bluuebunny/crossref_metadata_2025_split huggingface dataset:
A novel compact broadband 5–35 GHz balun
Authors: Chramiec Jerzy , Janiczak Bogdan J. , Kitliński Marek 
Published: January 2007

AbstractIn this paper, operating principle and modeling procedure of a new, compact, planar balun aimed at microwave and millimeter‐wave applications have been described. The structure of balun involves microstrip line‐symmetrical slotline‐bilateral slotline transitions with a novel version of multibranch broadband slotline stub. The designed experimental balun circuit covering the C‐ to K‐band frequency range clearly demonstrates the advantages of the design. Requirements resulting from balun application to doubly balanced circuits or as antenna feeder have been taken into account. In both cases, very satisfactory operation of the device in the frequency range of 5–35 GHz has been obtained in circuit manufactured on a layered low‐loss low‐permittivity dielectric substrate, with external dimensions of 7 × 8 mm2. © 2007 Wiley Periodicals, Inc. Microwave Opt Technol Lett 49: 622–625, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.22218
Internal low‐profile metal‐plate monopole antenna for DTV portable multimedia player applications
Authors: Yu Yeon‐Sik , Jeon Seung‐Gil , Park Hoon , Seo Dong‐Hyun , Choi Jae‐Hoon 
Published: January 2007

AbstractA low‐profile metal‐plate monopole antenna for mobile handset operating over Digital‐TV (DTV; 470–850 MHz) frequency band is proposed. The antenna consists of a folded rectangular patch and two slits, and has a small volume of 65 × 25 × 5 mm3. The measured return loss for the proposed antenna at DTV frequency band is better than 10 dB. The antenna has omni‐directional or monopole‐like radiation patterns, with good antenna gain even for such a compact size. © 2007 Wiley Periodicals, Inc. Microwave Opt Technol Lett 49: 593–595, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.22219
A new configuration to improve the active loop technique for transistor large signal characterization in the Ka band
Authors: Yattoun Ismail , Peden Alain 
Published: January 2007

AbstractThis article presents a new configuration to improve the conventional active loop technique with pre‐matching. This reduces the power requirements of the loop amplifier when synthesizing high reflection coefficient for high power transistors. The active loop technique is very efficient in characterizing power transistors but the output power of the loop amplifier can be a strong limitation as it can exhibit non‐linear behavior when high power is needed. The proposed new configuration improves the active loop capabilities as it allows a larger reflection coefficient to be synthesized with higher linearity of the loop amplifier. Theoretical results show the interest of the new active loop and experimental measurements in the Ka band validate the linear behavior improvement of the active loop for high reflection coefficients. © 2007 Wiley Periodicals, Inc. Microwave Opt Technol Lett 49: 589–593, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.22220
Orthogonally proximity‐coupled patch antenna for a passive RFID tag on metallic surfaces
Authors: Son Hae‐Won , Choi Gil‐Young 
Published: January 2007

AbstractA new wideband rectangular patch antenna for radio frequency identification tags mountable on metallic surfaces is presented. An orthogonally proximity‐coupled feed structure, in which the direction of the microstrip feedline is orthogonal to that of the resonant length of the radiating patch, is explored to perform simple and wideband impedance matching between an antenna and a tag chip without any additional matching networks. The proposed antenna has wideband characteristics and good cross‐polarization, which are validated by simulations and measurements. © 2007 Wiley Periodicals, Inc. Microwave Opt Technol Lett 49: 715–717, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.22222
A new CPW‐fed half‐loop antenna
Authors: Sun Jwo‐Shiun , Lee Yi‐Chieh , Wang Chuan‐Jyun 
Published: January 2007

AbstractA novel and simple structure for a CPW‐fed half‐loop antenna is presented. The proposed antenna covered the ultra‐wideband bandwidth (3.1–10.6 GHz) to even higher band (∼20 GHz) for VSWR <2. Tapered slot structure and half‐loop antenna exhibited high band and low band, respectively. The measured results are in fairly good agreements with those of simulated ones. © 2007 Wiley Periodicals, Inc. Microwave Opt Technol Lett 49: 684–686, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.22223
Internal GSM/DCS dual‐band open‐loop antenna for laptop application
Authors: Kuo Cheng‐Hao , Wong Kin‐Lu , Chang Fa‐Shian 
Published: January 2007

AbstractA novel open‐loop antenna with a coupled‐line gap for application as an internal laptop antenna for GSM/DCS dual‐band operation is presented. Owing to the use of the coupled‐line gap, the proposed antenna can operate both as a half‐wavelength loop structure at 900 MHz and a one‐wavelength loop structure at 1800 MHz. The antenna is easily printed on a dielectric substrate with a low cost and is then integrated to the supporting metal frame of the laptop display to achieve a compact size of 9 mm in height and 70 mm in length, making it very promising to be embedded within the casing of the laptop as an internal antenna. Design considerations of the proposed antenna are described, and experimental and simulation results of the constructed prototype are presented. Effects of the coupled‐line gap on the dual‐band operation of the proposed antenna are also analyzed. © 2007 Wiley Periodicals, Inc. Microwave Opt Technol Lett 49: 680–684, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.22224
A 30‐GHz 10‐dB low noise amplifier using standard 0.18‐μm CMOS technology
Authors: Tu Hsin‐Lung , Yang Tsung‐Yu , Liang Kung‐Hao , Chiou Hwann‐Kaeo 
Published: January 2007

AbstractA three‐stage 30‐GHz low noise amplifier (LNA) was designed and fabricated in a standard 0.18‐μm CMOS technology. The LNA has demonstrated a 10‐dB gain and a minimum noise figure of 5.2 dB at 30 GHz. The achieved input 1‐dB compression point (IP1 dB) and third order intercept point (IP3) are −7 and +2.5 dBm, with total current of 16 mA from a 1.5‐V power supply. To the author's knowledge, the LNA shows the best overall performances ever reported in standard 0.18‐μm CMOS process. © 2007 Wiley Periodicals, Inc. Microwave Opt Technol Lett 49: 647–649, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.22226
Novel Wilkinson power divider based on left‐handed transmission lines
Authors: Li JiuSheng , Zou YongZhuo 
Published: January 2007

AbstractIn this paper, a novel Wilkinson power divider utilizing left‐handed transmission lines (LHTLs) is presented. The proposed device was fabricated by using the lumped L–C (−λ/4) LHTLs instead of the right‐handed transmission lines branch arms of the conventional Wilkinson power divider. Both the measured and simulated results show that the designed power divider has a wide bandwidth of return loss and isolation, and its size is 50% smaller than conventional Wilkinson power dividers. The measured results are good well with the simulated ones. © 2007 Wiley Periodicals, Inc. Microwave Opt Technol Lett 49: 712–715, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.22227
End‐fed modified planar dipole antenna for DTV signal reception
Authors: Chi Yun‐Wen , Wong Kin‐Lu , Yeh Shih‐Huang 
Published: January 2007

AbstractA novel end‐fed modified planar dipole antenna for digital television (DTV) signal reception in the 470–806 MHz band is presented. The antenna is of a narrow rectangular shape (10 mm wide and 235 mm long) and is printed on a dielectric substrate. The antenna comprises a step‐shaped radiating strip (arm 1) and a narrow rectangular radiating strip (arm 2), both separated by an L‐shaped feed gap whose one open end located at the shorter edge or end edge of the antenna. Across this open end of the L‐shaped feed gap, the antenna can be excited to provide a wide bandwidth (2.5:1 VSWR) of larger than 50%, which is much wider than that of a corresponding conventional center‐fed dipole antenna and allows the proposed antenna easily cover the 470–806 MHz band for DTV signal reception. In addition, over the operating band, the radiation performance of the proposed antenna is similar to that of the conventional center‐fed dipole antenna. The proposed end‐fed modified planar dipole antenna is studied in detail in this paper. © 2007 Wiley Periodicals, Inc. Microwave Opt Technol Lett 49: 676–680, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.22229
Design of microstrip dual‐band bandpass filter with controllable bandwidth
Authors: Guan Xuehui , Ma Zhewang , Cai Peng , Anada Tetsuo , Hagiwara Gen 
Published: January 2007

AbstractA dual‐band microstrip bandpass filter with controllable bandwidth is proposed by using new dual‐band resonators. The resonator consists of a pair of shunt open stubs, including a stepped‐impedance open stub. The open stubs produce three transmission zeros, which result in sharp attenuations near the passbands, and large isolations between the two passbands. Design formulas of this type of filters are provided. A dual‐band bandpass filter operating at 2.4 and 5.2 GHz is designed and tested, and the measured characteristics agree well with the theoretical simulations. © 2007 Wiley Periodicals, Inc. Microwave Opt Technol Lett 49: 740–742, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.22232
RF MEMS asymmetric capacitive switch with high‐isolation at selected low‐microwave frequency
Authors: Qian Jiangyuan , Chang Hung‐Pin , Cetiner Bedri A. , Bachman Mark , De Flaviis Franco , Li G.P. 
Published: January 2007

AbstractAn asymmetric RF microelectromechanical systems (MEMS) capacitive switch with a novel architecture employing mode switching from a coplanar waveguide (CPW) mode to a coupled slotline (CSL) mode is reported for selected frequency within the 2–10 GHz low microwave frequency range. An additional metal‐insulator‐metal (MIM) capacitor is introduced on one end of the switch membrane as a tuning capacitor. The signal line of CSL is used as a tuning inductor. These two tuning elements together can improve the isolation of a regular capacitive RF MEMS switch by about 20 dB at the induced additional low resonant frequency ranging from 2 to 10 GHz. The measurements of the fabricated asymmetric switch demonstrated excellent isolation improvements. © 2007 Wiley Periodicals, Inc. Microwave Opt Technol Lett 49: 702–706, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.22235
Miniaturized optical fiber Bragg grating sensor interrogator based on echelle diffractive gratings
Authors: Xiao Gaozhi , Sun Fengguo , Zhang Zhiyi , Lu Zhenguo , Liu Jiaren , Wu Fang , Mrad Nezih , Albert Jacques 
Published: January 2007

AbstractAn Optical fiber Bragg grating sensor interrogation device based on monolithically integrated echelle diffractive grating and detector arrays on an InP chip is designed and prototyped. The device weighs less than 60 g and measures smaller than 45 mm × 30 mm × 15 mm, and it is specifically designed for potential integration into aerospace applications. This study discusses this device's operation principle and presents some initial experimental results reflecting its performance. © 2007 Wiley Periodicals, Inc. Microwave Opt Technol Lett 49: 668–671, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.22236
The high isolation dual‐band inverted F antenna diversity system with the small N‐section resonators on the ground plane
Authors: Kim Ki‐Jin , Ahn Kwang‐Ho 
Published: January 2007

AbstractThe high isolated dual‐band inverted‐F diversity systems for portable devices, operating in 2.4 GHz band (2400–2484 MHz) and 5.2 GHz band (5150–5350 MHz), are presented. To reduce the mutual coupling and get high isolation between two internal dual‐band antennas, we proposed the small N‐section resonators in the form of slots on the ground plane. The optimized small size resonators for high isolation, antenna radiation efficiency, and high effective diversity are analyzed. Because of their small size, N‐section resonators can be widely used in small diversity systems that require high isolation between antennas. © 2007 Wiley Periodicals, Inc. Microwave Opt Technol Lett 49: 731–734, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.22238
Novel ROF network architecture for providing both wireless and wired broadband services
Authors: Yu Jianjun , Jia Zhensheng , Yu Jianguo , Wang Ting , Chang Gee Kung 
Published: January 2007

AbstractWe propose and experimentally demonstrate that a novel and low‐cost radio over fiber network architecture for providing wireless and wired dual services at 2.5 Gb/s. The base‐band signals are directly detected by a low‐cost receiver with a 2 GHz bandwidth low‐pass filter, while the RF signals are down‐converted by a mixer and an electrical local oscillator signal. Our experimental results show the millimeter wave in this network architecture exhibits less than 1 dB power penalty over 20 km fiber after providing the dual services. © 2007 Wiley Periodicals, Inc. Microwave Opt Technol Lett 49: 659–662, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.22243
Novel bandpass filter with wide stopband using double‐sided parallel‐strip line
Authors: Zhang Xiu‐Yin , Li Jia‐Lin , Xue Quan 
Published: January 2007

AbstractA novel bandpass filter using double‐sided parallel‐strip line (DSPSL) is proposed in this paper. Based on the differential characteristics of DSPSL, the proposed filter has a wide stopband up to the third spurious resonance frequency. Also, this filter can achieve high power‐handling capability because the linewidth of DSPSL is wider than that of microstrip with the same characteristic impedance. A demonstration filter was designed, fabricated, and measured. Theoretical and experimental results are presented and show good agreement. © 2007 Wiley Periodicals, Inc. Microwave Opt Technol Lett 49: 722–724, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.22244
Investigations of the circulation effects in the structure using ferrite coupled slot‐line section
Authors: Kusiek A. , Marynowski M. , Mazur J. 
Published: January 2007

AbstractThis paper describes investigations of the longitudinally ferrite circulator realized in slot‐line technology. The proposed planar structure of circulator allowed to achieve small dimensions of the device. Also, the insertion losses comparable to ones actually published for microstrip structures were obtained. The basic steps of design procedure using scattering matrix of the circulator arrangement were presented. The S‐parameters of circulator were simulated and next verified via experiment. The operation bandwidth from 12 to 19 GHz with reflection loss and isolation better than 10 dB and average insertion loss 2.5 dB were measured for fabricated model of circulator. © 2007 Wiley Periodicals, Inc. Microwave Opt Technol Lett 49: 692–696, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.22246
Application of algebraic domain decomposition combined with Krylov subspace iterative methods to solve 3D vector finite element equations
Authors: Ping X. W. , Chen R. S. 
Published: January 2007

AbstractIn this paper, a parallel algorithm based on MPI (Message Passing Interface) parallel computing library for the finite element method is presented to analyze three‐dimensional electromagnetic devices. The algebraic domain decomposition method is used in the algorithm. The original problem is decomposed into several subproblems according to its features. Each of them is allocated to one process in one computation node and solved independently with a direct method. The data are exchanged by communication between adjacent subdomains with overlapped data based on the MPI network. The example of its application is given. Numerical shows that the proposed algorithm can get excellent performance vs. price ratio and can save much memory and CPU time than sequential computing. © 2007 Wiley Periodicals, Inc. Microwave Opt Technol Lett 49: 686–692, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.22247
Design of microwave devices by segmentation, finite elements, reduced‐order models, and neural networks
Authors: Cid Juan M. , García Jesús , Monge Javier , Zapata Juan 
Published: January 2007

AbstractAn accurate and fast neural model for complex microwave circuits is efficiently obtained by using segmentation and exploiting the knowledge of frequency response obtained from reduced order models. Information arriving from the excited modes in the connection ports of the regions to be modeled is included analytically. The frequency response modeling is similar to that of reduced order Padé models, which are used to compute the necessary training data easily. Overall optimization can then be used efficiently. Several examples that illustrate the capacities of the method are also presented. © 2007 Wiley Periodicals, Inc. Microwave Opt Technol Lett 49: 655–659, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.22448
Real‐time adaptive methods for treatment of mobile organs by MRI‐controlled high‐intensity focused ultrasound
Authors: de Senneville Baudouin Denis , Mougenot Charles , Moonen Chrit T.W. 
Published: January 2007

AbstractFocused ultrasound (US) is a unique and noninvasive technique for local deposition of thermal energy deep inside the body. MRI guidance offers the additional benefits of excellent target visualization and continuous temperature mapping. However, treating a moving target poses severe problems because 1) motion‐related thermometry artifacts must be corrected, 2) the US focal point must be relocated according to the target displacement. In this paper a complete MRI‐compatible, high‐intensity focused US (HIFU) system is described together with adaptive methods that allow continuous MR thermometry and therapeutic US with real‐time tracking of a moving target, online motion correction of the thermometry maps, and regional temperature control based on the proportional, integral, and derivative method. The hardware is based on a 256‐element phased‐array transducer with rapid electronic displacement of the focal point. The exact location of the target during US firing is anticipated using automatic analysis of periodic motions. The methods were tested with moving phantoms undergoing either rigid body or elastic periodical motions. The results show accurate tracking of the focal point. Focal and regional temperature control is demonstrated with a performance similar to that obtained with stationary phantoms. Magn Reson Med 57:319–330, 2007. © 2007 Wiley‐Liss, Inc.
Basis function cross‐correlations for Robust k‐space sample density compensation, with application to the design of radiofrequency excitations
Authors: Mitsouras Dimitris , Mulkern Robert V. , Afacan Onur , Brooks Dana H. , Rybicki Frank J. 
Published: January 2007

AbstractThe problem of k‐space sample density compensation is restated as the normalization of the independent information that can be expressed by the ensemble of Fourier basis functions corresponding to the trajectory. Specifically, multiple samples (complex exponential functions) may be contributing to each independent information element (independent basis function). Normalization can be accomplished by solving a linear system based on the cross‐correlation matrix of the underlying Fourier basis functions. The solution to this system is straightforward and can be obtained without resorting to discretization since the cross‐correlations of Fourier basis functions are analytically known. Furthermore, no restrictions are placed on the k‐space trajectory and its point‐spread function. Additionally, the linear system can be used to elucidate key trade‐offs involved in k‐space trajectory design. The approach can be used to compensate samples acquired for image reconstruction or designed for low flip angle radiofrequency (RF) excitation. Here it is demonstrated for the latter application, using reversed spiral trajectories. In this case the linear system approach enables one to easily incorporate additional constraints such as smoothness to the solution. For typical RF excitation durations (<20 ms) it is shown that density compensation can even be achieved without numerical iteration. Magn Reson Med 57:338–352, 2007. © 2007 Wiley‐Liss, Inc.
Diffusion imaging of the in vivo heart using spin echoes–considerations on bulk motion sensitivity
Authors: Gamper Urs , Boesiger Peter , Kozerke Sebastian 
Published: January 2007

AbstractCardiac diffusion MRI based on stimulated‐echo acquisition mode (STEAM) techniques is hampered by its inherent low signal‐to‐noise ratio (SNR) efficiency. Diffusion imaging using standard spin‐echo (SE) techniques, on the other hand, offers higher SNRs but has been considered impractical for the beating heart due to excessive signal attenuation from cardiac bulk motion. In this work the effect of systolic cardiac motion on different diffusion‐encoding schemes was studied in detail. Numerical simulations based on in vivo motion data (acquired by MRI tagging techniques) demonstrate an up to 10‐fold decrease in bulk motion sensitivity of the diffusion encoding if the first‐order moment of the diffusion‐encoding gradients is nullified. It is shown that the remaining systolic phase pattern on the myocardium does not influence the magnitude images if the spatial resolution is chosen to be higher than 4 mm. Given these relatively low resolution requirements, we obtained in vivo diffusion‐weighted (DW) short‐axis images from four healthy volunteers using an SE‐based diffusion‐encoding sequence with excitation and refocusing in orthogonal planes for field of view (FOV) reduction. The results showed no significant signal loss due to cardiac motion, and the direction of the principal eigenvalues was found to be in good agreement with known myocardial fiber orientation. Magn Reson Med 57:331–337, 2007. © 2007 Wiley‐Liss, Inc.
Development of a compact MRI system for measuring the trabecular bone microstructure of the finger
Authors: Iita Nachiko , Handa Shinya , Tomiha Sadanori , Kose Katsumi 
Published: January 2007

AbstractA compact MRI system for measuring the trabecular bone (TB) microstructure of the finger using a high‐field‐strength (1.0T) permanent magnet was developed. The entire system was installed in a 0.6 m × 1.2 m space. One male and 36 female subjects participated in the imaging experiments. The TB of the distal phalanx of the middle finger was imaged at a voxel resolution of (160 μm)3 using a three‐dimensional (3D) driven equilibrium spin‐echo (SE) imaging sequence (imaging time = ∼14 min). The image data sets obtained yielded two distinct peaks for the bone and marrow in image intensity histograms when no motion was present. The structural parameters obtained through 3D image analysis show that this compact system is potentially useful for evaluating bone quality. Magn Reson Med 57:272–277, 2007. © 2007 Wiley‐Liss, Inc.