bluuebunny/crossref_metadata_2025_split huggingface dataset:
A compact tri‐band bandpass filter using novel stub‐loaded resonator
Authors: Yu Bin , Jia Baofu , Zhu Zhaojun 
Published: September 2015

ABSTRACTIn this letter, a compact tri‐band bandpass filter (BPF) using novel stub‐loaded resonator is proposed. The resonator consists of one short stub and four open stubs which are symmetric about the middle open stub. Two coupling gaps were formed by the four bended open stubs, which contribute to the performance of second and third passband. The filter was designed, fabricated, and measured. Three passbands were designed to operate at 1.0, 2.4, and 3.5 GHz, respectively. The measured results of the tri‐band BPF exhibit a reasonable agreement with simulated results. The circuit only occupies 0.106 λg × 0.064 λg, where λg is the guided wavelength at lower passband center frequency. © 2015 Wiley Periodicals, Inc. Microwave Opt Technol Lett 57:2797–2800, 2015
Bandpass filter with wide stopband using loaded short‐section of parallel‐coupled lines
Authors: Marimuthu Jayaseelan , Abbosh Amin M. , Henin Bassem 
Published: September 2015

ABSTRACTA compact third order bandpass filter (BPF) using dual and trimode resonators is proposed. To achieve compact size with wide and highly attenuated stopband with achievable fractional bandwidth (FBW), the proposed filter is designed using a dual‐mode resonator in the form of a low‐impedance feeding network and a trimode resonator formed using a miniaturized (one twelfth of a wavelength) parallel‐coupled structure loaded with folded open‐ended stubs of high/low‐impedances and a semiannular resonator. To enable using easy to manufacture dimensions, the coupled structure of the resonator is designed to have moderate mode impedances. A complete design procedure for the filter is explained. Finally, a compact penta‐mode BPF with 35% FBW with sharp upper and lower cutoffs is built and tested. The simulated and measured performance of the filter show less than 0.3 dB insertion loss in the passband and more than 32 dB attenuation across a wide stopband with sharp upper (107 dB/GHz) and lower cutoff (96 dB/GHz) skirts. © 2015 Wiley Periodicals, Inc. Microwave Opt Technol Lett 57:2824–2829, 2015
Phase random metasurfaces for broadband wide‐angle radar cross section reduction
Authors: Shen Yang , Pei Zhibin , Pang Yongqiang , Wang Jiafu , Zhang Anxue , Qu Shaobo 
Published: September 2015

ABSTRACTUltrathin phase random metasurfaces (PRMSs) for reducing radar cross section (RCS) over a wide range of frequencies and incident angles are presented. The PRMSs are formed by arraying disk‐shaped metal patches of random sizes on an ultrathin grounded dielectric layer. The electromagnetic wave incident on the PRMS feels a rough surface due to the random phase value of each inclusion. The energy is then redirected irregularly and thus the backward RCS reduction in the specular direction can be achieved. The bandwidth of RCS reduction can be broadened by expanding the distribution interval of the metal patch sizes. The experimental validation is performed and the measured result shows an acceptable agreement with the corresponding simulation. © 2015 Wiley Periodicals, Inc. Microwave Opt Technol Lett 57:2813–2819, 2015
Erbium‐doped fiber laser for remote fiber grating sensor system
Authors: Gu Han‐Wen , Chen Jing‐Fu , Shiu Run‐Kai , Peng Peng‐Chun , Chen De‐Hua , Zhang Yan‐Xiang , Jhang Jhih‐Jiang 
Published: September 2015

ABSTRACTThis article proposes an erbium‐doped fiber laser for remote fiber grating sensor system. Experimental results demonstrated that the sensitivity of wavelength of temperature tested from 25 to 85°C was 5 pm/°C and locating the proposed fiber sensor system 110 km away from the monitoring station ensured a high signal‐to‐noise ratio. The proposed fiber laser will facilitate the development of long‐distance or large‐scale fiber sensor systems and can be easily extended to multipoint sensing applications. © 2015 Wiley Periodicals, Inc. Microwave Opt Technol Lett 57:2809–2813, 2015
A novel tetraskelion dielectric resonator antenna for wideband applications
Authors: Kumar Jitendra , Mukherjee Biswajeet , Gupta Navneet 
Published: September 2015

ABSTRACTA novel tetraskelion dielectric resonator antenna (DRA) excited by a coaxial probe is investigated for wideband applications. The material used for investigation is Rogers TMM10i, which is a ceramic thermoset polymer composite material having a dielectric constant (
) of 9.8. The proposed geometry offers a wideband of 57.5% for an impedance bandwidth for |S11| < −10 dB from 3.85 to 6.96 GHz. The antenna covers most of the wireless systems like C‐band, WLAN, and Wi‐MAX applications. The experimentally measured results show the efficiency of 90% for the operational bandwidth and peak gain of 4.1 dBi at 5.25 GHz. It is also observed that the new proposed configuration reduces the DRA volume by 52% as compared with conventional rectangular DRA; with reduced volume of 6.48 cm3. The simulated and experimental results are well in agreement. © 2015 Wiley Periodicals, Inc. Microwave Opt Technol Lett 57:2781–2786, 2015
Compact UWB bandpass filters with two superposable notched bands
Authors: Yu Yingxin , Xiao Fei , Wang Ling , Tang Xiaohong , Guo Yingjiang 
Published: September 2015

ABSTRACTIn this article, compact microstrip ultrawideband (UWB) bandpass filters with two superposable notched bands are discussed. By cascading n + 1 T‐shaped structures where n = 1 or 2 to a three coupled‐line section, UWB bandpass frequency response with one or two notched bands can be obtained. The analysis shows that these notched bands are superposable and can be relatively independently adjusted in wide frequency range. The simulated and measured results are presented for verification. The filters are characterized by easy tuning and compact size. © 2015 Wiley Periodicals, Inc. Microwave Opt Technol Lett 57:2819–2824, 2015
Novel Q‐factor enhancement technique for on‐chip spiral inductors and its application to cmos low‐noise amplifier designs
Authors: Meng Fanyi , Ma Kaixue , Yeo Kiat Seng , Xu Shanshan 
Published: September 2015

ABSTRACTIn this article, a novel Q‐factor enhancement technique for on‐chip spiral inductors is presented. Symmetric return ground structure in traditional on‐chip spiral inductors is modified and shifted toward the side with stronger magnetic field caused by asymmetrical windings of inductors. In full‐wave electro‐magnetic simulation, it is observed that by applying this technique, inductor with higher Q‐factor and larger inductance is obtained with no cost of additional chip area. Using the proposed technique, on‐chip inductors are customized for a three‐stage cascode low‐noise amplifier (LNA) design. Fabricated in a commercial 65‐nm CMOS process, the LNA features peak gain of 26.3 dB, 21.8 mW power consumption, noise figure of 5.3 dB, output P1 dB of −4 dBm, and core size of 0.15 mm2. In the comparison with prior arts, the proposed design achieves the highest gain and figure‐of‐merit. © 2015 Wiley Periodicals, Inc. Microwave Opt Technol Lett 57:2883–2886, 2015
Quad reconfigurable antenna using dual‐patch elements
Authors: Abou Al‐Alaa M. , Elsadek H. A. , Abdallah E. A. 
Published: September 2015

ABSTRACTA quad reconfigurable antenna using 2 × 1 array of rectangular patches is investigated in this article starting from conventional microstrip antenna array with two elements. It offers reconfigurability for frequency, pattern, gain, and polarization in the same design. Modifications are added for conventional 2 × 1 antenna array to get multifunction reconfigurable antenna to change in frequency, pattern, gain, and polarization, simultaneously. Frequency reconfigurability is achieved between 1.88 and 2.45 GHz, the main beam direction of radiation pattern rotates between 0 and 30 degree (elevation angle). The proposed design offers antenna gain that can be switched between 5.7 and 7.8 dBi. Also, this design reconfigures between linear and circular polarization at 2.45 GHz. The proposed design is simulated using the CST Microwave studio 2012. The antenna array is fabricated using thin film photolithographic technique. The scattering parameters are measured using vector network analyzer E8719A. Measurements and simulations show good agreement. © 2015 Wiley Periodicals, Inc. Microwave Opt Technol Lett 57:2876–2883, 2015
Perforate‐arrays as an all‐dielectric gradient index metamaterial for HPM lens
Authors: Zhao Xue‐Long , Yuan Cheng‐Wei , Liu Lie , Peng Sheng‐Ren , Cai Dan 
Published: September 2015

ABSTRACTAll‐dielectric metamaterials have high potential for practical applications in high power microwave (HPM) area. In this article, a beam deflected flat lens made of all‐dielectric metamaterial is proposed. Owning to the angular symmetry of the element, the lens is able to neglect the incoming microwave polarization. © 2015 Wiley Periodicals, Inc. Microwave Opt Technol Lett 57:2859–2862, 2015
Ultrawideband bandpass filters based on coupled electromagnetic band gap structures
Authors: Martinez‐Iranzo Ursula , Moradi Bahareh , Garcia‐Garcia Joan 
Published: September 2015

ABSTRACTIn this letter, an ultrawideband (UWB) bandpass filter design, using coupled electromagnetic band gap structures, is proposed. Theoretical analysis is used to establish clear relations between physical parameters and the main filter characteristics. UWB bandpass filter from 3.1 to 10.7 GHz has been fabricated and measured. © 2015 Wiley Periodicals, Inc. Microwave Opt Technol Lett 57:2857–2859, 2015
Compact microstrip omnidirectional ultrawideband antenna with dual broadband nested U‐shaped slots and flat frequency response
Authors: Naghar A. , Alejos A. V. , Aghzout O. , Essaidi M. 
Published: September 2015

ABSTRACTIn this article, we present a compact ultrawideband antenna with dual broadband‐notched characteristics centered at 3.4 and 5.5 GHz. The proposed antenna consists of a rectangular patch with a modified ground plane structure and 50 Ω microstrip‐fed line. By etching two opposite U‐shaped slots in the radiating patch, the notched bands of 3.375–3.945 GHz for WiMAX and 5.425–6.150 GHz for WLAN and HYPERLAN/2 were achieved. The antenna also offers a flat frequency response so minimizing the formation of spurs and precursors that ensures optimal time domain performance for ultrawideband radio applications. The return loss was measured to better than −10 dB over the entire band from 3.1 to 10.6 GHz. The antenna gain was larger than 2 dBi all over the frequencies with a flatness of 2.5 dB and an omnidirectional radiation pattern in the H‐plane. © 2015 Wiley Periodicals, Inc. Microwave Opt Technol Lett 57:2854–2856, 2015
Miniaturized narrow band‐pass filter with quarter‐wavelength short stubs using U‐shaped folded transmission line
Authors: Son Kwang Chul , Shrestha Bhanu , Yoon Ki‐Cheol 
Published: September 2015

ABSTRACTIn this article, the miniaturized narrow band‐pass filter (BPF) with 90° short stubs using a U‐shaped folded transmission line is suggested. A U‐shaped transmission line is adopted instead of a conventional transmission line to reduce the size of the BPF on the low dielectric substrate. The size of the conventional narrow BPF is reduced by more than 70% due to the reduction of the length of the transmission line within the inverter. The experimental results show that the insertion loss and return loss are 1.61 dB and 15.4 dB, respectively, with bandwidth of 5% at the center frequency of 5.8 GHz. The designed BPF shows a harmonics rejection up to third (3f0) and fifth (5f0), with more than 18 dB rejection level in the simulation and experimental results. The size of the filter is 19 × 8.6 mm2. © 2015 Wiley Periodicals, Inc. Microwave Opt Technol Lett 57:2862–2865, 2015
Reflective shearing point diffraction interferometer
Authors: Zhu Wenhua , Chen Lei , Gu Chenfeng , Zheng Donghui , Cao Hui , Han Zhigang 
Published: September 2015

ABSTRACTA novel point diffraction interferometer with reflective shearing optical structure is developed. The substrate of interferometer has an angle with optical axis, and the incident converging spherical wavefront will be reflected by the front and rear surfaces of the substrate, respectively. Then, an interferogram with carrier frequency is obtained. Using Fourier transform algorithm, the wavefront can be retrieved from one single interferogram. In this article, the intensity distribution formulas of interferogram are derived, and the system error and the major parameters of interferometer are also discussed. The new design with compact structure and high resolution is contrast adjustable and suitable for dynamic wavefront measurement. © 2015 Wiley Periodicals, Inc. Microwave Opt Technol Lett 57:2845–2848, 2015
Magnetically biased graphene‐based switches for microwave applications
Authors: Bukvic Branko , Budimir Djuradj 
Published: September 2015

ABSTRACTThis article presents a magnetically biased graphene‐based switch for coplanar waveguides (CPW) resonator applications. Graphene patches are set in the gap between signal and ground lines, thus, obtaining the whole structures act as switchable elements. Graphene was modeled as a general material with appropriate surface conductivity. The presented CPW resonator structure acts like a switch in ON state even for magnetic bias field of around 0.5 T. The simulated S parameters of the CPW resonator structure with different magnetic field biasing are presented. © 2015 Wiley Periodicals, Inc. Microwave Opt Technol Lett 57:2956–2958, 2015
Three dimensions localization of tumors in confocal microwave imaging for breast cancer detection
Authors: Ahadi Mojtaba , Isa Maryam , Saripan M. Iqbal , Hasan W. Z. W. 
Published: September 2015

ABSTRACTBasis of the microwave imaging is the contrast in dielectric properties of breast normal tissue and tumor. Confocal microwave imaging involves transmitting an ultrawideband signal through number of antennas and records the scattered signals. Then by synthetically focusing reflections from the breast, we can make image from breast. In this article, we demonstrate the feasibility of detecting 10‐ and 5‐mm tumors in three dimensions with different antenna arrangements with different number of antennas. Two models of hemispherical array are presented. An image formation algorithm is presented for 3D image making. Successful detection of 10‐ and 5‐mm tumors are achieved with the hemispherical arrangement. The influences of the different breast sizes for tumor detection are also explored. © 2015 Wiley Periodicals, Inc. Microwave Opt Technol Lett 57:2917–2929, 2015
An mimo F‐shaped dielectric resonator antenna for 4G applications
Authors: Roslan Siti Fairuz , Kamarudin Muhammad Ramlee , Khalily Mohsen , Jamaluddin Mohd Haizal 
Published: September 2015

ABSTRACTA multiple input multiple output (MIMO) F‐shaped dielectric resonator antenna (DRA) for mobile device is presented in this article. The F‐shaped DRA is mounted on FR4 as a substrate. The measured impedance bandwidth for Port 1 is 36% (2.30–3.31 GHz) while Port 2 is 31% (2.30–3.14 GHz), respectively with isolation of −33 dB. Two orthognal modes are excited in this design which are
mode at Port1 and
at Port 2. Correlation coefficient of a MIMO F‐shaped DRA is 0.04 with diversity gain nearly 10 dB over operating frequency. The antenna provides gain 1.99 dBi for Port 1 and 1.85 dBi for Port 2 at frequency 2.6 GHz. The parameters, isolation, gain, correlation coefficient, and diversity gain of the MIMO rectangular dielectric resonator antenna are studied, and reasonable agreement between the measured and simulated results is observed. © 2015 Wiley Periodicals, Inc. Microwave Opt Technol Lett 57:2931–2936, 2015
Compact dual‐polarized UWB diversity antenna
Authors: Srivastava Gunjan , Mohan Akhilesh 
Published: September 2015

ABSTRACTA compact planar multiple‐input multiple‐output (MIMO)/diversity antenna for portable UWB applications with a size of 27 mm × 28 mm is proposed in this letter. This diversity antenna consists of a microstrip fed crescent‐shaped antenna and a CPW fed circular slot antenna which are orthogonal to each other to obtain dual polarization. Different patterns and polarization diversities of antennas are used to achieve wideband isolation. Moreover, to further enhance the isolation a cross‐shaped slot is etched into the ground plane and a sickle shaped metallic strip is introduced between the two radiating elements. This sickle shape metallic strip not only enhances the isolation, but it also produces an additional resonance at 8.9 GHz. Both the UWB antennas in MIMO systems cover the entire UWB spectrum with low mutual coupling. The isolation between the antenna elements is better than 16 dB. The diversity performance is evaluated in terms of envelope correlation coefficient (ECC) and channel capacity loss (CCL). Both of them are within their acceptable limits (ECC < 0.5, CCL < 0.4 bit/s/Hz). © 2015 Wiley Periodicals, Inc. Microwave Opt Technol Lett 57:2951–2955, 2015
CPW‐fed flower‐shaped patch antenna for broadband applications
Authors: Patre Situ Rani , Singh Surya P. 
Published: September 2015

ABSTRACTIn this article, the simulation and experimental studies on a novel compact and broadband coplanar waveguide (CPW)‐fed flower‐shaped microstrip patch antenna are reported. The proposed flower‐shaped patch is a modified version of circular patch. Although the proposed antenna has largest radius (= 12.5 mm) equal to the radius of a circular patch, it provides much wider impedance bandwidth and lower first resonant frequency as compared with the CPW‐fed circular patch antenna. The flower‐shaped patch itself is capable of providing good impedance match with the CPW feed without any modification of feed line and ground plane. The simulated input and radiation characteristics of the proposed antenna are compared with the corresponding experimental characteristics over the operating frequency range. The simulated and experimental input VSWR bandwidth (VSWR ≤ 2) of antenna are found to be 4.59:1 (2.2–10.1 GHz) and 4.81:1 (2.2–10.6 GHz), respectively. The antenna provides bidirectional and omnidirectional patterns in E‐ and H‐planes, respectively, along with average gain value of 3.89 dB and good radiation efficiency (more than 75%) over whole operating frequency range. Time domain behavior of the antenna is also analyzed along with system fidelity factor and group delay. © 2015 Wiley Periodicals, Inc. Microwave Opt Technol Lett 57:2908–2913, 2015
Comparative study on post‐polymerization modification of C1 poly(benzyl 2‐ylidene‐acetate) and its C2 analog poly(benzyl acrylate)
Authors: Krappitz Tim , Theato Patrick 
Published: September 2015

ABSTRACTThe present study investigates the challenging approach of post‐polymerization modification on polymers with a sterically demanding reaction center. Therefore, the general possibility to functionalize polymethylene moieties was investigated. Poly(benzyl 2‐ylidene‐acetate) was synthesized by polymerization of benzyl 2‐diazoacetate utilizing [(L‐prolinate)RhI(1,5‐dimethyl‐1,5‐cyclooctadiene)] as a catalyst. Subsequently, the modification of C1 polymerized poly(benzyl 2‐ylidene‐acetate) with amines was analyzed and the obtained data set was compared with experimental data derived for the C2 analog poly(benzyl acrylate). This is the first study on post‐polymerization modification utilizing densely functionalized polymethylenes as starting materials. © 2015 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2016, 54, 686–691
Di‐nuclear zinc complexes containing tridentate imino‐benzotriazole phenolate derivatives as efficient catalysts for ring‐opening polymerization of cyclic esters and copolymerization of phthalic anhydride with cyclohexene oxide
Authors: Chang Chin‐Hsiang , Chuang Hui‐Ju , Chen Ting‐Yi , Li Chen‐Yu , Lin Chia‐Her , Lee Ting‐Yu , Ko Bao‐Tsan , Huang Hsi‐Ya 
Published: September 2015

ABSTRACTZinc catalysts incorporated by imino‐benzotriazole phenolate (IBTP) ligands were synthesized and characterized by single‐crystal X‐ray structure determinations. The reaction of the ligand precursor (C1DMeIBTP‐H or C1DIPIBTP‐H) with diethyl zinc (ZnEt2) in a stoichiometric proportion in toluene furnished the di‐nuclear ethyl zinc complexes [(μ‐C1DMeIBTP)ZnEt]2 (1) and [(μ‐C1DIPIBTP)ZnEt]2 (2). The tetra‐coordinated monomeric zinc complex [(C1PhIBTP)2Zn] (3) or [(C1BnIBTP)2Zn] (4) resulted from treatment of C1PhIBTP‐H or C1BnIBTP‐H as the pro‐ligand under the similar synthetic method with ligand to metal precursor ratio of 2:1. Single‐crystal X‐ray diffraction of bimetallic complexes 1 and 2 indicates that the C1DMeIBTP or C1DIPIBTP fragment behaves a NON‐tridentate ligand to coordinate two metal atoms. Catalysis for ring‐opening polymerization (ROP) of ε‐caprolactone (ε‐CL), β‐butyrolactone (β‐BL), and lactide (LA) of complexes 1 and 2 was systematic studied. In combination with 9‐anthracenemethanol (9‐AnOH), Zn complex 1 was found to polymerize ε‐CL, β‐BL, and L‐LA with efficient catalytic activities in a controlled character. This study also compared the reactivity of these ROP monomers with different ring strains by Zn catalyst 1 in the presence of 9‐AnOH. Additionally, Zn complex 1 combining with benzoic acid was demonstrated to be an active catalytic system to copolymerize phthalic anhydride and cyclohexene oxide. © 2015 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2016, 54, 714–725
Commercial Sphagnum peat moss is a vector for exotic ectomycorrhizal mushrooms
Authors: Ángeles-Argáiz Rodolfo Enrique , Flores-García Andrés , Ulloa Miguel , Garibay-Orijel Roberto 
Published: September 2015

Abstract

Sphagnum peat moss is one of the most commonly used substrates for forest plant and houseplant production. It is extracted from peat bogs in the circumboreal region and exported worldwide. Commercial peat moss is pasteurized, and is therefore believed to be free of viable ectomycorrhizal propagules. We used a bioassay with Pinus montezumae to demonstrate that commercial peat moss carries viable ectomycorrhizal spores, able to form mycorrhizae. Ectomycorrhizal fungi on seedling root-tips were sequenced for phylogenetic analyses using the ITS rDNA barcode region. We found three species: Suillus brevipes, Sphaerosporella brunnea, and Thelephora terrestris. S. brevipes and T. terrestris were found as viable inoculum transported in the peat moss, while S. brunnea was a greenhouse contaminant. S. brevipes and T. terrestris have biological characteristics (such as heat resistant and long living spores) that facilitate their survival to the extraction, transport, and storage processes of peat moss. This allows them to colonize nursery seedlings and to become potential invasive species in plantation areas. S. brevipes and T. terrestris are two of the most introduced fungi by anthropic activities; it has been argued that the vehicle for the introductions are their pine symbionts. This is the first time it has been demonstrated that peat moss is an important vehicle for the introduction of these fungi; a fact potentially related to the pattern of introduction of these ectomycorrhizal species from the northern hemisphere to elsewhere in the world.