bluuebunny/crossref_metadata_2025 huggingface dataset:
Characterization of parasitics from scattering parameters of laser diode
Authors: Zhang Shangjian , Zhu Ninghua , Liu Yong , Liu Yongzhi
Published: November 2007

A novel method for characterizing the parasitics of parasitic network is proposed based on the relations between the scattering parameters of a semiconductor laser chip and laser diode. Experiments are designed and performed using our method. The analysis results are in good agreement with the measurements. Furthermore, how the parasitics change with the parasitic element values are investigated. The method only needs reflection coefficient of laser diode to be measured, which is simple because of the developed electrical‐domain measurement techniques. © 2007 Wiley Periodicals, Inc. Microwave Opt Technol Lett 50: 1–4, 2008; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.22987
An angular offset launching technique for bandwidth enhancement in multimode fiber links
Authors: Oh C. W. , Moon S. , Veetil Suhas P. , Kim D. Y.
Published: November 2007

We propose an angular offset technique for launching optical signals into multimode fibers (MMFs) used in short distance optical fiber links. The signal is launched onto the angled facet of an MMF. The presented method shows better bandwidth enhancement in comparison with the conventional lateral offset launching method with a little power penalty. This method is simple and can be easily adopted in transmitters for high‐speed MMF links. © 2007 Wiley Periodicals, Inc. Microwave Opt Technol Lett 50: 165–168, 2008; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.22988
Closed‐form physical optics expressions for the radar cross section of perfectly conducting plane angular sectors
Authors: Vallecchi Andrea
Published: November 2007

Closed‐form expressions for the physical optics (PO) field scattered in the far zone by perfectly electrically conducting (PEC) plane angular sectors with a conical‐section boundary are derived in terms of incomplete cylindrical functions (ICFs). The developed representations are very efficient from a computational point of view and constitute a useful tool to analytically predict the radar cross section (RCS) of metal plates with both convex and concave curved edges. The correctness of the proposed scattered field formulas is demonstrated through comparisons with the results obtained by an accurate completely numerical PO approach. A sample analysis of the scattering from a more elaborate geometry, which can be seen as a juxtaposition of angular sectors, is also presented. © 2007 Wiley Periodicals, Inc. Microwave Opt Technol Lett 50: 160–165, 2008; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.22989
Applications of resonant‐type metamaterial transmission lines to the design of enhanced bandwidth components with compact dimensions
Authors: Sisó G. , Gil M. , Bonache J. , Martín F.
Published: November 2007

In this article, it is demonstrated that metamaterial transmission lines implemented by means of complementary split rings resonators are useful for the design of planar microwave components with small dimensions and broad operational bandwidths. These characteristics are achieved thanks to the small electrical size of complementary split rings resonators and to the controllability of the dispersion diagram in such artificial lines. The technique is illustrated by means of the design of a rat‐race hybrid coupler. The performance and size of this metamaterial‐based component is compared with those characteristics and dimensions of the classical (distributed) implementation. It is clearly demonstrated that by replacing the conventional transmission lines in the design with metamaterial transmission lines conveniently engineered, the functionality of the device is preserved over broader bandwidths and, additionally, significant size reduction is achieved. These characteristics and the absence of lumped elements in the design are of interest for applications in which cost and compatibility with fully planar technology are fundamental aspects. The most relevant contribution of the article is the demonstration of the compatibility between the resonant artificial lines and the design of broad band and high performance microwave components. © 2007 Wiley Periodicals, Inc. Microwave Opt Technol Lett 50: 127–134, 2008; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.22990
An over 40 channel multi‐wavelength laser source
Authors: Lu Z.G. , Liu J.R. , Zhang X.P.
Published: November 2007

We have demonstrated an over 40‐channel multi‐wavelength laser comb source with the 50‐GHz equal frequency spacing between the adjacent channels over the C‐band wavelength range. The output spectra could be described by using the simplified stimulated four‐wave nonlinear coupled equations taking into account the third‐order nonlinear optical interaction in the single‐mode dispersion‐shifted fibers. © 2007 Wiley Periodicals, Inc. Microwave Opt Technol Lett 50: 92–94, 2008; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.22993
Radiation properties of an omnidirectional planar microstrip antenna
Authors: Bancroft Randy
Published: November 2007

The pattern and directivity of an ideal omnidirectional antenna, collinear coaxial, and omnidirectiontal microstrip antenna (OMA) are compared. The radiation of an OMA originates from the arraying of two radiating edges along each element. The width of the (OMA) elements determines omni‐plane pattern variation. © 2007 Wiley Periodicals, Inc. Microwave Opt Technol Lett 50: 55–58, 2008; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.22995
Comparison of dual‐band printed dipoles for WLAN mobile communication devices
Authors: Nepa P. , Manara G. , Mugnaini S. , Tribellini G. , Cioci S. , Albasini G. , Sacchi E.
Published: November 2007

A research activity is described in this article, which is devoted to the design and characterization of dual‐band printed dipoles working in the wireless local area network (WLAN) frequency bands at 2.415–2.485 GHz and 5.15–5.35 GHz. In particular, four different prototypes have been designed and compared to check the effectiveness of the design procedure through comparisons between simulations and measurements. Attention is focused on the performance of the different printed dipoles for their application in WLAN mobile terminals. © 2007 Wiley Periodicals, Inc. Microwave Opt Technol Lett 50: 81–87, 2008; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.23000
Microstrip‐CPW bandpass filter for antenna application
Authors: Balalem Atallah , Machac Jan , Omar Abbas
Published: November 2007

This article presents a quasi‐lumped bandpass filter with CPW‐microstrip ports. The structure serves as CPW‐microstrip transmission in addition to its filtering function. The filter was integrated with a microstrip patch antenna. To enable the filter design, the characteristic impedance of the slotted microstrip line and the coupling strength of microstrip to microstrip, CPW to CPW and microstrip to CPW transitions were calculated. © 2007 Wiley Periodicals, Inc. Microwave Opt Technol Lett 50: 51–55, 2008; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.23001
Electromagnetically coupled notch filters and effect of resonator geometries
Authors: Harikrishna J. V. S. , Karekar R. N. , Aiyer R. C.
Published: November 2007

Electromagnetically coupled notch filters is a relatively recent innovation. Resonators with three ring geometries (square, triangular, and circular) and L (half wave) are fabricated (all 2.4 GHz) on TMM4 (εr = 4.5, h = 0.762 mm) substrates (without ground plane) and coupled electromagnetically to a 50‐Ω microstrip feed line (on separate TMM4 substrate with ground plane) under it. The comparisons show that square is found to give best notch effect (−37.2 dB) followed by triangular, L, and circular. These notch filters not only offer improved matching performance over their in‐plane coupled counterparts but also provide other flexibilities like easy resonator replacement, multi frequency operation. © 2007 Wiley Periodicals, Inc. Microwave Opt Technol Lett 50: 48–51, 2008; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.23002
A 3.5 GHz low‐power and phase noise differential CMOS VCO
Authors: Jang Sheng‐Lyang , Wu Y.‐J. , Lee Chien‐Feng
Published: November 2007

A novel low‐power differential Colpitts voltage‐controlled oscillator (VCO) is proposed and implemented in a 0.18‐μm CMOS 1P6M process. The proposed circuit topology consists of two single‐ended Colpitts LC‐tank VCOs, and the differential VCO is obtained by using a cross‐coupled nMOS pair. At the supply voltage of 1.8 V, the output phase noise of the VCO is −120.56 dBc/Hz at 1 MHz offset frequency from the carrier frequency of 3.64 GHz, and the figure of merit is −185.9 dBc/Hz. Total power consumption is 3.8 mW. Tuning range is about 487 MHz, from 3.64 to 3.15 GHz, while the control voltage was tuned from 0 to 1.8 V. © 2007 Wiley Periodicals, Inc. Microwave Opt Technol Lett 50: 153–156, 2008; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.23003
Multipreconditioned GMRES method for electromagnetic wave scattering problems
Authors: Rui P. L. , Yong H. , Chen R. S.
Published: November 2007

A new multipreconditioned generalized minimal residual method (GMRES) combined with the multilevel fast multipole method (MLFMM) is proposed for efficiently solving large dense complex linear systems that arise in electromagnetic wave scattering problems. The MLFMM is used to accelerate the matrix‐vector product operations, and the multipreconditioning technique is employed to speed up the convergence rate of the GMRES iterations. Unlike traditional preconditioning techniques, which usually work alone, the multipreconditioned GMRES algorithm has the capability to combine different preconditioning techniques all together. Numerical results show that the convergence rate of the GMRES method can be significantly improved by automatically taking advantages of all available preconditioners. © 2007 Wiley Periodicals, Inc. Microwave Opt Technol Lett 50: 150–152, 2008; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.23004
Hyper‐wide band TEM horn array design for multi band ground‐penetrating impulse radar
Authors: Turk Ahmet Serdar , Nazli Hakkı
Published: November 2007

The array configuration of the partially dielectric‐loaded TEM (PDTEM) horn structure that can maintain very broadband antenna characteristics over a bandwidth ratio greater than 50:1 is proposed to obtain an efficient impulse signal radiation for ultra‐wide band radar and communication systems. It is shown that proper array combinations of TEM horn antennas can remarkably improve the impulse radiation performance yielding high gain and low input reflection levels over the hyper‐wide operational band. © 2007 Wiley Periodicals, Inc. Microwave Opt Technol Lett 50: 76–81, 2008; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.23007
Compact circular polarized patch antenna with harmonic rejection
Authors: Yo Tzong‐Chee , Lee Chien‐Ming , Luo Ching‐Hsing
Published: November 2007

Design of circularly polarized antenna using circular patch with single feed is proposed. The circular polarization (CP) property with second harmonic rejection can be achieved by embedding two circular slots in the patch resonator. By changing the size and position of the slots, two orthogonal modes with equal amplitude and 90° out of phase are simultaneously excited. In the meanwhile, the embedded slots blocking the second harmonic signal is especially suitable for the circuits with nonlinear elements, such as rectify antenna (rectenna). Furthermore, the patch is simple and compact with 12% of the antenna area reduction. © 2007 Wiley Periodicals, Inc. Microwave Opt Technol Lett 50: 45–48, 2008; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.23009
Design of the tree‐shaped UWB antenna using fractal concept
Authors: Park Jong K. , An Hee S. , Lee Jung N.
Published: November 2007

In this article, we have proposed a novel tree‐shaped ultra‐wideband antenna for UWB applications. We have used the partial ground plane technique and the fractal concept to achieve an ultra‐wideband impedance matching. It is found that as the number of iteration increases, the lower‐edge of the impedance bandwidth is moved to the low frequency and the level of the impedance matching over the operating frequency band (3.1–4.8 GHz) is improved. Prototypes of the proposed antennas have been successfully implemented and good radiation characteristics in the operating frequency bands have been achieved. The effect of the angle between upper and lower trapezoids on the return loss was also studied. © 2007 Wiley Periodicals, Inc. Microwave Opt Technol Lett 50: 144–150, 2008; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.23010
Improved circuit model for coplanar‐waveguide to microstrip‐line transition on silicon substrate
Authors: Hua Qi , Yin Wen‐Yan , Zhou Liang , Mao Jun‐Fa , Kang Kai , Zhu Lei
Published: November 2007

An improved equivalent circuit model is proposed to accurately characterize a metal via transition, between a finite ground coplanar waveguide (FGCPW) and a finite ground thin film microstrip line (FGTFML), which was fabricated using standard CMOS technology. This circuit model with only a few lumped‐circuit elements is established and optimized to achieve a wide frequency range of operation, i.e., 1.0–30.0 GHz. A via transition circuit is fabricated and the measured results have evidently validated the predicted results derived from our proposed circuit model. © 2007 Wiley Periodicals, Inc. Microwave Opt Technol Lett 50: 141–144, 2008; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.23011
Ladder‐type filter based on bulk acoustic wave resonators with improved out‐of‐band rejection
Authors: Verdú J. , Menéndez O. , de Paco P.
Published: November 2007

Filters based on bulk acoustic wave (BAW) resonators are called to replace actual surface acoustic wave filters. The transmission response of BAW‐based ladder‐type filters presents a steep rejection near the passband, but a poor out‐of‐band (OoB) rejection. This article describes how modifying the basic configuration of this type of filters, its OoB rejection can be improved. © 2007 Wiley Periodicals, Inc. Microwave Opt Technol Lett 50: 103–107, 2008; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.23015
Long‐period gratings ARC‐induced in B/Ge codoped fibers: Thermal behavior and uniform exposure to UV‐radiation
Authors: Rego Gaspar
Published: November 2007

The thermal behavior of long‐period gratings arc‐induced in B/Ge codoped fibers is presented. We also demonstrated the possibility to erase gratings written in Ge‐doped and B/Ge codoped fibers through uniform exposure to UV‐laser radiation. The gratings spectra were afterward recovered by thermal annealing. Permanent thermally induced refractive index changes were found. © 2007 Wiley Periodicals, Inc. Microwave Opt Technol Lett 50: 68–71, 2008; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.23014
A dual‐band and wideband planar inverted‐F antenna for WLAN applications
Authors: Janapsatya J. , Esselle K. P. , Bird T. S.
Published: November 2007

A dual‐band planar inverted‐F antenna (PIFA), presented here, covers both 2.4‐ and 5‐GHz bands used in all IEEE 802.11 WLAN standards. Computed and measured return loss and radiation patterns of the antenna are presented and are in reasonable agreement. Experimental results indicate a very wide 32.5% operational bandwidth in the 5‐GHz band. © 2007 Wiley Periodicals, Inc. Microwave Opt Technol Lett 50: 138–141, 2008; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.23016
General analysis of single‐mode fiber Fabry–Perot cavity with birefringence
Authors: Chen Haiyan
Published: November 2007

In this letter, a general analysis on the output performance of single‐mode fiber Fabry–Perot (SMF F‐P) cavity with birefringence is carried out and demonstrated experimentally. The effect of magnitude of birefringence on the output characteristics of SMF F‐P cavity is discussed. Numerical results are consistent with experiment. © 2007 Wiley Periodicals, Inc. Microwave Opt Technol Lett 50: 101–103, 2008; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.23018
Design of a band‐selective filter for UWB applications and its characteristic when combined with band‐notched antennas
Authors: Chung Kyungho , Choi Jaehoon
Published: November 2007

A compact microstrip band‐selective filter for ultra‐wideband (3.1–10.6 GHz) radio system is proposed. The filter combines an optimum pseudo‐bandpass filter and a coupled resonator bandstop filter on both sides of the meandered 50‐Ω microstrip line. Three coupled resonators are modified to have S‐shape to miniaturize the filter. The measured results show that the filter has wide passband of 146.7% (2.1–10.15 GHz) with low insertion loss and the stop‐band of 7.42% (5.29–5.85 GHz) for 3‐dB bandwidth. The measured group delay variation is less than 0.7 ns within the passband except the stop band. Finally, the filter is combined with band‐notched antennas and then received power levels of the antennas with and without the filter are also examined at the notch frequency. © 2007 Wiley Periodicals, Inc. Microwave Opt Technol Lett 50: 98–101, 2008; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.23019
Multi‐band internal monopole antenna for mobile station
Authors: Min Kim Sung , Suk Yoon Ki , Bin Park Su , Geun Yang Woon , Ki Kim Nam , Lee Jong Hyuk
Published: November 2007

In this paper, we propose a multi‐band internal monopole type antenna for mobile station. We design and implement the multi‐band internal monopole type antenna for cellular (824–894 MHz), GPS (Global Positioning System: 1575.42 MHz), K‐PCS (Korea‐Personal Communication Service: 1750–1870 MHz), and S‐DMB (Satellite‐Digital Multimedia Broadcasting: 2630–2655 MHz) frequency bands with three branch lines. The antenna size of example design is 42.5 mm × 7 mm × 6.5 mm. Ground size is 67 mm × 42 mm, and the proposed antenna is located at 3 mm away from the top portion of ground plane. The proposed antenna shows a monopole‐like radiation pattern. Measured peak gains are −1.63 dBi at 0.859 GHz, 1.76 dBi at 1.575 GHz, 3.89 dBi at 1.810 GHz, and 5.57 dBi at 2.642 GHz. © 2007 Wiley Periodicals, Inc. Microwave Opt Technol Lett 50: 241–244, 2008; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.23024
Comments on “Magnitude of the Voltage Reflection Coefficient of Terminated Reciprocal Uniform Lossy Transmission Lines”
Authors: Dutta Roy S. C.
Published: November 2007

It is pointed out that the results reported in the above titled letter [Torrungrueng et al., Microwave Opt Technol Lett 49 (2007), 1516–1519] are already known. © 2007 Wiley Periodicals, Inc. Microwave Opt Technol Lett 50: 176–177, 2008; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.23029
Low profile and small size frequency notched planar monopole antenna from 3.5 to 23.64 GHz
Authors: Naeem Khan Salman , Xiong Jiang , He Sailing
Published: November 2007

A small size and low profile microstrip fed frequency notched planar monopole ultra wideband (UWB) antenna with an arc shaped slot etched on a circular disk is proposed. The effect of different dimensions of the slotted arc are analyzed and optimized to obtain simultaneously the UWB and the band rejected performance. The return loss from (3.5–23.64 GHz) along with a notched frequency band (5.23–5.8 GHz) and quasi omni‐directional radiation pattern is observed. © 2007 Wiley Periodicals, Inc. Microwave Opt Technol Lett 50: 235–236, 2008; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.23030
A flat gain/power responses 618 GHz power amplifier MMIC with high PAE by using transformer networks
Authors: Yu Shu‐Jenn , Hsu Wei‐Chou , Lee Ching‐Sung , Chang Chian‐Sern , Wu Chang‐Luen , Chang Ching‐Hsueh
Published: November 2007

A two‐stage power amplifier monolithic microwave integrated‐circuit, operating between 6 and 18 GHz by implementing AlGaAs/InGaAs/GaAs pseudomorphic high electron mobility transistors is presented. This devised power amplifier has demonstrated flat gain and power responses over a wide bandwidth by employing a novel design approach of combined prematched LC network and multisection impedance transformer network. Superior gain flatness of ±1.5 dB and power flatness of ±1.1 dBm over 6–18 GHz bandwidth, respectively, have been successfully achieved. With a dual‐bias configuration, the power amplifier shows average small‐signal gain of 13 dB, 2‐dB gain compression power of 32.4 dBm and high power‐added efficiency (PAE) of 24–34.5%. In additions, by using off‐chip combiner techniques, the balanced power amplifier shows superior maximum output power of 36.5 dBm and PAE of 22–33.1%. © 2007 Wiley Periodicals, Inc. Microwave Opt Technol Lett 50: 205–208, 2008; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.23033
FDTD analysis of pulse propagation on microstrip line and an exponentially parallel plate antenna produced by photoconductive switches applied bias voltage
Authors: Yanwu Zhu , Shunxiang Shi , Yanling Sun
Published: November 2007

The d'Alembents formula with one free end was used to understand the pulse produced by photoconductive semiconductor switch (PCSS) and propagating in microstrip‐line at the bias voltage. A total reflection border was given for keep the steady electric field in order that the propagation of pulse in the microstrip line could be analyzed by finite time difference domain method. The reflection parameter of this border was computed. The border and a simple model of photoconductive switches were used to analyze the process of pulse transmitting in the microstrip line. The electric field distributions at the different time were given. The experiment result has proven that there is excellent agreement between the simulated and measured version of pulse output. An exponentially parallel plate antenna loaded with dielectric using PCSS was designed and analyzed. © 2007 Wiley Periodicals, Inc. Microwave Opt Technol Lett 50: 168–172, 2008; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.23035
A low power CMOS divide‐by‐3 LC‐tank injection locked frequency divider
Authors: Jang Sheng‐Lyang , Hsung Yeh Wei , Lee Chien‐Feng , Juang M.‐H.
Published: November 2007

This article presents a divide‐by‐3 CMOS injection locked frequency divider (ILFD) fabricated in a 0.18um CMOS process. The ILFD circuit is realized with a complementary Colpitts CMOS LC‐tank oscillator with an injection MOS connected between the voltage controlled oscillator (VCO) output and ground. The self‐oscillating VCO is injection‐locked by third‐harmonic input to obtain the division order of three. Measurement results show that at the supply voltage of 1.8 V, the free‐running frequency is from 2.63 to 3.29 GHz. At the incident power of −6.5 dBm, the locking range is from the incident frequency 8.84 to 9.90 GHz. At the supply voltage of 1.8 V, the core power consumption is 3.06 mW. The chip area is 0.972 × 0.574 mm2. © 2007 Wiley Periodicals, Inc. Microwave Opt Technol Lett 50: 259–263, 2008; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.23036
Compact multiport antenna with isolated ports
Authors: Coetzee J. C. , Liu Y.
Published: November 2007

The small element spacing of compact multiport arrays introduces strong mutual coupling between the antenna ports. Because of this coupling, the input impedance of the array changes when elements excitations are varied, and consequently, the array cannot be matched for an arbitrary excitation. Decoupling networks have in the past been used to provide an additional connection between antenna ports to cancel the coupling between elements. An alternative approach is to design the antenna so that each port does not excite a single element, but instead all elements simultaneously. The geometry of the antenna is optimized so that this direct excitation of elements counteracts the mutual coupling, thus, yielding decoupled ports. This article describes the design of such a four‐port antenna. © 2007 Wiley Periodicals, Inc. Microwave Opt Technol Lett 50: 229–232, 2008; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.23038
Coherence‐free microwave photonic filter using a electro‐absorption modulator in a double pass configuration and its application for harmonic suppression
Authors: Ning G. , Zhou J. Q. , Aditya S. , Shum P.
Published: November 2007

A simple coherence‐free microwave photonic filter configuration is presented. It is based on an electroabsorption modulator in a double pass configuration, modulating the optical signal at different times. The configuration is free from the velocity mismatch and polarization dependence problems of elecro‐optic modulator. Measured results confirm the theoretical expressions and demonstrate a robust notch filter response without phase‐induced intensity noise. Application of the filter in suppressing the second harmonic of modulating radio frequency signal is also demonstrated. © 2007 Wiley Periodicals, Inc. Microwave Opt Technol Lett 50: 226–229, 2008; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.23039
Investigation of interconnect loss due to coupling between two parallel microstrip lines in high‐speed design
Authors: Li Li‐Ping , Li Yu‐Shan , Pan Jian , Jia Chen , Zhang Mu‐Shui
Published: November 2007

Loss due to coupling between two parallel microstrip lines is investigated in this paper. It is found that the transmission characteristic of the aggressor line was impaired by coupling. Most energy would be coupled to the victim line at resonant frequencies determined by the space between traces and the coupled length, which seriously affects the transmitted signals with high data rate. Two coupled microstrip lines are analyzed in terms of even and odd modes to explain this additional loss mechanism. Several design parameters are simulated. It is clearly shown that resonant frequencies increase with the space between traces and decrease with the coupled length. Electromagnetic simulations are also performed to illustrate this extra loss mechanism. Good agreement is seen between analytical and experimental analyses. © 2007 Wiley Periodicals, Inc. Microwave Opt Technol Lett 50: 197–202, 2008; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.23041
A compact spiral stripline‐loaded monopole antenna with a vertical ground plane
Authors: Khang Nguyen Truong , Lee Keekeun , Choo Hosung , Park Ikmo
Published: November 2007

In this letter, we propose a compact spiral stripline‐loaded monopole antenna on a vertical ground plane. The measured results show that the antenna has a fractional bandwidth of 12.1% for a voltage standing wave ratio (VSWR) less than 2 at the center frequency of 1.10 GHz, as well as a good omni‐directional radiation pattern. The small size of 0.04 λo × 0.04 λo × 0.04 λo makes it promising for use as an internal antenna in mobile handsets. © 2007 Wiley Periodicals, Inc. Microwave Opt Technol Lett 50: 250–252, 2008; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.23043
Tunable negative tap microwave photonic filter using an SOA in a Sagnac loop
Authors: Ning Guoxiang , Shum Ping , Aditya S.
Published: November 2007

A novel tunable coherence‐free microwave photonic filter configuration is presented. This all‐optical structure realizes negative taps and works as a bandpass notch filter. The configuration is based on a Sagnac loop interferometer containing a single‐drive intensity modulator and a polarization‐maintaining semiconductor optical amplifier that generates phase difference between the clockwise and counterclockwise propagating waves inside the Sagnac loop. Measured results demonstrate a robust tunable bandpass notch response. © 2007 Wiley Periodicals, Inc. Microwave Opt Technol Lett 50: 225–226, 2008; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.23044
CMOS switched resonator frequency divider tuned by the switch gate bias
Authors: Jang Sheng‐Lyang , Tsai Lin‐yen , Lee Chien‐Feng
Published: November 2007

A switched resonator injection‐locked frequency divider (ILFD) designed and fabricated using a standard 0.18‐μm CMOS process is presented. The designed ILFD consists of double cross‐coupled MOS switching pairs that use the current reuse technique to save power dissipation, and a switched LC resonator. The latter is composed of an inductor, a capacitor, and an inductor–MOS–inductor composite in parallel. The gate bias of MOSFET in the switched resonator is used to tune the free running ILFD frequency and extend the locking range of the ILFD. Measurement results show that at the supply voltage of 1.8 V, the divider free‐running frequency is from 3.8 to 4.5 GHz, and at the incident power of 0 dBm the locking range is from the incident frequency of 7.6 to 9.26 GHz. © 2007 Wiley Periodicals, Inc. Microwave Opt Technol Lett 50: 222–225, 2008; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.23045
GaInp/GaAs HBT broadband inductorless receiver
Authors: Wu Tzung‐Han , Meng Chinchun , Huang Guo‐Wei
Published: November 2007

A GaInP/GaAs HBT broadband RF front‐end consisting of a low‐noise wideband amplifier and a micromixer is demonstrated in this article. The major advantage of this work is the elimination of inductors and thus the chip area can be greatly saved. The bandwidth of the RF front‐end is up to 7 GHz. The measured conversion gain is higher than 25 dB from 1 to 7 GHz and the noise figure of the RF front‐end is less than 8 dB within the bandwidth. © 2007 Wiley Periodicals, Inc. Microwave Opt Technol Lett 50: 247–250, 2008; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.23048
Lossy LC ladder matching network for ultra‐wideband CMOS Gilbert cell mixer design
Authors: Liao Hsien‐Yuan , Tseng Ching‐Ming , Chiou Hwann‐Kaeo
Published: November 2007

A 0.18‐μm CMOS broadband mixer for ultra‐wideband receivers is presented. A lossy LC ladder is utilized to achieve the broadband impedance match at the RF port. This circuit achieves high conversion gain of 10.4 dB, with 3‐dB bandwidth from 0.3 to 10.9 GHz and low power consumption of 15 mW under 2.5‐V supply voltage. © 2007 Wiley Periodicals, Inc. Microwave Opt Technol Lett 50: 220–222, 2008; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.23050
Erratum: An omnipotent Smith chart for lossy nonreciprocal transmission lines
Authors: Wu Yongle , Huang Haiyu , Liu Yuanan
Published: November 2007

Originally published in Microwave Opt Technol Lett 49: 2392–2395, 2007. © 2007 Wiley Periodicals, Inc. Microwave Opt Technol Lett 50: 263, 2008; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.23053
Erratum: Low phase noise 3‐42‐Gzilchlc signal generation using high‐order longitudinal modes of a coaxial loop cavity
Authors: Wang Xinyue , Wang Ziyu
Published: November 2007

Originally published Microwave Opt Technol Lett 49 (2007), 2329–2331. © 2007 Wiley Periodicals, Inc. Microwave Opt Technol Lett 50: 264, 2008; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.23054
DIChirp: direct injection bandwidth estimation
Authors: Ozturk Yusuf , Kulkarni Manish
Published: November 2007

Ideally, network bandwidth estimation algorithms should be independent of the end system performance. If end system capabilities are involved, then the measurement will be of the system throughput and will not indicate a correct assessment of network bandwidth. Packet dispersion‐based active bandwidth estimation schemes including Pathload, TOPP and pathChirp use delay correlation where the network‐induced delay on packets transmitted at certain rates is translated into bandwidth estimation. Since packet dispersion‐based active measurement schemes use delay correlation, bandwidth estimations are distorted by the host protocol stack‐induced delay variations. Studies revealed that the host protocol stack‐induced delay variations due to context switching are stovepiped in the network‐induced delay variations and impact the measurement process. This study explores the delay variations introduced by the host protocol stack in packet dispersion‐based techniques. The impact of host protocol delay variations and context switching on bandwidth estimation is analyzed and a new active bandwidth estimation tool minimizing the impact of context switching is proposed. Direct Injection Chirp (DIChirp) bypasses the TCP/IP protocol stack and directly interfaces with the network hardware. It uses the kernel for scheduling the outgoing packets, thus achieving more accurate estimation of bandwidth. Experiments revealed that the host protocol and context switching‐induced delay variations can be as high as 800µs and could result in bandwidth estimation errors near 20%. Experiments also revealed that the DIChirp is superior to the pathChirp implementation in performance estimation since the datapath utilized by DIChirp is less prone to delay variations induced by context switching. Copyright © 2007 John Wiley & Sons, Ltd.
Delay‐dependent robust passive control for a class of nonlinear systems with time‐varying delays
Authors: Qiu Jiqing , Gao Zhifeng , Xia Yuanqing , Zhang Jinhui
Published: November 2007

In this paper, the problem of robust passive control for a class of nonlinear systems with time‐varying delays is considered. The uncertainties investigated in this paper are norm bounded and time varying, and they enter all system matrices. Based on the Lyapunov–Krasovskii functionals approach, a new robust passive control criterion is proposed in terms of linear matrix inequalities, which is dependent on the size of time delay. We also design a state feedback controller that guarantees a robust asymptotically stable and strictly passive closed‐loop system for all admissible uncertainties. Finally, two numerical examples are given to illustrate the effectiveness of the developed techniques. Copyright © 2007 John Wiley & Sons, Ltd.
A review of charge transport and recombination in polymer/fullerene organic solar cells
Authors: Pivrikas A. , Sariciftci N. S. , Juška G. , Österbacka R.
Published: November 2007

The charge carrier transport and recombination in two types of thermally treated bulk‐heterojunction solar cells is reviewed: in regioregular poly(3‐hexylthiophene) (RRP3HT) mixed with 1‐(3‐methoxycarbonyl)propyl‐1‐phenyl‐[6,6]‐methanofullerene (PCBM) and in the blend of poly[2‐methoxy‐5‐(3,7‐dimethyloctyloxy)‐phenylene vinylene] (MDMO‐PPV) mixed with PCBM. The charge carrier mobility and bimolecular recombination coefficient have been comparatively studied by using various techniques including Time‐of‐Flight (ToF), Charge Extraction by Linearly Increasing Voltage (CELIV), Double Injection (DI) transients, Current–Voltage (I–V) technique. It was found that the carrier mobility is at least an order of magnitude higher in RRP3HT/PCBM blends compared to MDMO‐PPV/PCBM. Moreover, all used techniques demonstrate a heavily reduced charge carrier recombination in RRP3HT/PCBM films compared to Langevin‐type carrier bimolecular recombination in MDMO‐PPV/PCBM blends. As a result of long carrier lifetimes the formation of high carrier concentration plasma in RRP3HT/PCBM blends is demonstrated and plasma extraction methods were used to directly estimate the charge carrier mobility and bimolecular recombination coefficients simultaneously. A weak dependence of bimolecular recombination coefficient on the applied electric field and temperature demonstrates that carrier recombination is not dominated by charge carrier mobility (Langevin‐type recombination) in RRP3HT/PCBM blends. Furthermore, we found from CELIV techniques that electron mobility in RRP3HT/PCBM blends is independent on relaxation time in the experimental time window (approx. hundreds of microseconds to tens of milliseconds). This reduced carrier bimolecular recombination in RRP3HT/PCBM blends implies that the much longer carrier lifetimes can be reached at the same concentrations which finally results in higher photocurrent and larger power conversion efficiency of RRP3HT/PCBM solar cells. Copyright © 2007 John Wiley & Sons, Ltd.
High speed laser processing for monolithical series connection of silicon thin‐film modules
Authors: Haas Stefan , Gordijn Aad , Stiebig Helmut
Published: November 2007

A detailed analysis of the monolithical series connection of silicon thin‐film modules with metal back contact fabricated by high‐speed laser ablation will be presented. In this study, optically pumped solid‐state lasers with wavelengths of 1064 nm and 532 nm were used for the patterning process. The influence of various laser parameters on the performance of amorphous and microcrystalline silicon modules will be discussed. In particular, the line‐scribing parameters for a TCO and Ag back contact system was analyzed in detail, since it is the most critical patterning step. A detailed description of the back contact ablation process will be presented and a criterion for flakeless patterning was defined. Finally the influence of the back contact patterning on the electrical behavior of silicon single junction cells was studied. The dark current density versus back‐contact patterning line length was analyzed by means of a developed SPICE (simulation program with integrated circuit emphasis) simulation model. Copyright © 2007 John Wiley & Sons, Ltd.
Nanoscale structure of solar cells based on pure conjugated polymer blends
Authors: Veenstra Sjoerd C. , Loos Joachim , Kroon Jan M.
Published: November 2007

This paper gives an overview of the status of photovoltaic devices based on blends of semiconducting polymers. The polymer blends form the bulk heterojunction in these photovoltaic devices. The fundamental mechanisms governing the performance of these devices are discussed as well as the specificities of these all‐polymer solar cells. The morphology of the polymer blend layer is expected to influence the device performance of these bulk heterojunctions. An overview is presented of factors that influence the morphology of the active layer of polymer blend photovoltaic devices together with a summary of tools available to study the structure of this layer. An advanced electron microscopy technique is applied to study the morphology of polymer blends of MDMO‐PPV and PCNEPV with differing molecular weights. It is shown that the molecular weight of the polymer influences the typical domain size from ∼200 nm down to less than 5 nm in these bulk heterojunction PV devices. No strong relation is observed between the typical length scale of the phase separated domains and the measured external quantum efficiency, indicating that the phases are intermixed. Copyright © 2007 John Wiley & Sons, Ltd.
Immunoproteomics of extracellular proteins of Chinese virulent strains of Streptococcus suis type 2
Authors: Zhang Wei , Lu Cheng Ping
Published: November 2007

Streptococcus suis type 2 (SS2) is a porcine zoonotic pathogen with worldwide distribution, and lacking suitable vaccine and virulent maker were bottleneck to control this infection. An immunoproteomic assay was used to identify antigenic proteins from the total extracellular proteins of the virulent Chinese SS2 strain ZY05719. The convalescent serum of a specific pathogen free (SPF) mini‐pig recognized nine protein spots on PVDF membrane. Antigenic proteins on a duplicate gel, as well as those with a similar placement of extracellular proteins from another virulent strain (HA9801) and an avirulent strain (T15) on 2‐D gels, were excised and identified by MALDI‐TOF‐MS. PMF of the protein spots were performed using the MASCOT server. Two proteins were found in all three strains. Comparative proteomic analysis between the two virulent strains and the avirulent strain revealed nine differential proteins, eight of which were successfully identified. Genes for six of the differentially expressed proteins were found in both virulent strains, and of those were present in the avirulent stain.
Quantitative proteomes and in vivo secretomes of progressive and regressive UV‐induced fibrosarcoma tumor cells: Mimicking tumor microenvironment using a dermis‐based cell‐trapped system linked to tissue chamber
Authors: Shi Yang , Elmets Craig A. , Smith Jeffery W. , Liu Yu‐Tsueng , Chen Yun‐Ru , Huang Cheng‐Po , Zhu Wenhong , Ananthaswamy Honnavara N. , Gallo Richard L. , Huang Chun‐Ming
Published: November 2007

The alterations of tumor proteome and/or in vivo secretome created by host‐tumor cell interaction may be crucial factors for tumors to undergo progression or regression in a host system. Two UV‐induced fibrosarcoma tumor cell lines (UV‐2237 progressive cells and UV‐2240 regressive cells) were used as models to address this issue. Hundreds of proteins including in vivo secretome have been identified and quantified via an isotope‐coded protein label (ICPL) in conjunction with high‐throughput NanoLC‐LTQ MS analysis. A newly designed technology using a dermis‐based cell‐trapped system was employed to encapsulate and grow 3‐D tumor cells. A tissue chamber inserted with a tumor cell‐trapped dermis was implanted into mice to mimic the tumor microenvironment. The in vivo secretome created by host‐tumor interaction was characterized from samples collected from tissue chamber fluids via ICPL labeling mass spectrometric analysis. Twenty‐five proteins including 14‐3‐3 proteins, heat shock proteins, profilin‐1, and a fragment of complement C3 with differential expression in proteomes of UV‐2237 and UV‐2240 cells were revealed. Three secreted proteins including myeloperoxidase, alpha‐2‐macroglobulin, and a vitamin D‐binding protein have different abundances in the in vivo secretome in response to UV‐2237 and UV‐2240 cells. Differential tumor proteomes and in vivo secretome were thus accentuated as potential therapeutic targets to control tumor growth.
Proteolytic cleavage of the Chlamydia pneumoniae major outer membrane protein in the absence of Pmp10
Authors: Juul Nicolai , Timmerman Evy , Gevaert Kris , Christiansen Gunna , Birkelund Svend
Published: November 2007

The genome of the obligate intracellular bacteria Chlamydia pneumoniae contains 21 genes encoding polymorphic membrane proteins (Pmp). While no function has yet been attributed to the Pmps, they may be involved in an antigenic variation of the Chlamydia surface. It has previously been demonstrated that Pmp10 is differentially expressed in the C. pneumoniae CWL029 isolate. To evaluate whether the absence of Pmp10 in the outer membrane causes further changes to the C. pneumoniae protein profile, we subcloned the CWL029 isolate and selected a clone with minimal Pmp10 expression. Subsequently, we compared the proteome of the CWL029 isolate with the proteome of the subcloned strain and identified a specific cleavage of the C‐terminal part of the major outer membrane protein (MOMP), which occurred only in the absence of Pmp10. In contrast, when Pmp10 was expressed we predominantly observed full‐length MOMP. No other proteins appeared to be regulated according to the presence or absence of Pmp10. These results suggest a close association between MOMP and Pmp10, where Pmp10 may protect the C‐terminal part of MOMP from proteolytic cleavage.
Proteome and phosphoproteome analysis of chromatin associated proteins in rice (Oryza sativa)
Authors: Tan Feng , Li Guosheng , Chitteti Brahmananda Reddy , Peng Zhaohua
Published: November 2007

The eukaryotic chromatin/chromosome stores genomic information, controls genetic material distribution, and plays an essential role in the establishment and maintenance of spatial and temporal gene expression profile. Despite over a century of research, the protein composition and higher level structure of chromatin still remain obscure, particularly in plants. In this report, we have developed a protocol for chromatin purification from rice suspension cells and examined proteins copurified with chromatin using both 2‐DE gel and shotgun approaches. Nine hundred seventy‐two distinct protein spots have been resolved on 2‐DE gels and 509 proteins have been identified by MALDI‐MS/MS following gel excision, which correspond to 269 unique proteins. When the chromatin copurified proteins are examined using shotgun method, a large number of histone variants in addition to the four common core histones have been identified. Other proteins identified include nucleosome assembly proteins, high mobility group proteins, histone modification proteins, transcription factors, and a large number of hypothetical and function unknown proteins. Furthermore, putative phosphoproteins copurified with chromatin have been examined using Pro‐Q Diamond phosphoprotein stain and followed by MALDI‐MS/MS. Our studies have provided valued new insight into chromatin composition in plants.
Protein partners in the life history of activated fibroblast growth factor receptors
Authors: Vecchione Anna , Cooper Helen J. , Trim Kimberley J. , Akbarzadeh Shiva , Heath John K. , Wheldon Lee M.
Published: November 2007

Fibroblast growth factor receptors (FGFRs) are a family of four transmembrane (TM) receptor tyrosine kinases (RTKs) which bind to a large family of fibroblast growth factor (FGF) ligands with varying affinity and specificity. FGFR signaling regulates many physiological and pathological processes in development and tissue homeostasis. Understanding FGFR signaling processes requires the identification of partner proteins which regulate receptor function and biological outputs. In this study, we employ an epitope‐tagged, covalently dimerized, and constitutively activated form of FGFR1 to identify potential protein partners by MS. By this approach, we sample candidate FGFR effectors throughout the life history of the receptor. Functional classification of the partners identified revealed specific subclasses involved in protein biosynthesis and folding; structural and regulatory components of the cytoskeleton; known signaling effectors and small GTPases implicated in endocytosis and vesicular trafficking. The kinase dependency of the interaction was determined for a subset of previously unrecognized partners by coimmunoprecipitation, Western blotting, and immunocytochemistry. From this group, the small GTPase Rab5 was selected for functional interrogation. We show that short hairpin (sh) RNA‐mediated depletion of Rab5 attenuates the activation of the extracellular‐regulated kinase (ERK) 1/2 pathway by FGFR signaling. The strategic approach adopted in this study has revealed bona fide novel effectors of the FGFR signaling pathway.