bluuebunny/crossref_metadata_2025_split huggingface dataset:
Identification of the intrinsic capacitive core for GaAs HEMTs by investigating the frequency behavior of the impedance parameters
Authors: Crupi Giovanni , Raffo Antonio , Schreurs Dominique M.M.‐P. , Avolio Gustavo , Caddemi Alina , Vannini Giorgio 
Published: March 2013

AbstractThe present study is focused on the analysis of the impact of the dips in the impedance parameters on the behavior of the hybrid parameters for scaled GaAs HEMTs. These dips turning into kink phenomena in the magnitude of the hybrid parameters consist of a sudden reduction of the magnitude of the impedance parameters at a given value of the frequency, due to the transition from a capacitive to an inductive behavior. A theoretical and experimental investigation is developed for determining the resonance frequency associated to such dips in terms of the equivalent circuit elements. The achieved formulas are exploited to propose a novel approach for the identification of the intrinsic capacitive core. © 2013 Wiley Periodicals, Inc. Microwave Opt Technol Lett 55:1237–1240, 2013; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.27544
A new hybrid‐polymer optically tunable dielectric and its measurement using a variation on the split‐post dielectrc resonator
Authors: Jess Nathan , Syrett Barry , McGarry Steve , Roy Langis 
Published: March 2013

AbstractAn apparatus based on the split‐post dielectric resonator was designed and verified for the purpose of measuring the microwave properties of optically sensitive materials.The apparatus was then used to confirm that a material consisting of micro sized photoconductive particles added to an insulating polymer would show an increase in the effective dielectric constant while under optical illumination. The semiconductor‐polymer composite showed a change in dielectric constant and dielectric loss tangent from 5.5 to 6.1 and 0.05 to 0.09 respectively. © 2013 Wiley Periodicals, Inc. Microwave Opt Technol Lett 55:1304–1305, 2013; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.27545
Compact and high performance microstrip diplexer for GPS and WLAN application
Authors: Deng Hong‐wei , Zhao Yong‐jiu , Fu Yong , Zhou Xiao‐jun , Liu Yan‐yun 
Published: March 2013

AbstractIn this article, a novel compact and high performance microstrip diplexer is designed for global position system (GPS) and wireless local area network (WLAN) applications. The compact diplexer consists of two filters with short centered stepped impedance resonators (SCSIRs) and quarter‐wavelength resonators (QWRs), operated at 1.575 GHz and 5.8 GHz, respectively. Due to the intrinsic characteristics and mutual loading effect of two filters, multiple transmission zeros can be generated to achieve sharp skirt, wide stopband, and high isolation of the diplexer. Moreover, more compact size can be obtained without the extra junction matching. Finally, a microstrip diplexer with 1 dB absolute bandwidth 100 MHz for GPS channel and 1 dB fractional bandwidth (FBW) of 3.45% at 5.8 GHz for WLAN channel is designed and fabricated. The simulated and measured results show a better agreement and validate the proposed theory. The size without the 50 Ω feedline is only 0.156 λg × 0.103λg, in which λg is the guided wavelength at 1.575 GHz. © 2013 Wiley Periodicals, Inc. Microwave Opt Technol Lett 55:1233–1237, 2013; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.27550
On the isolation of two LTE700/2300/2500 antennas in the laptop computer
Authors: Wong Kin‐Lu , Lin Po‐Wei , Wu Tsung‐Ju 
Published: March 2013

AbstractA simple technique for achieving enhanced isolation between two long‐term evolution (LTE)700/2300/2500 antennas for the multiple‐input multiple‐output operation in the laptop computer is presented.The two antennas are mounted along the top edge of the supporting metal plate, which is generally disposed on the inner surface of the upper cover of the laptop computer. Improved isolation (measured S21 better than −30 dB in the LTE700 band and −26 dB in the LTE2300/2500 bands) between the two antennas is easily achieved by adjusting the supporting metal plate to have a length of about 110 mm in the longitudinal direction (orthogonal to the lateral direction or the top‐edge direction of the supporting metal plate). Because the length is close to a quarter wavelength of a frequency in the LTE700 band, the excited surface currents in the supporting metal plate will become stronger in the longitudinal direction, which hence causes weaker surface currents flowing along the top edge of the supporting metal plate. This behavior leads to enhanced isolation between the antennas mounted along the top edge of the supporting metal plate. Details of the proposed isolation technique are described, and the obtained results are presented and discussed. © 2013 Wiley Periodicals, Inc. Microwave Opt Technol Lett 55:1370–1375, 2013; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.27555
All‐optical binary‐to‐octal encoder based on a semiconductor optical amplifier: Application to eight‐level amplitude‐shift keying signaling
Authors: Cortés Obed Pérez , Ortiz Horacio Soto , Valdez Juan Carlos Domínguez 
Published: March 2013

AbstractAn all‐optical encoder performing a binary to octal amplitude shift keying conversion based on cross‐polarization modulation and cross‐gain modulation in a semiconductor optical amplifier is presented. The encoder is experimentally demonstrated by making, in a separated signal of different wavelength, an eight‐level ASK signaling of three parallel binary waveforms. © 2013 Wiley Periodicals, Inc. Microwave Opt Technol Lett 55:1316–1321, 2013; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.27559
Switchable photonic‐crystal‐grating diode using coherent atomic gas
Authors: Serebryannikov Andriy E. , Lakhtakia Akhlesh 
Published: March 2013

AbstractAsymmetry in a regular dielectric photonic crystal of finite thickness created by periodically altering one of its two pupils results in the exhibition of diode‐like passbands that can be switched on/off by injecting/removing a coherent atomic gas.The diode‐like operation is accompanied by diffraction‐enabled deflection of the transmitted wave, within a stop band of the gas‐free structure. Alteration of the oscillator strength can be used to engineer the passband characteristics. © 2013 Wiley Periodicals, Inc. Microwave Opt Technol Lett 55:1248–1250, 2013; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.27562
Multiple mode resonance BPF design using suspended stripline with source‐load coupling structure
Authors: Ho Min‐Hua , Hong Wanchu , Lin Hong‐Yin , Chen Po‐Fan 
Published: March 2013

AbstractA multiple‐mode resonance bandpass filter of suspended stripline structure is proposed in this article with a source‐load coupling feed design. Equivalent quasilumped elements circuit model is developed to represent the proposed filter's discontinuities and to emulate its frequency responses. The odd‐ and even‐mode equivalent half circuits extracted from the derived LC circuit model are also examined for analyzing the circuit's mode resonances. Multiple resonances, which relate to two odd modes and two even modes, are observed. The circuit's physical layout of the proposed filter is guided by the LC circuits, and then the circuit's dimensions are optimized by sonnet simulation. Experiment is conducted to verify the filter's performance and agreements between the simulations and the measurements are observed. © 2013 Wiley Periodicals, Inc. Microwave Opt Technol Lett 55:1382–1385, 2013; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.27565
A miniaturized dual‐band antenna for long‐term evolution system template
Authors: Lin Chih Peng , Lin T.Y. , Huang Jie‐Huang , Jou Christina F. 
Published: March 2013

AbstractLong‐term evolution (LTE) (fourth generation mobile networks) has utilized multiple‐input–multiple output (MIMO) technology to achieve very high data rates in both uplink and downlink. MIMO is based on the multiple antenna systems within the small size mobile terminal. One of the challenges is to miniaturize the mobile terminal. In this article, a compact antenna with the dual‐band characteristics, which meet the specification of the LTE frequency band (680–900 MHz and 2.28–2.82 GHz) is proposed. The bandwidths of both the lower and the higher frequency bands are 320 and 540 MHz, respectively. The total size of the antenna is 54 × 26.6 mm2. A fairly good agreement has been shown between the simulation and experimental results. The study on the effect of the various antenna parameters has also been discussed. © 2013 Wiley Periodicals, Inc. Microwave Opt Technol Lett 55:1379–1382, 2013; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.27566
Dual‐polarized multiband frequency selective surface with miniaturized hilbert element
Authors: Lv Yuan‐Yuan , Chen Wen‐Ling 
Published: March 2013

AbstractA novel Hilbert frequency selective surface (FSS) is proposed and experimental studied. By etching the FSS elements as two iteration Hilbert curve and arraying the Hilbert FSS elements symmetrically, it is experimentally found that the proposed FSS is dual‐polarized, and several stopbands are exhibited within the operating frequency band. It is also observed that the proposed Hilbert FSS element achieved a size reduction of 93.6% when compared to the conventional square patch FSS resonated at the similar frequency. © 2013 Wiley Periodicals, Inc. Microwave Opt Technol Lett 55:1221–1223, 2013; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.27570
Low power saw‐less WCDMA transmitter with quadrature driver amplifier and injection‐locked frequency divider
Authors: Jiang Peichen , Guan Rui , Zhou Jianjun 
Published: March 2013

AbstractA direct conversion transmitter with low noise and low power is presented in this article.A quadrature driver amplifier is used to remove the Inphase‐Quadrature crosstalk in a passive mixer operating with 50% duty cycle local oscillator (LO). In the quadrature LO generation, an inductor‐less injection‐locked frequency divider is utilized to reduce the phase noise contribution with cost of a small current and area. Fabricated in 65 nm CMOS process, a transmitter prototype is designed for wideband code division multiple access (WCDMA) application. Measurement results show that the proposed transmitter achieves 1 dBm maximum output power at 2.53 GHz, 1.7% error vector magnitude (EVM), and −158.5 dBc/Hz output noise at the receiver (RX) band, eliminating the need for the surface acoustic wave (SAW) filter in a traditional transmitter design, with an area of 0.18 mm2 and a total power consumption of 37.8 mW. © 2013 Wiley Periodicals, Inc. Microwave Opt Technol Lett 55:1217–1221, 2013; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.27571
Investigation on ZPT ceramics applied as dielectric resonator antenna for ultra wideband systems
Authors: de Medeiros J. L. G. , de Araújo W.C. , d'Assunção A. G. , de Mendonça L. M. , de Oliveira J. B. L. 
Published: March 2013

AbstractThis article presents an investigation about dielectric resonator antennas. The configuration of antenna is reported using an new structure cylindrical in the shape of disc dielectric, which has its molar representation given by Zn0,8Pb0,2TiO3 (ZPT) stacked vertically about a ground plane and excited by a coaxial probe. The process of construction and characterization of the dielectric resonator are presented. The numerical procedure is performed through of the HFSS commercial software based in the finite‐element method. An excellent agreement between theoretical and experimental results is observed. © 2013 Wiley Periodicals, Inc. Microwave Opt Technol Lett 55:1352–1355, 2013; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.27576
Three‐stage doherty amplifier with uneven input splitter
Authors: Seo M. , Song M. , Gu J. , Kim H. , Ham J. , Park C. , Yang Youngoo 
Published: March 2013

AbstractThis article presents a new high‐efficiency three‐stage Doherty power amplifier (DPA) using a simple uneven power splitter. The proposed three‐way uneven power splitter, which was designed based on a multiway Wilkinson power divider, was applied to the three‐stage DPA. Also, the proposed structure is much simpler and uses fewer lumped components than the conventional one. Using the uneven input splitter, each individual amplifier in the DPA has an appropriate input power level. It results in a proper load modulation of the three‐stage Doherty amplifier. The proposed three‐stage DPA has been implemented for the E‐UTRA‐13 band of from 746 to 756 MHz. For the LTE‐frequency‐division duplexing release 9 downlink signal with a peak‐to‐average power ratio of 10 dB and a signal bandwidth of 5 MHz, a high power‐added efficiency of 42.3% and an adjacent channel leakage power ratio of −37 dBc at an offset of 2.7 MHz were experimentally achieved at an average output power of 30 dBm. © 2013 Wiley Periodicals, Inc. Microwave Opt Technol Lett 55:1405–1409, 2013; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.27581
Hybrid dielectric resonator integrated pyramidal horn antenna
Authors: Ain Mohd Fadzil , Othman Ali , Ahmad Zainal Arifin 
Published: March 2013

AbstractThis article presents the design, simulation, and fabrication of hybrid dielectric resonator integrated pyramidal horn antenna (HDRIPHA) operating from frequency range of 10–18 GHz to cover most of the existing Ku‐band microwave frequencies. The designed HDRIPHA is analyzed and optimized using power modeling software CST Microwave Studio ®. The designed HDRIPHA assembly consists of hybridizing a circular sector dielectric resonator (DR) with a printed strip monopole, which is simply fed inside the horn with cavity back. The combination effect of two radiators produces multiple resonances frequency and provides wideband 51.65% of 10 dB return loss impedance bandwidth centered at 15.1 GHz. The designed HDRIPHA provides an average gain of 15 dBi with flexibility in the impedance bandwidth, and the far‐field radiation characteristics appear to be satisfied within the operating bandwidth. Both simulation and measurement results for the gain, reflection characteristics, and radiation patterns of the designed HDRIPHA over the operating frequency range of 10–18 GHz are presented. The measured results were compared and have been found to have good agreement as predicted in the simulated results. © 2013 Wiley Periodicals, Inc. Microwave Opt Technol Lett 55:1299–1303, 2013; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.27586
Mushroom‐shaped dielectric resonator antenna for WiMAX applications
Authors: Kumari Runa , Behera Santanu Kumar 
Published: March 2013

AbstractA compact mushroom‐shaped dielectric resonator antenna (MSDRA) excited by microstrip line feeding, with partial ground plane has been designed and studied theoretically as well as experimentally. The proposed antenna has been developed for world‐wide interoperability for Microwave Access (WiMAX) applications centered at about 3.5 GHz. The total size of the antenna is 62 mm × 50 mm. The gain for the antenna is found to vary from 3 to 3.6 dBi. Parametric studies are performed to investigate the performance of the antenna. The effects of finite ground plane and radius size of mushroom (half cylindrical)‐shaped dielectric resonator on the antenna performance has been evaluated. The investigations on the S‐parameter, gain, directivity, and radiation characteristics show a fairly good agreement which justifies that the MSDRA can be well suited for Wireless communication systems. © 2013 Wiley Periodicals, Inc. Microwave Opt Technol Lett 55:1360–1365, 2013; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.27590
Wideband high‐gain aperture coupled antenna for ku band phased‐array systems
Authors: Bilgic Mustafa Murat , Yegin Korkut 
Published: March 2013

AbstractAperture coupled microstrip antenna is presented for Ku band phased‐array applications. We show that radial open circuit terminated microstrip feed and hourglass aperture shape provide better coupling, high gain, wide bandwidth and small in‐band gain variation. Eight‐element antenna array with fixed beam tilt is formed and measured to validate simulations. © 2013 Wiley Periodicals, Inc. Microwave Opt Technol Lett 55:1291–1295, 2013; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.27594
Inverted‐F antenna with periodic patterned structures for multiband applications
Authors: Yang Xiaodong , Yang Rui , Xie Yongjun , Lei Zhenya , Bao Di , Rahman A. , Hu Haipeng 
Published: March 2013

AbstractBy introducing periodic patterned structures to planar inverted‐F antenna (PIFA), a novel triple‐band antenna has been achieved and is presented.The transmission line model for periodic patterned ground plane loaded PIFA is extracted. Simulations are confirmed by the experimental results, which ensure that the proposed antenna is well suited for WLAN and WiMAX applications. © 2013 Wiley Periodicals, Inc. Microwave Opt Technol Lett 55:1365–1367, 2013; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.27597
Broadband monopole antenna with convex conical reflector for 802.11a standard
Authors: Všetula P. , Raida Z. 
Published: March 2013

AbstractIn this article, we present a study dealing with the design, optimization, and manufacturing of different versions of a broadband monopole antenna with a convex conical reflector. These antennas are created by a wire monopole that is placed into the axis of a convex conical reflector. The principle of antennas is based on the transformation of the impedance of a coaxial transmission line to the open space impedance via a circular waveguide. The results of simulations performed in CST Microwave Studio are mutually compared. Then, the simulated versions of broadband monopole antennas were optimized with respect to specified objectives. According the available materials, we built selected versions of the antenna and experimentally verified their properties. © 2013 Wiley Periodicals, Inc. Microwave Opt Technol Lett 55:1243–1247, 2013; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.27598
Disease‐modifying therapy for Alzheimer's disease: Challenges and hopes
Authors: Iwata Atsushi , Iwatsubo Takeshi 
Published: March 2013

AbstractDespite enormous efforts to develop disease‐modifying drugs for Alzheimer's disease (AD), effective therapies have yet to be found. We have endured failure for a number of reasons, such as low specificity in drug candidates, inaccurate diagnosis and incorrect timing in the intervention. To help overcome these problems, modern research findings have been incorporated into new criteria and guidelines for the clinical diagnosis of AD. In addition, attempts to intervene during the earliest stages of the disease are planned, as this is probably when AD is most receptive to disease‐modifying therapies. We discuss these issues and provide perspective into the future of drug development.
Alterations in adipocytokines and cGMP homeostasis in morbid obesity patients reverse after bariatric surgery
Authors: Felipo Vicente , Urios Amparo , García‐Torres Maria L. , El Mlili Nisrin , del Olmo Juan A. , Civera Miguel , Ortega Joaquin , Ferrandez Antonio , Martínez‐Valls Jose , Cassinello Norberto , Montoliu Carmina 
Published: March 2013

AbstractObjective:Obesity‐associated nonalcoholic fatty liver disease (NAFLD), covering from simple steatosis to nonalcoholic steatohepatitis (NASH), is a common cause of chronic liver disease. Aberrant production of adipocytokines seems to play a main role in most obesity‐associated disorders. Changes in adipocytokines in obesity could be mediated by alterations in cyclic GMP (cGMP) homeostasis. The aims of this work were: (1) to study the role of altered cGMP homeostasis in altered adipocytokines in morbid obesity, (2) to assess whether these alterations are different in simple steatosis or NASH, and (3) to assess whether these changes reverse in obese patients after bariatric surgery.Design and Methods:In 47 patients with morbid obesity and 45 control subjects, the levels in blood of adipocytokines, cGMP, nitric oxide (NO) metabolites, and atrial natriuretic peptide (ANP) were studied. Whether weight loss after a bariatric surgery reverses the changes in these parameters was evaluated.Results:NO metabolites and leptin increase (and adiponectin decreases) similarly in patients with steatosis or NASH, suggesting that these changes are due to morbid obesity and not to liver disease. Inflammation and cGMP homeostasis are affected both by morbid obesity and by liver disease. The increases in interleukin 6 (IL‐6), interleukin 18 (IL‐18), plasma cGMP, ANP, and the decrease in cGMP in lymphocytes are stronger in patients with NASH than with steatosis. All these changes reverse completely after bariatric surgery and weight loss, except IL‐18.Conclusion:Altered cGMP homeostasis seems to contribute more than inflammation to changes in leptin and adiponectin in morbid obesity.
How best to use partial meal replacement in managing overweight or obese patients with poorly controlled type 2 diabetes
Authors: Leader Natasha J. , Ryan Lynne , Molyneaux Lynda , Yue Dennis K. 
Published: March 2013

AbstractObjective:To compare patient compliance and benefits, over 12 months, of 1 versus 2 partial meal replacement (PMR) for the management of overweight/obese subjects with inadequately controlled type 2 diabetes.Design and Methods:Thirty‐six overweight patients with inadequately controlled type 2 diabetes (BMI > 27 kg/m2 and HbA1c > 7.5% [58 mmol/mol]) were randomized to receive 1 or 2 PMR/day, while maintaining usual lifestyle. Subjects were seen monthly and adjustment of medications was made to prevent hypoglycemia. Compliance was assessed by counting unused sachets.Results:Patients on 2 PMR/day lost almost 4 kg compared with only 0.5 kg in the 1 PMR/day group. This difference was statistically significant (P < 0.05). Overall PMR was about 30% as effective as in our previous study on total meal replacement. Reductions in weight, waist, and HbA1c were better in the 2 PMR/day group while patient dropout and compliance were not worse over a 12‐month period.Conclusion:PMR provides a further management option for overweight/obese individuals with type 2 diabetes. The initial recommendation should be 2 PMR/day.