 2011; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.26089
Compact CPW‐FED printed monopole antenna with super‐wideband performance
Authors: Akbari Mohammad , Koohestani Mohsen , Ghobadi Changiz. , Nourinia Javad 
Published: April 2011

AbstractThis letter presents a new printed monopole antenna with super‐wideband performance useful for various ultra wideband communication applications. The antenna has a compact structure, and the total size is 24 × 24 × 1.6 mm3. The antenna structure consists of a hexagonal patch radiator with a modified 50 Ω coplanar waveguide line for excitation. By using a trident shaped feed line structure the super wide bandwidth is obtained. Measurement results show that the impedance bandwidth for S11 ≤ −10 dB is enhanced largely to more than 174%. Radiation patterns are given at 4, 6, and 9.5 GHz. © 2011 Wiley Periodicals, Inc. Microwave Opt Technol Lett, 2011; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.26090
A simple U‐shaped printed ultra‐wideband antenna with WLAN band rejection
Authors: Mishra Sanjeev Kumar , Gupta Rajiv Kumar , Mukherjee Jayanta 
Published: April 2011

AbstractIn this article, a novel printed ultra‐wideband (UWB) antenna with band stop characteristics is proposed. The proposed antenna is a simple U‐shaped monopole structure where a rectangular strip is placed on both sides at the top of semi annular ring monopole structure. The band rejection characteristic is achieved by introducing a pair of L‐shaped slots in the ground plane to prevent interference due to wireless local area network (WLAN) systems operating within ultra‐wideband. To achieve the desired UWB response with WLAN band notched characteristics, the dimensions of rectangular strip, L‐shaped slot, symmetrical step slot on the both edge of ground plane, a single slot in the center of the ground plane and the gap between the ground plane and the radiating structure are optimized. Frequency rejection characteristics depend on the dimension of L‐shaped slot and can be fine controlled using other parameters. The antenna structure is designed, fabricated and tested. The simulation and measurement results show that the return loss = −10 dB from 3.09 to 10.6 GHz with band stop characteristics in 5.11–6.14 GHz frequency band. The radiation characteristics show its suitability for indoor wireless communication. © 2011 Wiley Periodicals, Inc. Microwave Opt Technol Lett, 2011; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.26091
Erratum: A novel reconfigurable multiband slot antenna fed by a coplanar waveguide using radio frequency microelectromechanical system switches
Authors: Bemani M. , Nikmehr S. 
Published: April 2011

AbstractOriginally published Microwave Opt Technol Lett 53: 751–757, 2011. © 2011 Wiley Periodicals, Inc. Microwave Opt Technol Lett 53: 1685, 2011; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.26162(Original article DOI 10.1002/mop.25828)
Female genital mutilation in Upper Egypt in the new millennium
Authors: Rasheed Salah M. , Abd‐Ellah Ahmed H. , Yousef Fouad M. 
Published: April 2011

AbstractObjectiveTo estimate the influence of the 2007 criminalization law on the prevalence and yearly incidence of female genital mutilation (FGM) in Upper Egypt and assess the attitudes of both the population and their health providers toward FGM.MethodsBetween September 15, 2008, and September 15, 2010, all girls and young women presenting at the Departments of Gynecology and Obstetrics or Pediatrics of Sohag and Qena University Hospitals were invited to answer a questionnaire, which was also presented to their parents. Another questionnaire was presented to all nurses, young physicians, and senior physicians working at either hospital.ResultsThe prevalence of FGM was 89.2%. The incidence was 9.6% in 2000, began to decrease in 2006, and had reached 7.7% at the end of the study period in 2009 (P = 0.05). In their vast majority, the procedures were performed by general practitioners. In total, 88.2%, 34.3% and 14.9% of nurses, young physicians, and senior physicians, respectively, approved the practice.ConclusionThe incidence of FGM is still very high in Upper Egypt in spite of the criminalization law. While general practitioners perform most procedures, most nurses are in favor of preserving the practice.
Performance characteristics of a combined hepatitis C virus core antigen and anti–hepatitis C virus antibody test in different patient groups
Authors: Yang Jeng‐Fu , Lin Ya‐Yun , Hsieh Meng‐Hsuan , Tsai Chiu‐Hung , Liu Shu‐Fen , Yu Ming‐Lung , Dai Chia‐Yen , Huang Jee‐Fu , Lin Wen‐Yi , Lin Zu‐Yau , Chen Shinn‐Chern , Chuang Wan‐Long 
Published: April 2011

AbstractWe evaluated the performance of a hepatitis C virus (HCV) antigen/antibody combination test [Murex HCV Antigen/Antibody Combination Test (Murex Ag/Ab test)] by comparing it with the current third‐generation HCV antibody enzyme immunoassay (anti‐HCV). A total of 403 serum samples were consecutively collected from four patient groups: healthy controls (n = 100); HCV‐infected patients (HCV group, n = 102); Human immunodeficiency virus (HIV)/HCV‐infected patients (HIV/HCV group, n = 100); and patients with uremia (uremia group, n = 101). Performances were evaluated for the Murex Ag/Ab, anti‐HCV, and HCV RNA in the HIV/HCV and uremia patient groups. In the HCV group, all 102 samples showed concordant positive and negative results for anti‐HCV, Murex Ag/Ab, and HCV RNA tests. In the HIV/HCV group, all 100 samples were positive for both anti‐HCV and Murex Ag/Ab tests, whereas 88 patients (88%) were HCV RNA positive. In the uremia group, 14 (69.0%) of the 23 anti‐HCV‐positive patients were HCV RNA positive, whereas 14 (77.8%) of the 18 Murex Ag/Ab–positive patients were HCV RNA positive. None of anti‐HCV‐negative or Murex Ag/Ab–negative patients were HCV RNA positive. Based on the HCV RNA assay, the sensitivities for both anti‐HCV and Murex Ag/Ab assays were 100%, whereas the specificities of these two assays were 89.7% and 95.4%, respectively. With good sensitivity and specificity, the Murex Ag/Ab assay could be a useful alternative diagnostic tool, especially in immunocompromised populations, such as patients with uremia or those infected with HIV.
Facial palsy as unusual complication of spontaneous intraparotid hematoma
Authors: Chen Chang‐Peng , Yang Miao‐Chun 
Published: April 2011

AbstractA 55‐year‐old healthy female without trauma history visited our hospital for rapidly progressive enlarging right side painful neck mass within 5 days and also with comorbid House‐Brackmann Grade V facial palsy for 2 days. Magnetic resonance imaging showed heterogenous mass derived from parotid to parapharyngeal space. Much blood clot could be observed at exploratory operation. Only inflammatory change, but not tumor, was mentioned in pathology report. Facial palsy was kept stationary in Grade III from postoperative 6 months.