bluuebunny/crossref_metadata_2025_split huggingface dataset:
Effect of fabrication strategy on the enantioseparation performance of β‐cyclodextrin‐functionalized polymethacrylate monoliths: A comparative evaluation
Authors: Lin Yuanjing , Guo Jialiang , Lin Hang , Wang Jincai , Somsen Govert W. , Crommen Jacques , Jiang Zhengjin 
Published: July 2017

AbstractTo evaluate the effect of the preparation strategy on the enantioseparation performance of β‐cyclodextrin‐functionalized monoliths, a series of β‐cyclodextrin‐functionalized organic polymeric monolithic columns were prepared through two‐step, single‐step, and one‐pot approaches, using the same cyclodextrin, linker–spacer, and crosslinker. Physicochemical characterization of the columns was carried out by determining the morphology, β‐cyclodextrin density, permeability, and chromatographic efficiency. For each type of monolithic column, the enantioresolution of 22 chiral compounds, including mandelic acid derivatives, nonsteroidal anti‐inflammatory drugs, N‐derivatized amino acids, and herbicides, was comparatively studied under optimum chromatographic conditions. The β‐cyclodextrin‐functionalized monolithic columns prepared through the one‐pot approach exhibited higher enantioresolution for most chiral compounds, and they have the advantage of good controllability and simple preparation. On the other hand, the enantioresolution obtained on columns prepared through the single‐step approach was quite unsatisfactory, and therefore the effect of using different linking spacers and crosslinkers was studied. A significant improvement of enantioresolution for 2‐chloro‐mandelic acid was obtained by using N,N‐methylenebisacrylamide instead of ethylene dimethacrylate as the crosslinker in the single‐step preparation.
Who is ethnic neighborhood tourism for anyway? Considering perspectives of the dominant cultural group
Authors: Maruyama Naho U. , Woosnam Kyle M. , Boley Bynum B. 
Published: July 2017

AbstractPast studies regarding “ethnic neighborhood tourism” (ENT) have primarily reflected perspectives of the ethnic minority group whose culture is represented to tourists. Therefore, this study explored how members of the ethnic “majority” group who live in the ethnic neighborhood perceive ENT in their own community. The interpretive analysis of 31 interviews with Japanese residents in a Brazilian neighborhood in Oizumi, Gunma, Japan, revealed that the Japanese residents are reluctant and somewhat antagonistic towards ENT in their community. This study also illustrates that ENT reinforced the ethnic divide within the town rather than healing past tensions between the 2 groups.
A multi‐functional tri‐mode patch antenna supporting dual‐band GPS and wireless communication system
Authors: Cai Y.‐M. , Li K. , Yin Y. , Zhao L. 
Published: July 2017

AbstractThis letter presents a trimode multi‐functional patch antenna for GPS and wireless communication applications. The antenna consists of a folded annular slot, a section of coaxial cable, shorting copper columns and the ground plane. Tri‐band operation is realized by exciting three different working modes including microstrip antenna mode, slot antenna mode and monopole antenna mode. The proposed antenna is designed to cover the GPS L1 and L2 bands, UMTS‐band 5. At the GPS bands, the antenna is unidirectional with right‐hand circular polarization. At the telecommunication band, an omnidirectional radiation pattern is realized with linear polarization. The design is fabricated by standard PCB technologies, and its performance is validated by measurement.
Dual‐band circularly polarized hybrid antenna for WLAN/WiMAX applications
Authors: Sharma Anand , Das Gourab , Gangwar Ravi Kumar 
Published: July 2017

AbstractIn this article, a dual‐band circularly polarized hybrid antenna is examined and discussed. In this composition, the diagonally trimmed square shaped slot (modified slot) acts as a radiator and the feeding network of CDRA. Modified slot has been adopted to excite the orthogonal modes (
and
) in CDRA, which is responsible for the origination of circularly polarized (CP) waves in lower frequency band (2.68–3.04 GHz). Furthermore, a combination of V‐shaped microstrip line with modified slot is utilized to generate CP waves in upper frequency band (5.12–5.34 GHz). The sense of polarization can be altered by taking mirror image of the modified slot. To verify the simulated outcomes, the archetype of proposed design is fabricated and tested. Experimental results show good settlement with simulated results. The proposed radiator operates over two frequency bands, i.e. 2.36–3.22 GHz and 5.0–5.34 GHz with the fractional bandwidth of 30.82 and 6.57%, respectively. Measured 3‐dB axial ratio bandwidth is ∼12.20 and 4.2% in lower and upper frequency band, respectively. The proposed antenna structure is quite appropriate for WLAN (2.4/5.2 GHz) and WiMAX (2.5 GHz) applications.
Single‐polarized wideband array antenna of all‐metal structure with modified TSA elements
Authors: Kim In‐Seon , Lee Chang‐Hoon , Choi Sam‐Yeul , Kim Joon‐Yong 
Published: July 2017

AbstractThis article presents a wideband wide‐angle tapered slot array (TSA) antenna with no grating lobes in the 6–18 GHz band and the required scan range (azimuth angle ≤ |42.5°|, elevation angle ≤ |22.5°|). The unit element in the array antenna is a modified type of the existing TSA elements. We studied the various parameters for the proposed structure to investigate their effect. A single antenna and an 8 × 8 array antenna with the proposed structure were designed and fabricated. The validity of the proposed structure and design procedure has been verified by the agreement between the simulated and measured results.
Ultrawideband doubly tapered slot antenna (DTSA) with integrated balun as a feed for time‐domain target detection
Authors: Pegwal Saurabh , Abegaonkar Mahesh P. , Koul Shiban K. 
Published: July 2017

AbstractThis article discusses the design of an ultrawideband doubly tapered slot antenna (DTSA) using an ultrawideband balun at its input feeding network. The proposed antenna with integrated balun is completely planar in nature with a conventional microstrip feed. The complete antenna structure with integrated balun realized on an 8 mil Rogers's RO4003C substrate shows a measured return loss of better than 10 dB from 4 to 36 GHz and measured peak gain of 2.08–8.44 dB for the entire band. The time domain characteristics of the transmitting/receiving system using the proposed ultrawideband (DTSA) antenna is also investigated giving a low variation in group delay (≤0.18 nsec). This transmitting/receiving system with the proposed antenna is further used to demonstrate possibility of using this antenna for target detection.
Dual‐mode dual‐band microstrip bandstop filter design with independently tunable center frequencies
Authors: Gorur Ali Kursad , Basmaci Filiz Ayse Nihan , Dogan Engin , Karpuz Ceyhun , Gorur Adnan 
Published: July 2017

AbstractIn this article, a novel dual‐mode dual‐band bandstop filter design with independently tunable center frequencies is presented by using dual‐mode square loop resonators. Tuning operation can be achieved with a constant fractional bandwidth. Varactor diodes are used instead of perturbation and reference elements. Two dual‐mode square loop resonators in different electrical lengths are coupled to a transmission line connecting input and output ports. Center frequencies of both stopbands can be independently tuned by changing the capacitances of varactor diodes of both perturbation and reference elements. While the perturbation and reference varactors tune even mode resonance frequency together, odd mode resonance frequency can only be tuned by reference varactors. The designed filter was also fabricated for the experimental studies and it exhibits acceptable tunability operations in measurements. Center frequencies of the first and second stopbands can be tuned between 2.2 and 2.54 GHz and between 3 and 3.38 GHz, respectively. Rejection levels for both stopbands were obtained as better than −13 dB in the whole tuning range.
A new double T‐U‐shaped biaxial compact double‐negative meta‐atom for multiband applications
Authors: Hossain Mohammad Jakir , Faruque Mohammad R. I. , Islam Mohammad T. 
Published: July 2017

AbstractIn this research, a new biaxial double‐negative (DNG) meta‐atom for multiband operation has been designed, fabricated, and measured that can work in the microwave region. The proposed meta‐atom structure offers DNG properties for three axes (x, y, and z) electromagnetic (EM) wave propagation through the meta‐atom structure. For along the x‐axis EM wave propagation, meta‐atom exhibits DNG characteristics in the L‐band. Similarly, for along the y‐axis EM wave propagation, it displays DNG characteristics in the C‐band. The meta‐atom shows DNG properties in Ku‐band for along the z‐axis propagation. Commercially available Computer Simulation Technology electromagnetic simulator was adopted to examine the design of the meta‐atom. The measured results showed good agreement with the simulated one. The meta‐atom has exhibited multiband response in conjunction with the DNG property over the certain frequency bands in the microwave spectra.
A bandwidth enhanced metasurface antenna for wireless applications
Authors: Rajak Neha , Chattoraj Neela 
Published: July 2017

AbstractThis article presents a two layer metasurface antenna in which the top layer is metasurface and the bottom layer is patch antenna. The metasurface enhances the bandwidth and gain of the patch antenna. The metasurface is composed of an array of radiating element which is arranged in 5 × 6 layout. Complementary split ring resonator is used as radiating element. The substrate used for metasurface and patch antenna is Rogers RO4350B having loss tangent of 0.0037, relative permittivity of 3.48 and thickness of 1.524 mm.The overall length and width of the total structure is 0.72λo × 0.95λo (38 × 50 mm2). The metasurface is acting as Double Negative material in which permeability and permittivity both are negative so as a result refractive index will also be negative. The waves coming out of the patch antenna is affected by the array of radiating element on the metasurface, which is above the patch antenna due to which equivalent relative permittivity and permeability of the structure changes and therefore there is change in the performance of the patch antenna. The proposed antenna resonates at 5.7 GHz with bandwidth enhancement from 150 to 260 MHz with gain of 5.8 dBi. The return loss bandwidth is found to be 2.83% (5.64–5.8 GHz) under simulation and 4.64% (5.62–5.78 GHz) under measurement at the resonating frequency when metasurface is used with patch antenna. Overall 39% increase in return loss bandwidth is achieved. The fractional bandwidth of 55.22% is achieved. The proposed antenna is useful for WiFi application.
Compact microstrip patch antenna proclaiming super wideband characteristics
Authors: Rahman M. N. , Islam M. T. , Mahmud M. Z. , Samsuzzaman M. 
Published: July 2017

AbstractIn this study, a compact crescent‐shaped microstrip patch antenna is proposed for super wideband (SWB) applications. The antenna consists of a rectangular, slotted partial ground plane and a crescent shape radiating patch to cover wider frequency band than the ultrawideband. The proposed antenna is fabricated on an FR4 substrate and is fed with a 50 Ω microstrip feed line. The substrate has a thickness of 1.60 mm with the relative permittivity of 4.4, and a dielectric loss tangent of 0.02. The proposed antenna has a compact size of 32 mm × 22 mm with the electrical dimension of 0.27λ × 0.18λ. The simulated results agree with the measured results. The result shows that the proposed antenna achieves reflection coefficient less than −10 dB (VSWR < 2) from 2.5 GHz to 29.0 GHz that is a 168.25% fractional bandwidth with 11.6:1 bandwidth ratio. The proposed antenna achieves the durable omnidirectional radiation pattern throughout the operating band with 6.10 dBi of maximum gain. The bandwidth dimension ratio of the presented antenna is 3462.02. As the antenna shows the SWB characteristics, it can be used in the high fidelity short pulse applications. The proposed antenna can be used in S, C, X, Ku, K, ISM, Wi‐Fi, WLAN, WiMAX, and MVDDS wireless communication systems.
A flexible UWB inverted‐F antenna for wearable application
Authors: Xu Li‐Jie , Wang Hui , Chang Yumei , Bo Yaming 
Published: July 2017

AbstractA novel flexible antenna is proposed for communication with implanted devices in this letter. Polyimide is adopted as flexible substrate for conformal property. Based on inverted‐F structure, bow‐tie shaped structure is introduced on the top layer to achieve wideband performance. Besides, top and bottom layers are connected with a metal wall, which not only helps with miniaturization, but also leads to single‐sided fabrication requirement. Furthermore, the communication link with implanted antenna is estimated. Finally, the proposed flexible antenna is measured both in the air and around wrist in conformal form, showing good agreement with simulation results.
Design of high return loss logarithmic spiral antenna
Authors: Morbidel Leonardo , Bulus Rossini Laureano A. , Costanzo Caso Pablo A. 
Published: July 2017

AbstractWe propose a new strategy for designing a logarithmic spiral antenna and the impedance adapter to operate in a frequency range of 1 to 10 GHz. Numerical and experimental results show a decrease in return loss being higher than 20 dB in almost the entire range of operation.
Mechanically pattern reconfigurable dual‐band antenna with omnidirectional/directional pattern for 2.4/5GHz WLAN application
Authors: Li Peng Kai , You Chang Jiang , Yu Hong Fang , Cheng Yu Jian 
Published: July 2017

AbstractA mechanically pattern reconfigurable dual‐band antenna with an omnidirectional radiation pattern or a directional pattern for 2.4/5GHz dual‐band WLAN application is presented. By manually rotating the top substrate, the antenna can operate at patch state or monopole state, respectively. A novel U‐gap structure consisting of an outer patch, an inner patch and a U‐shaped gap is introduced to achieve the dual band feature at both operation states. The measured overlapped bands of the two states are 2.4–2.56 GHz and 5.22–6 GHz, covering the 2.4–2.48 GHz and most of the 5.15–5.85 GHz WLAN band. The measured peak gain is 2.4 dBi at 2.5GHz, 6.2 dBi at 5.5 GHz for monopole state, and 5.8 dBi at 2.5 GHz, 7.2 dBi at 5.5 GHz for patch state.
A fully integrated W‐band pulse compression radar CMOS transceiver
Authors: Oh Juntaek , Jang Jingyu , Hong Songcheol 
Published: July 2017

AbstractA fully integrated ultra‐wideband (UWB) W‐band pulse compression radar transceiver in a 65‐nm CMOS technology is presented. The transceiver adopts a pulse compression scheme for high power spectral density with low TX leakage. Two identical voltage controlled oscillators, which are coupled through the second harmonic, are designed to achieve high output power and low phase noise without buffers. A transformer‐based local oscillator distribution network is proposed to achieve both small chip area and high port‐to‐port isolation. The transceiver chip produces 7.5‐GHz UWB RF pulses with 14.5‐dBm peak output power in the tuning range of 75–81 GHz, while the receiver shows a dynamic range of above 60 dB. The radar module was realized with waveguide transitions from a micro‐strip to a WR‐10 waveguide, and was capable of differentiating two targets with 6.5‐cm separation within 30 m distance.
Finger‐worn end‐fire antenna for MM‐wave applications
Authors: Mantash M. , Denidni T. A. 
Published: July 2017

AbstractA novel antenna candidate for intelligent wearable systems at 30 GHz is presented in this letter. It consists of a compact axial‐mode helical antenna with a ground plane mounted on a plastic ring. This choice allows to achieve a wide bandwidth and circular polarization in a compact package. A prototype is manufactured, and the different classical key antenna metrics are investigated: return loss, realized gain, axial ratio and radiation pattern. The bandwidth and radiation characteristics obtained make the wearable ring antenna suitable to be used for MM‐wave applications within the frequency band from 25 to 33 GHz.
Assessment of multilayered graphene technology for flexible antennas at microwave frequencies
Authors: Elmobarak Husameldin A. , Rahim Sharul K. A. , Abedian Mohammad , Soh Ping Jack , Vandenbosch Guy A. E. , Yew Chiong Lo 
Published: July 2017

AbstractAs it has outstanding electrical and mechanical properties, like high conductivity, durability, and flexibility, graphene may be an interesting material also for conformal and wearable antennas. Whereas mono‐atomic graphene layers have been proven to perform inadequately at microwave frequencies, in this article the performance of multilayered graphene‐based sheets (GBS) fabricated onto a polymer substrate is assessed when used as flexible planar and conformal antennas. This is accomplished through studying a simple microstrip antenna topology. Challenges related to the fabrication process of these antennas are discussed, for example adhesion issues and the occurrence of air gaps on the substrate layer. The graphene‐based technology is compared to a classical technology involving copper as metal. Bending of the antennas is also discussed. The main conclusion is that multilayered graphene does perform adequately as conductor in antennas at microwave frequencies, with the possibility of providing a slightly higher gain than copper.
Gain enhancement of a compact 2.4‐GHz meander antenna using inductive feed and capacitive load
Authors: Chen Ja‐Hao , Yang Chun‐Kai , Cheng Chen‐Yang , Yu Cheng‐Chi , Hsu Cheng‐Hsing 
Published: July 2017

AbstractIn this study, a compact printed meander antenna with enhanced peak gain for 2.4‐GHz applications was investigated. Inductive feed and capacitive load techniques were used in the meander antenna's design to optimize peak gain performance. A measured maximum peak gain of 4.49 dBi, input reflection coefficient of −15 dB, and fractional bandwidth of 7.23% were achieved using a 1.6‐mm‐thick FR4 substrate. The low‐profile antenna occupied an area of 26 × 15.6 mm2. The proposed antenna can be implemented in standard printed circuit board processes without any lumped elements or via holes, and it introduces very little fabrication complexity.
Dual‐band impedance transformer using two parallel open‐ and shorted‐stubs with total quarter guided wavelength
Authors: Ma Xing‐Bing , Jiang Ting 
Published: July 2017

AbstractThis article presents a dual‐band (DB) impedance transformer with novel parallel‐stubs‐loaded structure. The proposed transformer consists of a traditional single band matching network (SBMN) and a DB stubs‐loaded transmission‐line network in series. The DB stubs‐loaded MN features an open‐stub and a shorted‐stub in parallel with total length λ1/4 (λ1 is guided wavelength from lower f1 of two matching frequencies). The considered load has frequency‐dependent complex impedance at two uncorrelated frequencies (f1, f2). Design equations are presented, and required circuit parameters are all obtained adopting derived analytical design formula. Good agreements between simulation and measurement are observed.
Compact tunable lowpass filter with sharp roll‐off and low insertion loss
Authors: Zhang Ting , Cai Zongqi , Yang Yang , Bao Jingfu , Wang Yiwen 
Published: July 2017

AbstractA novel continuously tunable lowpass filter (LPF) with compact size, sharp roll‐off and low insertion loss is presented in this paper. The filter employs two varactor diodes, a pair of open‐ended coupled lines and a U‐shape step impedance line (SIL) with an open‐ended stub loaded at the center of the SIL to form a very compact layout. The odd‐ and even‐mode analysis and equivalent circuit model are demonstrated for estimation of the transmission characteristics. Tuning the DC voltage applied on the varactor diodes, the varactor capacitance accordingly changes leading to a varying cutoff frequency fc. The measured results show that the achieved 3‐dB fc tuning range is 60.6% (1.15–2.15 GHz). The measured insertion loss (IL) and roll‐off rate are 0.2‐0.4 dB and 50–73 dB/GHz, respectively. The overall size of the LPF is only 0.005λg2, which shows a competitive advantage comparing with the state‐of‐the‐art work.
A tri‐band slot antenna loaded with split ring resonators
Authors: Paul Princy Maria , Kandasamy Krishnamoorthy , Sharawi M. S. 
Published: July 2017

AbstractA compact tri‐band slot antenna with independent tuning capability of its resonant frequencies is proposed in this article. A microstrip line fed square slot is loaded with split ring resonators (SRR) to obtain multiband characteristics. The slot is designed to resonate at 2.6 GHz. Two SRRs with single and multiple splits are loaded with the slot, which provide additional resonances at 4.3 and 4.7 GHz, respectively. Parametric analysis of the antenna shows that its resonance frequencies are controlled independently. The proposed antenna is fabricated on an FR4 substrate with a size of 60 × 60 × 1.56 mm2. The proposed design offers stable omnidirectional patterns and >3.8 dBi at all the resonating frequency bands.
Forming a transparent atmospheric optical channel by use of vortical laser beam
Authors: Artyschenko Stepan V. , Pasternak Yury G. , Proskurin Dmitry K. , Fedorov Sergey M. 
Published: July 2017

AbstractIt was shown that promising way to reduce a power loss of optical waves transmitted through atmosphere is use of spatially inhomogeneous optical waves with phase front in form of flat spiral. Vortical optical beam used to separate aerosol (due to light pressure on water particles) and create a cone wherein droplets concentration is substantially reduced. Unlike known method to create a transparent atmospheric optical channel based on use evaporation of aerosol particles via high‐power laser radiation, proposed method is substantially less energy‐consuming since when moving aqueous aerosol particle from area of laser beam propagation no evaporation occurs.
Design of curved frequency selective surface with high roll off
Authors: Begam Nurnihar , Samaddar Poulami , Saha Snehasish , Sarkar Sushanta , Chanda (Sarkar) Debasree , Sarkar Partha P. 
Published: July 2017

AbstractIn this article, band pass cylindrical double‐layer frequency selective surfaces (FSSs) are investigated using method of moment (MOM). “Plus”‐shaped slots are used to design the FSSs. The dielectric substrate is considered as air. A good bandwith and sharp roll off are achieved for curved FSS. Theoretical and measured investigations have been done by FEKO simulator and microwave test bench setup, respectively.
An ingestible capsule system for in‐body core temperature monitoring
Authors: Zhang Ke , Liu Changrong , Yang Xinmi , Liu Xueguan , Guo Huiping 
Published: July 2017

AbstractAn ingestible capsule system monitoring in‐body core temperature is presented and an in vitro measurement is carried out. The capsule system composed of essential electrical components, antenna, and power supply is codesigned for the sake of minimizing the overall size and maximizing the transmission distance. To meet these properties, a multilayered PIFA antenna is applied to be integrated with the circuit. The proposed capsule antenna is demonstrated experimentally at 433‐MHz industrial, scientific and medical (ISM) band. The total length of capsule is 31.4 mm and the volume of capsule antenna is 147 mm3. Experimental results are well agreed with theoretical predictions.