bluuebunny/crossref_metadata_2025_split huggingface dataset:
The grooved‐dielectric Fresnel zone plate: An effective terahertz lens and antenna
Authors: Hristov H. D. , Rodriguez J.M. , Grote W. 
Published: March 2012

AbstractA number of microwave and terahertz grooved‐dielectric Fresnel zone plate (FZP) and ordinary lenses and antennas are studed and compared numerically. Although the microwave (38 GHz) eight‐step FZP lens is certainly inferior, the corresponding terahertz (1.5 THz) FZP lens is comparable in focusing action to the ordinary one. By use of a new design approach to the terahertz FZP lens/antenna the typical unwanted focusing shift from the design frequency is removed and even better focusing performance is obtained within a limited frequency band. Thus, at terahertz frequencies the dielectric FZP lens or antenna is a lightweight and an effective option to the ordinary lens or antenna. © 2012 Wiley Periodicals, Inc. Microwave Opt Technol Lett 54:1343–1348, 2012; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.26812
Efficient, high gain with low side lobe level antenna structures using parasitic patches on multilayer superstrate
Authors: Vaidya Avinash R. , Gupta Rajiv K. , Mishra Sanjeev K. , Mukherjee J. 
Published: March 2012

AbstractIn this article, we propose efficient high gain with low side lobe level (SLL) antenna structures using parasitic patches (PPs) on multilayer superstrates. The antenna structures consist of a microstrip antenna that feeds an array of square PPs fabricated on multilayer FR4 superstrates. The patches fabricated on multilayer superstrate are suspended in air with the help of dielectric rods at integral multiple of λ0/2. The structure with 9 × 9 array of square PPs on a superstrate layer at λ0/2 provides a gain of 19 dB, which increases to 21.1 and 21.8 dB when the superstrate layer height is increased to 1.0 and 1.5 λ0, respectively. However, SLL increases with increase in superstrate height. Gain enhancement with low SLL is achieved using PPs on multilayer superstrate. The antenna with 3 × 3 and 9 × 9 array of square PPs on superstrate layers at 0.5 and 1.5 λ0, respectively provides a gain of 22.7 dB with 92% efficiency, SLL of −22.3 dB and front to back lobe ratio of more than 20 dB. Structure is designed, fabricated, and tested. The measured VSWR is <2 over 5.725–5.875‐GHz frequency band. The proposed structure is an attractive solution for several wireless communication systems, such as base station cellular systems, satellite systems, and point‐to‐point links. © 2012 Wiley Periodicals, Inc. Microwave Opt Technol Lett 54:1488–1493, 2012; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.26818
CMOS transconductance‐enhanced Colpitts‐like quadrature voltage‐controlled oscillator
Authors: Jang Sheng‐Lyang , Liu Wei‐Chih , Huang Jhin‐Fang , Chang Chia‐Wei 
Published: March 2012

AbstractA new fully integrated CMOS quadrature voltage‐controlled oscillator (QVCO) is presented.The QVCO is composed of two cross‐coupled nMOSFETs in shunt with a parallel‐tuned LC resonator and was implemented in 0.18 μm CMOS technology. The source of nMOSFET is in series with a degenerated pMOSFET modulated by the VCO output signal. The negative resistance cell in the QVCO is a transconductance‐enhanced Colpitts‐like cell used to improve the start‐up oscillation. The QVCO is tunable from 7.04 to 8.08 GHz. Although the tuning voltage varies from 0 to 2 V. The phase noise of the QVCO operating at 7.09 GHz is −120.5 dBc/Hz at 1 MHz offset, while the QVCO draws 4 mA and uses 4 mW consumption. © 2012 Wiley Periodicals, Inc. Microwave Opt Technol Lett 54:1453–1455, 2012; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.26820
Photonic synthesis of continuous‐wave millimeter‐wave signals using a passively mode‐locked laser diode and selective optical filtering
Authors: Acedo P. , Carpintero G. , Criado A.R. , de Dios C. , Yvind K. 
Published: March 2012

AbstractWe report a photonic synthesis scheme for continuous wave millimeter‐wave signal generation using a single passively mode‐locked laser diode (PMLLD), optical filtering and photomixing in a fast photodiode.The phase noise of the photonically synthesized signals is evaluated and inherits the characteristics of the PMLLD electrical power spectrum. © 2012 Wiley Periodicals, Inc. Microwave Opt Technol Lett 54:1416–1419, 2012; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.26822
Planar log‐periodic bow‐tie dipole array antenna with reduced size and enhanced front‐back ratio
Authors: Yeo Junho , Lee Jong‐Ig 
Published: March 2012

AbstractIn this article, a planar log periodic bow‐tie dipole array (LPBDA) antenna with reduced size and enhanced front‐back ratio (FBR) for ultra‐high frequency band is presented.It is comprised of bow‐tie‐shaped printed dipole elements instead of printed strip dipole elements. The results show that as the flare angle of the bow‐tie dipole elements increases, the lowest operating frequency shifts toward lower frequency with an effect of size reduction. In addition, the gain variation of the LPBDA is much less and the FBR is also improved. © 2012 Wiley Periodicals, Inc. Microwave Opt Technol Lett 54:1435–1441, 2012; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.26825
Wideband to narrowband frequency reconfiguration using PIN diode
Authors: Ismail Muhamad Faizal , Rahim Mohamad Kamal A. , Majid Huda A. 
Published: March 2012

AbstractA frequency reconfigurable antenna using log‐periodic technique is reported. A 13 square patches fed by inset feed line technique are connected with a single transmission line by a log‐periodic array formation to form a wideband frequency from 3 to 6 GHz. By applying 13 PIN diodes at the transmission line with a quarter wavelength radial stub biasing, three different sub‐band frequencies (3–4, 3.7–5, and 4.8–6 GHz) are configured by switching ON and OFF the PIN diodes. The antenna has a directive radiation pattern and gain about 6–8 dB at all sub‐bands. Simulated and measured results with antenna design are presented and they show that a good agreement in term of return loss. © 2012 Wiley Periodicals, Inc. Microwave Opt Technol Lett 54:1407–1412, 2012; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.26826
Printed spiral‐slot multimode antenna miniaturization for digital television signal receptions
Authors: Lin Ding‐Bing , Tang I‐Tseng , Chang En‐Tsao 
Published: March 2012

AbstractA compact printed spiral‐slot multimode antenna operated at its quarter wavelength (λ/4) mode as the fundamental resonant mode for digital television (DTV) signal receptions is presented. To achieve broadband characteristics, the proposed antenna is constructed by embedding the eight different quarter‐wavelength spiral slots on system ground plane and is fed using a 50‐Ω microstrip. The eight spiral slots also generate eight λ/4 resonance modes to cover the DTV reception band (470–862 MHz) throughout the world. Further, the proposed antenna has a simple planar eight‐spiral‐slot structure and occupies a small area of 20 × 20 mm2 only on the system ground plane (20 × 70 mm2). The impedance matching and bandwidth of the proposed antenna are significantly affected by the sheet metal on the signal line. The antenna is able to realize an omnidirectional radiation pattern over the entire frequency band. Further, the measurement results agree with the simulation ones. © 2012 Wiley Periodicals, Inc. Microwave Opt Technol Lett 54:1369–1371, 2012; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.26828
Ultrawideband‐printed hexagonal monopole antennas with WLAN band rejection
Authors: Mandal Tapan , Das Santanu 
Published: March 2012

AbstractIn this article, a printed regular hexagonal monopole antenna fed by a microstrip line has been presented for ultrawide bandwidth. The antenna is then modified to possess band rejection at the wireless local area network (WLAN) (5.15–5.88 GHz) by an inverted U‐shape slot within the radiating patch. The length and width of the U‐shape slot offer sufficient freedom for selecting and shifting the notched band. The impedance and radiation characteristics are presented and discussed in detail. From the results, it has been observed that the impedance BW, defined by VSWR ≤ 2, can reach a value of 10.04 GHz (3.11–13.15 GHz), while band stop function is in the frequency bands of 5.15–5.88 GHz. The proposed antenna peak gain varies 1.53–4.05 dB over the whole 2.74–11.05 GHz excluding in 4.95–5.92 GHz notch band. © 2012 Wiley Periodicals, Inc. Microwave Opt Technol Lett 54:1520–1525, 2012; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.26831
Measurement of the paraelectric property of bulk ferroelectrics under high DC bias at microwave frequencies
Authors: Wu C.‐Y. , Wang T. , Ren A.‐K. 
Published: March 2012

AbstractA microstrip‐based test fixture that can measure the paraelectric property of bulk ferroelectrics under high DC bias up to 2 kV at microwave frequencies is presented.In the measurement, a rectangular‐cuboid ferroelectrics with a pair of electrodes at opposite sides which represents a lumped capacitor is placed between a gap of a microstrip line. Blocking capacitors and a‐quarter‐wavelength stub lines are used to make sure that the vector network analyzer is double safe in the presence of high voltage. Thru‐reflect‐line calibration method is used to de‐embed the ferroelectric capacitor from blocking circuits and DC bias networks. The simulation and measurement results indicate that the method is suitable and safe for measuring the paraelectric property of bulk ferroelectrics at microwave frequencies under high DC bias. © 2012 Wiley Periodicals, Inc. Microwave Opt Technol Lett 54:1493–1496, 2012; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.26844
Compact wideband bandstop filter using embedded capacitor
Authors: Qian Kewei 
Published: March 2012

AbstractA new type of compact bandstop filter (BSF) using embedded capacitor in LTCC substrate is presented in this letter.Stopband rejection depth and bandwidth can be controlled simply by the value of the capacitor, while good return loss is realized by adjusting the impedance of two open‐circuited stubs. Further, filter size is miniaturized by the meandered closed‐loop structure. A lossless transmission line model analysis is used to derive design equations. To validate the proposed topology, a BSF centered at 4.5 GHz with bandwidth of 70% is designed and built. The implementation area is 0.35 λg × 0.25 λg, where λg is the guided wavelength at the mid‐stopband frequency. © 2012 Wiley Periodicals, Inc. Microwave Opt Technol Lett 54:1511–1514, 2012; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.26848
A dual‐wideband antenna with an open L‐slot for WLAN/WiMAX applications
Authors: Luo Yang , Yin Ying‐zeng , Guo Yuan‐yuan , Zhao Yang 
Published: March 2012

AbstractA dual‐wideband antenna with an open L‐slot for wireless local area network (WLAN)/worldwide interoperability for microwave access (WiMAX) applications is proposed.A rectangular radiator with an open L‐slot etched on the ground is used to cover 2.4∼3.69 GHz. To achieve dual‐band characteristic, a rectangular strip is inserted on the rectangular radiator horizontally to generate another band covering 5.15∼ 5.85 GHz. The two bands are relatively independent with each other. Experimental results show that the antenna can operate at two separate impedance bands (S11<−10 dB) of 1330 MHz (2.37∼ 3.70 GHz) and 1140 MHz (4.95∼ 6.09 GHz), which can cover all the 2.4/5.2/5.8 GHz WLAN bands and the 2.5/3.5/5.5 WiMAX bands. Detailed design steps and experimental results are studied and investigated in this article. © 2012 Wiley Periodicals, Inc. Microwave Opt Technol Lett 54:1499–1502, 2012; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.26852
Scattering amplitude computations for dielectrics that depend on two spatial variables
Authors: Hooshyar M. A. 
Published: March 2012

AbstractA modified method of lines combined with a suitable transformation of the resulting coupled differential equations is developed for solving TM plane waves incident on cylindrical structures with dielectric properties that are function of two spatial directions. Numerical performance of the method is presented and found to be satisfactory. © 2012 Wiley Periodicals, Inc. Microwave Opt Technol Lett 54:1496–1499, 2012; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.26853
Divide‐by‐4 injection‐locked frequency divider using two linear mixers
Authors: Chang Chia‐Wei , Jang Sheng‐Lyang , Juang Miin‐Horng 
Published: March 2012

AbstractThis letter proposes a wide locking range and operation range divide‐by‐4 injection‐locked frequency divider (ILFD) in the TSMC 0.18‐μm 1P6M RF‐CMOS process.The divide‐by‐4 ILFD uses an active inductor to increase the tuning range and a transistor composite to serve an injection device with two linear mixers to enhance the locking range of ILFD. At the supply voltage of 1.7 V, and at the incident power of 0 dBm the operation range of the divide‐by‐4 is about 5.8 GHz, from the incident frequency 3.6 to 9.4 GHz, the percentage is 89.2%. The locking range of the divide‐by‐4 is 1.8 GHz, from the incident frequency 6.8 to 8.6 GHz, the percentage is about 23.4%. The core power consumption is 7.6 mW. The die area is 0.503 × 0.36 mm2. © 2012 Wiley Periodicals, Inc. Microwave Opt Technol Lett 54:1359–1362, 2012; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.26854
Hybrid real‐binary differential evolution algorithm applied to antenna optimization
Authors: Xie Lei , Jiao Yong‐Chang 
Published: March 2012

AbstractAs a powerful optimization approach, differential evolution algorithm has been applied to real‐ and binary‐valued optimization problems in electromagnetics. However, for some optimization problems a vector to be optimized consists of both real and binary components. This article describes a hybrid real‐binary differential evolution (RBDE) algorithm that works with real and binary values in the same vector. The proposed approach is demonstrated on designing a nonuniform antenna array and an ultrawideband antenna. Numerical experiments show that the RBDE algorithm is an effective technique. © 2012 Wiley Periodicals, Inc. Microwave Opt Technol Lett 54:1460–1463, 2012; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.26856
Coplanar waveguide‐fed dual‐band antenna for wireless local area network applications
Authors: Sun Xiaolei , Cheung S. W. , Yuk T. I. 
Published: March 2012

AbstractThis article presented a dual‐band monopole antenna fed by a coplanar waveguide (CPW) for wireless device applications in the 802.11b/a wireless local area network (WLAN) standards. The antenna consists of a rectangular radiator, two rectangular slots cut on both sides of the radiator, a semiring slot on the radiator, and a CPW feed for easy integration with other components on the printed circuit board. Parametric studies are carried out on the semiring slot and rectangular slots. The rectangular radiator generates two resonant bands at about 2.4 GHz for the 802.11b standard and 5.5 GHz for the upper band of the 802.11a. The semiring slot forms a resonator/bandstop filter to separate the radiator into two parts, hence generating another resonant band at around 5 GHz to cover the lower band of the 802.11a standard. The two rectangular slots improve impedance matching for the 802.11a standard. Simulation and measurement results of the proposed antenna show good agreements. Results show that the proposed dual‐band antenna has good performances in terms of radiation pattern, peak gain, and radiation efficiency. The bandwidth for the 802.11a standard can be easily adjusted using dimensions of the semiring and rectangular slot, giving an easy way for engineers to design antennas for wireless device applications for the WLAN standards. © 2012 Wiley Periodicals, Inc. Microwave Opt Technol Lett 54:1391–1396, 2012; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.26859
Eccentric exercise does not affect common drive in the biceps brachii
Authors: Beck Travis W. , Kasishke Paul R. , Stock Matt S. , DeFreitas Jason M. 
Published: March 2012

AbstractIntroduction:The purpose of this study was to investigate the effects of eccentric exercise on common drive.Methods:Eleven men, age 23.6 ± 2.1 (mean ± SD) years, performed trapezoid isometric muscle actions of the dominant forearm flexors immediately before and after 1 of 2 interventions: (a) 6 sets of 10 maximal eccentric isokinetic muscle actions of the forearm flexors; or (b) 10 minutes of quiet resting. Surface electromyographic signals were recorded from the biceps brachii and decomposed into individual motor unit action potential trains. Mean firing rate patterns were calculated for each motor unit, and all possible combinations were cross‐correlated to measure common drive.Results:The peak cross‐correlation coefficients were generally in the 0.2–0.5 range and occasionally as high as 0.7.Conclusion:These coefficients were not, however, affected by the eccentric exercise, despite a 19.5% decrease in strength, indicating that the eccentric exercise did not affect common drive. Muscle Nerve, 2012
Changes in human muscle oxygen saturation and mean fiber conduction velocity during intense dynamic exercise—effect of muscular training status
Authors: Kilen Anders , Gizzi Leonardo , Jensen Bente Rona , Farina Dario , Nordsborg Nikolai Baastrup 
Published: March 2012

AbstractIntroduction: In this study we investigated whether an association exists between muscle fiber conduction velocity (MFCV) and local muscle oxygen saturation (StO2) in the superficial part of the latissimus dorsi muscle of runners and swimmers during exhaustive dynamic exercise. Methods: Participants performed arm cranking with increasing intensity until exhaustion. Results: Runners' MFCV was unchanged with increasing arm‐cranking exercise intensity, but was higher (P < 0.05) than swimmers' MFCV at the same workload. Swimmers' MFCV increased (P < 0.05) with increasing exercise intensity and reached values at exhaustion similar to those of the runners. StO2 was similar in swimmers and runners at rest and decreased with increasing exercise intensity. StO2 was higher (P < 0.05) at the same workload in swimmers compared with runners. StO2 and MFCV were significantly but very weakly correlated in both swimmers and runners. Conclusion: No association exists between surface MFCV and StO2 in either trained or untrained human skeletal muscle during exhaustive intense dynamic exercise. Muscle Nerve, 2012
Genitourinary dysfunction in male rats after bilateral neurectomy of the motor branch of the sacral plexus
Authors: Juárez Margarita , Hernández Isela , Cruz Yolanda 
Published: March 2012

AbstractAimsTo determine the contribution of the striated musculature anatomically related to the urethra on urinary continence in conscious male rats. We tested whether the bilateral neurectomy of the motor branch of the sacral plexus (MBSP), a nerve that innervates the bulbospongiosus, ischiocavernosus, and external urethral sphincter, is a reliable procedure to induce changes in voiding pattern that can be used as indicators of urinary incontinence in unanesthetized male rats.MethodsMicturition behavior was videotaped and urinary parameters measured 24 h before and at day 2 and 10 after surgery.ResultsIntact animals have a stereotyped behavior of micturition consisting in urination in the corner of the cage. Neurectomized animals lost place preference for voiding demonstrated by leakage of urine throughout the cage while eating, walking, or sleeping. Voiding frequency was double and voiding duration was triple the amount before surgery. Urine flow rate and voiding volume were also significantly decreased. Necropsy showed that 10 days post‐denervation semen material was accumulated in the urethra and in the bladder.ConclusionIn male rats the perineal striated muscles are crucial to maintaining normal urinary continence, preventing retrograde ejaculation, and to expelling urine and seminal secretions. Bilateral neurectomy of the MBSP may not be appropriate for long term survival urinary studies because effects on urinary parameters can be contaminated and/or masked by impaired seminal fluid expulsion, as a consequence of impairment of striated urethral muscle function. Neurourol. Urodynam. 31:1288–1293, 2012. © 2012 Wiley Periodicals, Inc.
Explicit high‐order time stepping based on componentwise application of asymptotic block Lanczos iteration
Authors: Lambers James V. 
Published: March 2012

SUMMARYThis paper describes the development of explicit time stepping methods for linear PDEs that are specifically designed to cope with the stiffness of the system of ODEs that results from spatial discretization. As stiffness is caused by the contrasting behavior of coupled components of the solution, it is proposed to adopt a componentwise approach in which each coefficient of the solution in an appropriate basis is computed using an individualized approximation of the solution operator. This has been accomplished by Krylov subspace spectral (KSS) methods, which use techniques from ‘matrices, moments and quadrature’ to approximate bilinear forms involving functions of matrices via block Gaussian quadrature rules. These forms correspond to coefficients with respect to the chosen basis of the application of the solution operator of the PDE to the solution at an earlier time. In this paper, it is proposed to substantially enhance the efficiency of KSS methods through the prescription of quadrature nodes on the basis of asymptotic analysis of the recursion coefficients produced by block Lanczos iteration for each Fourier coefficient as a function of frequency. The potential of this idea is illustrated through numerical results obtained from the application of the modified KSS methods to diffusion equations and wave equations. Copyright © 2012 John Wiley & Sons, Ltd.
A Duhamel approach for forced vibrations of rotating axisymmetric bodies
Authors: Carmignani C. , Forte P. , Melani G. 
Published: March 2012

SUMMARYIn this work a novel approach for the determination of the dynamic behaviour of a rotating device subject to forces fixed with respect to a stationary reference system is developed. The procedure can be applied to any axisymmetric rotating structure and it is particularly convenient for components of complex geometry for which an accurate dynamic characterization is fundamental. It is based on the application of Duhamel's integral. The time evolution of the system is obtained with the determination of the impulse response of the body using one single finite element transient analysis. By combining the results of the transient analysis with the time history of the forces applied to the rotating body, it is possible to determine the ground‐based vibration response of the component. Copyright © 2012 John Wiley & Sons, Ltd.
What drives breast cancer heterogeneity: oncogenic events or cell of origin?
Authors: Ginestier Christophe , Charafe‐Jauffret Emmanuelle , Birnbaum Daniel 
Published: March 2012

AbstractBreast cancer is known to show considerable inter‐tumoural heterogeneity. It is widely accepted that combinations of oncogenic events have a major role in determining tumour phenotype. However, accumulating evidence suggests that the identity of the cell that acquires the first oncogenic event, the so‐called cell of origin, may define the molecular subtype of the resulting tumour. Recent work published in the Journal of Pathology by Natrajan and colleagues questions the origin of breast cancer heterogeneity. After studying BRCA1 tumours, they suggest that genomic alterations are not sufficient to determine tumour behaviour. These and other recent observations underscore the importance of defining what is causing tumour heterogeneity, so that appropriate therapy can be given. Copyright © 2012 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.