bluuebunny/crossref_metadata_2025 huggingface dataset:
Time‐domain optimization for UWB antenna based on correlated energy gain
Authors: Xie Ze‐ming , Li Yong , Ding Huan‐huan
Published: November 2010

The correlated energy gain (CEG) is introduced to describe the time‐domain characteristics of the UWB antenna for pulse radio systems. To improve the time‐domain performance of the pulse UWB system, a planar goblet‐like UWB antenna is proposed. The dimensions of the antenna are optimized using the mean effective CEG (MCEG) as the cost function. Because the MCEG considers the radiating energy and the pulse shape preserving capability simultaneously, the designed antenna can achieve good time‐domain characteristics. The designed antenna is fabricated and measured in time‐domain. Good pulse shape fidelity is observed. © 2010 Wiley Periodicals, Inc. Microwave Opt Technol Lett 53:97–102, 2011; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.25638
Experimental study of two‐tone intermodulation products in a communications modulator
Authors: Madero‐Ayora María J. , Allegue‐Martínez Michel , Crespo‐Cadenas Carlos , Reina‐Tosina Javier , Navarro‐Lázaro Javier
Published: November 2010

This article presents the experimental nonlinear characterization of a quadrature modulator following a two‐tone test approach. The observed intermodulation products show different slopes with respect to the desired carrier level that can be predicted by a simple model. Measurements for two‐tone tests versus carrier level and tone spacing are discussed. © 2010 Wiley Periodicals, Inc. Microwave Opt Technol Lett 53:58–61, 2011; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.25639
A novel digital active homodyne demodulation scheme based on square‐wave phase modulation for interferometric fiber‐optic sensors
Authors: Feng Xiujuan , Zhang Chunxi , Liang Sheng , Li Chuansheng , Zhang Chaoyang
Published: November 2010

A novel digital active homodyne demodulation scheme to eliminate the signal fading in interferometric fiber‐optic sensors is proposed. The error signal is obtained by the square‐wave phase modulation and then the digital correlation detection technique is applied to demodulate the low‐frequency environmental phase drift and generate the offset phase, which is then fed back the integrated optical phase modulator to lock the interferometer in quadrature. The high‐frequency signal phase can be read out and recovered from the photodetector output with the interferometer in quadrature. The simulation and experimental results verify the feasibility of the proposed scheme, which obviates the feedback integrator saturation and the system resetting problem encountered in the conventional active homodyne detection schemes. © 2010 Wiley Periodicals, Inc. Microwave Opt Technol Lett 53:20–23, 2011; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.25640
A fully integrated low voltage (0.5 V) X‐band CMOS low noise amplifier
Authors: Liu Baohong , Zhou Jianjun , Mao Junfa
Published: November 2010

In this article, a 0.5 V X‐band low noise amplifier (LNA) composed of two common‐source stages is designed and fabricated with 0.18 um CMOS technology.Based on the structure of cascaded common‐source stages and forward body bias technology, the supply voltage is reduced. Measurement results show that the circuit can operate at supply voltage of 0.5 V with 8 mA current occupation. The gain is 9.1 dB, noise figure is 5.0 dB, and IIP3 is −8.5 dBm at frequency of 8.9 GHz. The whole performance of the amplifier defined by two kinds of figure‐of‐merits is compared with some published LNAs. © 2010 Wiley Periodicals, Inc. Microwave Opt Technol Lett 53:17–20, 2011; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.25641
Design of triple‐band antenna for PCS/WLAN/UWB applications
Authors: Park Sang Y. , Park Jong K.
Published: November 2010

In this article, we have proposed a triple‐band antenna with L and T‐shaped stubs for PCS/WLAN/UWB applications. The proposed antenna consists of two symmetrical strips, two‐steps, and L and T‐shaped stubs. Two techniques are used to produce the resonances at each frequency bands, the low dispersion, and good impedance matching. The proposed antenna has an omni‐directional radiation pattern, compact size, low dispersion, and low cost. © 2010 Wiley Periodicals, Inc. Microwave Opt Technol Lett 53:235–238, 2011; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.25642
Application of hybrid finite‐difference mode‐matching method to analysis of structures loaded with axially symmetrical posts
Authors: Kusiek A. , Mazur J.
Published: November 2010

In this study, a new hybrid method is proposed to the analysis of waveguide structures loaded with arbitrary configuration of axially symmetrical posts.The method is based on a combination of finite difference frequency domain method, mode‐matching technique, and an analytical iterative scattering procedure. The results concerning the accuracy of the proposed technique are discussed. The validity of the proposed approach is verified with the analytical mode‐matching method, own measurements, commercial software, and the results published in literature. © 2010 Wiley Periodicals, Inc. Microwave Opt Technol Lett 53:189–194, 2011; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.25644
Analysis of transient electromagnetic scattering using UV method enhanced time‐domain integral equations with Laguerre polynomials
Authors: Wang Quanquan , Shi Yifei , Li Mengmeng , Fan Zhenhong , Chen Rushan , Xia Mingyao
Published: November 2010

In this article, the multilevel UV algorithm is utilized to reduce both the memory requirement and CPU time in the time‐domain combined field integral equation (TD‐CFIE) method to analyze transient electromagnetic scattering from conducting structures.The UV method is kernel‐independent, and is based on the rank‐deficiency feature of the impedance submatrix which represents far interaction. To obtain an unconditionally stable solution, finite orders of weighted Laguerre polynomials are used as temporal basis functions and the unknown expansion coefficients of the time variable are solved recursively order by order, as the so‐called matching‐on‐in‐order (MOO) procedure. RWG basis function is used as the spatial basis function for its flexibility in modeling arbitrary geometries. The spatial and temporal testing procedures are separate, and both of them are carried on with the Galerkin's method. Numerical results are given to verify the proposed method. © 2010 Wiley Periodicals, Inc. Microwave Opt Technol Lett 53:158–163, 2011; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.25646
Modified bow‐tie slot antenna for the 2.4/5.2/5.8 GHz WLAN bands with a rectangular tuning stub
Authors: Yoon Joong Han , Lee Young Chul
Published: November 2010

In this article, a novel design for the modified bow‐tie slot antenna with a rectangular tuning stub for 2.4/5.2/5.8 GHz triple‐band applications is presented. The prototype consists of a modified bow‐tie slot, the strip line in the bow‐tie slot, and the rectangular tuning stub for the feeding. The simulation results showed that the impedance matching of the proposed modified bow‐tie slot antenna was greatly affected by the feed gap and the strip line in the bow‐tie slot. The experiment results indicate that the impedance bandwidth (return loss: −10 dB definition) of the proposed antenna was about 1.405 GHz for the 2.4 GHz band and 1.305 GHz for the 5 GHz band. The radiation patterns and gains in the experiment results are also presented and discussed. © 2010 Wiley Periodicals, Inc. Microwave Opt Technol Lett 53:126–130, 2011; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.25647
Measurement of tag antenna by a time domain reflectmetry
Authors: Chang The Nan , Shie Wein
Published: November 2010

In this article, an RFID tag antenna etched on a grounded substrate is designed and tested. It takes two differentially connected photonic band gap elements. For each differential port, tag's reflection coefficient in frequency domain is transformed from two measured time domain waveforms. The first one as the input waveform is referred to an open‐circuited transmission line, whereas the second one as the response waveform is obtained by connecting one half of the tag at the end of each associated transmission line. As the TDR can provide differential signal, measurement of the tag's impedance becomes easy. Waveform in time domain is truncated according to Nicolson's ramping algorithm. © 2010 Wiley Periodicals, Inc. Microwave Opt Technol Lett 53:90–93, 2011; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.25649
Bandwidth enhancement of epsilon negative zeroth‐order resonator antennas using a Co2Y hexagonal ferrite helical loading
Authors: Ji Jeong Keun , Kim Gi Ho , Seong Won Mo
Published: November 2010

A method to extend the bandwidth of epsilon negative (ENG) zeroth‐order resonator (ZOR) antennas using a Co2Y hexagonal ferrite (Ba2Co1Zn0.7Cu0.3Fe12O22) is presented.It is accomplished by using the ferrite helical loading for shunt inductance of ENG ZOR unit cell. The Co2Y hexagonal ferrite has been developed for performance improvement of mobile handset antennas. The permittivity of the developed Co2Y hexagonal ferrite is about 9.3, and the permeability is about 4. An ENG ZOR antenna based on simplified planar mushroom structure unit cell was fabricated, and bandwidth enhancement and good radiation performance were achieved. © 2010 Wiley Periodicals, Inc. Microwave Opt Technol Lett 53:87–90, 2011; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.25650
Construction of 2D training database based on high‐frequency RCS prediction methods
Authors: Park Sang‐Hong , Jung Joo‐Ho , Kim Hyo‐Tae , Kim Kyung‐Tae
Published: November 2010

For automatic target recognition using inverse synthetic aperture radar images, training data used have been mostly obtained from measured targets.However, because of cost and secrecy, securing an actual enemy aircraft is very difficult. In this article, to determine whether this problem can be solved using computer simulation, we constructed a training database using three high‐frequency radar cross‐section prediction methods: physical optics (PO), physical theory of diffraction (PTD), and shooting and bouncing ray (SBR). Then, we used the polar mapping classifier to quantify their accuracy in classifying images. The combinations of SBR with PTD and PO with PTD had almost the same accuracy and both were more accurate than when SBR and PO were used alone. © 2010 Wiley Periodicals, Inc. Microwave Opt Technol Lett 53:223–229, 2011; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.25652
Average power handling capability of thin‐film microstrip line under dc‐bias conditions
Authors: Wu Hung‐Wei , Weng Min‐Hang
Published: November 2010

Average power handling capability (APHC) of the thin‐film microstrip line (TFML) under dc‐bias conditions (<1 V) is proposed for the first time. The TFMLs with a 20‐μm‐thick polyimide thin films are fabricated on a low‐resistivity silicon substrate (ρ ≤ 10 Ω cm). Losses and APHC are extracted from the measured S‐parameters up to 50 GHz. This study has also been studied on the different roughness and thermal conductivity of the polyimide film to evaluate the APHC of the dc‐biased TFML. It is believed that the evaluations are useful for the high‐dense microwave monolithic integrated circuits. © 2010 Wiley Periodicals, Inc. Microwave Opt Technol Lett 53:84–87, 2011; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.25653
A compact metamaterial‐inspired multilayered slot antenna
Authors: Zhang Hualiang , Xin Hao , Bortolin Robert , Kudva Jayanth
Published: November 2010

A low‐profile, compact and easily integrated antenna for RF/microwave applications is presented in this article. The designed antenna works around 430 MHz and can be easily scaled to other frequencies. Metamaterial‐inspired slot loop antennas are used as the radiating elements. To shrink the total size of the antenna, periodical structures are loaded to the original slot loop. It is found that with this modification, the total size of the antenna is reduced and the impedance matching of the antenna is improved. To further improve the performance of the proposed antenna, a floating ground plane and a parasitic slot were added, made possible by the multilayered structure of the antenna. As a result, the bandwidth and gain of proposed antenna are increased. © 2010 Wiley Periodicals, Inc. Microwave Opt Technol Lett 53:219–223, 2011; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.25654
Dipole antenna with integrated balun for ultra‐wideband radio 6–9 GHz
Authors: Karlsson Magnus , Owais Owais , Östh Joakim , Serban Adriana , Gong Shaofang , Jobs Magnus , Grudén Mathias
Published: November 2010

A fully integrated dipole antenna with a balun for ultra‐wideband (UWB) radio in the band 6–9 GHz utilizing a flexible and rigid printed circuit board is presented in this article. The balun utilizes broadside‐coupled microstrips and is integrated in the rigid part of the printed circuit board, whereas the radiator is placed in the flexible part. The antenna with the balun covers the frequency‐band 6.0–8.5 GHz at voltage standing wave ratio (VSWR) < 2.0, and 5.5–11.0 GHz at VSWR < 2.5. Moreover, simulated and measured radiation patterns and antenna efficiency above 86.0% are observed. © 2010 Wiley Periodicals, Inc. Microwave Opt Technol Lett 53:180–184, 2011; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.25656
Modified Chebyshev bandstop filter with transmission zeros at real frequencies
Authors: Malherbe Johannes A. G. , Swiatko Adam
Published: November 2010

The logarithmic periodic transmission line filter has been shown to be an attractive alternative to elliptic function filters when a high rate of cutoff is needed.In this article, it is shown that an improved passband and bandedge response can be obtained if impedances obtained from a Chebyshev prototype are used, and the stopband width increased by shifting the resonant frequencies of the stubs away from the centre frequency in a non‐periodic fashion. © 2010 Wiley Periodicals, Inc. Microwave Opt Technol Lett 53:177–180, 2011; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.25657
Empirical and deterministic approach for the optimization of wideband RF power amplifiers' behavior modeling and predistortion structure
Authors: Fares Marie‐Claude , Boumaiza Slim , Wood John
Published: November 2010

This article presents an approach to determining the smallest number of coefficients of a Parallel Hammerstein (PH) model to reduce the development complexity of wideband RF power amplifiers' (PA) modeling and predistortion schemes. The visualization of the impulse responses of the different filters of the PH yields a systematic and single‐iteration approach for determining the optimal modeling structure, for example, filters' lengths. The approach was used to determine an optimal structure that linearizes the response of a 400‐watt LDMOS Doherty PA driven with a four carrier WCDMA signal. In the experiments conducted, the number of coefficients in the PH was reduced by about a factor of 2.5 without compromising its modeling and linearization performance. © 2010 Wiley Periodicals, Inc. Microwave Opt Technol Lett 53:116–118, 2011; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.25660
Miniaturization of rectangular microstrip patch antenna using optimized single‐slotted ground plane
Authors: Sarkar S. , Majumdar A. Das , Mondal S. , Biswas S. , Sarkar D. , Sarkar P. P.
Published: November 2010

In this article, a new design for single‐layer rectangular microstrip patch antenna has been proposed.This design uses a ground plane with a single slot. It has been shown that by using this slotted ground plane, the resonant frequency has been lowered considerably, thus, reducing the size of the antenna. Using this design, the size of the antenna is reduced by about 90%. It has been also shown that the resonant frequency can be reduced further by increasing the length of the slot. © 2010 Wiley Periodicals, Inc. Microwave Opt Technol Lett 53:111–115, 2011; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.25661
Small‐meandered coplanar antenna in UHF bands
Authors: Boucher S. , Sharaiha A.
Published: November 2010

A low profile, electrically small coplanar antenna with omnidirectionnal radiation is presented. The antenna is less than λ0/400 in height and λ0/14 in lateral dimension. It is matched to 50 Ω without the need for external matching. The antenna's geometry and concept design using short‐circuiting and line‐meandering techniques are presented in this article. Simulated and measured return losses are also provided here, as well as efficiency and radiation patterns. The measurements verify that the fabricated antenna, which is proposed for its terminal (110 mm × 73 mm) features an excellent impedance match, gain, and omnidirectional radiation in a large bandwidth (10%). © 2010 Wiley Periodicals, Inc. Microwave Opt Technol Lett 53:72–77, 2011; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.25663
Antenna covering GSM/PCN/bluetooth and GPS bands
Authors: Chang The‐Nan , Chuang Yu‐Chou
Published: November 2010

In this article, design and implementation of a monopole antenna covering GSM/PCN/Bluetooth and GPS bands are demonstrated. The antenna is modified from a symmetrical self‐complementary strip‐slot structure. However, one arm of the U‐shaped slot on the ground plane is extended to the rim of the printed circuit board. It is investigated that this extension makes the antenna well matched at a wideband. Without this extension, the antenna can only be worked at three separated narrow bands. © 2010 Wiley Periodicals, Inc. Microwave Opt Technol Lett 53:34–40, 2011; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.25664
Ultrawideband microstrip integrated‐antenna‐filter
Authors: Lim Eng Hock , Leung Kwok Wa
Published: November 2010

A new three‐port integrated‐antenna‐filter (IAF) module is proposed for ultrawideband applications.The IAF is designed by closely packing a slot antenna and a patch filter on a single substrate. The reflection coefficient, mutual coupling, input impedance, radiation pattern, and insertion loss of the proposed configuration are studied. Since it was found that the mutual coupling between antenna and filter parts of the IAF is very small across a very wide bandwidth, the two parts can be designed almost independently. © 2010 Wiley Periodicals, Inc. Microwave Opt Technol Lett 53:32–34, 2011; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.25665
A 2.76‐mW, 3‐ to 10‐GHz ultrawideband LNA using 0.18‐μm CMOS technology
Authors: Chang Jin‐Fa , Lin Yo‐Sheng
Published: November 2010

A low‐power (2.76 mW) common‐gate (CG) low‐noise amplifier (LNA) for ultrawideband (UWB) systems using standard 0.18 μm CMOS technology is demonstrated.Instead of the traditional single parallel inductor (LS1 only), we propose a new matching network consisting of a series LS1–RS1 in series with a parallel LS2–RS2 to enhance the input matching bandwidth. Flat and high S21 was achieved by using the connecting inductor LC and the peaking inductor LD2 to compensate the gain loss at medium frequency and high frequency, respectively. In addition, for suitable values of LC and LD2, flat and low noise figure (NF; i.e., a nearly critically damped Q‐factor for the second‐order NF frequency response) can also be achieved. Over the 3–10 GHz band of interest, the LNA achieved S21 of 10.1 ± 1.7 dB, minimum NF of 3.9 dB (at 4 GHz) and an average NF of 4.6 dB. The power dissipation was 2.76 mW, and the corresponding figure of merit was 4.3. Both are of the best results ever reported for a CMOS UWB LNA. © 2010 Wiley Periodicals, Inc. Microwave Opt Technol Lett 53:94–97, 2011; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.25667
A bioinspired microstrip antennas based on the idea of a cockroach antenna
Authors: Mahmoud Mahmoud N. , Elkamchouchi H.
Published: November 2010

Insects possess garden variety of traits, but for some who lack the ability of vision, their species would have been extinct long ago. Through ingenuity of creation, these species adapted to the environment by developing antennas where they can use the basic principles of wave propagation to feel the surrounding objects. In this article, a new design for broadband microstrip antennas was investigated. The main aim is to make the patch like a cockroach antenna. The antenna has shown to yield percentage bandwidth about 120% for a substrate with permittivity of 4.5. For using air substrate, the antenna was fabricated, and the percentage bandwidth was 42%. Furthermore, some modifications were made to increase the bandwidth of air substrate antennas until it successfully reached 114%. © 2010 Wiley Periodicals, Inc. Microwave Opt Technol Lett 53:135–139, 2011; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.25668
Broadband printed dipole with integrated via‐hole balun for WiMAX applications
Authors: Ávila‐Navarro E. , Antón J. , Blanes José M. , Reig C.
Published: November 2010

A broadband balanced printed dipole antenna for WiMAX applications (2.5/3.6 GHz) is presented. An integrated via‐hole balun is used to feed the antenna and a Yagi‐like scheme is proposed to improve the gain. The design has been optimized by means of parametric FDTD simulations. The antenna was fabricated and measured, giving a bandwidth higher than 50% and a gain higher than 4 dBi. © 2010 Wiley Periodicals, Inc. Microwave Opt Technol Lett 53:52–55, 2011; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.25671
Dual‐band ferrite chip antenna for global positioning system and bluetooth applications
Authors: Bae Seok , Hong Yang Ki , Lee Jae Jin , Park Ji Hoodn , Jalli Jeevan , Abo Gavin S. , Seong Won Mo , Park Sang Hoon , Kum Juk Sik , Ahn Won Ki , Kim Gi Ho
Published: November 2010

Dual‐band ferrite chip antenna having 105 mm3 of volume was fabricated with Ba3Co2Fe24O41(Co2Z)‐glass composite and antenna performance was evaluated. The permeability and permittivity of the composite were in the range of 1.92–2.12 and 7.33–7.45, respectively, from 1.575 to 2.45 GHz. Magnetic and dielectric loss tan δ of Co2Z‐glass composite was <3.5% in the 1.5–3.0 GHz range. The 3D average gain and bandwidth of the 40h‐shake‐milled and sintered Co2Z‐glass composite antenna were −1.27 dB and 355 MHz at 1.575 GHz, −4.08 dB and 270 MHz at 2.45 GHz, respectively. Simulated S‐parameter spectrum is in good agreement with experimental results. © 2010 Wiley Periodicals, Inc. Microwave Opt Technol Lett 53:14–17, 2011; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.25672
A highly compact semielliptic shape ultrawideband monopole antenna
Authors: Naser‐Moghadasi M. , Rousta H. , Virdee B. S.
Published: November 2010

This article describes a compact microstrip‐fed planar monopole antenna, which comprises of a semielliptic shape radiation element on a partially modified ground‐plane. This antenna is different from the traditional monopole antenna as its ground‐plane is arc‐shaped near the vicinity of the radiating element, and it embodies two square slots disposed on either sides of the feed‐line. The modifications implemented to the ground‐plane improve the antenna's input impedance bandwidth and its radiation performance across the ultrawideband (UWB) frequency range. The resulting antenna prototype exhibits a return‐loss lower than 10 dB between 3.1–11.5 GHz, and a radiation pattern that is comparable with the traditional monopole antenna. © 2010 Wiley Periodicals, Inc. Microwave Opt Technol Lett 53:229–231, 2011; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.25674
High selectivity miniaturized broadband filter
Authors: Packiaraj D. , Vinoy K.J. , Ramesh M. , Kalghatgi A. T.
Published: November 2010

Design of a compact broadband filter using tightly coupled line sections in defected (A slot is cut in the ground) microstrip medium operating from 3.1–6.8 GHz has been reported in this article. Filter has been designed and analyzed using an equivalent circuit model based on even and odd mode parameters of coupled line sections. The proposed filter has attenuation poles on either side of the pass band resulting in improved selectivity. This filter features spurious‐free response up to third harmonic frequency. Experimental results of the filter have been validated against the analytical and full wave simulations. © 2010 Wiley Periodicals, Inc. Microwave Opt Technol Lett 53:184–187, 2011; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.25676
Continuously tunable microwave photonic notch filter based on the differential group delay
Authors: Jin Yongxing , Dong Xinyong , Zhou Junqiang , Shum Perry Ping
Published: November 2010

A continuously tunable microwave photonic notch filter is proposed and experimentally demonstrated. This filter is based on the differential group delay generated by a high‐birefringence linearly chirped fiber Bragg grating. The tunability is realized by applying gradient tension to the grating. Free spectral range tuning by 9.27 GHz with more than 35 dB notch rejection is achieved. © 2010 Wiley Periodicals, Inc. Microwave Opt Technol Lett 53:121–123, 2011; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.25679
A novel compact broadband printed monopole antenna for mobile handsets
Authors: Kang Gaojian , Du Zhengwei
Published: November 2010

A novel compact broadband printed antenna for mobile handsets is proposed and studied.The proposed antenna occupies an area of 20 × 16 mm2, consisting of an inverted‐S monopole for 2‐GHz band and an inverted‐L branch for 3‐GHz band. It achieves a bandwidth of 560 MHz at the 2‐GHz band (1.66–2.22 GHz) and 500 MHz at the 3‐GHz band (3.24–3.74 GHz) for −10 dB return loss, covering GSM (1710–2170 MHz), DCS (1710–1880 MHz), PCS (1850–1990 MHz), PHS (1880–1930 MHz), UMTS (1920–2170 MHz), and WiMAX (3400–3600 MHz) bands. Numerical simulation and verifying experimental results are presented and discussed. © 2010 Wiley Periodicals, Inc. Microwave Opt Technol Lett 53:118–121, 2011; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.25680
Doherty power amplifier with cascaded peaking cells
Authors: Lee Mun‐Woo , Kam Sang‐Ho , Lee Yong‐Sub , Jeong Yoon‐Ha
Published: November 2010

The Doherty power amplifier (DPA) with cascaded peaking cells is reported.The auxiliary peaking cell at the input of the main peaking cell is employed to enhance the efficiency and linearity of DPA. For the experimental validation, the main DPA and an auxiliary peaking cell are designed using Si LDMOSFETs and a GaN HEMT, respectively. From the measured results, the power‐added efficiency is increased at a 6‐dB back‐off power and the adjacent channel leakage ratio is enhanced over a whole output power range. © 2010 Wiley Periodicals, Inc. Microwave Opt Technol Lett 53:208–211, 2011; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.25682
An interdigitated split‐ring resonator for metamaterials
Authors: Sohn Sung‐Min , Vaughan J. Thomas , Gopinath Anand
Published: November 2010

An interdigitated split‐ring resonator is proposed and obtains negative permittivity (εr), magnetic permeability (μr), and negative refractive index (n) over a narrow frequency band. This article demonstrates that the proposed structure has a linear frequency response the geometry of the structure and small planar resonators for low frequency metamaterials are possible. The experimental results show that the resonators exhibit a negative refractive index at frequencies of a few hundred MHz to a few GHz. © 2010 Wiley Periodicals, Inc. Microwave Opt Technol Lett 53:174–177, 2011; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.25683
Polyamides – Still Strong After Seventy Years
Authors: Marchildon Keith
Published: November 2010

Polyamides are a subject of enduring interest because of their variety, their complex internal structures, their commercial importance and versatility, and their various chemistries of preparation and of long‐term use. The present review introduces these polymers and then discusses the first of the above aspects, namely the variety of the polyamides. Here, together, the full family is presented, classified conveniently according to the types and combinations of monomers from which they are constructed.

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Progressive resistance voluntary wheel running in the mdx mouse
Authors: Call Jarrod A. , Mckeehen James N. , Novotny Susan A. , Lowe Dawn A.
Published: November 2010

Exercise training has been minimally explored as a therapy to mitigate the loss of muscle strength for individuals with Duchenne muscular dystrophy (DMD). Voluntary wheel running is known to elicit beneficial adaptations in the mdx mouse model for DMD. The aim of this study was to examine progressive resistance wheel running in mdx mice by comprehensively testing muscle function before, during, and after a 12‐week training period. Male mdx mice at ∽4 weeks age were randomized into three groups: Sedentary, Free Wheel, and Resist Wheel. Muscle strength was assessed via in vivo dorsiflexion torque, grip strength, and whole body tension intermittently throughout the training period. Contractility of isolated soleus muscles was analyzed at the study's conclusion. Both Free and Resist Wheel mice had greater grip strength (∽22%) and soleus muscle specific tetanic force (26%) compared with Sedentary mice. This study demonstrates that two modalities of voluntary exercise are beneficial to dystrophic muscle and may help establish parameters for an exercise prescription for DMD. Muscle Nerve 42: 871–880, 2010
Patterns of gene expression in muscle and fat in tumor‐bearing rats: Effects of CRF2R agonist on cachexia
Authors: Argilés Josep M. , Fontes‐Oliveira Cibely Cristine , Fuster Gemma , Ametller Elisabet , Figueras Maite , Olivan Mireia , Lopez‐Soriano Francisco J. , Qu Xiaoyan , Demuth Jeffrey , Stevens Paula , Varbanov Alex , Wang Feng , Isfort Robert J. , Busquets Sílvia
Published: November 2010

The hypothesis we tested was that administering corticotropin‐releasing factor receptor agonists preserves muscle mass during cancer that is related to changes in tissue gene expression. cDNA microarrays were used to compare mRNAs from muscle and adipose tissues of non‐treated and agonist‐treated tumor‐bearing rats. In muscle of non–tumor‐bearing agonist‐treated animals we observed decreased expression of genes associated with fatty acid uptake and esterification. In tumor‐bearing animals, CRF2R agonist administration produced decreased mRNA content of the atrogene lipin‐1. In white adipose tissue, agonist treatment of non–tumor‐bearing animals induced genes typically related to muscle structure and function. The fact that this treatment decreased expression of atrogenes could have clinical application. In addition, agonist treatment changed the gene pattern of adipose tissue to render it similar to that of skeletal muscle; thus, treatment with this agonist alters the gene pattern to what could be called “muscularization of white adipose tissue.” Muscle Nerve 42:936–949, 2010
Voluntary exercise induces structural remodeling in the hearts of dystrophin‐deficient mice
Authors: Costas Jeffrey M. , Nye David J. , Henley Jessica B. , Plochocki Jeffrey H.
Published: November 2010

In this exploratory study, we test the hypothesis that voluntary exercise affects the progression of dystrophic changes in the left ventricle of the heart. Wild‐type (C57BL/10ScSn) and dystrophin‐deficient (mdx) mice, aged 7 weeks, were divided into sedentary and exercise‐treated groups and tested for differences in cardiac histomorphometry. Exercised mdx mice were found to exhibit significantly enlarged ventricles and thinner lateral ventricular walls than sedentary mdx mice (P < 0.05). Trichrome staining indicated the presence of fibrotic lesions in the left ventricular myocardium in 20% of the exercised mdx group. Fibrotic lesions were not found in control or sedentary mdx mice. No histomorphometric differences were found between treatment groups in wild‐type mice. Our findings suggest voluntary exercise may accelerate the progression of ventricular dilation and fibrosis in young mdx mice. The effects of exercise on cardiac remodeling should be considered during the treatment of cardiac disease in dystrophin‐deficient patients. Muscle Nerve 42: 881–885, 2010
Characterizing spinal muscular atrophy with electrical impedance myography
Authors: Rutkove Seward B. , Shefner Jeremy M. , Gregas Matt , Butler Hailly , Caracciolo Jayson , Lin Connie , Fogerson Patricia M. , Mongiovi Phillip , Darras Basil T.
Published: November 2010

Electrical impedance myography (EIM) is a non‐invasive, painless technique for the evaluation of neuromuscular disease, and here we evaluate its potential application in spinal muscular atrophy (SMA). Twenty‐one SMA patients and 18 healthy children underwent EIM of biceps brachii and tibialis anterior using a commercially available impedance device. Hand‐held dynamometry and ultrasound assessment of subcutaneous fat thickness were also performed. All EIM parameters differed significantly between both SMA patients and normal subjects and between type 2 and type 3 SMA patients. In addition, EIM had an accuracy level as high as 93% for correctly categorizing patients as type 2 or type 3. Multiple regression analyses confirmed a strong association between EIM and dynamometry. These results confirm that EIM can accurately categorize patients with SMA. Because EIM requires no patient effort and is rapid to apply, it may serve a useful role in future SMA clinical trials. Muscle Nerve 42: 915–921, 2010
Distinct cytokine patterns associated with different forms of chronic dysimmune neuropathy
Authors: Gironi Maira , Saresella Marina , Marventano Ivana , Guerini Franca Rosa , Gatti Andrea , Antonini Giovanni , Ceresa Lara , Morino Stefania , Beghi Ettore , Angelici Alberto , Mariani Enrica , Nemni Raffaello , Clerici Mario
Published: November 2010

To better understand the presumed immune system dysregulation of chronic dysimmune neuropathy (CDN) patients, we designed a study to evaluate the levels of pro‐ and anti‐inflammatory cytokines in the most common forms of CDN: chronic inflammatory demyelinating polyneuropathy (CIDP), and anti‐myelin‐associated glycoprotein (MAG)‐related polyneuropathy (MAGnp). Sixteen patients fulfilled diagnostic criteria for CIDP, 14 were diagnosed with MAGnp, and 36 were classified as exhibiting “chronic idiopathic polyneuropathy” (CIP). Cytokine production in mitogen‐stimulated peripheral blood mononuclear cells (PBMCs) was analyzed by flow cytometry. CIDP and MAGnp patients were compared with CIP patients, those with monoclonal gammopathy without polyneuropathy (MGUS), and healthy controls (HC). We observed an increase in pro‐inflammatory cytokines in the CIDP group, whereas interleukin‐10 (IL‐10) was augmented in the MAGnp patients. These distinctive immune alterations may represent a biological tool in differential diagnosis and future therapeutic approaches. Muscle Nerve 42: 864–870, 2010
Altered MEF2 isoforms in myotonic dystrophy and other neuromuscular disorders
Authors: Bachinski Linda L. , Sirito Mario , Böhme Maria , Baggerly Keith A. , Udd Bjarne , Krahe Ralf
Published: November 2010

Because of their central role in muscle development and maintenance, MEF2 family members represent excellent candidate effectors of the muscle pathology in myotonic dystrophy (DM). We investigated the expression and alternative splicing of all four MEF2 genes in muscle from neuromuscular disorder (NMD) patients, including DM1 and DM2. We observed MEF2A and MEF2C overexpression in all NMD muscle, including 12 MEF2‐interacting genes. Exon 4 and 5 usage in MEF2A and MEF2C was different between DM and normal muscle, with DM showing the embryonic isoform. Similar splicing differences were observed in other NMD muscle. For MEF2C, missplicing was more pronounced in DM than in other dystrophies. Our data confirm dysregulation of MEF2A and MEF2C expression and splicing in several NMD, including DM. Our findings demonstrate that aberrant splicing in NMD is independent from expression of mutant repeats, and suggests that some aberrant splicing, even in DM, may be compensatory rather than primary. Muscle Nerve 42: 856–863, 2010
Time course of skeletal muscle loss and oxidative stress in rats with walker 256 solid tumor
Authors: Guarnier Flávia A. , Cecchini Alessandra L. , Suzukawa Andréia A. , Maragno Ana Leticia G.C. , Simão Andréa N.C. , Gomes Marcelo D. , Cecchini Rubens
Published: November 2010

Reactive oxygen species oxidize proteins and modulate the proteasomal system in muscle‐wasting cancer cachexia. On day 5 (D5), day 10 (D10), and day 14 (D14) after tumor implantation, skeletal muscle was evaluated. Carbonylated proteins and thiobarbituric acid reactive substances were measured. Chemiluminescence was employed for lipid hydroperoxide estimation. Glutathione, superoxide dismutase, and total radical antioxidant capacity were evaluated. The proteasomal system was assessed by mRNA atrogin‐1 expression. Increased muscle wasting, lipid hydroperoxide, and superoxide dismutase, and decreased glutathione levels and total radical antioxidant capacity, were found on D5 in accordance with increased mRNA atrogin‐1 expression. All parameters were significantly modified in animals treated with α‐tocopherol. The elevation in aldehylde levels and carbonylated proteins observed on D10 were reversed by α‐tocopherol treatment. Oxidative stress may trigger signal transduction of the proteasomal system and cause protein oxidation. These pathways may be associated with the mechanism of muscle wasting that occurs in cancer cachexia. Muscle Nerve 42: 950–958, 2010
Functional performance and muscle strength phenotypes in men and women with Danon disease
Authors: Stevens‐Lapsley Jennifer E. , Kramer Laurel R. , Balter Jaclyn E. , Jirikowic Jean , Boucek Dana , Taylor Matthew
Published: November 2010

Danon disease is a rare X‐linked myopathy that is characterized clinically by a triad of cardiomyopathy, skeletal myopathy, and cognitive impairment. The purpose of this investigation was to quantify functional performance, muscle weakness, and quadriceps activation in individuals with Danon disease as compared with healthy individuals. Four males (ages 10–34 years) and 4 females (ages 16–50 years), with the genetic markers of Danon disease, were compared with 8 healthy males (ages 22–34 years) and 8 healthy females (ages 23–41 years) and previously reported norms. Affected males and females had decreased functional performance, significant generalized muscle weakness, and decreased quadriceps strength and activation when compared with healthy individuals. Affected males had larger deficits in function, strength, and activation when compared with affected females. The results indicate that, although the presentation of Danon disease is variable and is typically only described in males, muscle weakness patterns exist in both affected males and females. Muscle Nerve 42: 908–914, 2010
Pseudometabolic presentation of dystrophinopathy due to a missense mutation
Authors: Veerapandiyan Aravindhan , Shashi Vandana , Jiang Yong‐Hui , Gallentine William Brian , Schoch Kelly , Smith Edward Clinton
Published: November 2010

Exercise intolerance with myalgia, muscle stiffness, and recurrent rhabdomyolysis due to mutations in the DMD gene can mimic metabolic myopathies leading to delayed or inaccurate diagnoses. In this retrospective chart review, we report 3 unrelated boys with exertional myalgia, muscle stiffness, myoglobinuria, and normal neurological examination due to an identical point mutation in the DMD gene: a hemizygous T‐to‐C change in exon 15 (c.1724T>C) resulting in an amino acid substitution of leucine to proline at codon 575. Two of the 3 boys had normal dystrophin immunostaining and Western blot analysis in muscle. This missense mutation has been reported twice before, with at least 1 patient exhibiting rhabdomyolysis. Our report, however, is the first to describe in detail the clinical findings associated with this specific mutation. Further studies and clinical reports are needed to better understand the pathogenicity of the mutation. Muscle Nerve 42: 975–979, 2010
Three‐dimensional responses of buried corrugated pipes and ANN‐based method for predicting pipe deflections
Authors: Kim Moon Kyum , Cho Seok Ho , Yun Ik Jung , Won Jong Hwa
Published: November 2010

This study investigated localized responses, such as circumferential stresses, on corrugation and pipe deflections. Also, this study examined the effect of corrugation geometry on the overall and localized response of corrugated pipes with refined three‐dimensional modeling of the entire soil–pipe interaction system, including corrugation. To investigate the availability of the traditional two‐dimensional method, the results from the three‐dimensional finite element method (FEM) were compared with those from the two‐dimensional FEM. The soil–pipe modeling techniques of this study were verified by comparing the FEM results by Utah State University and analytical results. An artificial neural network (ANN)‐based model to predict vertical deflections of buried corrugated pipes was developed to overcome the shortcomings of existing methods and obtain results that are close to the level of accuracy of FEM results. In order to train an ANN, analyses on a large amount of data were executed with various standardized pipe geometries and burial depths regulated by the Korea Highway Corporation using the two‐dimensional FEM verified in this study. The widely used back propagation algorithm was adopted. The ANN‐based model developed in this study was shown to be an effective tool by comparing the results with test data and sensitivity analyses were executed based on the data from the developed ANN. Copyright © 2010 John Wiley & Sons, Ltd.
Measurement‐based link scheduling for maritime mesh networks with directional antennas
Authors: Hazra Sukanta K. , Seah Winston K. G.
Published: November 2010

The proliferation of wireless transceivers and the availability of the unlicensed band has given a boost to the deployment of wireless networks, with IEEE802.11/WiFi being the major driver in this arena. In this research, we consider a wireless mesh network designed for long‐distance communication with a typical deployment scenario of a maritime mesh network. This network uses an antenna system made up of multiple fixed‐beamwidth antennas. Compared to most other directional antenna schemes which use directional antenna for transmission and omni‐directional antenna for reception, our system uses directional antennas for both transmission and reception where a pair of transmitter–receiver antennas needs to be aligned and have an acceptable channel quality before transmission can take place. Through efficient use of directional antennas for both transmission and reception, and spatial reuse in transmission, we are able to realize a high‐capacity mesh network. In this paper, we present a practical approach to achieve contention‐free medium access, namely, a measurement‐based link‐scheduling algorithm. We evaluate the performance of the link‐scheduling algorithm using simulations and show that it is able to exploit the spatial diversity provided by the directional antennas to outperform comparable schemes for wireless mesh networks. We also briefly discuss implementation issues to demonstrate the viability of the approach. Copyright © 2010 John Wiley & Sons, Ltd.
ETUS: An enhanced triple umpiring system for security and performance improvement of mobile ad hoc networks
Authors: Kathirvel Ayyaswamy , Srinivasan Rengaramanujam
Published: November 2010

A mobile ad hoc network is a self‐created, self‐organized and self‐administering set of nodes connected via wireless links without the aid of any fixed infrastructure or administrator. Protecting the network layer from malicious attacks is an important and challenging issue in both wired and wireless networks and the issue becomes even more challenging in the case of wireless mobile ad hoc networks. In this paper we propose a solution using a triple umpiring system (TUS), which provides security for routing and data‐forwarding operations. In our system each node's behaviour from source to destination is closely monitored by a set of three umpires. If any misbehaviour is noticed, umpires flag off the guilty node from the circuit. We have proposed two enhancements to the basic TUS for salvaging the circuit during disruptions in route reply and data‐forwarding phases. The model with these two enhancements is called ETUS. We have implemented TUS and ETUS by modifying the popular Ad hoc On‐Demand Distance Vector protocol. Extensive simulation studies using QualNet 5.0 establish the soundness of the proposal. Copyright © 2010 John Wiley & Sons, Ltd.
Splitting positive definite mixed element methods for pseudo‐hyperbolic equations
Authors: Liu Yang , Li Hong , Wang Jinfeng , He Siriguleng
Published: November 2010

Splitting positive definite mixed finite element (SPDMFE) methods are discussed for a class of second‐order pseudo‐hyperbolic equations. Depending on the physical quantities of interest, two methods are proposed. Error estimates are derived for both semidiscrete and fully discrete schemes. The existence and uniqueness for semidiscrete schemes are proved. © 2010 Wiley Periodicals, Inc. Numer Methods Partial Differential Eq 28: 670–688, 2012
A uniform error estimate in time for spectral Galerkin approximations of the magneto‐micropolar fluid equations
Authors: Ortega‐Torres E.E. , Rojas‐Medar M.A. , Cabrales R.C.
Published: November 2010

We consider Galerkin approximations for the equations modeling the motion of an incompressible magneto‐micropolar fluid in a bounded domain. We derive an optimal uniform in time error bound in the H1 and L2 ‐norms for the velocity. This is done without explicit assumption of exponential stability for a class of solutions corresponding to decaying external force fields. Our study is done for no‐slip boundary conditions, but the results obtained are easily extended to the case of periodic boundary conditions. © 2010 Wiley Periodicals, Inc. Numer Methods Partial Differential Eq 28: 689–706, 2012
Isocitrate dehydrogenase 1/2 mutational analyses and 2‐hydroxyglutarate measurements in Wilms tumors
Authors: Rakheja Dinesh , Mitui Midori , Boriack Richard L. , DeBerardinis Ralph J.
Published: November 2010

Background

L‐2‐Hydroxyglutaric aciduria (L‐2‐HGA) is an uncommon inborn error of metabolism, in which the patients are predisposed to develop brain tumors. Elevated levels of D‐2‐hydroxyglutarate have been demonstrated with malignant gliomas and myeloid leukemias associated with somatic mutations of the genes encoding NADP(+)‐dependent isocitrate dehydrogenases (IDH1 and IDH2, respectively). Recently, we noted a Wilms tumor in a child with L‐2‐HGA. Given the accumulating evidence that both enantiomers of 2‐hydroxyglutarate are associated with cellular transformation, we investigated if sporadic Wilms tumors are associated with IDH1 or IDH2 mutations or with elevated levels of 2‐hydroxyglutarate.

Procedure

We retrieved 21 frozen Wilms tumor tissues. In 20 cases, we sequenced exon 4 and flanking intronic regions of IDH1 and IDH2. In all 21 cases, we measured 2‐hydroxyglutarate levels by liquid chromatography‐tandem mass spectrometry.

Results

We did not find mutations at the hot spots IDH1 codon 132 or IDH2 codon 172. Two cases (1 with favorable histology and 1 with unfavorable histology) showed heterozygous change c.211G>A (p.Val71Ile) in IDH1, a change previously reported as a mutation but listed as a single nucleotide polymorphism in the NCBI SNP database. We did not find increased levels of 2‐hydroxygluatric acid in any sample.

Conclusions

Our results suggest that IDH1 codon 132 or IDH2 codon 172 mutations or elevated 2‐hydroxyglutarate levels do not play a role in the biology of sporadic Wilms tumors. The significance of heterozygous change c.211G>A (p.Val71Ile) in IDH1, seen in two tumors, is not clear. Pediatr Blood Cancer 2011;56:379–383. © 2010 Wiley‐Liss, Inc.