bluuebunny/crossref_metadata_2025_split huggingface dataset:
Particle swarm optimization of dipole arrays for superior MIMO capacity
Authors: Olgun Ugur , Tunc Celal Alp , Aktas Defne , Ertürk Vakur B. , Altintas Ayhan 
Published: December 2008

AbstractThe particle swarm optimization (PSO) technique is employed to design MIMO arrays for superior capacity. A channel model based on the method of moments solution of the electric field integral equation is utilized with PSO for arrays of dipole elements. Freestanding and printed dipole arrays are analyzed and optimized. Their adaptive performance in the MIMO channel is compared. Numerical results in the form of mean capacity, including comparisons with genetic algorithm results and measurements, are given. © 2008 Wiley Periodicals, Inc. Microwave Opt Technol Lett 51: 333–337, 2009; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.24027
CPW‐fed ultra‐wideband antenna with dual band‐notched characteristics
Authors: Zhou Haijin , Yin Yingzeng , Deng Jingya , Liu Qizhong 
Published: December 2008

AbstractIn this article, the design and analysis of a CPW‐fed UWB antenna with dual band‐notched characteristics are presented. The measured bandwidth defined by VSWR <2 of the proposed antenna is from 2.8 to 11.7 GHz, except the bandwidths of 3.35–4.35 GHz for WiMAX and C‐band satellite communication, together with 5.2–5.9 GHz for WLAN. Moreover, this novel monopole antenna exhibits a nearly omnidirectional radiation pattern in the H‐plane and a dipole‐like radiation pattern in the E‐plane. © 2008 Wiley Periodicals, Inc. Microwave Opt Technol Lett 51: 330–332, 2009; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.24030
Semi‐infinite reflection model of a multilayered dielectric through equivalent permittivity calculation
Authors: Mostarshedi S. , Richalot E. , Picon O. 
Published: December 2008

AbstractThis article proposes a semi‐infinite model for a multilayered dielectric. It is based on an equivalent permittivity which is valid only for reflection. Here the model is applied to building windows. Inserting the new permittivity into Green's functions associated with a semi‐infinite medium allows the fast calculation of reflected EM fields in the vicinity of building facades. © 2008 Wiley Periodicals, Inc. Microwave Opt Technol Lett 51: 290–294, 2009; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.24032
A high‐directive bowtie radar antenna with a pyramidal reflector for ultra wideband radar imaging applications
Authors: Kwag Young K. , Hassanein Ahmed D. , Edwards David J. 
Published: December 2008

AbstractWe propose a novel bowtie radar antenna with a pyramidal reflector, which shows low return loss and high directional gain, capable of covering the whole ultra wideband (UWB) frequency band. The measured return loss is less than −10 dB over 3.0–11.7 GHz, and the radiation pattern is unidirectional with a high front‐to‐back ratio for UWB radar imaging applications. © 2008 Wiley Periodicals, Inc. Microwave Opt Technol Lett 51: 387–390, 2009; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.24043
Elimination of the multiple‐solutions ambiguity in permittivity extraction from transmission‐only measurements of lossy materials
Authors: Hasar U. C. 
Published: December 2008

AbstractA simple yet powerful method is proposed for removing the multiple solutions problem in the complex permittivity, ϵ, determination from measured transmission scattering (S‐) parameter measurements of lossy materials. The method uses amplitude‐only measurements at two slightly separated frequencies to estimate an accurate initial guess. For this purpose, we derive a one‐variable objective function for fast evaluation, which lends itself to measurement automation. The method provides an estimation for real and imaginary parts of the ϵ, which can be utilized as a measure for checking the correctness of initial ϵ estimate. The method is very useful for band‐limited measurements. © 2008 Wiley Periodicals, Inc. Microwave Opt Technol Lett 51: 337–341, 2009; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.24048
Development of multilayer liquid crystal polymer Ka‐band downconverter modules
Authors: Aihara Kunia , Zhang Zhaonian , Pham Anh‐Vu , Zeeb David , Flack Tom , Stoneham Ed 
Published: December 2008

AbstractA Ka‐band downconverter module is developed using liquid crystal polymer (LCP) thin‐film surface mount packages. The package utilizes vias to connect the RF input from the PCB signal launch onto the package substrate. The use of an LCP enclosure provides excellent moisture resistance in a compact structure. The multichip package has a measured loss of 0.4 dB at Ka‐band. © 2008 Wiley Periodicals, Inc. Microwave Opt Technol Lett 51: 364–367, 2009; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.24051
Shielded coplanar striplines for RF integrated applications
Authors: Aziz M. Abdel , Issa H. , Kaddour D. , Podevin F. , Safwat A. M. E. , Pistono E. , Duchamp J.‐M. , Vilcot A. , Fournier J.‐M. , Ferrari P. 
Published: December 2008

AbstractIn this article, shielded coplanar striplines (S‐CPS) are studied to achieve slow‐wave transmission lines in a CMOS process. The slow‐wave propagation is achieved by placing floating strips below the CPS transmission line. The propagation parameters of such transmission lines are derived by simulations by means of a “full wave” 3D EM software. Quality factors as high as 35 at 10 GHz together with effective dielectric constants of 78 are reported. If these simulation results are confirmed by measurements, this would open the door to the possible realization of integrated transmission line‐based RF circuits such as power dividers, phase‐shifters, or filters of medium bandwidth below 10 GHz. © 2008 Wiley Periodicals, Inc. Microwave Opt Technol Lett 51: 352–358, 2009; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.24054
A novel Z‐bridged electromagnetic bandgap power plane for suppression of simultaneous switching noise
Authors: Chen Wei‐Hua , Zhang Hou , Wang Jian , Shen Kai 
Published: December 2008

AbstractA novel z‐bridged electromagnetic bandgap power plane is proposed for ultra‐wideband suppression of simultaneous switching noise (SSN) in high‐speed digital circuits. The z‐shaped bridge effectively increases the inductance between two adjacent unit cells. Stopband of −30 dB is realized from 260 MHz to 6.76 GHz. The excellent SSN suppression performance is validated both numerically and experimentally; good signal integrity performance can be obtained by using differential transmission lines. © 2008 Wiley Periodicals, Inc. Microwave Opt Technol Lett 51: 483–486, 2009; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.24056
A Sierpinski‐based resonator applied for low loss and miniaturized bandpass filters
Authors: Weng Min‐Hang , Jang Ling‐Sheng , Chen Wei‐Yu 
Published: December 2008

AbstractIn this article, the resonant behaviors of the Sierpinski‐based fractal resonators were investigated first. The design guideline for the filter using the nth order resonator is then developed. A two‐pole filter example centered at 2.2 GHz based on the 3rd order Sierpinski‐based resonators was designed and fabricated. Measured results have a good agreement with the simulated results and verify the advantages of the size and insertion loss reduction as compared with the filter using conventional patch resonators. © 2008 Wiley Periodicals, Inc. Microwave Opt Technol Lett 51: 411–413, 2009; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.24061
Thermal characteristics of an all‐optical add‐drop multiplexer using fiber Bragg gratings and Mach–Zehnder interferometer
Authors: Son Yong‐Hwan , Won Yong‐Yuk , Hong Moon‐Ki , Han Sang‐Kook 
Published: December 2008

AbstractIn this article, the output spectrum have been numerically analyzed in order to investigate the temperature characteristics of the all‐optical add/drop multiplexer. It is shown that the center Bragg wavelength shifts by about 0.014223 nm when the temperature increases by 1°C in a range of −30°C to 90°C. The experiment results show that there is a shift of about 0.011266 nm when the temperature changes by 1°C. Therefore, the center wavelength of a certain channel can be changed in case of the variation of temperature from −17°C to +17°C in the wavelength division multiplexing system with a 25‐GHz channel spacing. In addition, the performance of a certain channel can be degraded because of the crosstalk effect, which is generated among the adjacent channels, when there is a variation of temperature from +8.3°C to −8.3°C. © 2008 Wiley Periodcals, Inc. Microwave Opt Technol Lett 51: 510–513, 2009; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.24065
WDM/SDM of intensity‐type fiber‐optic sensors
Authors: Jiang Yi , Tang Caijie , Zhang Fojian 
Published: December 2008

AbstractA novel method for multiplexing intensity‐type fiber‐optic sensors using wavelength division multiplexing (WDM) and spatial division multiplexing (SDM) is proposed and demonstrated. A variation of ±0.2 dB at a loss of −10.95 dB is obtained, which is comparable with that obtained by the traditional method. The experimental results show that the sensor at the up‐leading fiber has no influence on the sensor at the down‐leading fiber. © 2008 Wiley Periodicals, Inc. Microwave Opt Technol Lett 51: 432–435, 2009; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.24071
A shorted square‐ring slot antenna with a branched slot for the 1575 MHz and 2.4 GHz dual‐band operations
Authors: Tsai Chin‐Long , Deng Sheng‐Ming , Tseng Ching‐Hung , Bor Sheau‐Shong 
Published: December 2008

AbstractA shorted square‐ring slot antenna with a branched slot is presented for the 1575 MHz and 2.4 GHz dual‐band operations. This proposed antenna can be designed by two steps. First, the shorted square‐ring slot antenna is designed for circular polarization in the GPS band. Then, a branched slot is added to the original structure to result linear polarization in the 2.4 GHz band. Because the added branched slot almost has no influence in the GPS band's characteristics, the design rule is very simple. The impedance and axial ratio bandwidths for the GPS band is 23.3% and 4.2%, respectively. Besides, the AR and antenna gain is 1.23 dB and 2.3 dBic at the frequency of 1575 MHz. The impedance bandwidth for the 2.4 GHz band is 4.5% and antenna gain at the center frequency of 2.445 GHz is 2.8 dBi. © 2008 Wiley Periodicals, Inc. Microwave Opt Technol Lett 51: 402–405, 2009; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.24073
Resonance shifting and plane impedance calculations for a rectangular cavity in printed circuit board using closed form solutions
Authors: Cantrell K. , Song H. 
Published: December 2008

AbstractA method for arbitrarily shifting the dominant mode frequency of a rectangular cavity in printed circuit boards (PCBs) is presented. Standard closed‐form and analytic solutions are used to determine the frequency, quality factor, and impedance of the cavity. Calculations are compared with 3D full wave finite element method (FEM) solutions. © 2008 Wiley Periodicals, Inc. Microwave Opt Technol Lett 51: 452–455, 2009; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.24080
A 3–10 GHz CMOS low‐noise amplifier using wire bond inductors
Authors: Yang Miyoung , Ha Mincheol , Park Youngjin , Eo Yunseong 
Published: December 2008

AbstractIn this article, a small‐sized 3–10 GHz CMOS LNA for ultra‐wideband (UWB) applications is presented. To reduce 2 on‐chip inductors, wire bond inductors are used instead of input inductor of multisectional reactive network and source degeneration inductor. The noise figure of low‐noise amplifier (LNA) is 4 dB at minimum and IIP3 + 1.1 dBm at 5 GHz, respectively. The current consumption is 4 mA at 1.8 V supply. The LNA chip size including pads is 1 mm × 1 mm. © 2008 Wiley Periodicals, Inc. Microwave Opt Technol Lett 51: 414–416, 2009; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.24082
Uniplanar coupled‐fed printed PIFA for WWAN operation in the laptop computer
Authors: Wong Kin‐Lu , Liao Shih‐Jia 
Published: December 2008

AbstractIn this article, a uniplanar printed PIFA (planar inverted‐F antenna) with a coupling feed for application as an internal laptop computer antenna for penta‐band WWAN (wireless wide area network) operation is presented. The proposed PIFA has a compact structure and can be easily printed on one side of a small 0.8‐mm thick FR4 substrate of size 11 × 59 mm2, making it very promising to be embedded inside the casing of the laptop computer, especially for the thin‐profile laptop computer. With the coplanar coupling feed, the large inductive input reactance of the PIFA at around 900 MHz is compensated, and dual‐resonance excitation for the antenna's lower band at about 900 MHz is obtained, which allows it to easily cover GSM850/900 operation. A wide operating band is also achieved for the antenna's upper band at about 1900 MHz, and a bandwidth of larger than 500 MHz is obtained to cover GSM1800/1900/UMTS operation. That is, the proposed PIFA covers all the five operating bands of GSM850/900/1800/1900/UMTS for WWAN operation. Details of the proposed PIFA are presented. © 2008 Wiley Periodicals, Inc. Microwave Opt Technol Lett 51: 549–554, 2009; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.24084
A compensated spherical reflector antenna using sub‐reflectarrays
Authors: Xu Shenheng , Rahmat‐Samii Yahya 
Published: December 2008

AbstractSpherical reflectors have been used as wide‐angle scanning antennas due to the unique geometric properties of the sphere. The inherent spherical aberration, however, causes considerable performance degradation. This article presents a novel sub‐reflectarray compensating technique to correct it. A microstrip reflectarray is a planar, inexpensive, passive device with unique capabilities of controlling reflection phases. By exploiting this feasible property, it is employed as an auxiliary phase corrector, and the phase errors caused by spherical aberration are compensated. Two examples, a 35‐m spherical reflector antenna at Ka‐band and a 1.5‐m breadboard spherical reflector, are presented, and simulation results show great performance improvement for both no scan and large scan cases. Because of the difficulty in measuring large reflector antennas at UCLA, it is part of future plan to collaborate with other institutions for the verification of the concept. However, we believe that the simulation results generated in this article should provide acceptable performance prediction of the proposed antenna design. © 2008 Wiley Periodicals, Inc. Microwave Opt Technol Lett 51: 577–582, 2009; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.24088
Erratum: Design of novel miniaturized and high quality Sierpinski square resonators
Authors: Weng Min‐Hang , Jang Ling‐Sheng , Chen Wei‐Yu , Hung Cheng‐Yuan , Yang Ru‐Yuan 
Published: December 2008

AbstractOriginal published in Microwave Opt Technol Lett 50:1469–1471, 2008. © 2008 Wiley Periodicals, Inc. Microwave Opt Technol Lett 51: 583, 2009; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.24089
The equiangular spiral antenna at low frequencies
Authors: McFadden Michael , Scott Waymond R. 
Published: December 2008

AbstractThe effect of the geometry of the equiangular spiral antenna on the lower cutoff frequency of operation is studied using the finite‐difference time‐domain method. Graphs are provided that allow calculation of the cutoff frequency from the desired performance and geometry. Additionally, the patterns of the antennas at cutoff are shown. © 2008 Wiley Periodicals, Inc. Microwave Opt Technol Lett 51: 536–540, 2009; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.24092
A compact ultra‐wideband bandpass filter with WLAN notch band
Authors: Hsiao Pai‐Yi , Weng Ro‐Min 
Published: December 2008

AbstractA compact ultra‐wideband (UWB) bandpass filter (BPF) with notch band is presented using a trilayer structure. The band elimination is essential for preventing the strong narrow band interference from the wireless local area networks within the allocated UWB spectrum. The sharp rejection of the unwanted band is introduced by adding a U‐shape resonator on the middle layer. The design is not only realized theoretically but also verified by a full‐wave electromagnetic simulation. The proposed UWB BPF is fabricated by an FR4 substrate material with the permittivity of 4.4 and the thickness of 0.8 mm. The total area is 8 mm × 6 mm. © 2008 Wiley Periodicals, Inc. Microwave Opt Technol Lett 51: 503–507, 2009; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.24093
A low power 20‐GHz low‐noise amplifier fabricated using 0.18‐μm CMOS technology
Authors: Liu J.‐X. , Kuo H.‐C. , Chu Y.‐K. , Yeh J.‐F. , Chuang H.‐R. 
Published: December 2008

AbstractA 20‐GHz CMOS low‐noise amplifier (LNA) fabricated with the 0.18 μm process is presented. This two‐stage cascaded common source LNA exhibits low power consumption with a satisfying performance such as overall gain and noise figure (NF). The measurement is performed on‐wafer. The 20‐GHz LNA has demonstrated a 9.3 dB gain, a 4.4 dB NF, a −10 dBm input P1dB, and a 0.65 dBm IIP3. The power consumption is 9.6 mW from a 1.2 V power supply. © 2008 Wiley Periodicals, Inc. Microwave Opt Technol Lett 51: 423–426, 2009; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.24098
An unconditionally stable FDTD method based on wave equation
Authors: Lin Hai , Wang Gaofeng , Liang Feng 
Published: December 2008

AbstractAn unconditionally stable finite‐difference time‐domain (US‐FDTD) method based on wave equation is introduced by making use of Laguerre polynomials as basis functions for expanding field components in time. This new wave‐equation‐based FDTD scheme is not only unconditionally stable but also requires less memory usage. Comparisons among the traditional FDTD, the conventional Laguerre‐polynomial US‐FDTD, and this proposed scheme are presented in the numerical examples in terms of the memory usage and computational time. © 2008 Wiley Periodicals, Inc. Microwave Opt Technol Lett 51: 529–532, 2009; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.24101
Novel microstrip antenna element and 2‐by‐2 array for satellite TV receivers
Authors: Soliman E. A. , Affandi A. M. , Badr K. H. 
Published: December 2008

AbstractA new microstrip antenna element is presented in this article. The proposed antenna is suitable for integration into an array for satellite TV receivers. It has two metal layers only, which reduces its fabrication cost significantly in comparison with other antennas with more layers. The presented results show that the proposed antenna offers wide impedance bandwidth, high isolation between feeding ports, dual‐polarization radiation, low cross‐polarization level, and high radiation efficiency. A 2‐by‐2 array based on the proposed element is also presented in this article. Planar corporate feeding networks with new routing approach are used. The presented results of the new array show that it is suitable for use as a building block for a larger array which can repalce the parabolic dish reflector in satellite TV receivers. © 2008 Wiley Periodicals, Inc. Microwave Opt Technol Lett 51: 458–463, 2009; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.24105
60 GHz UWB over fiber system using photodiode‐based frequency up‐conversion
Authors: Gary R. , Cabon B. , Le Guennec Y. 
Published: December 2008

AbstractThis article describes the first optical mixing procedures for 60 GHz transmission of UWB signals, using an optical fiber for the long haul transmission and photodiode (PD)‐based up‐conversion of the UWB signal on a 60 GHz frequency carrier for picocellular network. Results show acceptable error vector magnitude (EVM) of less than 10% after optical up‐conversion. © 2008 Wiley Periodicals, Inc. Microwave Opt Technol Lett 51: 421–423, 2009; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.24107
A tunable capacitor using a finger patterned electrode
Authors: Chul Lee Young , Hyun Ko Kyung 
Published: December 2008

AbstractUsing a lead zinc niobate (PZN) thin film dielectric, a tunable metal‐insulator‐metal (MIM) capacitor is presented and investigated in this article. To improve its tunability and bias characteristics, the finger patterned electrode in the top metal is devised. The capacitors were fabricated on a low‐resistivity Si substrate employing lead zinc niobate (PZN) thin film dielectric. The fabricated capacitor, whose line width and spacing was 2.5 and 2.0 μm, respectively, achieved the effective capacitance tunability of 22.9% at 5.5 V. This achieved tunability is higher value of 10% than that of the conventional rectangular MIM capacitor at 900 MHz. © 2008 Wiley Periodicals, Inc. Microwave Opt Technol Lett 51: 418–421, 2009; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.24108
A theoretical structural analysis of the factors that affect 1JNH, 1hJNH and 2hJNN in N–H···N hydrogen‐bonded complexes
Authors: Alkorta Ibon , Blanco Fernando , Elguero José 
Published: December 2008

AbstractCalculations of 1 JNH, 1h JNH and 2h JNN spin–spin coupling constants of 27 complexes presenting N–H·N hydrogen bonds have allowed to analyze these through hydrogen‐bond coupling as a function of the hybridization of both nitrogen atoms and the charge (+1, 0, − 1) of the complex. The main conclusions are that the hybridization of N atom of the hydrogen bond donor is much more important than that of the hydrogen bond acceptor. Positive and negative charges (cationic and anionic complexes) exert opposite effects while the effect of the transition states ‘proton‐in‐the‐middle’ is considerable. Copyright © 2008 John Wiley & Sons, Ltd.
Retrospective correction for induced magnetic field inhomogeneity in measurements of large‐vessel hemoglobin oxygen saturation by MR susceptometry
Authors: Langham Michael C. , Magland Jeremy F. , Floyd Tom F. , Wehrli Felix W. 
Published: December 2008

AbstractMR susceptometry‐based blood oximetry relies on phase mapping to measure the difference in magnetic susceptibility between intravascular blood and surrounding tissue. The main source of error in MR susceptometry is the static field inhomogeneity caused by an interface between air and tissue or between adjacent tissue types. High‐pass filtering has previously been used in conjunction with shimming to reduce the effect of low spatial‐frequency modulations of the phase caused by large‐scale induced magnetic fields. We demonstrate that high‐pass filtering is not optimum for MR susceptometry because the results are sensitive to filter size. We propose an alternative method that acquires data without scanner‐implemented default shimming, and fits, after appropriate weighting and masking, the static field inhomogeneity to a second‐order polynomial. Compared to shimming the retrospective correction technique improved agreement between hemoglobin saturations measured in different segments of a vessel (femoral versus popliteal artery and vein) from three standard errors to less than one. Magn Reson Med, 2008. © 2008 Wiley‐Liss, Inc.