bluuebunny/crossref_metadata_2025 huggingface dataset:
Novel dual‐band hybrid coupler using improved simplified CRLH transmission line stubs
Authors: Gong Jian‐Qiang , Liang Chang‐Hong , Wu Bian
Published: August 2010

In this article, a novel dual‐band hybrid coupler is designed by adopting improved simplified composite right‐/left‐handed (ISCRLH) transmission line (TL) stubs.An ISCRLH TL stub is composed of two ISCRLH TL unit cells with input and output uniform TL sections at the terminals, which can produce specified impedance and phase shift at two (arbitrary) different frequencies. The conditions for synthesizing the dual‐band ISCRLH TL stub are discussed in detail, and then such a stub is applied to implement a novel dual‐band hybrid coupler in microstrip configuration, and excellent agreement between the simulated and measured results is achieved, which reveal good performance and dual‐band operation. The novel device is small, fully planar, and easily designed and fabricated. © 2010 Wiley Periodicals, Inc. Microwave Opt Technol Lett 52:2473–2476, 2010; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.25491
Experimental investigation of the uncontrolled higher harmonic impedances effect on the performance of high‐power microwave devices
Authors: Ghannouchi Fadhel M. , Hashmi Mohammad S.
Published: August 2010

This article assesses and quantifies the impact of higher harmonic terminations on the current and voltage waveforms of microwave devices.Previous works have shown that it is very difficult to obtain “ideal” textbook waveforms, due to the effect of higher harmonic terminations. The emergence of waveform measurement systems has made it possible to investigate the shapes of current and voltage waveforms for design purposes. This article further expands on this issue and quantifies the impact of the uncontrolled higher harmonics on the waveforms. The impact is first explained using theory and then demonstrated with simulation and actual large‐signal measurements. © 2010 Wiley Periodicals, Inc. Microwave Opt Technol Lett 52:2480–2482, 2010; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.25494
Wideband folded sectorial bowtie antenna with Γ‐shaped strip feed
Authors: Zhang Zhiya , Fu Guang , Gong Shuxi , Zuo Shaoli , Chen Xi , Yan Yali
Published: August 2010

A wideband folded sectorial bowtie antenna with Γ‐shaped strip feed is designed. This feed mechanism is easy to adjust the impedance match. The folded sectorial bowtie antenna (FSBA) shows many advantages over the ordinary sectorial bowtie antenna (SBA). It achieves an impedance bandwidth of 94% for VSWR ≤ 2 ranging from 2.7 to 7.5 GHz, unidirectional radiation patterns, low back radiation, and low cross polarization over the whole operating band. The design is optimized numerically and validated experimentally. It is sufficient for accommodating recent wireless communication services such as WiFi, WiMAX, and lower UWB, etc. © 2010 Wiley Periodicals, Inc. Microwave Opt Technol Lett 52:2444–2447, 2010; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.25495
Leaky‐wave antenna with arbitrary scan in the frequency band
Authors: Shekhar Sameer , Abbaspour‐Tamijani Abbas
Published: August 2010

A wide‐angle frequency‐scanned leaky‐wave antenna design is presented. The proposed antenna operates in the nonfundamental mode and uses a meandered feed line to produce the exact phase‐delay relationship necessary for achieving the desired scan in the specified frequency band. Experimental results obtained for a four‐element antenna designed for the 6.05 – 6.75 GHz frequency band, show a low‐loss scanned radiation pattern in the range of ± 45°. The measured gain is 5.75 ± 0.5 dBi. © 2010 Wiley Periodicals, Inc. Microwave Opt Technol Lett 52:2441–2444, 2010; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.25496
Ultra‐wideband pulse waveform generation based on combining subnanosecond Gaussian pulses
Authors: Protiva Pavel , Mrkvica Jan , Macháč Jan
Published: August 2010

A technique for generating ultra‐wideband pulse waveforms is described in this article.It consists in combining subnanosecond Gaussian pulses from multiple sources. This method enables us to form complex pulse waveforms without the need to use transmission line pulse forming networks and delay lines. Two designs for an experimental generator utilizing the pulse combining principle are presented. The first generator is composed of two positive Gaussian pulsers and one negative Gaussian pulser. Analog time shifters were used to control the timing of each pulser. The circuit can be used as the generator of a Gaussian doublet. The second generator is composed of four identical Gaussian pulsers. Programmable ECL logic delay chips were employed to adjust the timing in this case. The measurements demonstrate the wide capability of the pulse combining scheme for controlling the spectral properties of the pulse waveform that is generated. © 2010 Wiley Periodicals, Inc. Microwave Opt Technol Lett 52:2401–2405, 2010; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.25498
UHF RFID reader front‐end having wideband and stable Tx/Rx isolation characteristic
Authors: Jang Hyeong‐Seok , Lim Won‐Gyu , Yu Jong‐Won
Published: August 2010

A UHF RFID reader front‐end structure having wideband and stable transmit/receive isolation characteristic is proposed. The proposed structure consists of a wideband balanced coupler and 4‐port feed antenna system. The wideband RFID reader front‐end has a high isolation feature insensitive to load variations. The transmit/receive isolation characteristic is achieved for UHF RFID band (860–960 MHz). The proposed structure has an isolation of more than 45 dB in the UHF RFID band according to the variations in matching and mutual coupling. © 2010 Wiley Periodicals, Inc. Microwave Opt Technol Lett 52:2467–2473, 2010; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.25501
Optimal antenna configuration for non‐cophase equal gain combining diversity using genetic algorithm
Authors: Ngamjaroen Tanongsak , Uthansakul Peerapong , Uthansakul Monthippa
Published: August 2010

The equal gain combining (EGC) diversity technique is generally known to have a performance close to an optimal maximal ratio combining technique while being less complex for realization.Therefore, the implementation of EGC in practice is of interest. However, the implementation of EGC diversity is cumbersome due to additional circuitry required for making a cophase signal in each branch. As a result, it is interesting to investigate whether non‐cophase EGC diversity is able to provide an acceptable performance while keeping much greater simplicity with only marginally inferior when compared with cophase method. As there is dimension constraint on wireless terminal, the problem of how to configure multiple antennas on such a limited area is of interest. This article studies the performance of non‐cophase EGC diversity through the problem antenna configuration. The genetic algorithm (GA) technique is applied to achieve an optimal solution using the average signal‐to‐noise ratio as a fitness function. The proof of proposed method has been confirmed through simulation as well as measurement results. The investigations reveal that the antenna configuration by using optimization technique provides the best performance on limited space for non‐cophase EGC diversity. © 2010 Wiley Periodicals, Inc. Microwave Opt Technol Lett 52:2462–2467, 2010; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.25502
A wideband‐stacked rectangular dielectric resonator antenna
Authors: Madhuri R. Gurram , Hadalgi Pradeep M. , Mallikarjun S. Lakshetty , Hunagund Prabhakar V.
Published: August 2010

A stacked rectangular dielectric resonator antenna (DRA) is studied experimentally. The achieved impedance bandwidth of two DR stacked antenna is about 73%. By stacking two different permittivity DRs, the multi‐band of single element DRA is changed to single wideband giving out improvement in bandwidth. The antenna parameters like radiation patterns and return loss are measured and presented. These antennas may provide applications in which large bandwidth is needed. © 2010 Wiley Periodicals, Inc. Microwave Opt Technol Lett 52:2432–2434, 2010; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.25503
The characteristic analysis of opened print slot antenna using FDTD
Authors: Shin Ho‐Sub , Jang Yong‐Woong
Published: August 2010

In this Letter, we analyzed a cross‐shaped‐fed opened print slot antenna using FDTD method. The VSWR, radiation patterns of this configuration are presented. The measured bandwidth of the proposed antenna is ∼ 86.1% (2.0 ≥ VSWR). The radiation pattern null of opened (etched ground plane) slot exhibited a much better than not‐opened (not etching ground plane) slot at the high frequency band. Offset and other design parameters of the antenna lead to the good impedance matching in a wide frequency band. The proposed open antenna obtained not only wide‐band but also good radiation patterns characteristics. This antenna may be applied for mobile system, WBAN, Home network, Biomedical instruments, and other wireless communication systems. © 2010 Wiley Periodicals, Inc. Microwave Opt Technol Lett 52:2459–2461, 2010; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.25504
Compact mobile handset MIMO antenna for LTE700 applications
Authors: Bae Hongpyo , Harackiewicz Frances J. , Park Myun‐Joo , Kim Taekyun , Kim Namhoon , Kim Deokyun , Lee Byungje
Published: August 2010

A compact mobile handset multiple‐input multiple‐output (MIMO) antenna for LTE700 applications is proposed.The proposed antenna consists of two side‐to‐side printed symmetrical printed inverted‐F antennas (PIFAs), a capacitively coupled feed, a suspended line, and a branch line. A wide impedance bandwidth at relatively lower frequency is achieved with the capacitively coupled feed. Good isolation (>12 dB) and low correlation coefficient (< 0.1) between the MIMO antennas are obtained by adding the branch line in conjunction with the suspended line. © 2010 Wiley Periodicals, Inc. Microwave Opt Technol Lett 52:2419–2422, 2010; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.25507
Four element textile array antenna on three dimensional orthogonal woven composites
Authors: Du Cheng‐Zhu , Zhong Shun‐Shi , Yao Lan , Qiu Yi‐Ping
Published: August 2010

A four element textile array antenna with a squint beam is proposed for aerospace applications.The patch, the substrate and the ground plane are woven together as a unity. Measured results are compared with the simulated, showing the usability of new generation of textile antenna. © 2010 Wiley Periodicals, Inc. Microwave Opt Technol Lett 52:2487–2488, 2010; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.25508
A 1‐kW switchable damped class‐E power amplifier for plasma processing applications
Authors: Kim Ji‐Yeon , Chun Sang‐Hyun , Jang Dong‐Hee , Kim Jong‐Heon , Kennedy Gray P.
Published: August 2010

In this article, a new highly efficient and highly stable 1 kW power amplifier is designed and fabricated for plasma processing applications.The efficiency of the generator was improved by using a class‐E type power amplifier consisting of one push–pull MOSFET and a high‐current driver IC instead of a conventional class‐C amplifier composed of several single ended MOSFETs. A switchable damper allows a selection of one of three different amplifier modes; these modes adjust the amplifier's efficiency and stability. The amplifier dimensions were reduced by 30% compared with the conventional class‐C power amplifier. Also, a drain efficiency of 80% was produced for a generator output power of 1 kW and operating frequency of 13.56 MHz. © 2010 Wiley Periodicals, Inc. Microwave Opt Technol Lett 52:2438–2441, 2010; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.25512
Dark soliton array generation: Theory and experiment
Authors: Vongchumyen C. , Mitatha S. , Ali J. , Yupapin P. P.
Published: August 2010

We present the fascinating results of dark soliton pulse array generation using the multilight sources via an optical multiplexer. The dark soliton array with different center wavelengths can be generated. The experimental setup was operated by using the brillouin‐enhanced fiber laser scheme, whereas the experimental results of the dark soliton array are generated and achieved. In application, the dark soliton array can be used to form the molecules/atom trapping array, which can be used to form the molecules/atoms memory array for molecular computer and communication. Moreover, the transmission molecules/atoms can be secured by using the dark‐bright soliton conversion behaviors. Results obtained have shown that the free spectrum range and the amplified power of 2.1 nm and 20 W of the bright soliton after dark‐bright soliton conversion with wavelength center at 1.50 μm can be achieved, respectively. © 2010 Wiley Periodicals, Inc. Microwave Opt Technol Lett 52:2397–2400, 2010; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.25514
Multiband planar monopole antenna for mobile handsets
Authors: Zhang Zhiya , Fu Guang , Gong Shuxi , Zuo Shaoli , Ran Tao
Published: August 2010

A multiband planar monopole antenna with wideband characteristic is proposed for GSM900, DCS1800, PCS1900, UMTS, IMT2000, wireless broadband internet service, WiMAX2350, and WLAN2400 applications.By using a meander structure, L‐shaped slots in the ground plane and tapered feeding line, wideband, and compact size characteristics can be achieved. The proposed antenna occupies an area of 50 × 19.5 mm2 barring the ground plane. Moreover, the antenna can be easily integrated with other parts of the circuits of mobile handsets due to its planar structure. A prototype has been fabricated and tested, and the experimental results validate the design procedure. © 2010 Wiley Periodicals, Inc. Microwave Opt Technol Lett 52:2395–2397, 2010; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.25515
Novel tri‐band whip antenna for handheld radio including GPS band
Authors: Prakash Thakur Jay , Hoon Kim Yang
Published: August 2010

Novel tri‐band‐whip antenna is investigated for 800/900 MHz bands digital and analog portable handheld radio application including GPS (1575 MHz) band.The tri‐band characteristics are obtained by including two monopole elements with single feed point. Prototype of the proposed antenna is presented and its detail experimental analysis is described. Antenna parameters such as return loss, efficiency, and radiation gain patterns are measured and compared for various structures of the Whip antenna. © 2010 Wiley Periodicals, Inc. Microwave Opt Technol Lett 52:2572–2575, 2010; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.25516
Slow‐wave fractal‐shaped compact microstrip resonant cell
Authors: Kurgan P. , Kitlinski M.
Published: August 2010

A novel fractal‐shaped compact microstrip resonant cell (CMRC) featuring a strong slow‐wave effect has been presented. Its vital usefulness in the process of microstrip line miniaturisation has been proved and experimentally validated on the basis of a compact 3‐dB branch‐line coupler illustrating the possibilities of the approach. A prototype example structure has been designed to mirror the characteristics of a conventional device, simultaneously presenting substantial size reduction. The measured results are in excellent accordance with theoretical characteristics confirming the utility of proposed novel fractal‐shaped CMRC in compact circuits developed in microstrip technology. © 2010 Wiley Periodicals, Inc. Microwave Opt Technol Lett 52:2613–2615, 2010; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.25517
Low protruding monopole antenna with a slot cut in the ground plane for laptop applications
Authors: Huang Chih‐Yu , Tsai Chia‐Chou , Yang Cheng‐Fu
Published: August 2010

Investigations on a dual‐band monopole antenna with a slot cut in the ground plane have been proposed for wireless local area network (WLAN) applications.The proposed antenna has a low protruding profile only 2 mm above the ground plane, thus allowing it to suitably integrate with the supporting metal frame of the laptop display. Good impedance matching can be achieved by adjusting antenna height and choosing adequate cutting slot position and size in the ground plane. It can provide two separate impedance bands for 2.4 and 5.2/5.8 GHz, making it easily covers the required bandwidths for WLAN operation. Details of the proposed antenna design and measured results are presented and discussed. © 2010 Wiley Periodicals, Inc. Microwave Opt Technol Lett 52:2610–2613, 2010; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.25518
Wideband planar antenna with modified ground plane
Authors: Owais Owais , Karlsson Magnus , Gong Shaofang , Ying Zhinong , Grudén Mathias , Job Magnus
Published: August 2010

In this article a miniaturized planar antenna is presented for broadband applications. Antenna miniaturization is achieved by modifying the ground plane that creates a different current path thus increasing the effective dimension of the antenna. In addition, dual chopping, slitting, and radiator position offsetting provide wideband behavior and relatively good impedance matching. The low profile antenna with its wide bandwidth, linear phase response and quasi‐omnidirectional radiation pattern is attractive for the existing and future communication devices of small size. Simulated and measured results for the proposed antenna are presented and analyzed. © 2010 Wiley Periodicals, Inc. Microwave Opt Technol Lett 52:2581–2585, 2010; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.25519
Ultra wideband bandpass filter using stub‐loaded quintuple‐mode resonator
Authors: Deng Hong‐Wei , Zhao Yong‐Jiu , Zhang Lu , Zhang Xue‐Shun , Zhao Wei
Published: August 2010

In this article, a compact ultra wideband (UWB) bandpass filter (BPF) with sharp rejection skirt is realized using quintuple‐mode stub‐loaded resonator.The resonator can generate three odd‐modes and two even‐modes in the desired band. By simply adjusting the lengths of open stubs in shunt and short‐circuited stubs, the first five resonant modes of the resonator can be roughly allocated within the 3.1–10.6 GHz UWB band meanwhile the sixth resonant mode in the upper‐stopband can be suppressed. The pair of short stubs can generate two transmission zeros near the lower and upper cut‐off frequencies, leading to a sharp rejection skirt. Finally, a quintuple‐mode UWB BPF is designed and fabricated and the measured results demonstrate the feasibility of the design process. © 2010 Wiley Periodicals, Inc. Microwave Opt Technol Lett 52:2579–2580, 2010; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.25520
Triple‐band antenna with slots for PCS/WLAN/UWB applications
Authors: Kim Ji Hae , Lee Jung Nam , Park Jong Kweon
Published: August 2010

A novel triple‐band antenna with H‐ and U‐shaped slots is proposed for personal communication system/wireless local area network/Ultra‐wideband (PCS/WLAN/UWB) operations.The proposed antenna has a trapezoidal patch, H‐ and U‐shaped slots, CPW feeding, and a stub for impedance matching. We have used the trapezoidal patch and a stub to produce the UWB frequency band and H‐ and U‐shaped slots to produce the PCS and WLAN bands, respectively. Prototypes of the proposed antenna have been successfully implemented and good radiation characteristics in the operating frequency bands have been achieved. Parametric studies are also presented and discussed. © 2010 Wiley Periodicals, Inc. Microwave Opt Technol Lett 52:2540–2544, 2010; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.25522
Contactless monitoring of Si substrate permittivity and resistivity from microwave to millimeter wave frequencies
Authors: Elhawil A. , Neve C.Roda , Olbrechts B. , Huynen I. , Raskin J.‐P. , Poesen G. , Stiens J. , Vounckx R.
Published: August 2010

A contactless and nondestructive technique is employed for characterizing single‐sided metallised silicon wafers. The reflection spectra are measured using a quasi‐optical millmeter‐wave setup in the frequency range 40–320 GHz. The results are compared with those provided by the coplanar waveguide method, in terms of accuracy and range of applicability. © 2010 Wiley Periodicals, Inc. Microwave Opt Technol Lett 52:2500–2505, 2010; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.25524
Small‐size 11‐band LTE/WWAN/WLAN internal mobile phone antenna
Authors: Chen Shu‐Chuan , Wong Kin‐Lu
Published: August 2010

This work presents an internal mobile phone antenna occupying a small board space of 600 mm2 on the system circuit board and providing three wide operating bands of at least 698–960, 1710–2690, and 5150–5825 MHz for the 11‐band long term evolution (LTE)/ wireless wide area network (WWAN)/wideband local area network (WLAN) operation.This includes three LTE bands of LTE700/2300/2500, five WWAN bands of GSM850/900/1800/1900/UMTS, and three WLAN 2.4/5.2/5.8 GHz bands. The antenna is a coupled‐fed shorted monopole, with a wide feeding strip in the coupling feed, a long shorting strip closely coupled to the shorted monopole, and a tuning stub connected to the shorting strip. The antenna's three wide operating bands are achieved and controlled by tuning the width of the feeding strip, the gap between the shorting strip and the shorted monopole, and the dimensions of the tuning stub. Operating principle of the proposed antenna is described in detail in this article. Results of the fabricated antenna are presented and discussed. The specific absorption rate results of the antenna with the presence of the user's head and hand are also studied. © 2010 Wiley Periodicals, Inc. Microwave Opt Technol Lett 52:2603–2608, 2010; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.25526
A low voltage folded cascode LNA for ultra‐wideband applications
Authors: Khemchandani Sunil L. , Ramos‐Valido Dailos , García‐Vázquez Hugo , Pulido‐Medina Ruben , del Pino Javier
Published: August 2010

A low noise amplifier scheme to achieve low‐voltage and wide‐bandwidth operation is presented. This circuit is based on folded cascode topology combined with wideband impedance matching and shunt peaking load. One of the drawbacks of the proposed scheme is that it uses more area than the conventional cascode due to the two additional inductors and capacitors to implement the capacitively coupled LC tanks. To reduce the area of the circuit, we have used stacked inductors, a brief study of these kinds of inductors is presented. Two low noise amplifiers have been fabricated using a mature 0.35 μm BiCMOS technology, one using the cascode conventional approach and the other using the proposed topology. Measurement results show that for the same transistors operating conditions, the low‐voltage amplifier performance is similar than the conventional cascode. By virtue of the small area of stacked inductors, the size of both low noise amplifiers is comparable. © 2010 Wiley Periodicals, Inc. Microwave Opt Technol Lett 52:2495–2500, 2010; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.25530
A new ultra‐wideband radar for detecting survivors buried under earthquake rubbles
Authors: Lv H. , Lu G. H. , Jing X. J. , Wang J. Q.
Published: August 2010

Existing ultra‐wideband (UWB) radars for buried survivor detection operated at high center frequencies and had limited penetration capability.A new UWB radar operating at a center frequency of 500 MHz is developed in this article. The experimental results show that it can detect the respiration of human subjects lying under a simulated earthquake rubble of about 2 m in thickness. Thus this new radar is practicable and promising for detecting buried survivors after an earthquake. © 2010 Wiley Periodicals, Inc. Microwave Opt Technol Lett 52:2621–2624, 2010; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.25539
Employing complementary split‐ring resonators for the wide stopband microstrip lowpass filter design
Authors: Tang Ching‐Wen , Yang Shih‐Chin
Published: August 2010

In this article, a novel microstrip lowpass filter with complementary split‐ring resonators (CSRRs) is presented.By properly controlling the width of the transmission line and rotating the angle of CSRRs, a wide stopband with sufficient rejection level can be achieved. The full‐wave electromagnetic simulator IE3D is used; moreover, the prototypical microstrip lowpass filter is fabricated and measured. Simulated results and experimental responses are compared; moreover, the match between simulation and measurement validates the proposed structure. © 2010 Wiley Periodicals, Inc. Microwave Opt Technol Lett 52:2592–2594, 2010; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.25541
Ku‐band multiway rectangular waveguide power divider
Authors: Song Kaijun , Fan Yong , Zhang Bo
Published: August 2010

A novel multiway rectangular waveguide power divider using coaxial probe array has been presented. The model of the entire power divider has been introduced, and the effect of the higher order modes generated in the power divider has been discussed. A Ku‐band eight‐way rectangular waveguide power divider has been designed and fabricated. Good agreement between the simulated response and measurements was demonstrated. The measured 15‐dB return loss and 1‐dB insertion loss bandwidth of the power divider are all found to be about 7 GHz. The power divider developed is suitable for various applications of wide bandwidth. © 2010 Wiley Periodicals, Inc. Microwave Opt Technol Lett 52:2560–2563, 2010; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.25542
UWB bandpass filter with notched band and improved upper stopband characteristics
Authors: Lee Jae Kwan , Kim Youngsik
Published: August 2010

In this article, we propose a novel ultra‐wideband bandpass filter with an improved upper stopband characteristic and a notched band. The proposed BPF is composed of a coupled double‐step impedance resonator, an interdigital slot, a dumbbell‐shaped defected ground, and an open‐loop defected ground. The measured results show a minimum insertion loss of 0.61 dB at 7.02 GHz except about 5 GHz for the WLAN band and a wide upper stopband with more than 30 dB attenuation at up to 20 GHz. The group delay variation in the passband is less than 0.4 ns. In addition, the proposed BPF has a compact size. © 2010 Wiley Periodicals, Inc. Microwave Opt Technol Lett 52:2520–2522, 2010; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.25544
Dual‐band hybrid coupler with source to load impedance matching
Authors: Cheung King Yin , Zheng Shao Yong , Chan Wing Shing , Man Kim Fung
Published: August 2010

A novel dual‐band hybrid coupler with source to load impedance transformation is presented together with detailed design formulas.Previous couplers were either dual‐band or impedance transforming but not both. A dual‐band impedance transforming coupler is designed accordingly for demonstration. Experimental results obtained agree well with both the numerical and simulated results. © 2010 Wiley Periodicals, Inc. Microwave Opt Technol Lett 52:2515–2519, 2010; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.25545
Compact groove‐loaded triband antenna for WLAN/WiMAX applications
Authors: Huang J.‐X. , Zhang F.‐S. , Zhang F. , Wang Y. , Yang Y.‐B. , Dong K.
Published: August 2010

A novel compact triband monopole antenna loaded with grooves for WLAN/WiMAX applications is proposed. Basically, the antenna structure is based on a pentagon‐shaped radiator and a coplanar waveguide feeding structure. Through introduction of four different grooves into the radiator and coplanar grounds, the antenna achieves triple band characteristics with a compact size of 20 × 30 × 1.6 mm3. As an investigation, an analysis of the grooves shows some important features affecting the impedance characteristics. Prototypes of the proposed antenna are fabricated and measured. Numerical and experimental results demonstrate that the proposed antenna satisfies the −10 dB impedance bandwidth requirements while covering the WLAN and WiMAX bands simultaneously. Meanwhile, radiation performances of the antenna in the operation bands are also observed and discussed. © 2010 Wiley Periodicals, Inc. Microwave Opt Technol Lett 52:2588–2592, 2010; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.25548
Hexagonal patch antenna with T‐shaped slot for frequency switching and conical radiation
Authors: Zhao Kainan , Chen Wenhua , Sun Jiawen , Feng Zhenghe
Published: August 2010

A compact hexagonal patch antenna with T‐shaped slot for frequency switching and conical radiation is presented in this article.By utilizing a PIN diode to change the configuration of the slot, two frequency bands centered at 2.29 and 2.11 GHz, respectively, are achieved. Moreover, approximations to conical beam patterns at the two frequency bands are obtained. The proposed antenna is promising for wireless communication applications because of its low profile, switchable resonant frequency, and omnidirectional radiation characteristics. Detailed design of the proposed antenna including the implementation of PIN diode is described. Measured and simulated results are also shown and discussed. © 2010 Wiley Periodicals, Inc. Microwave Opt Technol Lett 52:2585–2588, 2010; View this article online at wileyonlinelibrary.com.. DOI 10.1002/mop.25549
A novel compact monopole slot antenna with controllable band‐notched characteristic for UWB applications
Authors: Liu Hsien‐Wen , Ku Chia‐Hao
Published: August 2010

A novel planar monopole slot antenna that possesses a controllable band‐notched property for ultra‐wideband (UWB) applications is presented. The antenna, which consists of a square slot patch with a vertical coupled strip, only occupies a small size of 15 (L) × 15 (W) × 1.6 (H) mm3. By properly inserting a thin gap between the coupled strip and the slot patch, the antenna can achieve a wide bandwidth covering 3.05–11.15 GHz with a sharp rejection band of 5.12–6.08 GHz, where the frequency rejection performance can be controlled flexibly by employing various strip widths and thin gaps. Good measured omnidirectional radiation patterns and transmission responses also indicate that the proposed antenna is well suitable for UWB operation. © 2010 Wiley Periodicals, Inc. Microwave Opt Technol Lett 52:2624–2627, 2010; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.25550
MIMO antenna using a decoupling network for 4G USB dongle application
Authors: Han Minseok , Choi Jaehoon
Published: August 2010

A compact MIMO antenna using a decoupling network for 4G USB dongle application is proposed. The proposed MIMO antenna consists of two parallel folded monopole antennas with the length of 100 mm and a decoupling network. To improve the isolation characteristic at the LTE band 13, a decoupling network was added between the two antennas placed close to each other. The decoupling network is simple and compact and consists of two sections of transmission line, a shunt reactive component and quarter‐wavelength jointed shorting structure. The proposed MIMO antenna has the isolation less than −15 dB at the LTE band 13 and the ECC is lower than 0.4 over the whole LTE band. © 2010 Wiley Periodicals, Inc. Microwave Opt Technol Lett 52:2551–2554, 2010; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.25551
Compact ultra‐wideband filter with dual notched bands based on complementary split ring resonators
Authors: Chu Qing‐Xin , Huang Jian‐Quan
Published: August 2010

A compact ultra‐wideband (UWB) bandpass filter (BPF) with double notched bands is presented in this article.The proposed BPF comprises one T‐shaped multiple modes resonator and two microstrip‐CPW transition structures etched with different complementary split ring resonators (CSRRs). A CSRR etched on the coupled surface is adopted to produce narrow stop band with high rejection level. Its notched response can be mainly controlled by tuning the length and width of the gap of the CSRR. The fabricated BPF achieved dual notched bands at 5.3 and 5.775 GHz with 10 dB rejection bandwidth of 4.5 and 2.6%, and rejection level of 21.49 and 17.35 dB, respectively. The proposed notched UWB BPF has the advantages of compact size, good selectivity, and flat group delay. © 2010 Wiley Periodicals, Inc. Microwave Opt Technol Lett 52:2509–2512, 2010; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.25554
Monocytes from children with clinically stable cystic fibrosis show enhanced expression of Toll‐like receptor 4
Authors: Sturges Nina C. , Wikström Matthew E. , Winfield Kaye R. , Gard Samantha E. , Brennan Siobhain , Sly Peter D. , Upham John W. ,   on behalf of AREST CF
Published: August 2010

Lung disease in patients with cystic fibrosis (CF) is characterized by recurrent bacterial respiratory infections and intense airway inflammation. Pattern recognition receptors such as Toll‐like receptor 2 (TLR2) and TLR4 identify bacterial pathogens and activate the innate immune response. We therefore hypothesized that increased expression of these receptors would be found on circulating immune cells from children with CF. A cohort of 66 young children (median age 3 years) with CF was studied and compared to both healthy controls (n = 14) and children without CF who were being investigated for recurrent respiratory infections (non‐CF disease controls; n = 17) of a similar age. Surface expression of TLR2 and TLR4 on peripheral blood monocytes was analyzed using flow cytometry. TLR4 expression was significantly higher in patients with CF compared to healthy controls (P = 0.017) and non‐CF disease controls (P = 0.025) but did not vary according to the presence or absence of pulmonary infection with Gram‐negative or Gram‐positive bacteria (P = 0.387) in the CF group. In contrast, TLR2 expression was similar across all three study groups (P = 0.930). The increased surface expression of TLR4 seen in young children with CF appears to be related to having CF per se and not related to current pulmonary infection. Pediatr. Pulmonol. © 2010 Wiley‐Liss, Inc.
The feasibility and validity of forced spirometry in ataxia telangiectasia
Authors: Vilozni Daphna , Berkun Yakov , Levi Yonit , Weiss Batya , Jacobson Jeffrey M. , Efrati Ori
Published: August 2010

Objectives

To explore the feasibility and validity of forced spirometry in patients with ataxia telangiectasia (A‐T).

Study design

Twenty‐eight patients (aged 3.7–19.3 years) performed spirometry on 47 occasions. Parameters studied were technical quality and relation to: predicted values, pulmonary illness.

Results

Start of test criteria for correct expiratory effort was significantly prolonged (183 ± 115 ms; P < 0.001). The rise‐time to peak flow in children free of respiratory symptoms (Group‐FRS; n = 8) increased by 16.2 ± 12.5 ms/year above recommended and in children having recurrent infections (n = 8) 30.4 ± 16.1 ms/year, P < 0.01. Expiration‐time was significantly shorter than requested (1.21 ± 0.47 sec) and was ended abruptly in 57% of the patients. FEV1 could not be established by 8/20 patients. The intra‐subject reproducibility met criteria (4.4 ± 2.7%, 5.2 ± 2.8%, 2.9 ± 3.2%, 6.3 ± 5.3%, for FVC, FEV0.5, PEF, FEF25–75, respectively). Group‐FRS showed yearly deterioration in FVC of 2.2%, while patients with hyper‐reactive airways (Group‐HRA; n = 12) had a deterioration rate of 3.6%/year. FEV0.5 deterioration rate was similar in both groups (2.2 and 2.0, respectively), but baseline values in Group‐HRA were significantly lower than those of Group‐FRS (P = 0.029) in similar young ages, indicating airway obstruction at early ages in Group‐HRA. FEV0.5 values deterioration also correlated with body mass index (P < 0.017).

Conclusion

Forced spirometry in A‐T patients is reproducible and has a distinct pattern, although curves do not meet other recommendations for acceptable criteria. The study insinuates that a rapid deterioration in lung function occurs in A‐T patients with recurrent respiratory infection, suggesting that early intervention may prevent further deterioration or improve their lung function. Further studies are needed to confirm our results. Pediatr Pulmonol. 2010; 45:1030–1036. © 2010 Wiley‐Liss, Inc.
Do New Zealand children with non‐cystic fibrosis bronchiectasis show disease progression?
Authors: Munro Karen A. , Reed Peter W. , Joyce Helen , Perry David , Twiss Jacob , Byrnes Catherine A. , Edwards Elizabeth A.
Published: August 2010

Background

There is minimal literature available on the long‐term outcome of pediatric non‐cystic fibrosis (CF) bronchiectasis.

Aim

To document 5‐year outcomes of children with chest computerized tomography (CT) scan diagnosed bronchiectasis from a tertiary New Zealand (NZ) respiratory clinic.

Methods

Review of a clinical database identified 91 children. Demographics, clinical data, lung function, chest X‐ray (CXR), sputum, presumed etiology, admission data, and the NZ deprivation index (NZDep) were collected. Univariate and multivariate regression were used to correlate clinical findings with lung function data and CXR scores using the Brasfield Scoring System.

Results

Of the 91 children, 53 (59%) were Pacific Island, 22 (24%) Maori, 14 (15%) European, and 2 (2%) Other. The median follow‐up period was 6.7 years (range 5.0–15.3 years) and median age at diagnosis was 7.3 years (range 11 months–16 years). Lung function data (n = 64) showed a mean decline of −1.6% predicted/year. In 30 children lung function declined (mean FEV1 −4.4% predicted/year, range 1–17%), remained stable in 13 and improved in 21 children (mean FEV1 of +3% predicted/year, range 1–15%). Reduced lung function was associated with male gender, chronic Haemophilus influenzae infection, longevity of disease, and Maori and Pacific Island ethnicity. There was a significant correlation with FEV1 and CXR score at beginning (n = 47, r = 0.45, P = 0.001) and end (n = 26, r = 0.59, P = 0.002) of the follow‐up period. The only variable consistently related to CXR score was chronic Haemophilus influenzae infection occurring in 27 (30%) (r2 = 0.52, P = <0.0001). Only four children were chronically infected with Pseudomonas species. Six children died.

Conclusion

In our experience despite management in a tertiary multidisciplinary bronchiectasis clinic, progression of lung disease continues in a group of children and young adults. Pediatr. Pulmonol. 2011; 46:131–138. © 2011 Wiley‐Liss, Inc.
Generation of high‐affinity fully human anti‐interleukin‐8 antibodies from its cDNA by two‐hybrid screening and affinity maturation in yeast
Authors: Ding Ling , Azam Mark , Lin Yu‐Huei , Sheridan James , Wei Shuanghong , Gupta Gigi , Singh Rakesh K. , Pauling Michelle H. , Chu Waihei , Tran Antares , Yu Nai‐Xuan , Hu Jiefeng , Wang Wei , Long Hao , Xiang Dong , Zhu Li , Hua Shao‐Bing
Published: August 2010

We have developed a technology for rapidly generating novel and fully human antibodies by simply using the antigen DNA. A human single‐chain variable fragment (scFv) antibody library was constructed in a yeast two‐hybrid vector with high complexity. After cloning cDNA encoding the mature sequence of human interleukin‐8 (hIL8) into the yeast two‐hybrid system vector, we have screened the human scFv antibody library and obtained three distinct scFv clones that could specifically bind to hIL8. One clone was chosen for further improvement by a novel affinity maturation process using the error‐prone PCR of the scFv sequence followed by additional rounds of yeast two‐hybrid screening. The scFv antibodies of both primary and affinity‐matured scFv clones were expressed in E. coli. All purified scFvs showed specific binding to hIL8 in reciprocal coimmunoprecipitation and ELISA assays. All scFvs, as well as a fully human IgG antibody converted from one of the scFv clones and expressed in the mammalian cells, were able to effectively inhibit hIL8 in neutrophil chemotaxis assays. The technology described can generate fully human antibodies with high efficiency and low cost.
Type‐1 polarized dendritic cells loaded with apoptotic prostate cancer cells are potent inducers of CD8+ T cells against prostate cancer cells and defined prostate cancer‐specific epitopes
Authors: Wieckowski Eva , Chatta Gurkamal S. , Mailliard Robbie M. , Gooding William , Palucka Karolina , Banchereau Jacques , Kalinski Pawel
Published: August 2010

BACKGROUND

In order to develop improved vaccines for patients with recurrent prostate cancer (PCa), we tested the feasibility of using type‐1 polarized dendritic cells (αDC1s) to cross‐present antigens from allogeneic PCa cells and to induce functional CD8+ T cell responses against PCa cells and against defined MHC class I‐restricted PCa‐relevant epitopes.

METHODS

Monocyte‐derived DCs from PCa patients were matured using the “standard” cytokine cocktail (IL‐1β/TNFα/IL‐6/PGE2) or using the αDC1‐polarizing cocktail (IL‐1β/TNFα/IFNα/IFNγ/poly‐I:C), loaded with UV‐irradiated LNCaP cells, and used to sensitize autologous CD8+ T cells.

RESULTS

αDC1s from PCa patients secreted 10–30 times higher levels of IL‐12p70 than sDCs. Importantly this elevated capacity for IL‐12p70 secretion was not inhibited by loading with apoptotic tumor cells. Compared to standard DCs, αDC1s induced higher numbers of CD8+ T cells capable of recognizing both the original PCa cells as well as another PCa cell line, DU145, in MHC class I‐restricted fashion. Furthermore, αDC1s induced higher numbers of CD8+ T cells recognizing defined PCa‐specific class I‐restricted peptide epitopes of prostate‐specific antigen and prostatic acid phosphatase: PAP135–143 (average 49‐fold higher), PAP112–120 (average 24‐fold), PSA141–150 (average 5.5‐fold), and PSA146–154 (average 11‐fold).

CONCLUSION

Type‐1 polarization of GM‐CSF/IL‐4‐generated DCs enhances their ability to present allogeneic tumor cells and to induce CD8+ T cells recognizing different PCa cells and multiple defined PCa‐specific epitopes. These observations help to develop improved immunotherapies of PCa for patients with different HLA types and lacking autologous tumor material. Prostate 71: 125–133, 2011. © 2010 Wiley‐Liss, Inc.
Computational modeling of laminin N‐terminal domains using sparse distance constraints from disulfide bonds and chemical cross‐linking
Authors: Kalkhof Stefan , Haehn Sebastian , Paulsson Mats , Smyth Neil , Meiler Jens , Sinz Andrea
Published: August 2010

Basement membranes are thin extracellular protein layers, which separate endothelial and epithelial cells from the underlying connecting tissue. The main noncollagenous components of basement membranes are laminins, trimeric glycoproteins, which form polymeric networks by interactions of their N‐terminal (LN) domains; however, no high‐resolution structure of laminin LN domains exists so far. To construct models for laminin β1 and γ1 LN domains, 14 potentially suited template structures were determined using fold recognition methods. For each target/template‐combination comparative models were created with Rosetta. Final models were selected based on their agreement with experimentally obtained distance constraints from natural cross‐links, that is, disulfide bonds as well as chemical cross‐links obtained from reactions with two amine‐reactive cross‐linkers. We predict that laminin β1 and γ1 LN domains share the galactose‐binding domain‐like fold.Proteins 2010. © 2010 Wiley‐Liss, Inc.
A density functional investigation of the reaction mechanism of H2O + HCNO
Authors: Mu Dan , Kong Wei‐Xin , Wang Song
Published: August 2010

A theoretical investigation of the H2O + HCNO reaction, which is carried out by means of CCSD(T)/6‐311G(d,p)//B3LYP/6‐311G(d,p)+ZPVE computational method to determine a set of reasonable pathways, there are seven product pathways, Pi with i = 1, 2, …, 7 are involved. It is shown that P1(H2O + NCOH), P2(CO + NH2 + OH), P4(HCN + HO2 + H), and P6(CO + NH2OH) are the major product channels; and P7(HOC + H2 + NO) is the minor product channels, whereas the other channels for P3(HNO + HCOH) and P5(HNO + H2CO) are very minor, the minor product channels. © 2010 Wiley Periodicals, Inc. Int J Quantum Chem, 2011
Stress‐induced nanostructures through laser‐assisted scanning probe nanolithography
Authors: Peng Luohan , Zhang Huiliang , Yang Bao , Tang Liqun , Hemmer Philip , Liang Hong
Published: August 2010

We demonstrate a methodology using a laser‐assisted scanning probe nanolithography (LASPN) technique to generate organized nanostructures. Experimental approach combined with finite element analysis was utilized to study the interfacial interactions between a gold‐coated probe of an atomic force microscope and a single crystal silicon substrate. Research results proved that the tip temperature had been raised via LASPN to 900 K at a laser power of 12 mW. Nanolines were formed during sliding while the silicon substrate was heated at a laser power of 5 mW. We propose an energy model to explain the phenomenon. SCANNING 32: 327–335, 2010. © 2010 Wiley Periodicals, Inc.
Ascorbate Promotes Epigenetic Activation of CD30 in Human Embryonic Stem Cells
Authors: Chung Tung-Liang , Turner Jennifer P. , Thaker Nilay Y. , Kolle Gabriel , Cooper-White Justin J. , Grimmond Sean M. , Pera Martin F. , Wolvetang Ernst J.
Published: August 2010

Human embryonic stem cells (hESCs) and induced pluripotent stem cells have the ability to adapt to various culture conditions. Phenotypic and epigenetic changes brought about by the culture conditions can, however, have significant impacts on their use in research and in clinical applications. Here, we show that diploid hESCs start to express CD30, a biomarker for malignant cells in Hodgkin's disease and embryonal carcinoma cells, when cultured in knockout serum replacement (KOSR)-based medium, but not in fetal calf serum containing medium. We identify the commonly used medium additive, ascorbate, as the sole medium component in KOSR responsible for CD30 induction. Our data show that this epigenetic activation of CD30 expression in hESCs by ascorbate occurs through a dramatic loss of DNA methylation of a CpG island in the CD30 promoter. Analysis of the phenotype and transcriptome of hESCs that overexpress the CD30 signaling domain reveals that CD30 signaling leads to inhibition of apoptosis, enhanced single-cell growth, and transcriptome changes that are associated with cell signaling, lipid metabolism, and tissue development. Collectively, our data show that hESC culture media that contain ascorbate trigger CD30 expression through an epigenetic mechanism and that this provides a survival advantage and transcriptome changes that may help adapt hESCs to in vitro culture conditions.