bluuebunny/crossref_metadata_2025_split huggingface dataset:
Novel method to determine base resistance in sige HBT from small‐signal S‐parameters measurement
Authors: Sun Yabin , Fu Jun , Wang Yudong , Zhou Wei , Li Xiaojin , Shi Yanling 
Published: January 2017

ABSTRACTA novel and robust method to determine the internal variable base resistance (RB) of SiGe HBT from small‐signal S‐parameters measurement is developed in present work. The proposed method is adopted in two kinds of SiGe HBT compact models, MEXTRAM and HICUM. With the aid of auxiliary collector resistance, the lower and upper limits of RB are built up and a narrow variation range of RB is obtained. Thus, RB can be directly estimated from the small‐signal S‐parameters measurement. The proposed method is successfully applied to several sizes of SiGe HBTs and the experiment results shows that average error between the lower and upper limits of RB is less than 3% over a wide range of bias points, which can satisfy the demands of most engineering applications. Therefore, we believe that the proposed technique is a reliable routine applicable to estimate the base resistance in SiGe HBTs. © 2017 Wiley Periodicals, Inc. Microwave Opt Technol Lett 59:555–560, 2017
2.4‐GHz CMOS linear power amplifier for IEEE 802.11N WLAN applications
Authors: Yoo Jinho , Lee Changhyun , Kang Inseong , Son Minoh , Sim Yonghoon , Park Changkun 
Published: January 2017

ABSTRACTIn this work, we design a linear CMOS power amplifier with a spiral‐type output transformer for IEEE 802.11n WLAN applications. We conduct studies to identify the proper output transformer and power stage structures for linear CMOS power amplifiers. The power amplifier is composed of a single differential‐pair for the power stage to mitigate the stability problems that frequently arise in high gain linear power amplifiers. Additionally, we investigate the output matching network using a spiral‐type output transformer to minimize the output return loss. To verify the feasibility of the power amplifier, we designed a 2.4‐GHz power amplifier with a 180‐nm SOI CMOS process. The designed power amplifier is measured using an IEEE 802.11n WLAN signal. The power amplifier achieves 21.28 dBm output power while the measured EVM satisfies the standard for 802.11n applications. © 2017 Wiley Periodicals, Inc. Microwave Opt Technol Lett 59:546–550, 2017
A compact CPW‐fed antenna with fractal S‐shaped patches for multiband applications
Authors: Cheong Hau Ran , Yeap Kim Ho , Lai Koon Chun , Teh Peh Chiong , Nisar Humaira 
Published: January 2017

ABSTRACTWe present the design of a novel compact coplanar waveguide‐fed antenna with fractal s‐shaped patches for multiband applications. The antenna consists of three fractal s‐shaped patches with different lengths. We demonstrate that the number of resonant frequencies is in direct proportion with the number of fractal s‐shaped patches. This is to say that, the number of resonant frequencies in a multiband antenna can be increased by increasing the number of patches. The resonant frequencies can be selected by carefully adjusting the length of the patches. We have designed our antenna to operate at 2.5/5.3/7.1/8.4 GHz. The measurement results show that the proposed antenna has 10 dB impedance bandwidths of 622 MHz (2.322–2.944 GHz), 466 MHz (5.113–5.579 GHz), 121 MHz (6.890–7.011 GHz) and 1080 MHz (8.206–9.286 GHz) to cover all the 2.4 GHz Bluetooth, 5.5 GHz WiMAX, and 2.4/5.2 GHz WLAN bands. The latter two bands of our proposed antenna fall within the X band range which finds vast applications in radar, aircraft, spacecraft and mobile or satellite communication system. The proposed antenna is printed on a single‐layered FR4 substrate, and it occupies a small volume of 17 × 18 × 1.6 mm3. The simulated and measured performance of the antenna confirms its omnidirectional radiation pattern and quad‐band operation. © 2017 Wiley Periodicals, Inc. Microwave Opt Technol Lett 59:541–546, 2017
A 5‐GHz highly linear floating‐body CMOS LNA with switched gain control
Authors: Lee Muyeon , Kwon Ickjin 
Published: January 2017

ABSTRACTA 5‐GHz highly linear floating‐body CMOS low‐noise amplifier (LNA) with switched gain control is presented. The proposed LNA achieves very low noise in gain mode and high linearity and very low power consumption in bypass mode. In the gain mode, the LNA consumes 19.5 mW of power and achieves a noise figure of 1.15 dB, a gain of 13.8 dB, and an input IP3 of 3 dBm at 5 GHz. In the bypass mode, the LNA consumes only 1 μW and achieves a gain of −4.3 dB and an input IP3 of 7 dBm at 5 GHz. © 2017 Wiley Periodicals, Inc. Microwave Opt Technol Lett 59:593–596, 2017
Approximate investigation on isosceles triangular microstrip antenna in fundamental mode
Authors: Maity Sudipta , Gupta Bhaskar 
Published: January 2017

ABSTRACT:Theoretical investigation on probe fed different isosceles
Triangular Microstrip Antenna is presented here for the first time. Tri‐linear transformation is modified to obtain the eigenfunction and eigenvalue. Since the trilinear transformation is available for equilateral triangle only, not for arbitrary isosceles triangle, our theory gives fairly accurate results for
60° at fundamental
mode only. Approximate expression is given here to predict the resonant frequency with an accuracy of 1.3%. Theoretical results on resonant frequency, input impedance and far‐field patterns are compared with experimental data to show the validity of our theory. It is found that our theory gives results order faster (approx. 60–100 times) than EM simulator. © 2017 Wiley Periodicals, Inc. Microwave Opt Technol Lett 59:614–618, 2017
Modified star‐star fractal (MSSF) super‐wideband antenna
Authors: Singhal Sarthak , Singh Amit Kumar 
Published: January 2017

ABSTRACTA microstrip line fed star‐star fractal antenna with notch loaded semi‐elliptical ground plane is presented for super wideband applications. An impedance bandwidth of 4.6–52 GHz, i.e., a bandwidth ratio of 11.31:1 is achieved for VSWR < 2. The antenna structure has advantages of compact dimensions and wider bandwidth over previously reported SWB structures. Radiation characteristics, i.e., co and cross polar radiation patterns, peak gain, and efficiency has been presented and discussed. The simulated and experimental results are found to be good agreement. © 2017 Wiley Periodicals, Inc. Microwave Opt Technol Lett 59:624–630, 2017
A broadband dual‐polarized antenna with chamfers
Authors: Wu Rui , Chu Qing‐Xin 
Published: January 2017

ABSTRACTA wideband dual‐polarized antenna is proposed. With chamfers in cross loop dipoles, the two resonating modes can be controlled, the first resonating mode can move lower and the second resonating mode can move higher by changing the size of the chamfer. Therefore, the radiator size is reduced to 48 mm × 48 mm (0.35 λ × 0.35 λ, λ is the wavelength at 2.2 GHz) and a wider bandwidth is achieved. Measured results show that the proposed antenna has a bandwidth of 48.8% from 1.7 to 2.8 GHz for VSWR < 1.5. Stable radiation pattern and stable gain are also obtained over the operating band. © 2017 Wiley Periodicals, Inc. Microwave Opt Technol Lett 59:631–635, 2017
Reduced size elliptic UWB antenna with inscribed third iteration sierpinski triangle for on‐body applications
Authors: Leyva‐Hernandez Roberto , Tirado‐Mendez Jose Alfredo , Jardon‐Aguilar Hildeberto , Flores‐Leal Ruben , Linares Y Miranda Roberto 
Published: January 2017

ABSTRACTIn this article, a combination of an elliptical UWB monopole with a series of Sierpinski triangle iterations inscribed in the planarized radiator is used to develop a highly‐impedance stability UWB antenna, performing from 700 MHz to 9 GHz. The fractal iteration is introduced in order to obtain a radiator size reduction and to improve the current distribution stability. With this implementation, a 31% radiator area reduction is obtained compared to a conventional circular or elliptical radiator. The antenna impedance matching is maintained over the entire bandwidth, even when an external lossy dielectric body is around or even in contact to the radiator. The antenna presents quasi‐omnidirectional radiation patterns and a gain around 0 dBi and group delay variations lower than 2 ns, making it suitable for short‐pulse communications systems and on‐body communications applications. © 2017 Wiley Periodicals, Inc. Microwave Opt Technol Lett 59:635–641, 2017
Dependance of ambient refractive index sensitivity with grating period of LPFG
Authors: Engles Derick , Prashar Shivendu , Malik Sham Sunder 
Published: January 2017

ABSTRACTThis study investigates the response of long period fiber grating (LPFG) to ambient index smaller than fiber cladding index at different grating periods. Here the basis of investigation is difference in resonant wavelength shifts of different ambient indices surrounding optical fiber cladding with periods. Mathematical approach using three layer geometry is implemented on standard fiber (SMF28e) to estimate cladding modes. The influence of grating periods (375 μm, 415 μm, 450 μm, 500 μm, and 550 μm) on LPFG index sensitivity is assessed for LP03, LP04, LP05, and LP06 cladding modes. The largest shift of 127 nm for a range of ambient refractive index (1–1.455) is achieved by LP06 mode at a grating period of 550 μm. © 2017 Wiley Periodicals, Inc. Microwave Opt Technol Lett 59:658–661, 2017
A lightweight waveguide horn antenna made via 3D printing and conductive spray coating
Authors: Tak Jinpil , Kang Do‐Gu , Choi Jaehoon 
Published: January 2017

ABSTRACTHerein, a lightweight, rapidly‐manufactured X‐band waveguide horn antenna, made by 3D printing and conductive spray coating, is proposed. The proposed antenna has the advantages of being low‐cost and lightweight and can be rapidly manufactured with an easy construction process. To metalize the inside of the horn antenna, the antenna CAD model is split into four pieces. The four assembly parts are 3‐D printed with polylactic acid (PLA) using the fused deposition modeling (FDM) method. After 3D printing, each part is metalized via conductive spray coating. Last, the sprayed parts are assembled using polycarbonate bolts and nuts. Experimental results show that the antenna weight is only 19.3% of a commercial computerized numerically controlled (CNC) machined metallic antenna. To verify the antenna performance, the reflection coefficient and gain characteristics of the proposed 3D printing horn antenna are compared with those of an aluminum horn antenna of the same size. © 2017 Wiley Periodicals, Inc. Microwave Opt Technol Lett 59:727–729, 2017
Multi‐wavelength L‐band gain‐clamped erbium‐doped fiber amplifier with high gain and flatness by using composite FBGS
Authors: Jiuru Yang , Chunyu Liu 
Published: January 2017

ABSTRACTThe gain‐clamped erbium‐doped fiber amplifiers (EDFA) can efficiently stabilize the gain fluctuation of signals, but with the price of gain–loss and worsened flatness. In this paper, we theoretically study the relationships between clamping and loss and propose a novel linear‐cavity gain controller based on a pair of composite fiber Bragg gratings (FBGs) to balance gain and clamping, which consist of a uniform FBG with high‐reflectivity and a chirp‐FBG with low‐reflectivity. The comprehensive experiments and comparisons are then conducted in terms of gain, flatness and clamping capability. Under the optimized central wavelength and reflectivity of FBGs, the ±0.1 dB stability of multi‐wavelength signals is achieved in ∼30 dB dynamic range. Moreover, our designed amplifier simultaneously guarantees the high average gain (∼24 dB) and low un‐flatness (∼±0.8 dB) in the range of 1570–1610 nm. This is a very promising technology for practicality of L‐band gain‐clamped EDFAs due to its simple configuration and adjustment. © 2016 Wiley Periodicals, Inc. Microwave Opt Technol Lett 59:691–695, 2017
Anisotropic fractal metasurface‐based antenna with contrary beams
Authors: Hongnara Tanan , Chaimool Sarawuth , Akkaraekthalin Prayoot 
Published: January 2017

ABSTRACTThe capabilities of the dual‐band bidirectional dipole antenna to couple near‐field with the metasurface have been investigated both numerically and experimentally. By properly positioning the radiating element with respect to the metasurface, the proposed antenna can emit in forward or in the backward direction. It is shown that the array of fractal closed ring resonators formed as the anisotropic metasurface can be excited to generate the opposite angular beams even though the reflection coefficient of the metasurface is high with the same value of 0.8. This is due to the fact that the conversion of evanescent to propagation waves from transmitting closely antenna to the far‐zone existed. To our knowledge, this is the first report for a metasurface applied to dualband antenna with contrary beams. This proposed metasurface‐based antenna concept may present new opportunities in the design of multi‐functional antennas. © 2017 Wiley Periodicals, Inc. Microwave Opt Technol Lett 59:715–720, 2017
Phase quantization effects of coded metasurface on agile scattering field control
Authors: Yang Huan‐Huan , Xu Li‐Ming , Yang Fan , Cao Xiang‐Yu , Xu Shen‐Heng , Gao Jun , Li Si‐Jia 
Published: January 2017

ABSTRACTThe phase quantization effects of coded metasurface on agile scattering control are presented. Different phase resolutions are computed for a coded metasurface to realize two representative scattering fields, namely anomalous reflection and diffuse reflection. Detailed analysis of the results indicates that 2‐bit coding is necessary to redirect the scattering beam to an arbitrarily focused direction and the derived beamwidth depends on the metasurface size and beam direction, while 1‐bit coding is sufficient to redirect the energy to the entire space evenly. Simulations of a 1‐bit coded metasurface are performed to validate the computations. Measurements of the metasurface are carried out to further verify the simulations and demonstrate the agile scattering performance. © 2017 Wiley Periodicals, Inc. Microwave Opt Technol Lett 59:738–743, 2017
Meander line‐based low profile RIS with defected ground and its use in patch antenna miniaturization for wireless applications
Authors: Ghosh Anumoy , Mitra Arijit , Das Santanu 
Published: January 2017

ABSTRACTA reactive impedance surface (RIS) comprising of 4 × 4 array of grounded unit cells having meander line structure is designed. A detailed impedance analysis of the RIS is presented and validated with simulation results. A triangular patch antenna with metallic ground plane is designed to resonate at 3.78 GHz. The metallic ground is substituted by the RIS which results in shifting of resonant frequency from 3.78 GHz to 2.90 GHz thus exhibiting 23.28% miniaturization. The metallic ground of RIS is made defected by etching a rectangular slotted loop which leads to 50.8% miniaturization as the resonant frequency of the structure shifts to 1.86 GHz which resembles to GSM communication frequency. A tuning parameter has been identified in the slotted loop to control the resonant frequency of the structure. Satisfactory gain, efficiency and stable radiation pattern with low cross polarization level in both E and H planes qualify the proposed structure as a promising candidate for practical wireless applications. A comparison of the proposed structure with previous works in literature is provided to demonstrate the superiority of the proposed technique in terms of the profile of RIS and its miniaturization capability. Experimental verification of the proposed structure is provided. © 2017 Wiley Periodicals, Inc. Microwave Opt Technol Lett 59:732–738, 2017
Associations of prenatal and childhood antibiotic use with child body mass index at age 3 years
Authors: Poulsen Melissa N. , Pollak Jonathan , Bailey‐Davis Lisa , Hirsch Annemarie G. , Glass Thomas A. , Schwartz Brian S. 
Published: January 2017

ObjectiveEarly‐life antibiotic exposure, whether through prenatal or childhood antibiotic use, may contribute to increased child body mass. Associations of prenatal and childhood antibiotic use with body mass index z‐score (BMIz) were evaluated at age 3 years.MethodsElectronic health records were utilized from 8,793 mothers and singleton children delivered at Geisinger Clinic in Pennsylvania between 2006 and 2012. Antibiotic orders were ascertained for mothers during pregnancy and for children through their age‐3 BMI measurement. Linear mixed‐effects regression models evaluated associations of prenatal and childhood antibiotic use with child BMIz.ResultsPrenatal antibiotic orders were not associated with child BMIz. Children in the three largest categories of lifetime antibiotic orders had higher BMIz compared with children with no orders; associations persisted when controlling for prenatal antibiotics (β [95% confidence interval]) (4‐5 child orders: 0.090 [0.011 to 0.170]; 6 to 8: 0.113 [0.029 to 0.197]; ≥9: 0.175 [0.088 to 0.263]; trend P value <0.001). Two or more first‐year orders were also associated with BMIz (1: 0.021 [−0.038 to 0.081]; 2: 0.088 [0.017 to 0.160]; ≥3: 0.104 [0.038 to 0.170]; trend P value < 0.001).ConclusionsAssociations of early‐life and lifetime childhood antibiotic use with increased child BMI highlight antibiotic exposure as a modifiable factor for reducing population‐level excess weight.
Fatty liver promotes fibrosis in monkeys consuming high fructose
Authors: Cydylo Michael A. , Davis Ashley T. , Kavanagh Kylie 
Published: January 2017

ObjectiveNonalcoholic fatty liver diseases (NAFLD) are related to development of liver fibrosis which currently has few therapeutic options. Rodent models of NAFLD inadequately model the fibrotic aspects of the disease and fail to demonstrate the spectrum of cardiometabolic diseases without genetic manipulation. This study aimed to document a monkey model of fatty liver and fibrosis, which naturally develop cardiometabolic disease pathophysiologies.MethodsTwenty‐seven cynomolgus monkeys (Macaca fascicularis) fed diets either low or high in simple carbohydrates, supplied as fructose [control and high‐fructose diet (HRr)], on low‐fat, cholesterol‐free background were studied. The HFr was consumed for up to 7 years, and liver tissue was histologically evaluated for fat and fibrosis extent.ResultsThe HFr diet increased steatosis, and its extent was related to duration of fructose exposure. Lipid droplet size also increased with HFr duration; however, compared with control, the lipid droplets were smaller on average. Fibrosis extent was significantly greater with fructose feeding and was predicted by fructose exposure, extent of fatty liver, and age.ConclusionsThese data are the first to demonstrate that high‐carbohydrate diets alone can generate both liver fat and fibrosis and thus allow further study of mechanisms and therapeutic options in the translational animal model.
What do people want to know about NIPT? Content analysis of questions emailed to national NIPT information websites
Authors: Tamminga Saskia , van Dussen Laura , Verweij E. J. (Joanne) , de Boer Marjon A. , Cornel Martina C. , Henneman Lidewij ,   for the Dutch NIPT Consortium
Published: January 2017

What's already known about this topic?

Several countries, including the Netherlands, have implemented non‐invasive prenatal testing (NIPT) in their national prenatal screening program
Access to relevant online health information is important as it increases informed decision making
What does this study add?

Visitors of national NIPT websites mostly request more information about testing beyond the currently available NIPT: a broader range of disorders (such as monogenic disorders) and increasing target group eligibility (such as low‐risk or twin pregnancies)
© 2017 The Authors. Prenatal Diagnosis published by John Wiley & Sons, Ltd.
Identification of technical risks in the photovoltaic value chain and quantification of the economic impact
Authors: Moser David , Del Buono Matteo , Jahn Ulrike , Herz Magnus , Richter Mauricio , De Brabandere Karel 
Published: January 2017

AbstractIn photovoltaic (PV) projects, it is important to establish a common practice for professional risk assessment, which serves to reduce the risks associated with related investments. The objective of this paper is to present a methodology on how to improve the current understanding of several key aspects of technical risk management during the PV project lifecycle, with the identification of technical risks and their economic impact. To achieve this, available statistical data of failures during a PV project have been collected with the aim to (i) suggest a guideline for the categorisation of failure and (ii) develop a methodology for the assessment of the economic impact of failures occurring during operation but which might have originated in previous phases. The risk analysis has the aim to assess the economic impact of technical risks and how this can influence various business models and the levelised cost of electricity. This paper presents the first attempt to implement cost‐based failure modes and effects analysis to the PV sector and to define a methodology for the estimation of economic losses because of planning failures, system downtime and substitution/repair of components. The methodology is based on statistical analysis and can be applied to a single PV plant or to a large portfolio of PV plants in the same market segment. The quality of the analysis depends on the amount of failure data available and on the assumptions taken for the calculation of a cost priority number. The overall results can be linked to the cost of periodic and corrective maintenance and form the basis to estimate the impact of various risk and mitigation scenarios in PV business models. Copyright © 2017 John Wiley & Sons, Ltd.
A randomized control intervention trial to improve social skills and quality of life in pediatric brain tumor survivors
Authors: Barrera Maru , Atenafu Eshetu G. , Sung Lillian , Bartels Ute , Schulte Fiona , Chung Joanna , Cataudella Danielle , Hancock Kelly , Janzen Laura , Saleh Amani , Strother Douglas , Downie Andrea , Zelcer Shayna , Hukin Juliette , McConnell Dina 
Published: January 2017

AbstractBackgroundTo determine if a group social skills intervention program improves social competence and quality of life (QOL) in pediatric brain tumor survivors (PBTS).MethodsWe conducted a randomized control trial in which PBTS (8‐16 years old, off therapy for over 3 months) were allocated to receive social skills training (eg, cooperation, assertion, using social cognitive problem solving strategies, role playing, games, and arts and crafts) in 8 weekly 2‐hour sessions, or an attention placebo control (games and arts and crafts only). Outcomes were self‐reported, proxy‐reported (caregiver), and teacher‐reported using the Social Skills Rating System (SSRS), to measure social competence, and the Pediatric Quality of Life (PedsQL4.0, generic) to measure QOL at baseline, after intervention, and at 6 months follow‐up. At baseline, SSRS were stratified into low and high scores and included as a covariate in the analysis.ResultsCompared to controls (n = 48), PBTS in the intervention group (n = 43) reported significantly better total and empathy SSRS scores, with improvements persisting at follow‐up. The PBTS in the intervention group who had low scores at baseline reported the greatest improvements. Proxy and teacher reports showed no intervention effect.ConclusionsParticipating in group social skills intervention can improve self‐reported social competence that persisted to follow up. The PBTS should be given the opportunity to participate in social skills groups to improve social competence.