bluuebunny/crossref_metadata_2025_split huggingface dataset:
A compact frequency‐doubling opto‐electronic oscillator using cascaded electroabsorption modulators
Authors: Lee Joo‐Young , Song Jong‐In 
Published: January 2016

ABSTRACTA compact frequency‐doubling optoelectronic oscillator (FD‐OEO) using two cascaded electro‐absorption modulators (EAMs) is proposed and experimentally demonstrated. The FD‐OEO is configured with two cascaded EAMs driven by signals having a 180° phase difference, so that the second EAM produces an output signal with a suppressed first‐order side band, thus generating a frequency doubled signal. The phase noise characteristics of the fundamental (10 GHz) and frequency‐doubled (20 GHz) signals are measured to be −94.25 dBc/Hz and −87.71 dBc/Hz, respectively, at a frequency offset of 10 kHz. © 2016 Wiley Periodicals, Inc. Microwave Opt Technol Lett 58:526–529, 2016
A linear CMOS power amplifier using class‐D to reduce the number of required inductors
Authors: Son Minoh , Yoo Jinho , Park Changkun 
Published: January 2016

ABSTRACTWe propose a linear class‐D amplifier for the driver stages of RF CMOS linear power amplifiers. To minimize the chip areas for the driver stages of the linear power amplifiers, we propose a technique for the class‐D amplifier to be operated as a linear amplifier. The linear gain and proper bias point for the linear operation are obtained with additional load capacitance and a feedback resistor, respectively. To verify the feasibility of the proposed linear class‐D amplifier, we designed a 1.8‐GHz CMOS linear power amplifier with a differential structure using 180‐nm RF CMOS technology. From the measured linearity and maximum average output power with a WCDMA modulated input signal, we successfully verify the linear operation of the proposed linear class‐D amplifier. © 2015 Wiley Periodicals, Inc. Microwave Opt Technol Lett 58:565–569, 2016
UWB patch antenna and breast mimicking phantom design and implementation for microwave breast cancer detection using TIME REVERSAL MUSIC
Authors: Bah Mamadou Hady , Hong Jing‐Song , Jamro Deedar Ali 
Published: January 2016

ABSTRACTIn this manuscript, a small size UWB patch antenna and a breast mimicking phantom are designed and implemented for microwave breast cancer detection using Time Reversal MUSIC. Some new techniques are applied to the antenna in order to achieve a broad bandwidth, high gain, and also to avoid the energy radiation toward the ground plane of the antenna. The resulting dielectric constant of the breast phantom is relatively close to the real normal breast tissues. After the design has been completed, some techniques of Time Reversal MUSIC were employed to mimic the breast cancer detection. The experimental results show that both temporal and spacial images of the target (tumor) are well represented. © 2016 Wiley Periodicals, Inc. Microwave Opt Technol Lett 58:549–554, 2016
Compact NB BPF is using modified slow wave resonator with wide upper stopband
Authors: Moattari A.M. , Karimi Gh. 
Published: January 2016

ABSTRACTA compact narrowband band pass filter (NB BPF) with wide stop‐band has been designed and fabricated. The presented filter based on modified slow wave resonator of microstrip is designed to achieve narrow bandwidth. The bandwidth of this filter capability of changing with the coupled lines is used in the middle of this structure filter. For the first time, by using transmission line theory and coupled line structure, the new design methodology of a narrowband BPF is employed and resonant frequency has been clearly explained. The filter has been designed for operating at center frequency 3.82 GHz, that suitable for WiMAX applications. The measured insertion loss (s21) and return loss (s11) are −0.38 dB and −33 dB, respectively at 3.82 GHz resonant frequencies. The proposed filter is designed, simulated and fabricated and the simulation results are in good agreement with measurement result. © 2016 Wiley Periodicals, Inc. Microwave Opt Technol Lett 58:616–619, 2016
Coupling matrix synthesis for dual‐band bandpass filters based on admittance poles and zeros
Authors: Chen Xianhong , Zhang Lijun , Xu Can , Liu Hui , Zheng Zhanqi 
Published: January 2016

ABSTRACTA novel coupling matrix synthesis method for dual‐band bandpass filter is presented in this article. The output admittance poles and zeros of the single‐band filter prototype are firstly obtained and then transformed into dual‐band prototype. Then the coupling matrix with predefined topology is optimized according to these poles and zeroes directly. This method can be achieved with no need to construct the characteristic function of dual‐band filter and reconfigure the coupling matrix. Symmetric and asymmetric dual‐band bandpass filter coupling matrix synthesis has been carried out to illustrate and validate this method. © 2015 Wiley Periodicals, Inc. Microwave Opt Technol Lett 58:603–606, 2016
Linearly polarized small patch array fed by corporate SIW network
Authors: García‐Marín E. , Masa‐Campos J. L. , Sánchez‐Olivares P. 
Published: January 2016

ABSTRACTIn this article, a linearly polarized 2 × 2 patch array uniformly fed by a corporate substrate integrated waveguide network for Ku band is presented. Undesired main beam steering is avoided by means of a fully corporate feeding network, although grating lobes may appear due to greater separation between radiating elements. Moreover, a reduced patch separation to avoid grating lobe appearance leads to an antenna matching coefficient degradation due to the proximity of antenna discontinuities. In consequence, a tradeoff approach has been developed, achieving a measured 4.1% matching bandwidth and a measured gain of 13.27 dBi, which corresponds to an 86% radiation efficiency. Good agreement between simulated and measured results is observed in all cases. © 2015 Wiley Periodicals, Inc. Microwave Opt Technol Lett 58:587–593, 2016
Improvement of stop‐band performance of a CPW bandpass filter using DGS
Authors: Mondal Pratik , Sahoo Manoranjan , Parui Susanta Kumar 
Published: January 2016

ABSTRACTA CPW‐based bandpass filter (BPF) is designed in S‐band by open ended series stubs. Two open ended stubs with opposite orientation are placed closely into a CPW line to offer greater field confinement. They provide band accept response with one attenuation zero. An enhanced selectivity is achieved by using four such stubs in symmetric manner. Defected ground structures (DGS's) are used to reject higher harmonics and to obtain a wide stop‐band. To validate the design, a prototype was fabricated. In good agreement with the theoretical results, the measured results of the S‐band bandpass filter achieve insertion loss of <0.2 dB, fractional bandwidth (FBW) of 67% with rising and falling edge selectivity of 35.9 dB/GHz and 45.7 dB/GHz respectively, and around 8‐GHz stop‐band. © 2015 Wiley Periodicals, Inc. Microwave Opt Technol Lett 58:593–597, 2016
Dual‐mode stub‐loaded resonator and its applications to single‐ and dual‐band bandpass filters
Authors: Zhang Bo , Huang Jianming , Li Shaosheng , Liu Yuanan 
Published: January 2016

ABSTRACTIn this letter, a novel dual‐mode stub‐loaded resonator is proposed with independently controllable coupling coefficients under different resonant modes. The main structure is constructed by loading a short‐circuited stub in the center of an open‐loop half‐wavelength resonator. Frequencies of first and second resonant modes can be adjusted by changing the dimensions of the loaded stub and open‐loop resonator, respectively. Additionally, a pair of edge‐coupled ear‐structures is added to adjust the difference between the coupling coefficients of different resonant modes. Finally, a dual‐band bandpass filter (BPF) with independently controllable bandwidths as well as a single‐band BPF with high selectivity are designed and fabricated to provide experimental validations on the predicted performances of the proposed filters. © 2016 Wiley Periodicals, Inc. Microwave Opt Technol Lett 58:623–626, 2016
Using intentionally mismatching method
Authors: Jang Youna , Park Minwon , Kim Heehwang , Lim Jongsik , Choi Kwansun , Ahn Dal 
Published: January 2016

ABSTRACTA new ring hybrid is proposed which we call the double ring hybrid. The double ring hybrid is implemented by cascading two branch line hybrids that have intentionally mismatched port impedances between branch line hybrids. The proposed double ring hybrid using two quadrature branch line hybrids not only has the same function as that of the conventional ring hybrid, but also has output ports in the same direction, since the isolation port is located on the opposite side of the output ports. Thus, unlike the conventional ring hybrid, the proposed double ring hybrid may be able to realize cascaded planar structures. The design equations are derived from the concept of the intentionally mismatched port impedances. The proposed double ring hybrid, regardless of whether the two branch line hybrids are connected, has a 12% reduced area compared to the conventional ring hybrid. © 2016 Wiley Periodicals, Inc. Microwave Opt Technol Lett 58:638–642, 2016
Hybrid cylindrical dielectric resonator antenna with monopole for tri‐polarized operation
Authors: Deng Changjiang , Feng Zhenghe , He Yan 
Published: January 2016

ABSTRACTA wideband tri‐polarized antenna is presented in this letter. The proposed hybrid structure consists of a cylindrical dielectric resonator (DR) and a copper cylinder. Tri‐polarized operation is achieved by exciting the HE11δx and HE11δy modes of the DR, and the λ/4 monopole mode of the copper cylinder. The resonant frequency of the monopole mode is well tuned to work cooperatively with the two HE11δ modes. Only one single substrate layer is required to integrate the three balanced feedings. A prototype of the proposed antenna is built and tested. The measured overlapping impedance bandwidth of the three ports is 410 MHz (2.38–2.79 GHz), and the isolation among the three ports is also less than −27 dB across the bandwidth. © 2016 Wiley Periodicals, Inc. Microwave Opt Technol Lett 58:635–638, 2016
Hybrid loop/monopole antenna with a passive bandstop circuit for the LTE/GPS operation in the tablet computer
Authors: Wong Kin‐Lu , Liao Zih‐Guang , Li Wei‐Yu 
Published: January 2016

ABSTRACTA hybrid loop/monopole antenna capable of covering the LTE operation in the 698–960/1710–2690 MHz band and the GPS operation at 1575 MHz for the tablet computer application is presented. With the obtained LTE/GPS operation, the antenna requires a small size of 8 × 40 × 3 mm3 only. The antenna is operated as a coupled‐fed loop antenna for the LTE operation and as a coupled‐fed monopole antenna for the GPS operation. The two antenna structures share the same radiation strip, except that the loop antenna with the end terminal thereof short‐circuited to the device ground plane of the tablet computer and the monopole antenna with the end terminal thereof open‐ended. The two antenna structures are configured into one antenna structure using a passive bandstop circuit connected between the end terminal of the antenna's radiation strip and the device ground plane. The bandstop circuit exhibits a very high impedance in the GPS band and a very low impedance in the LTE band, thereby making the antenna operated as a loop antenna for the LTE operation (698–960/1710–2690 MHz) and a monopole antenna at 1575 MHz for the GPS operation. Details of the proposed hybrid loop/monopole antenna are described. Operating principle of the antenna is addressed, and experimental results of the fabricated antenna are presented and discussed. © 2016 Wiley Periodicals, Inc. Microwave Opt Technol Lett 58:630–635, 2016
A broadband KU‐band microstrip reflectarray antenna using single‐layer fractal elements
Authors: Xue Fei , Wang Hong‐Jian , Yi Min , Liu Guang 
Published: January 2016

ABSTRACTA novel single‐layer microstrip reflectarray element with fractal structure is proposed. Ansoft HFSS is used to analyze the reflect phase for the fractal element in honeycomb lattice. A 469‐element prime focus microstrip reflectarray antenna composed of the proposed fractal elements is designed, manufactured, and measured. The measured gain level of 29.8 dB is obtained at the center frequency of 13.58 GHz with 1‐dB gain bandwidth of 15.3%. © 2016 Wiley Periodicals, Inc. Microwave Opt Technol Lett 58:658–662, 2016
A miniaturized triple band‐notched MIMO antenna for UWB application
Authors: Yang Zi‐Xian , Yang Hong‐Chun , Hong Jing‐Song , Li Yang 
Published: January 2016

ABSTRACTIn this article, a miniaturized multiple‐output (MIMO) antenna with Triple Band‐Notched Characteristics for ultra‐wideband (UWB) application is proposed. With two half‐planar‐monopoles as radiators to achieve miniaturization, the overall size of this antenna is only 28 × 22 mm2 (0.46 λg×0.36 λg) = 616 mm2 (0.16
), where λg is the guided wavelength at the lowest operation frequency. By introducing a T‐shaped stub on the ground plane, not only is the isolation between radiators greatly enhanced, the impedance (−10 dB S11) performance is also improved significantly. Two C‐shaped slots are etched into each radiator to obtain three notched bands (3.4–3.9 GHz, 5.05–5.85 GHz, 7.9–8.4 GHz) for blocking WiMAX, WLAN, and X‐band satellite communication services. The simulated results are studied and the measured results show that the impedance bandwidths of the proposed antenna covers all UWB band from 3.1 to 10.6 GHz except the notched bands, while a low mutual coupling of less than −18 dB is achieved at the entire band. Furthermore, the measured radiation performances and envelope correlation coefficient also demonstrate the proposed antenna could be a good candidate for UWB system. © 2016 Wiley Periodicals, Inc. Microwave Opt Technol Lett 58:642–647, 2016
Dipole‐ and loop‐mode switchable origami paper antenna
Authors: Lee Dongju , Seo Yunsik , Lim Sungjoon 
Published: January 2016

ABSTRACTA pattern‐switchable origami antenna is designed with paper using inkjet‐printing technology. The proposed antenna can be switched between loop and dipole antenna modes by folding and unfolding the paper, respectively. Eutectic gallium‐indium liquid metal is introduced in order to avoid cracks in the conductive ink when the paper is folded. The performance of the proposed antenna is demonstrated through simulation and measurement results. © 2016 Wiley Periodicals, Inc. Microwave Opt Technol Lett 58:668–672, 2016
Dual band loop‐type ground radiation antenna for mobile devices
Authors: Jeon Jihwan , Zahid Zeeshan , Kim Hyeongdong 
Published: January 2016

ABSTRACTA dual band loop‐type ground antenna is proposed. Loop‐type feeding structures and capacitors have been employed to excite current loops for lower and higher frequency bands. Resonance frequencies of both bands can be controlled using the capacitors. The antenna requires minimal ground clearance and can easily be installed in mobile devices. Measured results show good impedance matching and good radiation performance of the proposed antenna. © 2016 Wiley Periodicals, Inc. Microwave Opt Technol Lett 58:666–668, 2016
Circular slot antenna with capacitive loading technique for broad circularly polarized bandwidth
Authors: Sim Chow‐Yen‐Desmond , Yeh Jiun‐Ting , Ban Yong‐Lin 
Published: January 2016

ABSTRACTA microstrip‐fed circular slot antenna design is proposed. To excite good CP (circularly polarized) radiation, the technique of loading a cross patch (with unequal arm lengths) into the circular slot is initially applied. Here, good impedance matching can be further attained by dividing the cross patch into two equal sections with a gap loaded in between them, in which this gap will induce a capacitive loading effects on the proposed antenna. The measured results shown that the proposed antenna has 10 dB impedance bandwidth of 36.4% (2116–3124 MHz), and its corresponding CP bandwidth (along 3 dB axial ratio, AR) was 12.3% (2345–2655 MHz). In addition to that, the proposed CP slot antenna has also yielded peak gains of more than 3.3 dBic across the CP bandwidth. Detailed process of designing the proposed CP slot antenna is explicitly shown, and vital parametric studies were also conducted by simulation. © 2016 Wiley Periodicals, Inc. Microwave Opt Technol Lett 58:715–720, 2016
Ultra‐wideband power divider employing coupled line and short‐ended stub
Authors: Yang Ziqiang , Luo Bangyu , Dong Jun , Yang Tao 
Published: January 2016

ABSTRACTA compact two‐way equal power divider using three‐line coupled structure is proposed. The effective length of the power divider is around a quarter‐wavelength. To enhance the bandwidth of operation, a half‐wavelength resonator is constructed by introducing a short‐ended stub to combine with the open‐ended microstrip line. A prototype of the power divider is designed and fabricated. The measured input return loss, output return loss, isolation, amplitude imbalance, and phase imbalance are better than 10.3, 14.4, 10.1, 0.2 dB, and 3.2°, respectively, across the entire ultra‐wideband (UWB). © 2016 Wiley Periodicals, Inc. Microwave Opt Technol Lett 58:713–715, 2016
Coplanar waveguides loaded with symmetric and asymmetric multisection stepped impedance resonators: Modeling and potential applications
Authors: Su Lijuan , Naqui Jordi , Mata Javier , Martín Ferran 
Published: January 2016

ABSTRACTThis article is focused on the analysis and modeling of coplanar waveguide (CPW) transmission lines loaded with multisection stepped impedance resonators (MS‐SIRs), transversely etched on the back substrate side. The considered structure consists of a CPW loaded with a 5‐section SIR (5S‐SIR) with wide (capacitive) central and external sections cascaded with narrow (inductive) sections. The general case of a 5S‐SIR with arbitrary lengths and widths of the different sections is considered. The structure is described by a pair of inductively coupled grounded series resonators coupled to the line through the capacitance of the central 5S‐SIR section. If the structure is symmetric, the transmission coefficient exhibits a single transmission zero. Hence, these structures can be used as notch filters exhibiting wide bandwidths, provided the inductance of the 5S‐SIR can be made small, and the capacitance can be enhanced by virtue of the broadside coupling. However, if symmetry is broken, two notches separated a distance that depends on the level of asymmetry and inductive coupling appear. Therefore, these structures are also useful for the implementation of differential sensors and comparators. The proposed model is validated through parameter extraction and experiment, and a proof‐of‐concept of a comparator is reported. © 2016 Wiley Periodicals, Inc. Microwave Opt Technol Lett 58:722–726, 2016
A fully integrated LTCC Wilkinson power divider/combiner using a parasitic compensated 100 OHM RF resistor for 60 GHz wireless applications
Authors: Kim Jae‐Sun , Moon Sung‐Min , Oh Hyun‐Myung , Kim Choul‐Young 
Published: January 2016

ABSTRACTThis letter shows a fully integrated Wilkinson power divider/combiner using low temperature co‐fired ceramic (LTCC) process. This power divider/combiner has a screen printed resistor. Therefore, this is helpful to reduce cost and to enhance productivity. Using short stubs and increased dc resistance for 100 Ohm resistor was proposed to compensate parasitic effects due to the large size of printed resistor in LTCC process. The measurement results reveal that the insertion loss is −1.07 dB (Back‐to‐Back: −2.15 dB) at 60 GHz. The measured return loss is better than −15dB in the whole band of interest (57–64 GHz). © 2016 Wiley Periodicals, Inc. Microwave Opt Technol Lett 58:720–722, 2016
A pseudospectral tau approximation for time delay systems and its comparison with other weighted‐residual‐type methods
Authors: Lehotzky Dávid , Insperger Tamás 
Published: January 2016

SummaryThis paper presents a method which applies pseudospectral tau approximation for retarded functional differential equations (RFDEs). The goal is to construct a system of ordinary differential equations, which provides a finite dimensional approximation of the original RFDE. The method can be used to determine approximate stability diagrams for RFDEs. Thorough numerical case studies show that the rightmost characteristic roots of the ordinary differential equation approximation converge to the rightmost characteristic roots of the original RFDE. Application of the method to time‐periodic RFDEs is also demonstrated, and the convergence of the stability boundaries is verified numerically. The method is compared with recently developed highly efficient numerical methods: the pseudospectral collocation (also called Chebyshev spectral continuous‐time approximation), the spectral Legendre tau method, and the spectral element method. The comparison is based on the stability analysis of three linear autonomous RFDEs. The efficiency of the methods is measured by the convergence rate of stability boundaries in the space of system parameters, by the convergence rate of the rightmost characteristic exponent and by the computation time of the stability charts. Copyright © 2016 John Wiley & Sons, Ltd.
Weight loss predictability by plasma metabolic signatures in adults with obesity and morbid obesity of the DiOGenes study
Authors: Stroeve Johanna H.M. , Saccenti Edoardo , Bouwman Jildau , Dane Adrie , Strassburg Katrin , Vervoort Jacques , Hankemeier Thomas , Astrup Arne , Smilde Age K. , van Ommen Ben , Saris Wim H.M. 
Published: January 2016

ObjectiveAim is to predict successful weight loss by metabolic signatures at baseline and to identify which differences in metabolic status may underlie variations in weight loss success.MethodsIn DiOGenes, a randomized, controlled trial, weight loss was induced using a low‐calorie diet (800 kcal) for 8 weeks. Men (N = 236) and women (N = 431) as well as groups with overweight/obesity and morbid obesity were studied separately. The relation between the metabolic status before weight loss and weight loss was assessed by stepwise regression on multiple data sets, including anthropometric parameters, NMR‐based plasma metabolites, and LC‐MS‐based plasma lipid species.ResultsMaximally, 57% of the variation in weight loss success can be predicted by baseline parameters. The most powerful predictive models were obtained in subjects with morbid obesity. In these models, the metabolites most predictive for weight loss were acetoacetate, triacylglycerols, phosphatidylcholines, specific amino acids, and creatine and creatinine. This metabolic profile suggests that high energy metabolism activity results in higher amounts of weight loss.ConclusionsPossible predictive (pre‐diet) markers were found for amount of weight loss for specific subgroups.