bluuebunny/crossref_metadata_2025 huggingface dataset:
Planar 4‐element UWB antenna array and time domain characterization
Authors: Yang Ying‐Ying , Chu Qing‐Xin
Published: September 2008

In this article, a novel planar ultra‐wideband (UWB) antenna array based on four identical UWB antenna elements for UWB applications is presented. The proposed antenna array yields an impedance bandwidth of 3.1–10.6 GHz with VSWR <2. Over the entire bandwidths, it has constant high gain, which is about 6.5–10.5 dBi, and a 60° 3‐dB beamwidth is obtained within the operational band. A planar 2‐element UWB antenna array and a band‐notched 4‐element UWB antenna array are also provided for references. Time domain descriptors of the proposed antenna array have been used to estimate short‐range UWB signal transmission, propagation, and reception. © 2008 Wiley Periodicals, Inc. Microwave Opt Technol Lett 50: 3118–3123, 2008; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.23874
Ultra‐wideband bandpass filter using hybrid microstrip‐defected‐ground structure
Authors: Tang I‐Tseng , Lin Ding‐Bing , Li Chi‐Min , Chiu Min‐Yuan
Published: September 2008

A novel ultra‐wideband (UWB) bandpass filter (BPF) with a fractional bandwidth (FBW) of about 110% is presented using the hybrid microstrip‐defected‐ground structure (DGS). The proposed filter was designed using a combination of hybrid microstrip‐defected‐ground structure lowpass filter (LPF) with typical quarter‐wavelength short‐circuited stubs highpass filter (HPF), followed by an optimization for tuning in‐band performance. The high selectivity LPF using hybrid microstrip and four backside slots on ground plane is equivalent to a typical 9‐ploe stepped‐impedance LPF. The proposed LPF is employed to attenuate the upper stopband and etching on the ground plane with four rectangular slots provides attenuation pole to suppress the second spurious harmonic. Four shunt quarter‐wavelength short‐circuited stubs are used to realize the lower stopband for an optimum distributed HPF. The design was successfully realized in theory and verified by full‐wave EM simulation of the full layout and the experiment. The proposed filter had a good performance, including an ultra‐wideband bandpass (3.1–10.6 GHz), low insertion loss, sharp rejection, and a group delay of about 0.12 ns over the most center band. The filter also demonstrated an UWB reject band from 11.4 GHz to more than 19 GHz at −30 dB. © 2008 Wiley Periodicals, Inc. Microwave Opt Technol Lett 50: 3085–3089, 2008; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.23875
Multiwavelength erbium‐doped fiber ring laser based on a fiber Sagnac loop filter
Authors: Liu Y. , Liu D. , Wang H.
Published: September 2008

We propose and experimentally demonstrate a multiwavelength erbium‐doped fiber ring laser using a fiber Sagnac loop filter. The fiber Sagnac loop filter served as the wavelength selection component within the ring laser cavity. By carefully tuning the setting of the polarization controller (PC) to effectively change the state of polarization of the light, three, four, and five lasing wavelengths were obtained from the output port of the ring laser. The proposed multiwavelength ring laser has the unique advantages of simple structure, changeable wavelength spacing, tunable number of lasing lines, and low cost. © 2008 Wiley Periodicals, Inc. Microwave Opt Technol Lett 50: 3053–3054, 2008; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.23876
Impact of interconnect effects on broadband transimpedance amplifiers
Authors: Shi Xiaomeng , Lu Zhenghao , Seng Yeo Kiat , Ma Jian‐Guo , Do Manh Anh , Li Erping
Published: September 2008

A novel interconnect model is used in the postlayout simulation of a broadband transimpedance amplifier. Simulation results employing the proposed model are verified by on‐wafer measurement results. The impact of interconnect effects on the circuit performance is analyzed. The importance of incorporating an adequate interconnect model is demonstrated. © 2008 Wiley Periodicals, Inc. Microwave Opt Technol Lett 50: 3017–3020, 2008; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.23878
High gain cavity‐backed slot antenna with a windowed metallic superstrate
Authors: Hanqing M. A. , Chu Qing‐Xin , Qiuyi Zhang
Published: September 2008

A novel technique for gain enhancement of cavity‐backed slot antenna is developed and discussed. The high gain radiation of the proposed antenna is achieved by a windowed metallic superstrate above the slot. The parametric studies of the proposed structure are provided, the radiation mechanism of the proposed antenna is investigated, and then the design guidelines for this type of radiators are described. The prototype is fabricated and found to have an impedance bandwidth of 12% and a gain of 12.3 dBi at the center frequency of 2.4 GHz. The characteristics of the proposed antenna have been validated by CST simulation software and experiments. © 2008 Wiley Periodicals, Inc. Microwave Opt Technol Lett 50: 3114–3118, 2008; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.23880
Coplanar UWB antenna with increased suppression characteristics
Authors: Lu Yingying , Lam Hung‐Jui , Bornemann Jens
Published: September 2008

The improved band‐notch capability of an ultra‐wideband antenna in coplanar technology is demonstrated. The printed‐circuit element includes not only a slot to attenuate narrowband services but also a coplanar‐waveguide filter in the feeding line to aid attenuation level and bandwidth in the same frequency range. The input match of the antenna increases from around 10 dB (VSWR = 2) in the UWB range to −1.29 dB (VSWR = 13.5) in the suppression band. The radiation patterns of the antenna remain largely uninfluenced by the bandstop measures added to the antenna. The performance is validated by comparison with different commercial full‐wave field solvers. © 2008 Wiley Periodicals, Inc. Microwave Opt Technol Lett 50: 3111–3114, 2008; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.23881
Application of negative group delay active circuits to the design of broadband and constant phase shifters
Authors: Ravelo B. , Le Roy M. , Pérennec A.
Published: September 2008

The new phase‐shifter configuration described in this report uses a negative group delay (NGD) active circuit. In this topology, a classical transmission line is set in cascade with an NGD circuit whose phase slopes are alike, but opposite, to get a constant and broadband phase shift. The proposed approach was validated through the design and measurement of a phase shifter, which exhibited a constant phase of 90° ± 5° over a 75% relative bandwidth around 1.6 GHz. Moreover, as the group delay of the NGD circuit compensated the transmission line one, the overall circuit group delay was kept to a small value in the operating frequency band. © 2008 Wiley Periodicals, Inc. Microwave Opt Technol Lett 50: 3078–3080, 2008; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.23883
Attosecond pulse generation using the multistage nonlinear microring resonators
Authors: Yupapin P. P. , Pornsuwancharoen N. , Chaiyasoonthorn S.
Published: September 2008

We propose a new system of an attosecond pulse generation by using the integrated nonlinear microring devices. A soliton light pulse with wavelength of 1550 nm is entered into the multistage microring resonators, where the ring radii of the recent integrated device product are within the range from 5 to 10 microns. Results obtained have shown that the ultrashort pulse width in the attoscale regime and beyond can be easily generated. When the input peak power of 12 W is applied into the system, the generated pulse with pulse width of 50 is achieved. © 2008 Wiley Periodicals, Inc. Microwave Opt Technol Lett 50: 3108–3111, 2008; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.23888
Ultra‐wideband folded loop antenna fed by coplanar waveguide
Authors: Lui W. J.
Published: September 2008

In this article, a novel and successful design of ultra‐wideband folded loop antenna is proposed and investigated. The antenna is fed by coplanar waveguide directly and can be fabricated easily by employing printed circuit board technology. It is studied both numerically and experimentally. From calculated and measured results, it may be observed that impedance bandwidth of over 130% for return loss lower than −9.54 dB and good omnidirectional radiation performance is obtained. © 2008 Wiley Periodicals, Inc. Microwave Opt Technol Lett 50: 3075–3077, 2008; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.23890
A triple broadband microwave filter synthesis using nonuniform lines
Authors: Huang Jhin‐Fang , Wen Jiun‐Yu , Lyu Zong‐Min
Published: September 2008

In this article, we propose a mapping method in which the system function of the filter in the z‐domain is found by discrete‐time domain techniques as well as by chain‐scattering matrices of various transmission‐lines to achieve a triple broadband microwave filter based on equal‐length nonuniform coupled lines. The main methodology for designing a triple band filter is using a wideband band‐pass filter to cascade two symmetrical band‐stop filters together to reach the desired bandwidth and low insertion loss. The band‐stop filter and band‐pass filter are five‐order Butterworth ones implanted and placed with a coupled‐serial‐shunted lines structure. The design process is finished by using optimization algorithms to tune the values of the characteristic impedances of each transmission line section. Experimental results agree significantly with the theoretical values. Measurement shows that the 3 dB pass bandwidths are about 650 MHz (1.35–1.8 GHz), 1.15 GHz (3.45–4.6 GHz), and 600 MHz (5.5–6.1 GHz) for Duroid substrates. The insertion loss is about 1.03, 1.15, and 2.05 dB at frequencies of 1.8, 3.45, and 5.85 GHz, respectively. © 2008 Wiley Periodicals, Inc. Microwave Opt Technol Lett 50: 3039–3045, 2008; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.23893
Ratiometric wavelength monitor based on singlemode‐multimode‐singlemode fiber structure
Authors: Hatta Agus Muhamad , Farrell Gerald , Wang Qian , Rajan Ginu , Wang Pengfei , Semenova Yuliya
Published: September 2008

An all‐fiber ratiometric wavelength monitor for optical wavelength measurement is proposed and investigated theoretically as well as experimentally. Two edge filters with opposite slope spectral responses based on the singlemode‐multimode‐singlemode (SMS) fiber structures are developed. A ratiometric wavelength measurement system employing the developed SMS edge filters demonstrates a high discrimination range of 20.41 dB and a potential wavelength measurement resolution of 10 pm over a wavelength range from 1530 to 1560 nm. © 2008 Wiley Periodicals, Inc. Microwave Opt Technol Lett 50: 3036–3039, 2008; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.23894
Miniaturized dual‐mode patch filter using slotted square resonator and meander spurline
Authors: Li Xiaohua , Liu Haiwen
Published: September 2008

A compact dual‐mode patch filter was designed and examined. Five pairs of slots and a pair of meander spurlines were applied to redirect the current flow on patch resonator, thus the resonance frequencies of the filter are reduced. Moreover, a computer‐aid design (CAD) method using radius base function neural network (RBFNN) is proposed to optimize this new filter. Measurements are given to verify this design and methodology. © 2008 Wiley Periodicals, Inc. Microwave Opt Technol Lett 50: 3059–3062, 2008; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.23897
A resonant cavity antenna based on an optimized thin superstrate
Authors: Ge Yuehe , Esselle Karu P.
Published: September 2008

A high‐gain, low‐profile electromagnetic band‐gap (EBG) resonator antenna based on a thin frequency‐selective‐surface (FSS) superstrate is presented. The superstrate thickness has been reduced from 0.25λg in the previous design to about 0.06λg without significantly affecting the antenna performance. The FSS superstrate is made out of standard low‐cost FR4 material. The high‐gain performance is achieved by optimizing the metallic patterns printed on the two surfaces of the superstrate so that a high‐Q resonant cavity is obtained. A prototype demonstrates that an EBG resonator antenna made out of a 0.8 mm thick optimized superstrate can provide a gain as high as over 21 dB at the operating frequency of 12 GHz. © 2008 Wiley Periodicals, Inc. Microwave Opt Technol Lett 50: 3057–3059, 2008; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.23898
Erratum: An integrated 8‐MW 2.4‐GHZ CMOS RF receiver for low‐power WPAN
Authors: Kwon Ickjin , Lee Minkyung
Published: September 2008

Originally published Microwave Opt Technol Lett 50: 2345–2348, 2008. © 2008 Wiley Periodicals, Inc. Microwave Opt Technol Lett 50: 3280, 2008; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.23901
Temperature sensor using Hi‐Bi erbium‐doped fiber loop mirror
Authors: Frazão Orlando , Egypto Diogo , Bittencourt Lucas Aragão , Giraldi Maria T. M. R. , Marques M. B.
Published: September 2008

In this letter, a temperature sensor using a fiber loop mirror containing a piece of highly birefringent erbium doped fiber is presented. A Hi‐Bi PANDA erbium‐doped silica fiber was used and compared with the conventional Hi‐Bi PANDA fiber. Different results for strain and temperature sensitivity were obtained. The temperature coefficient sensitivity was −2.22 nm/°C and significantly higher when compared with others conventional Hi‐Bi fibers. Strain experiments were also performed. © 2008 Wiley Periodicals, Inc. Microwave Opt Technol Lett 50: 3152–3154, 2008; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.23907
CPW‐fed compact meander and L‐shape monopole antenna for dual‐band WLAN applications
Authors: Ham Chung‐Kyun , Baik Jung‐Woo , Kim Young‐Sik
Published: September 2008

A compact coplanar waveguide (CPW)‐fed monopole antenna is proposed for dual‐band wireless local area network (WLAN) applications. The proposed antenna, which consists of a meander strip and a L‐shaped strip, has compact size of 20 mm × 17 mm × 1.6 mm including the ground. The impedance bandwidth with 10 dB return loss is about 330 MHz (2.3–2.63 GHz) for 2.4 GHz band and 950 MHz (4.93–5.88 GHz) for 5 GHz band. The measured peak gains are 1.7 dBi at lower and 2.8 dBi at higher band, respectively. © 2008 Wiley Periodicals, Inc. Microwave Opt Technol Lett 50: 3147–3149, 2008; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.23914
Second harmonic power combining technique for low phase noise cross‐coupled push push VCO
Authors: Chiou Hwann‐Kaeo , Zou Yu‐Lin
Published: September 2008

An even‐mode power combining technique was developed for a high‐performance K‐band push–push voltage control oscillator (VCO) in standard 0.18 μm CMOS technology. The VCO was designed based on linear time variant (LTV) phase noise model. The obtained frequency tuning range and maximum output power were 1.95 GHz and −9.68 dBm with core power consumption of 3.6 mW at maximum oscillation frequency of 26.7 GHz. The push–push VCO demonstrated a phase noise of −117.5 dBc/Hz at 1 MHz offset, which resulted in an excellent FoM of −199.82 dBc/Hz. © 2008 Wiley Periodicals, Inc. Microwave Opt Technol Lett 50: 3242–3246, 2008; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.23917
On the design of four layered circular microstrip patch antenna
Authors: Kumar Raj , Malathi P. , Thakare Yogesh B.
Published: September 2008

This article presents a simple design expression to calculate resonant frequency (fr) of a four‐layered circular microstrip patch. The resonant frequencies calculated by present method are in good agreement with the calculated value by FDTD method. The average % deviation for circular microstrip patch (CMP) with and without cover is 0.4 and 0.56%, respectively. The average % deviation against FDTD method for composite and suspended CMP is 0.5 and 0.61%, respectively. The change in fr for composite/suspended CMP decreases as the height of the cover increases. The average and maximum % deviation for intentional or unintentional spaced dielectric is 0.43 and 0.85%, respectively upto ratio of h4/h3 = 14. The intentional or unintentional air‐gap brings down the fr of CMP. As air‐gap increases, the fr tends towards the fr of CMP. Spaced dielectric effect on fr is more for small air‐gap. The effect of loaded ice or superstrate on covered CMP further lowers down the resonant frequency. Its effect is more on fr for small h4/h3 ratio. The incremental % change due to loaded superstrate on covered CMP is less than 0.4% and average % deviation against FDTD method is 0.89%. This expression is suitable for computer aided design. © 2008 Wiley Periodicals, Inc. Microwave Opt Technol Lett 50: 3206–3212, 2008; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.23920
Compact odd‐order band‐pass filters using capacitively coupled spiral resonators
Authors: Behdad Nader
Published: September 2008

In this article, a new topology for designing compact, band‐pass filters of odd‐order (N = 3, 5, 7, …) is presented. The technique is based on using resonators with parallel RLC type resonance with high loaded quality factor (QL) in conjunction with the capacitively loaded, slow‐wave transmission lines. Using the approach presented in this article compact band‐pass filters with bandwidths as small as 5% to as wide as 50% can easily be designed. The principles of operation of the proposed filter along with experimental results of several different fabricated prototypes are presented and discussed in this article. © 2008 Wiley Periodicals, Inc. Microwave Opt Technol Lett 50: 3172–3175, 2008; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.23921
Transformer‐coupled injection for a V‐band divide‐by‐three injection‐locked frequency divider
Authors: Chiou Hwann‐Kaeo , Chen Hsien‐Jui
Published: September 2008

A simple transformer‐coupled injection technique is proposed for a V‐band divide‐by‐three injection‐locked frequency divider (ILFD) in 0.18 μm CMOS technology. This technique provides an effective current injection and results in wide locking range of ILFD. The measured frequency range of the ILFD is from 56.5 to 66.4 GHz while varying the tuning voltage Vtune is from 0 to 1.8 V under an injection power of 5 dBm. The DC power dissipation of the core circuit only consumes a current of 3 mA with a single 1 V power supply. © 2008 Wiley Periodicals, Inc. Microwave Opt Technol Lett 50: 3169–3172, 2008; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.23922
Dual‐band branch‐line coupler with two center‐tapped stubs
Authors: Kim TaeGyu , Lee Byungje , Park Myun‐Joo
Published: September 2008

A new dual‐band operation scheme is proposed for the branch‐line coupler using two center‐tapped branches. The proposed coupler has two branches with a stub line attached at the center. Only two stubs are required for the dual‐band operation, which reduces the circuit complexity and minimizes the structural change from the conventional branch‐line coupler. © 2008 Wiley Periodicals, Inc. Microwave Opt Technol Lett 50: 3136–3139, 2008; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.23924
A compact wideband parallel‐strip 180° hybrid coupler
Authors: Chiu L. , Xue Q. , Chan C. H.
Published: September 2008

In this study, a wideband compact parallel‐strip 180° hybrid coupler with the center frequency of 2 GHz is presented. By replacing the 270° section in the 180° hybrid coupler with a parallel‐strip phase reversal swap, the total circuit size is reduced by half. In this structure, the phase gradients of the four arms of the coupler are equalized; therefore, the operation bandwidth is dramatically enhanced. S‐parameters of the coupler are simulated and measured with good agreement. As predicted from the measured data, the bandwidth of the 90% combining efficiency is increased from 45 to 124%. The proposed design achieves more than −25 dB signal suppression within the whole measured frequency range (0–4 GHz) as opposed to 1.8 to 2.2 GHz of the conventional design. The proposed 180° hybrid coupler can serve as a wideband in‐phase/differential power divider/combiner, which are essential for many RF and microwave subsystem designs. © 2008 Wiley Periodicals, Inc. Microwave Opt Technol Lett 50: 3271–3274, 2008; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.23926
Novel compact meander‐slot DGS with high quality factor
Authors: Zhu Yizhi , Zhang Xiaojuan , Li Chao , Li Fang , Fang Guangyou
Published: September 2008

This article presents a novel meander‐slot defected ground structure (DGS) for microstrip lines. Compared with conventional DGSs, the meander‐slot DGS takes more compact size, provides steeper band rejection property and has higher quality factor (Q factor). A meander‐slot DGS resonated at 3.851 GHz is illustrated and its Q factor reaches 22.39. Characteristics of this kind of DGS are investigated with variable dimension parameters. Finally, a narrow‐band stop filter based on cascaded meander‐slot DGSs is designed and fabricated. The measured results indicate that this filter provides sharp narrow‐band‐rejection from about 3.7–4 GHz, which shows good agreement with simulation. © 2008 Wiley Periodicals, Inc. Microwave Opt Technol Lett 50: 3128–3131, 2008; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.23940
3D EIT for breast cancer imaging: System, measurements, and reconstruction
Authors: Ye Gang , Lim Kim Hwa , George Rhett T. , Ybarra Gary A. , Joines William T. , Liu Qing Huo
Published: September 2008

Electrical impedance tomography (EIT) is a developing imaging modality for early detection of breast cancer. In an EIT system, a low‐frequency current is applied sequentially between different electrode pairs while voltage measurements are made at other electrodes to arrive at the electrical impedance values. The set of impedance measurement data is then computed to produce a 3D electrical conductivity map of the volume to be imaged. In this work, the design, measurements, and inversion of a full 3D EIT system are discussed. Experimentally determined EIT images of phantom objects are presented. © 2008 Wiley Periodicals, Inc. Microwave Opt Technol Lett 50: 3261–3271, 2008; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.23932
Wide‐locking range divide‐by‐4 injection‐locked frequency dividers
Authors: Jang S.‐L. , Liu C.‐C.
Published: September 2008

This article studies two wide‐locking range divide‐by‐4 injection locked frequency dividers (ILFDs) employing tunable active inductor (TAI), which are used to extend the locking range and to reduce die area. The CMOS differential ILFD is based on a TAI‐C tank Colpitts voltage‐controlled oscillator (VCO). The quadrature ILFD uses TAI‐C tanks and cross‐coupled switching pairs, the dynamic threshold MOSFETs (DTMOSs) are used to lower the supply voltage and power consumption. The ILFDs were fabricated in the 0.18‐μm 1P6M CMOS technology. At the supply voltage of 1.8 V, at the incident power of 0 dBm the locking range in the Colpitts ILFD in the divide‐by‐4 mode is about 5.45 GHz, from the incident frequency 3.75 to 9.2 GHz. The core power consumption is 4.93 mW. At the supply voltage of 1.4 V, at the incident power of 0 dBm the locking range in the QILFD in the divide‐by‐4 mode is about 7.41 GHz (103.6%), from the incident frequency 3.45–10.86 GHz. The core power consumption is 7.56 mW. The die area is 0.541 × 0.534 mm2. © 2008 Wiley Periodicals, Inc. Microwave Opt Technol Lett 50: 3229–3232, 2008; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.23933
A novel 2.4 GHz and 6.8 GHz dual‐band transmitter using defected ground structure
Authors: Chen Xiaoqun , Shi Xiaowei , Guo Yuchun , Xiao Changmin
Published: September 2008

A novel dual‐band module transmitter is presented in this article. It works as a power amplifier at 2.4 GHz that satisfies the 802.11b/g wireless LAN standard and performs as an active frequency doubler at 6.8 GHz with the stop band characteristics of defected ground structure (DGS). The equivalent circuit unit and the stop band characteristics of the microstrip DGS are analyzed and simulated. For the proposed transmitter, second harmonic suppression is below −52.6 dBc in the amplifier mode, and fundamental suppression is below −41 dBc in the frequency doubler mode. It achieves 13.7 dBm of P1 dB and its gain is 16.5 dB at amplifier mode, and its maximum output is 7.8 dBm at 6.8 GHz in frequency double mode. © 2008 Wiley Periodicals, Inc. Microwave Opt Technol Lett 50: 3225–3228, 2008; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.23935
Experimental validation of percolation‐based models for propagation prediction
Authors: Azaro R. , Martini A. , Massa A.
Published: September 2008

In this letter, an experimental validation of percolation‐based approaches for the prediction of wave propagation in random media is presented. Measurements are collected in a real controlled environment, where the obstacles are stochastically placed in a two‐dimensional grid according to a known nonuniform density distribution. The obtained results show that, in spite of their simplicity, percolation‐based approaches can be applied in real propagation problems. © 2008 Wiley Periodicals, Inc. Microwave Opt Technol Lett 50: 3190–3192, 2008; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.23937
Antenna miniaturization with ferrite ferroelectric composites
Authors: Petrov R. V. , Tatarenko A. S. , Srinivasan G. , Mantese J. V.
Published: September 2008

A magneto‐dielectric composite with nickel zinc ferrite and bismuth strontium titanate has been synthesized and characterized in terms of permeability and permittivity and used as substrates for antenna miniaturization. The objective was to achieve high‐ and equal permeability and permittivity for antenna miniaturization and impedance matching to free‐space. Studies on antennas operating at 100 MHz indicate low‐losses and a miniaturization factor of 7–10, in agreement with theory. But a 1.3 GHz microstrip antenna on the composite substrate, however, shows high losses and miniaturization by a factor of 3. Theoretical estimates on antenna properties are compared with data. © 2008 Wiley Periodicals, Inc. Microwave Opt Technol Lett 50: 3154–3157, 2008; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.23939
Loaded frequency selective surfaces using substrate integrated waveguide technology
Authors: Xu Rong‐Rong , Zong Zhi‐Yuan , Yang Guo , Wu Wen
Published: September 2008

In this article, a novel miniaturized frequency selective surface (FSS) is presented, in which each periodic cell consists of a ring slot resonator loaded with four ceramic chip capacitors for reducing the cell size. To eliminate the undesired coupling between unit cells, the unit cell is placed in the substrate integrated waveguide cavity structure. A S‐band bandpass FSS with such structures is designed and fabricated, both simulated and measured results show that the proposed FSS provides high transmission at 2.45 GHz and there is no other frequency resonance up to 15 GHz. Also, it has very good stability to oblique incidence. Furthermore, the dimension of the proposed FSS is miniaturized to 0.083λ0 (λ0 refer to the resonant wavelength). © 2008 Wiley Periodicals, Inc. Microwave Opt Technol Lett 50: 3149–3152, 2008; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.23945
Biochemical screening for neuroblastoma in infants: A feasibility study
Authors: Craft A. W. , Dale G. , McGill A. , Seviour J. , Spence E. M.
Published: September 2008

Neuroblastoma is the most common solid tumour of childhood with an incidence of about 1:10,000 births. Prognosis depends on age and stage at presentation and for disseminated disease presenting after the age of 1 year has scarcely altered at all in the past 20 years. In Japan a method has been pioneered of mass population screening of 6‐month‐old babies using a urine test for the catecholamine metabolites vanillylmandelic acid and homovanillic acid. They have been able to detect the majority of cases at 6 months and have improved the overall prognosis from 25% to 75% survival. A pilot study to assess the feasibility of such a study in the UK has been carried out in the north of England. Methodology has been established for the collection of urine by health visitors and biochemical analysis by gas chromatography with both flame ionisation and mass spectrometry detection; 4,897 samples have been collected, and reference ranges have been established.
Long‐term results in the treatment of acute nonlymphocytic leukemia: A pediatric oncology group study
Authors: Krischer Jeffrey P. , Steuber C. Philip , Vietti Teresa J. , Culbert Steven J. , Ragab Abdelsalam H. , Morgan Samuel K. , Berry D. H. , Hvizdala Eva , Thomas Paul J. , Land Vita J. , Castleberry Robert P.
Published: September 2008

Complete remission (CR), 5‐year remission duration (RD), and overall 5‐year survival rates are 74%, 28%, and 25%, respectively, for previously untreated children with acute nonlymphocytic leukemia diagnosed between 1977 and 1981, following induction therapy with vincristine, doxorubicin and prednisone (VAP), consolidation therapy with 6‐thioguanine, cytosine arabinoside (TA) and cyclophosphamide/vincristine/cytosine arabinoside/prednisone (COAP), and maintenance therapy of alternating TA and COAP with or without VAP pulses. Approximately 20% are free of their disease for more than 5 years. High white blood cell counts (WBC) at diagnosis and M3 and M6 morphology were associated with lower CR rates, while M5 morphology was associated with higher CR rates. Patients with M1 morphology had shorter remission duration as compared to those with M4 or M5 morphology. Low WBC and age between 2 and 10 years at diagnosis were associated with longer remission durations and survival. Patients with M4 morphology also survived longer. The observed CR rates are comparable to other studies initiated at the same time as this study but survival is less than those reported more recently. Low WBC at diagnosis and M4/M5 morphology may identify relatively favorable prognostic groups.
Oral mucositis and salivary methotrexate concentration in intermediate‐dose methotrexate therapy for children with acute lymphoblastic leukemia
Authors: Ishii Eiichi , Yamada Shin‐Ichi , Higuchi Shun , Honjo Tetsu , Igarashi Hisaji , Kanemitsu Satomi , Kai Takashi , Ueda Kohji
Published: September 2008

The relationship between salivary methotrexate (MTX) concentration and severity of oral mucositis after administration of MTX was investigated in six children with acute lymphoblastic leukemia. They received two administrations of MTX at 500 mg/m2 with one third given bolusly and the remainder by 24‐hour continuous infusion. No significant difference among patients or administration session was observed in serum MTX concentration. Detectable concentrations of salivary MTX (> 0.01 μM) were observed during nine of the ten infusions. A concentration of 0.1 μM or more, apparently lasting at least 12 hours, was observed during one infusion and followed by severe mucositis. During two of the ten infusions for different patients, concentrations of 0.04 to 0.07 μM and 0.02 to 0.04 μM, apparently lasting at least 12 and 18 hours, respectively, were observed, followed by moderate mucositis. During the other seven infusions, either much shorter or no increase in salivary MTX concentration was observed, with only mild or no subsequent mucositis. Analysis by Kendall's rank method showed a statistical correlation between concentration at 6 hours of infusion and severity of oral mucositis. The findings suggest that the early secretion of MTX into saliva has a significant role in the development of oral mucositis in leukemic children.
Continuous infusion of recombinant interleukin‐2 and lymphokine‐activated killer cells in refractory malignancies
Authors: Christiansen Neal P. , Kennedy B. J. , Ochoa Augusto C. , Skubitz Keith M. , Bach Fritz H.
Published: September 2008

Adoptive immunotherapy with recombinant interleukin‐2 (rlL‐2) and lymphokineactivated killer (LAK) cells has been reported to effect the regression of tumor in patients with a variety of malignancies. Responses have occurred in patients treated with highdose bolus rlL2 as well as lower‐dose continuous intravenous infusion. Ten patients who had been extensively pretreated with systemic chemotherapy with or without additional radiation therapy were treated with continuous infusion rlL2 and LAK cells. Five patients received rlL2 alone for 96‐120 hours prior to leukapheresis in addition to rlL2 at the time of LAK cell infusion. Three patients received LAK cells that had been cultured for 14 days in an automated tissue culture system. No responses were seen in this tenpatient cohort. While the lack of response in these patients may be related to any one or more of several variables, patients who have been heavily pretreated may not respond as well as patients who have received little to no systemic chemotherapy.
Eight‐drugs‐in‐one‐day chemotherapy in postirradiated adult patients with malignant gliomas
Authors: Rozental Jack M. , Robins H. Ian , Finlay Jonathan , Healey Barbara , Levin Allan B. , Steeves Richard A. , Kohler Peter C. , Schutta Henry S. , Trump Donald L.
Published: September 2008

Fifteen patients, 12 with glioblastoma multiforme and 3 with anaplastic astrocytoma, were treated with “eight‐drugs‐in‐one‐day” chemotherapy methylprednisolone 300 mg/m2, vincristine 1.5 mg/m2 (maximum of 2 mg/cycle), CCNU 75 mg/m2, procarbazine 75 mg/m2, hydroxyurea 3,000 mg/m2, cisplatin 90 mg/m2, cytosine arabinoside 300 mg/m2, and imidazole carboxamide 150 mg/m2. All patients had prior brain irradiation but none had previous chemotherapy. The population included 10 patients with progressive disease after irradiation and 5 who presented within 2 months of completing radiation. Patients received an average of 5 monthly cycles of chemotherapy. Three patients achieved a complete and 2 a partial response (CR + PRrate was 33%). The median survival time was 46 weeks, Myelosuppression was the doselimiting toxicity. Leucocyte counts between 2.0‐4.5 × 103/mm3 were observed in 40% of patients, between 1.0‐<2.0 × 103/mm3 in 33%, and < 1.0 × 103/mm3 in 7%. Platelet counts between 50‐130 × 103/mm3 were observed in 27% of patients, and < 50 × 103/mm3 in 33%. Six patients suffered infections, 4 had reversible renal toxicity, 2 developed paresthesias, and one a debilitating myopathy related to treatment with dexamethasone. Ototoxicity was seen in 3 patients. Two patients developed pulmonary emboli. Nine patients had nausea and vomiting, in one case associated with Candida esophagitis. One long‐term survivor developed necrosis of the corpus callosum and dementia. Four patients discontinued treatment after an average of 3.5 cycles because of toxicity. Although extremely toxic, this regimen has modest activity in previously irradiated adult patients with malignant glioma.
Lung cancer in childhood
Authors: Epstein David M. , Aronchick Judith M.
Published: September 2008

A 16‐year‐old boy had unresolving right lower lobe consolidation due to primary adenocarcinoma of the lung. Lung cancer is rare in children, is usually adenocarcinoma or undifferentiated histology, and frequently presents with advanced disease. It may be confused with atelectasis attributable to a foreign body or bronchial adenoma, plasma cell granuloma, pulmonary sequestration, or chronic infection. We review the clinical features of pediatric lung cancer and differences in lung cancer between children and adults.
Successful treatment of a radiation‐associated extradural osteosarcoma with chemotherapy in an adolescent girl
Authors: Kellie Stewart J. , Hutchison Robert E. , Robertson James T. , Pratt Charles B.
Published: September 2008

Bone sarcomas are the most common second malignant neoplasms in survivors of a malignant solid tumor in childhood. In contrast to de novo tumors, secondary bone cancers are typically associated with a poor prognosis, reflecting both a preponderance of primary sites that preclude complete resection in the flat bones of the axial skeleton, and the tendency for local invasiveness or distant metastasis. We describe a patient who developed malignant extradural osteosarcoma of the temporal bone 6 years after successful treatment for a malignant cerebellar astrocytoma with surgical resection and local irradiation. A complete resection of the sarcoma was not possible; however, she achieved a biopsy‐proven complete response after intensive chemotherapy with ifosfamide, followed by cisplatin and doxorubicin. At age 13, she remains free of recurrence 3 years after completing all therapy. In view of the rarity of prolonged disease control after incomplete resection for osteosarcoma, this report suggests the value of intensive combination chemotherapy in achieving a durable unmaintained remission in our patient.
Acute vincristine neurotoxicity in the presence of hereditary motor and sensory neuropathy type I
Authors: McGuire Stephen A. , Gospe Sidney M. , Dahl Gary
Published: September 2008

Acute vincristine neurotoxicity leading to a severe motor and sensory neuropathy has been noted in patients with hereditary motor and sensory neuropathy type I (HMSN‐I). The case of a 2‐year‐old boy with acute lymphocytic leukemia and HMSN‐I is reported, and additional cases from the literature are reviewed. Severe vincristine neurotoxicity in patients with HMSN‐I may be secondary to impairment of both slow andfast axonal transport. Vincristine should be used with caution in patients with a family history of polyneuropathy.
Double autologous bone marrow transplantation for acute myelogenous leukemia in a patient treated for Hodgkin's disease
Authors: Russell J. A. , Jones A. R. , Houwen B. , Poon M.‐C. , Ruether B. A.
Published: September 2008

A 30‐year‐old man developed acute myelogenous leukemia nearly 3 years after treatment of Hodgkin's disease with radiation and three chemotherapy combinations. Remission was induced with one cycle of highdose Ara‐C therapy. Three cycles of consolidation chemotherapy were given. The patient then had two autologous bone marrow transplants, the first after conditioning with 5 Gy total body irradiation, the second after Melphalan 140 mg/m2. The procedures were well tolerated, although hematological reconstitution was very slow after the second autotransplant. The patient has been disease‐free for over 4 years. Such patients may be more vulnerable to transplant‐related complications because of their previous exposure to chemotherapy and radiation, which may damage several organs including the bone marrow. This report demonstrates that patients with secondary acute myelogenous leukemia may tolerate a double autotransplant procedure and achieve durable remissions.
Clinical features of late‐onset Pompe disease: A prospective cohort study
Authors: Wokke John H.J. , Escolar Diana M. , Pestronk Alan , Jaffe Kenneth M. , Carter Gregory T. , van den Berg Leonard H. , Florence Julaine M. , Mayhew Jill , Skrinar Alison , Corzo Deyanira , Laforet Pascal
Published: September 2008

The objective of this 12‐month study was to describe the clinical features of late‐onset Pompe disease and identify appropriate outcome measures for use in clinical trials. Assessments included quantitative muscle testing (QMT), functional activities (FAA), 6‐min walk test (6MWT), and pulmonary function testing (PFT). Percent predicted values indicated quantifiable upper and lower extremity weakness, impaired walking ability, and respiratory muscle weakness. Significant declines in arm and leg strength and pulmonary function were observed during the study period. The outcome measures were demonstrated to be safe and reliable. Symptom duration was identified as the best predictor of the extent of skeletal and respiratory muscle weakness. Muscle Nerve 38: 1236–1245, 2008
American Association of Neuromuscular & Electrodiagnostic Medicine evidenced‐based review: Use of surface electromyography in the diagnosis and study of neuromuscular disorders
Authors: Meekins Gregg D. , So Yuen , Quan Dianna
Published: September 2008

Surface electromyography (sEMG) measures myoelectrical signals recorded from sensors placed on the skin surface. The non‐invasive nature of sEMG makes it a potentially useful technology for studying diseases of muscle and nerve. Reviews published by the American Association of Neuromuscular and Electrodiagnostic Medicine (AANEM) and the Therapeutics and Technology Assessment Subcommittee of the American Academy of Neurology (AAN), covering 1964–1994 and 1952–1998, respectively, concluded that sEMG adds no clinical utility over conventional needle EMG (nEMG) for the diagnosis of neuromuscular disease. The AANEM sEMG task force reevaluated the diagnostic utility and added value of this technology for the study of neuromuscular disease based on a contemporary review of relevant literature published between January 1994 and February 2006. The present review concludes that sEMG may be useful to detect the presence of neuromuscular disease (level C rating, class III data), but there are insufficient data to support its utility for distinguishing between neuropathic and myopathic conditions or for the diagnosis of specific neuromuscular diseases. sEMG may be useful for additional study of fatigue associated with post‐poliomyelitis syndrome and electromechanical function in myotonic dystrophy (level C rating, class III data). Muscle Nerve 38: 1219–1224, 2008
Axial myoclonus in paraproteinemic polyneuropathy
Authors: Vetrugno Roberto , Liguori Rocco , D'Alessandro Roberto , D'Angelo Roberto , Alessandria Maria , Montagna Pasquale
Published: September 2008

We describe a patient with a paraproteinemic anti–myelin‐associated glycoprotein (anti‐MAG) antibody polyneuropathy and concomitant axial myoclonic jerks. Neurophysiological investigation revealed that axial jerks were asymmetrical and exaggerated by lying in bed. They disappeared during mental arousal and sleep. Analysis of axial myoclonus showed that the first activated muscle was the left rectus abdominis with subsequent rostral and caudal propagation of a propriospinal type. Plasmapheresis substantially reduced the frequency and intensity of axial myoclonic jerks. In our patient, propriospinal myoclonus was associated with anti‐MAG polyneuropathy, but the causal relationship remains unclear. Muscle Nerve 38: 1330–1335, 2008
Withdrawal reflexes in adductor muscles elicited by electrical and magnetic stimulation of the obturator nerve
Authors: Ertekin Cumhur , Bademkiran Fikret , Yalin Sevket , Karapinar Nevin , Uysal Hilmi
Published: September 2008

The withdrawal reflex in the short head of the biceps femoris muscle after electrical stimulation of the sural nerve at the ankle has been investigated in numerous studies. These studies have described two distinct responses: early (R‐II) and late (R‐III). However, withdrawal reflex activity of the adductor muscles in the legs has not been studied systematically. Adductor muscle reflex activity is important because it can produce serious clinical problems, such as adductor spasticity and spasms, during bladder surgery. The present study examined withdrawal reflex features of adductor muscles obtained by electrical and magnetic stimulation of the obturator nerve (ON) in 34 normal healthy subjects. Early adductor muscle withdrawal reflex responses were elicited by ipsilateral ON electrical stimulation with a mean latency of 45.7 ± 2.0 ms (responses in 94% of subjects). Reflex responses were also obtained using magnetic stimulation at a similar incidence rate. Contralateral ON electrical stimulation resulted in a similar reflex, but with a lower incidence. ON and femoral nerve electrical and magnetic coil stimulation produced similar low‐incidence responses in the vastus medialis. These findings indicate that short latency adductor withdrawal reflexes are easily obtained on both sides following electrical or magnetic stimulation of the ON, and they can be elicited by both nociceptive and nonnociceptive stimuli. These reflexes prepare the body for a proper response to incoming signals and likely serve to protect the pelvic floor and pelvic organs. Muscle Nerve, 2008
Preferential central nucleation of type 2 myofibers is an invariable feature of myotonic dystrophy type 2
Authors: Pisani Valerio , Panico Maria Beatrice , Terracciano Chiara , Bonifazi Emanuela , Meola Giovanni , Novelli Giuseppe , Bernardi Giorgio , Angelini Corrado , Massa Roberto
Published: September 2008

The clinical features of myotonic dystrophy type 1 (DM1) and type 2 (DM2) may present striking similarity, whereas, in some cases, the DM2 phenotype may be so mild that the diagnosis may be missed. Therefore, the identification of disease‐specific histopathological patterns for DM1 and DM2 may help clinicians to correctly address genetic studies. We performed a comparative morphological and morphometric analysis on muscle biopsies from 10 DM1 and 11 DM2 patients, comparing type 1 and type 2 fibers as to: fiber type predominance, transverse diameter, atrophy and hypertrophy factors, and prevalence of central nuclei. In DM1 cases we observed preferential type 1 fiber atrophy and a higher prevalence of central nucleation among type 1 fibers in all cases. In DM2 muscle biopsies, high rates of atrophic and hypertrophic type 2 fibers were observed in most cases, and preferential central nucleation in type 2 fibers was present in all cases. As opposed to DM1, in which type 1 fibers display most of the histological changes, preferential atrophy and hypertrophy of type 2 fibers may be considered as markers of DM2. A higher prevalence of central nuclei among hypertrophic type 2 fibers has a predictive value for the diagnosis of DM2. Thus, morphometric and fiber type‐based histological analysis of muscle biopsies may help differentiate between DM1 and DM2 and guide molecular analysis. © 2008 Wiley Periodicals, Inc. Muscle Nerve, 2008
Analytical solution to 1D coupled water infiltration and deformation in unsaturated soils
Authors: Wu L. Z. , Zhang L. M.
Published: September 2008

An analytical solution to 1D coupled water infiltration and deformation is derived using a Fourier integral transform. Exponential functional forms are used to represent the hydraulic conductivity–pore‐water pressure relationship and the soil‐water characteristic curve. Fredlund's incremental‐linear constitutive model for unsaturated soils is adopted. The analytical solution considers arbitrary initial pore‐water pressure distributions and flux and pressure boundary conditions. The corresponding analytical solutions to coupled steady‐state problems are also obtained. The analytical solutions demonstrate that the coupling of seepage and deformation plays an important role in water infiltration in unsaturated soils. In the early stages of infiltration, the difference between uncoupled and coupled conditions becomes marked over time, and in late stages, the difference caused by the coupling effects diminishes toward the steady state. The difference between the uncoupled and coupled conditions increases with decreasing desaturation coefficient (α). Pore‐water pressure or deformation changes caused by the coupling effects are mainly controlled by the degree of soil volume change due to a change in soil suction (H). The smaller the absolute value of H, the greater the effect of coupling on the infiltration and deformation. The ratio of rainfall intensity to saturated permeability (q/ks) also has a strong influence on the coupled seepage and deformation. Copyright © 2008 John Wiley & Sons, Ltd.