bluuebunny/crossref_metadata_2025 huggingface dataset:
Dual band‐notched annular monopole antenna with tunable structure for UWB application
Authors: Jeng Bo‐Ming , Luo Ching‐Hsing
Published: April 2013

A novel annular monopole antenna with a dual‐band rejection characteristic for ultra‐wideband (UWB) applications is proposed.This antenna comprises an annular‐shape radiating element with a tuning stub and a backside elliptical radiating element that is connected to it by a shorting pin, to create dual‐notched bands at 3.2–4.4 GHz and 4.8–5.9 GHz across the UWB frequency band from 2.5 to 14.5 GHz, to filter the WIMAX and WLAN signals. Measurements demonstrate that the proposed antenna provides a very large bandwidth from 2.5 to 14.5 GHz (141%, voltage standing wave ratio 2). A good monopole‐like radiation pattern except the notched bands is obtained. Details of the proposed antenna design and the simulated results are presented and discussed. © 2013 Wiley Periodicals, Inc. Microwave Opt Technol Lett 55:1546–1549, 2013; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.27609
Card‐type slot antenna for UHF RFID tag close to the chest of a human body
Authors: Chiu Chien‐Wen , Ou Chen‐An , Wang Hwang‐Cheng , Chuang Yu‐Chou
Published: April 2013

This article presents a UHF radio frequency identification tag antenna used in proximity to the chest of a human body for student ID card identification.The proposed tag antenna is a rectangular slot‐type patch structure printed on a PVC card. For near‐body applications, stratified square plates with physical parameters are used as a human model. The radiation properties of the slotted tag antenna placed near the model and the absorption effects due to human body are investigated. The research used the HFSS simulator to optimally design the antenna and employed the FEKO simulator to verify the simulated results. The designed tag was constructed for testing the reading range. The measured reading range achieved is around 4.2 m as the tag is put close to the chest. © 2013 Wiley Periodicals, Inc. Microwave Opt Technol Lett 55:1626–1631, 2013; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.27610
Design and fabrication of EBG and CWP antennas using inkjet printing technology
Authors: Kanso Ahmad , Arnaud E. , Chreim Hassan , Monédière Thierry , Thévenot Marc , Beaudrouet Eloi , Dossou‐yovo Christelle , Noguéra Remi
Published: April 2013

This article presents a solution to bypass the cost and flatness problems for low‐cost electronic devices which is the inkjet printing. This process allows the use of flexible substrate materials, such as paper or plastics, suitable for a real‐to‐real process. More precisely, the procedure to design an electromagnetic band gap antenna using frequency selective surfaces and coplanar wire‐patch antenna for 2.5‐GHz applications is detailed. This kind of antenna has been designed before, but the used substrate is expensive and thin. These antennas were fabricated using inkjet printing technology on a flexible, low‐cost paper substrate using a simple, fast, and cheap process compared to the photolithography technology. The design characteristics of the antennas were verified and the experimental measurements were successfully compared to the simulated ones. © 2013 Wiley Periodicals, Inc. Microwave Opt Technol Lett 55:1520–1526, 2013; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.27613
Scattered field FETD modeling of oblique plane wave incidence from a circular PEC cylinder: TMz polarization
Authors: Bavelis Konstantinos , Mias Christos
Published: April 2013

Oblique TMz polarized plane wave scattering from a perfectly electrically conducting cylinder of circular cross‐section is modeled using a finite‐element time‐domain formulation in terms of the scattered electric field using a modal nonreflecting boundary condition and both nonperiodic and periodic formulations.© 2013 Wiley Periodicals, Inc. Microwave Opt Technol Lett 55:1516–1520, 2013; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.27614
Chaotic ultra‐wideband over fiber link based on optical feedback laser diode
Authors: Zhang Mingjiang , Zheng Jianyu , Wang Anbang , Wang Yuncai , Jiang Junfeng , Liu Tiegen
Published: April 2013

A chaotic ultra‐wideband (UWB) over fiber link based on optical feedback laser diode which generates the chaotic laser signals is proposed and demonstrated. Flexible generation of up to 1.44 Gb/s on‐off keying chaotic‐UWB signals is successfully achieved. Without utilizing any dispersion compensation module, the signals with bit rate of 1.44 Gb/s were detected using a digital signal processing receiver after 20‐km optical fiber and 0.6‐m wireless channel transmission. © 2013 Wiley Periodicals, Inc. Microwave Opt Technol Lett 55:1504–1507, 2013; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.27615
Compact and weightlight electromagnetic band gap superestrate antenna for C‐band TT&C applications
Authors: Tellechea Amagoia , Iriarte Juan Carlos , Ederra Iñigo , Gonzalo Ramón , Monjas Fernando , Arenas Silvia , Manrique Rodrigo , Montesano Antonio
Published: April 2013

This article proposes the design of a 2 (2 array electromagnetic band gap superstrate antenna capable to fulfill the specific radiofrequency (RF) requirements of a C‐band (3.7 GHz) TT&C telecommunication system from geostationary orbits. Design efforts are focused on overall volume reduction while complying with RF performances over the required frequency bandwidth, trying to provide an advantageous alternative to the bulky horn antennas usually used for TT&C operations in current satellites. © 2013 Wiley Periodicals, Inc. Microwave Opt Technol Lett 55:1457–1461, 2013; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.27616
Frequency‐tunability of a miniaturized waveguide filter loaded with a split‐ring‐resonator
Authors: Park Wook‐Ki , Han Seong‐Tae , Oh Soon‐Soo
Published: April 2013

In this article, we describe a frequency‐tunability procedure for a waveguide single‐pole bandpass filter adopting a split‐ring resonator (SRR). The tuning procedure is, in this article, achieved by inserting a metal or ferrite tuning screw, depending on the desired tuning direction. The screw plays a role in the adjustment of the magnetic field passing through the center of the SRR. The discrepancy between the proposed waveguide filter and the evanescent‐mode filter has been included. The aperture size of the waveguide filter is decreased by about 70% in comparison with conventional waveguides. The wide tuning bandwidths and lower insertion losses obtained by both simulation and measurement confirm the validity of the proposed technique. © 2013 Wiley Periodicals, Inc. Microwave Opt Technol Lett 55:1649–1653, 2013; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.27618
Performance evaluation of an all‐fiber ratiometric wavelength monitor system using edge filters based on sms fiber structures
Authors: Hatta Agus M. , Semenova Y. , Farrell G.
Published: April 2013

This article presents performance evaluation of the use of one or two edge filter(s) based on singlemode‐multimode‐singlemode (SMS) fiber structure on an all‐fiber ratiometric wavelength monitor system.Several aspects of noise, polarization‐dependent loss (PDL), and temperature‐dependent loss (TDL) that can influence the system's performance were investigated. It was demonstrated that the use of two SMS edge filters can improve the system's resolution and wavelength error when compared with the use of one edge filter. © 2013 Wiley Periodicals, Inc. Microwave Opt Technol Lett 55:1645–1649, 2013; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.27619
Design of a multi‐input multi‐output antenna with improved isolation using RF choke for long‐term evolution mobile application
Authors: Ga Deukhyeon , Lee Youngki , Choi Jaehoon
Published: April 2013

A multi‐input multi‐output (MIMO) antenna with improved isolation using radio frequency choke (RFC) is proposed.The proposed MIMO antenna consists of two radiating elements and an RFC that is located in between the two radiating elements. To improve the isolation between the two radiating elements of the MIMO antenna, the RF signal is suppressed at the desired frequency band by utilizing an RFC. The isolation is improved by ∼20 dB at the center frequency. The fabricated antenna satisfies the 6 dB return loss in long‐term evolution band 13 from 746 to 787 MHz. The measured average efficiency and gain of the MIMO antenna are about 30.5% and −1.5 dBi, respectively. The measured envelope correlation coefficient is less than 0.4 over the frequency band of interest. © 2013 Wiley Periodicals, Inc. Microwave Opt Technol Lett 55:1569–1574, 2013; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.27623
A low phase noise differential dual‐resonance complementary colpitts VCO
Authors: Jain Sanjeev , Jang Sheng‐Lyang , Juang Miin‐Horng
Published: April 2013

A dual‐resonance complementary Colpitts voltage‐controlled oscillator (VCO) is proposed to serve as a dual‐band oscillator operated at 4.3 and 11.7 GHz.The VCO consists of two single‐ended dual‐resonance LC‐tank complementary Colpitts oscillators sharing a common varactor‐switching LC resonator. The proposed VCO has been implemented with the TSMC 0.18 μm 1P6M CMOS technology and the core power consumption is 3.60/3.96 mW at the supply voltage of 1.2 V. The VCO has figure of merit −192.7/−189.4 dBc/Hz at high/low band, respectively. The die area of the dual‐band VCO is 0.822 × 0.628 mm2. © 2013 Wiley Periodicals, Inc. Microwave Opt Technol Lett 55:1494–1497, 2013; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.27626
Microwave bandpass filters with tunable center frequencies and reconfigurable transmission zeros
Authors: Zhou Rongguo , Mandal Iman , Zhang Hualiang
Published: April 2013

This article presents the design of a microwave bandpass filter with tunable center frequencies and reconfigurable transmission zeros. The tuning of the center frequencies is realized by loading varactors at the ends of the λ/2 resonator. The reconfiguration of transmission zero is implemented through varactors in combination with tapped λ/4 stubs. The equivalent circuit models of the tunable filters are provided. The transmission zeros can be set to be at the lower side, the upper side, or both sides of the passband. The design concept is demonstrated by measurement results for both one transmission zero case and two transmission zeros case. The tuning frequency ranges are 680–890 MHz and 680–1020 MHz for one zero case and two zeros case, respectively. © 2013 Wiley Periodicals, Inc. Microwave Opt Technol Lett 55:1526–1531, 2013; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.27628
Isolation improvement of a TRx stacked microstrip patch antenna using double spur‐line band rejection filters
Authors: Batgerel Ariunzaya , Eom Soon‐Young
Published: April 2013

In this article, we present a TRx stacked microstrip patch antenna with improved isolation using double spur‐line band rejection filters (DSL‐BRFs).The typical TRx stacked microstrip patch antenna designed to operate at Ku‐band with downlink frequency band of 12.25–12.75 GHz and uplink frequency band of 14.0–14.5 GHz had inherent isolation of 16 dB within TRx‐band. The isolation performance of the antenna was improved by at least 23.45 dB in Rx‐band and 17.82 dB in Tx‐band after introducing the DSL‐BRFs into Tx‐ and Rx‐feed networks, respectively. Because the DSL‐BRFs are compatible to be embedded in 50‐Ω transmission lines, the TRx antenna with the filters are remained in as same size as the antenna without filters. © 2013 Wiley Periodicals, Inc. Microwave Opt Technol Lett 55:1444–1448, 2013; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.27632
Miniaturization of asymmetric coplanar strip‐fed staircase ultrawideband antenna with reconfigurable notch band
Authors: Li Yingsong , Li Wenxing , Ye Qiubo
Published: April 2013

A compact asymmetric coplanar strip‐fed staircase ultrawideband (UWB) antenna with notch band reconfigurable characteristic is proposed and investigated numerically and experimentally.The reconfigurable notch bands are realized by using a spur‐slot and an ideal switch. By controlling the switch at OFF and ON states, the notch bands of the proposed UWB antenna can work at 3.5 and 8.2 GHz, respectively. Numerical and experimental results show that the proposed antenna is capable of working for entire UWB application and providing the reconfigurable notch bands. © 2013 Wiley Periodicals, Inc. Microwave Opt Technol Lett 55:1467–1470, 2013; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.27634
Broadband bandpass filter using parallel‐coupled microstrip line and coupled open stub resonator
Authors: Marimuthu Jayaseelan , Abbosh Amin , Henin Bassem
Published: April 2013

A novel broadband bandpass filter with multiple resonant modes based on parallel‐coupled microstrip line is proposed. The required cutoff frequency and out‐of‐band performance are achieved by placing L‐shaped capacitive cross‐coupling open stubs at the middle resonator with appropriate dimensions. A compact broadband bandpass filter of dimensions 18 × 29 mm2 is fabricated and tested for performance confirmation. The proposed filter demonstrates a wide bandwidth (from 3 to 7 GHz), as well as excellent out‐of‐band performance with more than 25‐dB rejection up to more than 12 GHz and sharp upper cutoff frequency due to the proper location of two transmission zeros. © 2013 Wiley Periodicals, Inc. Microwave Opt Technol Lett 55:1640–1644, 2013; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.27637
Capacitive‐coupled resonator‐based bandpass filter with controllable multiple transmission zeros at stopband
Authors: Huang Hui‐Hsiang , Horng Tzyy‐Sheng
Published: April 2013

This letter proposes novel design for a compact LTCC bandpass filter with high rejection over a wide stopband operating in the 3.4–3.6‐GHz worldwide interoperability for microwave access band. The presented bandpass filter has feedback paths for the grounding inductor and the coupled capacitor to provide controllable multiple transmission zeros at 2.4/5‐GHz wireless local area network band, which enhances the desired stopband rejection. The presented design derives simple formulas for synthesizing a bandpass filter to meet the specification requirement in the passband insertion loss and passband return loss as well as the stopband attenuation. The bandpass filter is designed and implemented using LTCC process and has an area of 2.0 × 1.25 mm2. Experiments results are very agreement with the full‐wave simulation results. © 2013 Wiley Periodicals, Inc. Microwave Opt Technol Lett 55:1563–1565, 2013; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.27643
Conical antenna design for the excitation of RTL chamber for cell experiments
Authors: Kim Tae‐Hong , Lee Hyeonjin
Published: April 2013

In this article, a conical antenna fed by coaxial line fed for the excitation of the radial transmission line (RTL) chamber is designed and fabricated. This antenna is analyzed by the finite‐difference time‐domain (FDTD) method and the input impedance is simulated. An RTL chamber was used by the device for in vitro experiments. The designed antenna has advantages, such as ultra‐broadband characteristic and omnidirectional radiation. The bandwidth of fabricated antenna has 630–2590 MHz at voltage standing wave ratio ≤ 2. © 2013 Wiley Periodicals, Inc. Microwave Opt Technol Lett 55:1558–1560, 2013; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.27646
Compact reconfigurable dual frequency microstrip patch antenna for 3G and 4G mobile communication technologies
Authors: Bekali Younes Karfa , Essaaidi Mohamed
Published: April 2013

We propose in this article, a novel compact reconfigurable patch antenna with frequency diversity. This antenna can be tuned by changing the switching mode of two PIN diodes from the ON–ON state to OFF–OFF state to switch it over two different mobile communication technologies, namely 3G and 4G. The antenna has a simple geometry and a small structure, its dimensions are 45 × 38 × 1.5 mm3 and it is printed on an FR4 substrate with a thickness of 1.5 mm. The prototype of this antenna has been fabricated and tested. The measurement results confirmed the simulation predictions in terms of frequency diversity performances. © 2013 Wiley Periodicals, Inc. Microwave Opt Technol Lett 55:1622–1626, 2013; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.27649
A study of wideband pulse shape distortion due to presence of obstacles
Authors: Mei Zicong , Sarkar Tapan K. , Salazar‐Palma Magdalena
Published: April 2013

It is observed that some antennas can transmit a signal conforming to the applied voltage to the far field without any distortion in the time domain, whereas other antennas can receive a signal from the far field which will induce a current on the antenna conforming to the shape of the incident field.With a pair of transmit/receive antennas chosen from this class, one can construct a communication system that will transmit a time‐domain wideband signal and receive it without any distortion of the pulse shape. In this article, we study the effects of the presence of obstacles along the path between the transmit and receive antennas, and we demonstrate that in some cases even when the signal is scattered by the obstacles, the shape of the received scattered pulse may not get distorted. © 2013 Wiley Periodicals, Inc. Microwave Opt Technol Lett 55:1618–1622, 2013; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.27650
A CPW‐FED compact inverted L‐strip UWB microstrip antenna
Authors: Gautam A. K. , Yadav Swati , Kanaujia Binod Kr
Published: April 2013

A novel CPW‐fed compact inverted L‐strip ultra wideband (UWB) microstrip antenna is proposed for ultra wide band applications. The proposed antenna possesses a method to minimize the monopole antenna by loading of inverted L‐strip over the conventional monopole patch antenna to lower the height of the antenna. The ground was vertically extended toward two sides of the single radiator. Therefore, the large space around the radiator that is usually wasted can be effectively saved. The antenna is practically fabricated and simulated. Measured results show a good agreement with simulated results. The prototype with overall size of 25 × 25× 1.6 mm3 achieves good impedance matching, constant gain, stable radiation patterns, and constant group delay over an operating bandwidth of 2.6–13.04 GHz (10.44 GHz). © 2013 Wiley Periodicals, Inc. Microwave Opt Technol Lett 55:1584–1589, 2013; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.27651
Slot‐array antenna for UHF RFID shelf applications
Authors: Choi Wonkyu , Bae Ji‐Hoon , Chae Jong‐Suk , Park Chan‐Won , Pyo Cheolsig
Published: April 2013

This article presents a linearly polarized slot‐array antenna that consists of a slot series‐fed by a microstrip line for radio frequency identification (RFID) shelf applications in the ultra‐high frequency band in which the end of the microstrip line is shorted to the ground plane by a via‐hole. The radiating element is a U‐shaped slot etched in the ground plane on one side of a substrate and the microstrip line for feeding is etched on the other. The designed 6 × 3 array antenna has the near‐field distribution of electric field intensity from 0.5 to 3.36 V/m for RFID shelf applications. The fractional bandwidth for a reflection coefficient of less than −10 dB is approximately 5.5% at 920 MHz, ranging from 892 to 943 MHz. The antenna installed in the RFID shelf stably reads pharmaceutical products with various package options on the shelf. © 2013 Wiley Periodicals, Inc. Microwave Opt Technol Lett 55:1511–1515, 2013; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.27653
Analytical models for predicting the effective permittivity of complementary metamaterial structures
Authors: Bait‐Suwailam Mohammed M. , Yousefi Leila , Alavikia Babak , Ramahi Omar M.
Published: April 2013

We present an analytical formula to calculate the resultant effective permittivity of a metamaterial medium composed of unit cells with complementary structures. Complementary metamaterial can be considered to be the complementary screen of artificial magnetic materials. Based on Babinet's principle and duality, complementary metamaterial provides a negative effective permittivity in the vicinity of its resonance frequency. The developed formula is general and predicts the effective permittivity for a specific topology. The derived model validated by comparison to results obtained using full‐wave simulation. © 2013 Wiley Periodicals, Inc. Microwave Opt Technol Lett 55:1565–1569, 2013; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.27655
A new X‐band triple‐split ring resonator duplexer with high selectivity and adjustable size using mu‐negative metamaterial technique
Authors: Yoon Ki‐Cheol , Lee Hyunwook , Lee Jong‐Chul , Kim Ki‐Byoung , Kim Seong‐Cheol
Published: April 2013

In this article, a narrow‐bandwidth duplexer with a triple‐split ring resonator (T‐SRR) using mu‐negative metamaterial is presented. The T‐SRR not only has negative permeability at the operating frequency band but also flexibility in size adjustment. The experimental results for insertion and return losses are 1.33 and 16.1 dB with a bandwidth of 10% at a RX center frequency of 8 GHz, and they are 1.27 and 16.8 dB at the same bandwidth at a TX center frequency of 10 GHz, respectively. © 2013 Wiley Periodicals, Inc. Microwave Opt Technol Lett 55:1537–1540, 2013; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.27656
All‐fiber temperature sensor based on few mode fiber and single‐mode fiber
Authors: Chen Daru , Jiang Xiaogang
Published: April 2013

We propose and demonstrate a novel all‐fiber temperature sensor that is a single‐end fiber modal interferometer (FMI) based on a segment of a few mode fiber (FMF) and a segment of a single‐mode fiber (SMF).The FMF spliced to a lead‐in SMF is used to expend the optical beam in the fiber and the sensing SMF with a well‐cleaved end is spliced to the FMF. Owing to the core mismatch between the FMF and the sensing SMF, part of the guided light propagates in the cladding of the sensing SMF and part of the guided light propagates in the core of the sensing SMF, which finally forms the FMI when the reflective light comes back to the FMF. Temperature sensing is achieved by measuring the wavelength shift of the FMI. A temperature sensor with an average sensitivity of 0.1 nm/°C in a temperature range from 33 to 833°C is presented. © 2013 Wiley Periodicals, Inc. Microwave Opt Technol Lett 55:1700–1703, 2013; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.27657
V‐band millimeter‐wave microstrip to rectangular waveguide transition
Authors: Hammou Djilali , Nedil Mourad , Kandil Nahi , Moldovan Emilia , Tatu Serioja O.
Published: April 2013

This article proposes a novel millimeter‐wave microstrip (MSL) to WR 12 standard rectangular waveguide transitions. These dissimilar structures are interconnected via a substrate integrated waveguide (SIW). The MSL and the SIW are integrated on the same ceramic substrate of 9.9 relative permittivity and 125 μm thickness. The MSL was first transformed into an air‐filled rectangular waveguide, and then a stepped impedance or horn transformer was used to match the WR12 standard rectangular waveguide. The central frequency of operation is 61 GHz as required in V‐band wireless communications applications. Commercial Finite Element Method Software and High Frequency Structure Simulator (HFSS) was used to perform the design and the optimization. The S parameter measurements of the back‐to‐back connected transitions show an insertion loss less than 1.5 dB and a return loss better than −10 dB over a 4 GHz band from 60 to 64 GHz. The high performance, the compact size, and the simple fabrication, enable similar transitions to be employed in a number of other millimeter‐wave applications. © 2013 Wiley Periodicals, Inc. Microwave Opt Technol Lett 55:1696–1700, 2013; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.27658
Beam tilting of single microstrip antenna using high permittivity superstrate
Authors: Attia Hussein , Siddiqui Omar , Ramahi Omar
Published: April 2013

Antenna beam tilting or steering requires multiple antenna elements to be phase shifted and arranged in the form of an array. This article presents a novel method to tilt the main beam of a microstrip patch by partially covering it with a high dielectric‐constant superstrate. The beam tilting is possible because of the dual‐slot radiation mechanism of the microstrip antenna. In effect, the electromagnetic radiation from the covered radiating slot reaches the far‐field with an additional phase with respect to the uncovered slot, resulting in an inclined beam whose angle depends on the superstrate's refractive index. Experimentally and numerically, a beam deflection of 25° is achieved when a microstrip patch is partially covered with a superstrate having a dielectric constant of 10. Moreover, the proposed structure provides gain enhancement of about 3 dB. © 2013 Wiley Periodicals, Inc. Microwave Opt Technol Lett 55:1657–1661, 2013; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.27659
Four‐element microstrip array with polarization diversity
Authors: Ma Shun‐Lai , Shih Chuang Jiashih , Row Jeen‐Sheen
Published: April 2013

A four‐element microstrip antenna array excited with a tunable feeding network is described.The feeding network is composed of three quasi‐lumped couplers and a 90° phase delay line. By controlling one dc bias, the network can provide the same amplitude and two different phase combinations, including (0°, 0°, 180°, 180°) and (0°, 90°, 180, 270°), for the four array elements. With the tunable feeding network, the excitation method of the array can be switched between sequentially rotated feed mechanism and differential‐feed mechanism. A reconfigurable array prototype is constructed. Experimental results show that the array has a broadside radiation and it can provide good linear and circular polarization performances at one frequency. Simulated results are also provided to validate the designs of the microstrip antenna array with switchable polarization. © 2013 Wiley Periodicals, Inc. Microwave Opt Technol Lett 55:1653–1657, 2013; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.27660
Radio‐frequency microfluidic interferometer in printed circuit board process
Authors: Blankenagel Bryan S. , Khadka Shiul , Hawkins Aaron R. , Warnick Karl F. , Mazzeo Brian A.
Published: April 2013

We report a process to integrate microfluidic channels on standard radio‐frequency (RF) printed circuit board (PCB) substrate. A 10.56‐GHz RF microstrip interferometer was fabricated using the proposed technique and used to compare electrical responses for liquids with various dielectric properties and thereby demonstrate the capability of RF PCB‐integrated microfluidic devices for biological sensing. Microchannels were milled into a substrate and prepreg outlines for microchannels were cut using a laser system. Substrates were adhered and bonded by clamping and baking. The RF interferometer responded to changes in liquid permittivity with high sensitivity relative to many other types of dielectric sensors. © 2013 Wiley Periodicals, Inc. Microwave Opt Technol Lett 55:1616–1618, 2013; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.2766
Analysis of the quality factor of the optical half‐wavelength resonator
Authors: Belyaev Boris A. , Tyurnev Vladimir V.
Published: April 2013

An electrodynamic analysis of an optical resonator comprising a half‐wavelength dielectric layer that is covered from both sides by quarter‐wavelength layers with higher and lower refractive indices (RIs) is carried out.For such a resonator, the dependences of the external quality factor on number and RIs of the layers are obtained first. That allows one to determine minimum number of the layers in the structure to achieve the required quality factor at practically any contrast of the RIs. The results of this study provide an easy way to optimize the structures of 1D photonic crystal devices, particularly high‐selectivity bandpass filters. © 2013 Wiley Periodicals, Inc. Microwave Opt Technol Lett 55:1613–1616, 2013; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.27662
A compact UWB CPW bandpass filter with short‐ended H‐shaped resonator and controllable notched band
Authors: Wang Kai , Wong Sai Wai , Chu Qing‐Xin
Published: April 2013

An ultra‐wideband (UWB) bandpass filter (BPF) using the hybrid microstrip and coplanar waveguide (CPW) structure is proposed in this article.The BPF composes of CPW feed lines and H‐shaped microstrip resonator. By a CPW/microstrip back‐to‐back coupling structure, the UWB BPF was realized with the passband covering the entire UWB band (3.1–10.6 GHz). A narrow notched band achieved by etching slots on the lower impedance part of the H‐shaped resonator to form an open circuit stub. At last, three U‐slot DGSs are used to achieve a good upper‐stopband rejection. The measured results are in good agreement with the simulated results. © 2013 Wiley Periodicals, Inc. Microwave Opt Technol Lett 55:1577–1581, 2013; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.27663
Widely tunable L‐band multiwavelength brillouin‐erbium fiber laser incorporating a bismuth‐based erbium‐doped fiber
Authors: Wei Yizhen , Zhou Xuefang , Wang Tianshu
Published: April 2013

We have demonstrated a widely wavelength tunable Brillouin‐erbium fiber laser (BEFL) with multiwavelength lasing in the L‐band region. The Brillouin pump (BP) is injected from the external cavity and preamplified by an intracavity bismuth‐based erbium‐doped fiber amplifier (Bi‐EDFA) before entering the single‐mode fiber. By combining the broadband gain of Bi‐EDFA and BP preamplification technique within the linear cavity, our BEFL exhibits a broad tuning range of 65 nm from 1555 to 1620 nm, which is the widest one achieved in L‐band BEFLs to the best of our knowledge. The maximum number of wavelengths obtained within this wavelength range is 12 channels with a spacing of approximately 0.088 nm. © 2013 Wiley Periodicals, Inc. Microwave Opt Technol Lett 55:1574–1577, 2013; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.27664
Design and implementation of a hybrid digital and RF front‐end module for 24‐GHz intelligent transport system pulse‐doppler radar
Authors: Ju Yeonghwan , Kim Sang‐Dong , Lee Jonghun
Published: April 2013

This article presents a hybrid digital and RF front‐end module (FEM) of a 24‐GHz pulse‐Doppler radar system for intelligent transport system applications. The conventional pulse generators use analog components such as step recovery diode. It is difficult to control the parameters of the pulse. In addition, the heterodyne architecture based transceivers show good performance, but they are very expensive. To overcome these limitations, a digital pulse generator was developed based on field‐programmable gate array platform to obtain high degree of freedom in a waveform design. Instead of the heterodyne architecture, a transceiver based on the homodyne architecture was developed. For the first time, hybrid digital FEM based 24‐GHz pulse‐Doppler radar was developed by combining a digital pulse generator and a homodyne‐based transceiver. Experimental results showed the feasibility of using a hybrid digital FEM for a 24‐GHz pulse‐Doppler radar. The developed hybrid digital FEM contributes to the advancement of the digital radar field. © 2013 Wiley Periodicals, Inc. Microwave Opt Technol Lett 55:1631–1638, 2013; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.27666
Dual‐band bandpass filters based on dual‐mode hilbert fractal resonator
Authors: Crnojevic‐Bengin Vesna , Zemlyakov Kirill , Jankovic Nikolina , Vendik Irina
Published: April 2013

We propose a compact planar dual‐mode resonator based on a Hilbert fractal curve that operates at two arbitrary frequencies. The resonator is used to design two types of dual‐band bandpass filters for WLAN applications, which exhibit a good trade‐off between compact size and high performances, with the overall sizes ranging from 0.22 × 0.21 to 0.44 × 0.1 guided wavelengths and measured insertion losses from 0.38 to 2.5 dB. At the same time, the fabrication of filters is quite simple and requires no modifications in the ground plane or use of vias. In addition, the proposed resonator is used to design single‐band filters as well. © 2013 Wiley Periodicals, Inc. Microwave Opt Technol Lett 55:1440–1443, 2013; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.27667
Erratum: Design of a multi‐band asymmetric patch antenna for wireless applications
Authors: Malekpoor Hossein , Jam Shahrokh
Published: April 2013

Originally published Microwave Opt Technol Lett 55:730–734, 2013. © 2012 Wiley Periodicals, Inc. Microwave Opt Technol Lett 55:1703, 2013; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.27669 (Original article DOI 10.1002/mop.27449)
Degree and Direction of Paid Employee/Volunteer Interchange in Nonprofit Organizations
Authors: Chum Antony , Mook Laurie , Handy Femida , Schugurensky Daniel , Quarter Jack
Published: April 2013

This study builds on an earlier one (Handy, Mook, and Quarter 2008) that examined the degree of interchangeability between volunteers and paid employees in nonprofit organizations. In the current study, we surveyed 836 nonprofits in Canada to understand what factors determine the degree of interchange between paid employees and volunteers, bearing in mind that this interchange can go in two directions: paid employees for volunteers and volunteers for paid employees. We found the degree of interchange to be widespread and in both directions. One of the most important predictors of the likelihood of interchange was the number of full‐time employees, suggesting that interchangeability occurs less frequently in organizations with a larger number of employees than in those with fewer employees. Religious congregations and organizations with workload increases were more likely to interchange tasks among volunteers and paid staff.
The Hospital Foundation Strategy and Performance Relationship
Authors: Marlin Dan , Geiger Scott W. , Ritchie William J.
Published: April 2013

Attracting philanthropic donations is a strategic imperative for many hospitals. A hospital can manage the giving process most effectively by developing a well‐managed hospital foundation. This study examines the hospital foundation strategy and performance relationship. Using a sample of 258 hospital foundations we identified different strategies and significant performance differences among them.
Obesity‐related dysregulation of the Tryptophan–Kynurenine metabolism: Role of age and parameters of the metabolic syndrome
Authors: Mangge Harald , Summers Kelli L. , Meinitzer Andreas , Zelzer Sieglinde , Almer Gunter , Prassl Ruth , Schnedl Wolfgang J. , Reininghaus Eva , Paulmichl Katharina , Weghuber Daniel , Fuchs Dietmar
Published: April 2013

Objective

Obesity‐related immune mediated systemic inflammation was associated with the development of the metabolic syndrome by induction of the tryptophan (TRP)–kynurenine (KYN) pathway. The study aimed to assess whether this holds true across the lifespan from juvenility to adulthood.

Design and Methods

Five hundred twenty‐seven participants aged between 10 and 65 years were analyzed. Standard anthropometric measures, carotid ultrasound, and laboratory analysis including interleukin‐6, ultra‐sensitive C‐reactive protein, lipids, glucose metabolism, neopterin, TRP, KYN levels, and the KYN/TRP ratio were performed.

Results

Overweight/obese (ow/ob) adults had significantly increased KYN serum levels and a significantly increased KYN/TRP ratio. In sharp contrast, ow/ob juvenile males aged ≤18 years showed decreased, females similar KYN and KYN/TRP ratio in comparison to their control counterparts. Also, adult ow/ob subjects with metabolic syndrome showed markedly increased KYN/TRP ratios contrary to decreased KYN/TRP ratios in ow/ob juveniles. Abdominal fat content, characterized by age normalized waist circumference, and not body mass index, had the strongest effect for an increase of the KYN/TRP ratio in adults.

Conclusions

TRP metabolism and obesity‐related immune mediated inflammation differs markedly between juveniles and adults. While childhood obesity seems to be dominated by a Th2‐driven activation, an accelerated production of Th1‐type cytokines may pave the way for later atherosclerotic endpoints.
Effectiveness of a Pharmacy Care Management Program for Veterans with Dyslipidemia
Authors: Smith Michael C. , Boldt Amy S. , Walston Cassandra M. , Zillich Alan J.
Published: April 2013

Objective

To evaluate the effectiveness of a care management program provided by clinical pharmacists for veterans with dyslipidemia.

Design

Retrospective cohort design.

Setting

Two primary care clinics at a Veterans Affairs Medical Center.

Patients

An intervention (IT) cohort of 213 patients referred for management of dyslipidemia by clinical pharmacists and a control cohort of 219 patients with dyslipidemia receiving usual care (UC).

Methods

Data were obtained from electronic medical records regarding drug therapy, lipid levels, and patient characteristics. Using multivariable regression models to adjust for baseline characteristics, the primary analyses compared mean final measured values of low‐density lipoprotein (LDL) cholesterol, total cholesterol (TC), high‐density lipoprotein (HDL) cholesterol, and triglycerides (TGs) among the IT and UC cohorts at the final follow‐up visits. Secondary analyses compared the proportion of patients achieving National Cholesterol Education Program/Third Report of the Expert Panel on Detection, Evaluation, and Treatment of High Blood Cholesterol in Adults (NCEP/ATPIII) concordant LDL goals and the time to achieve LDL goals between the two groups.

Results

Compared with the UC cohort, the adjusted difference in the mean final measured LDL for the IT cohort was −10.4 mg/dl (95% confidence interval [CI] −16.1 to −4.6, p < 0.001) and TC was −12.7 (95% CI −21.3 to −4.1, p=0.004). There were no significant differences in the adjusted mean final measured HDL or TGs between the two groups. The NCEP/ATPIII goal LDL was met in 80.3% of patients in the IT cohort and 65.3% of patients in the UC cohort (odds ratio [OR], 2.6; 95% CI 1.6–4.3, p<0.001). Time to achieve goal LDL was significantly shorter for the IT cohort compared with the UC cohort (risk ratio, 1.8; 95% CI 1.2–2.8, log‐rank p=0.002).

Conclusion

Veterans referred to a clinical pharmacist for treatment of dyslipidemia achieved significant reductions in TC and LDL. A greater proportion of patients achieved NCEP/ATPIII goal LDL, and the time to attainment of LDL goals was shorter in the pharmacist‐managed cohort, supporting a continued role for pharmacy care management in the treatment of patients with dyslipidemia.
New Concepts in Geophysical Surveying and Data Interpretation for Permafrost Terrain
Authors: Hauck Christian
Published: April 2013

This review focuses on advances in applications of geophysical methods to permafrost terrain that have emerged in 2007–12. Improvements in the four main geophysical techniques presently used in permafrost research (i.e. electric, electromagnetic, seismic and radar methods) and new or resurrected methods for permafrost applications are discussed. Advances in geophysical monitoring and quantitative interpretation of geophysical survey results are presented, especially for ground ice and water content. Electrical resistivity is now used operationally for long‐term monitoring of ice content, as well as for short‐term process studies. Quantitative approaches to determine realistic ice and liquid water content values and their spatial and temporal variability exist, but need to be further refined to be widely applicable for geotechnical and numerical modelling purposes. Copyright © 2013 John Wiley & Sons, Ltd.
Rethinking Labour Migration Channels: the Experience of Latvia from EU Accession to Economic Recession
Authors: McCollum David , Shubin Sergei , Apsite Elina , Krisjane Zaiga
Published: April 2013

With the onset of recession in the UK in 2008, it was assumed that immigration from other European Union countries would decline. However, this has been shown to not be the case, with the volume of new arrivals from most of the East‐Central European ‘Accession 8’ countries actually increasing. The focus of this paper is Latvia, a country that had a relatively buoyant economy following its accession to the European Union in 2004 but that now has one of the highest unemployment and emigration rates in Europe. Interviews carried out with labour providers, policymakers, and employers are used to examine the labour migration channels that reflect and structure labour migration flows from Latvia and how these have evolved in the period between accession and recession. The findings indicate that intermediaries such as labour providers, the state, and informal social networks exert considerable influence on the nature of labour migration flows and that the relative importance of these channels displays significant temporal and spatial variations. This research represents an original contribution to the literature on labour migration channels by focusing on movements from a low‐wage to higher‐wage economy in the context of the introduction of free movement of labour between Eastern and Western Europe and the later onset of severe global recession. These findings are of relevance to how labour market channels are theorised and suggest that analysts need to be sensitive to how the function served by intermediaries, and their influence on migration systems, evolves over time and across space. Copyright © 2013 John Wiley & Sons, Ltd.
Towards a trust management system for cloud computing marketplaces: using CAIQ as a trust information source
Authors: Habib Sheikh Mahbub , Ries Sebastian , Mühlhäuser Max , Varikkattu Prabhu
Published: April 2013

Cloud computing enables information technology related services in a more dynamic and scalable way than before—more cost‐effective than before due to the economy of scale and of sharing resources. Usually, cloud providers describe their promised behaviour—regarding functional and non‐functional aspects of the service provision—by way of service level agreements (SLAs). For different providers offering similar functionality, SLAs are often insufficiently claimable and inconsistent with the aspects considered important by customers. Therefore, customers face problems identifying a trustworthy cloud provider solely on the basis of its SLA. To support customers in reliably identifying trustworthy cloud providers, we propose a multi‐faceted trust management system architecture for cloud computing marketplaces and related approaches. This system provides the means for identifying trustworthy cloud providers in terms of different attributes, for example, compliance, data governance and information security. In this article, we present the first realization of our proposed trust management system using the Consensus Assessment Initiative Questionnaire, initiated by the Cloud Security Alliance, as one of the sources of trust information. In particular, our proposed approach contributes to the challenge of extracting trust information from Consensus Assessment Initiative Questionnaires completed by cloud providers. Finally, our implemented system and related approaches are experimented using real datasets. Copyright © 2013 John Wiley & Sons, Ltd.
Graphene Nanomesh Promises Extremely Efficient In Vivo Photothermal Therapy
Authors: Akhavan Omid , Ghaderi Elham
Published: April 2013

Reduced graphene oxide nanomesh (rGONM), as one of the recent structures of graphene with a surprisingly strong near‐infrared (NIR) absorption, is used for achieving ultraefficient photothermal therapy. First, by using TiO2 nanoparticles, graphene oxide nanoplatelets (GONPs) are transformed into GONMs through photocatalytic degradation. Then rGONMs functionalized by polyethylene glycol (PEG), arginine–glycine–aspartic acid (RGD)‐based peptide, and cyanine 7 (Cy7) are utilized for in vivo tumor targeting and fluorescence imaging of human glioblastoma U87MG tumors having ανβ3 integrin receptors, in mouse models. The rGONM‐PEG suspension (1 μg mL−1) exhibits about 4.2‐ and 22.4‐fold higher NIR absorption at 808 nm than rGONP‐PEG and graphene oxide (GO) with lateral dimensions of ≈60 nm and ≈2 μm. In vivo fluorescence imaging demonstrates high selective tumor uptake of rGONM‐PEG‐Cy7‐RGD in mice bearing U87MG cells. The excellent NIR absorbance and tumor targeting of rGONM‐PEG‐Cy7‐RGD results in an ultraefficient photothermal therapy (100% tumor elimination 48 h after intravenous injection of an ultralow concentration (10 μg mL−1) of rGONM‐PEG‐Cy7‐RGD followed by irradiation with an ultralow laser power (0.1 W cm−2) for 7 min), whereas the corresponding rGO‐ and rGONP‐based composites do not present remarkable treatments under the same conditions. All the mice treated by rGONM‐PEG‐Cy7‐RGD survived over 100 days, whereas the mice treated by other usual rGO‐based composites were dead before 38 days. The results introduce rGONM as one of the most promising nanomaterials in developing highly desired ultraefficient photothermal therapy.
Bright Far‐Red/Near‐Infrared Conjugated Polymer Nanoparticles for In Vivo Bioimaging
Authors: Ding Dan , Liu Jie , Feng Guangxue , Li Kai , Hu Yong , Liu Bin
Published: April 2013

A highly emissive far‐red/near‐infrared (FR/NIR) fluorescent conjugated polymer (CP), poly[(9,9‐dihexylfluorene)‐co‐2,1,3‐benzothiadiazole‐co‐4,7‐di(thiophen‐2‐yl)‐2,1,3‐benzothiadiazole] (PFBTDBT10) is designed and synthesized via Suzuki polymerization. Formulation of PFBTDBT10 using 1,2‐distearoyl‐sn‐glycero‐3‐phosphoethanolamine‐N‐[methoxy(polyethylene glycol)‐2000] (DSPE‐PEG2000) and DSPE‐PEG5000‐folate as the encapsulation matrix yielded CP‐loaded DSPE‐PEG‐folic acid nanoparticles (CPDP‐FA NPs) with bright FR/NIR fluorescence (27% quantum yield) and a large Stoke's shift of 233 nm in aqueous solution. CPDP‐FA NPs show improved thermal/photostabilities and larger Stoke's shifts as compared to commercially available quantum dots (Qdot 655) and organic dyes such as Alexa Fluor 555 and Rhodamine 6G. In vivo studies of CPDP‐FA NPs on a hepatoma H22 tumor‐bearing mouse model reveal that they could serve as an efficient FR/NIR fluorescent probe for targeted in vivo fluorescence imaging and cancer detection in a high contrast and specific manner. Together with the negligible in vivo toxicity, CPDP‐FA NPs are promising FR/NIR fluorescent probes for future in vivo applications.