bluuebunny/crossref_metadata_2025_split huggingface dataset:
Circularly polarized microstrip antenna using asymmetric ring‐sector slots embedded on the ground plane
Authors: Baik Jungwoo , Kim Sangjoong , Kim Youngsik 
Published: January 2007

AbstractA single‐feed circularly polarized (CP) microstrip antenna using asymmetric ring‐sector two‐pair slots embedded on the ground plane is proposed. Asymmetric ring‐sector two‐pair slots on the ground plane can easily increase the antenna gain 2.8 dBi (5.0 dBi versus 2.2 dBi) higher than that of the same substrate material, operating frequency, and radiating patch shape of a conventional microstrip with slotted ring segment on the patch. Antenna gain and CP performance can be adjusted the ring‐sector slot size. Details of the antenna design are described, and obtained performances are presented and analyzed. © 2007 Wiley Periodicals, Inc. Microwave Opt Technol Lett 49: 602–604, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.22210
A very compact 62‐GHz transmitter LTCC SiP module for wireless terminals applications
Authors: Lee Young Chul , Park Chul Soon 
Published: January 2007

AbstractA 10 × 21 × 1 mm3, very compact low temperature cofired ceramic (LTCC) system‐in‐package (SiP) transmitter module is presented for future wireless terminal applications. Five GaAs monolithic microwave integrated circuits (MMIC) chipsets including a power amplifier, driver amplifier, mixer, and two frequency multipliers are integrated into a LTCC multilayer circuit for the heterodyne transmitter. The fabricated transmitter module achieves an output of 13 dBm at a RF frequency of 62 GHz, an IF frequency of 2.4 GHz, and an local oscillator frequency of 59.6 GHz. The up‐conversion gain is 11 dB; while the local oscillator signal is suppressed below −20.6 dBc with the image rejection mixer, and the image and spurious signals are also suppressed below −29.6 dBc. © 2007 Wiley Periodicals, Inc. Microwave Opt Technol Lett 49: 575–578, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.22211
Back‐propagation based nonbinary optical code for OCDMA with fiber gratings
Authors: Min Seong‐Sik 
Published: January 2007

AbstractA new optical code is proposed for OCDMA networks with optical gratings and balanced detection, in which the back‐propagation algorithm of a neural network is applied to nonbinary optical code generation. The proposed codes have high security level and a code ratio of at least 1.0. © 2007 Wiley Periodicals, Inc. Microwave Opt Technol Lett 49: 632–636, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.22213
Wide band planar modified triangular monopole antennas
Authors: Ray K. P. , Kumar G. , Anob P. V. 
Published: January 2007

AbstractVarious new configurations of planar triangular monopole antennas have been investigated. Effect of flaring angle of planar triangular monopole antennas on the bandwidth has been studied. A compact configuration of vertex chopped equilateral triangular monopole antenna has been proposed for ultra wide bandwidth ratio of 9.2:1. Orthogonal vertex chopped equilateral triangular monopole antenna is proposed for obtaining the improved azimuthal omnidirectional radiation pattern. © 2007 Wiley Periodicals, Inc. Microwave Opt Technol Lett 49: 628–632, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.22214
Numerical analysis of large reflector system used as a ground station antenna
Authors: Farahat Nader , Mittra Raj , Carrión José , Sanchez Jesus 
Published: January 2007

AbstractIn this paper we investigate a large dual‐reflector (Cassegrain) antenna system, typically used as a ground station antenna in the space communication link. The study includes the blockage effects of the subreflector and the struts on the radiation performance of the antenna, as well as the estimation of the combination to the pattern degradation due to the panel gaps. © 2007 Wiley Periodicals, Inc. Microwave Opt Technol Lett 49: 597–602, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.22215
Broad‐band power divider based on radial waveguide
Authors: Song Kaijun , Fan Yong , Zhang Yonghong 
Published: January 2007

AbstractA broad‐band power divider using coaxial probes and a radial waveguide is presented. The simple modeling of this power divider and design method based on equivalent circuits has been developed. A four‐way radial waveguide power divider has been designed, fabricated, and measured. Close agreement is obtained between the measured results and the simulated results. The measured 15‐dB return loss bandwidth of the broad‐band multiple‐port structure is demonstrated to be 81.5% and its 0.5‐dB insertion loss bandwidth 84.6%. © 2007 Wiley Periodicals, Inc. Microwave Opt Technol Lett 49: 595–597, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.22216
Stopband‐improved dual‐mode bandpass filter using side‐slit patch resonator
Authors: Li Rui , Zhu Lei 
Published: January 2007

AbstractA rectangular patch resonator with four equal slits etched on sides is presented to make up a stopband‐improved dual‐mode filter. By stretching these four side slits towards the patch center, the first resonant frequency gets a gradual decrease while its second one keeps almost unchanged. This feature is attractive in widening upper stopband while miniaturizing overall size in filter design. To realize a relatively wide passband with DC‐blocking, the narrowed feed lines are deeply inserted into their respective slits, resulting in the enhanced capacitive coupling degree. Our studies imply that the spacing between the first two resonant frequencies of this resonator itself is increased by about 50% while the first spurious resonant frequency is fully rejected by introducing a pair of open‐circuited stubs in the feed lines. In final, a dual‐mode filter is optimally designed with a fractional bandwidth of 4.5% at 1.60 GHz and predicted results are confirmed by experiment. © 2007 Wiley Periodicals, Inc. Microwave Opt Technol Lett 49: 717–720, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.22221
Experimental characterization of a broadband dual‐polarized microstrip antenna for X‐band SAR applications
Authors: Wang Wei , Liang Xian‐Ling , Zhang Yu‐Mei , Zhong Shun‐Shi , Guo Yan 
Published: January 2007

AbstractThe design and development of a broadband dual‐polarized 16 × 16 element microstrip antenna array for X‐band application is introduced. The measured bandwidth is about 17.8% for voltage standing wave ratios <1.5. The polarization isolation is better than 45 dB. The cross‐polarization component is at the level of −37 dB below the main lobe. © 2007 Wiley Periodicals, Inc. Microwave Opt Technol Lett 49: 649–652, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.22225
Accurate computation of the impedance elements of the magnetic‐field integral equation with RWG basis functions through field‐domain and source‐domain integral swapping
Authors: Ubeda Eduard , Heldring Alex , Rius Juan M. 
Published: January 2007

AbstractWe present a new strategy to compute the impedance elements of the Magnetic‐Field Integral Equation (MFIE) formulation in Method of Moments (MoM) with a discretization of low‐order divergence‐conforming basis functions (RWG). The impedance matrix elements are accurately computed by swapping the inner‐ and outer‐integrals in the accurate computation of a MoM–MFIE discretization with low‐order curl‐conforming basis functions (nxRWG). © 2007 Wiley Periodicals, Inc. Microwave Opt Technol Lett 49: 709–712, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.22228
A hyperbolic summation method to focus B‐scan ground penetrating radar images: An experimental study with a stepped frequency system
Authors: Ozdemir Caner , Demirci Sevket , Yigit Enes , Kavak Adnan 
Published: January 2007

AbstractThere are many techniques to focus raw B‐scan ground penetrating radar (GPR) images mainly distorted from well‐known hyperbolic dispersion. In this study, we apply a hyperbolic summation (HS)‐type focusing technique to the simulated and measured GPR data at C‐band frequencies. The formulation of the proposed HS method is presented. Numerical GPR images for different metal targets are generated by the help of a physical optics simulation code. An experimental set‐up is constructed with the help of a stepped frequency radar system and corresponding B‐scan images are generated. Proposed HS method is applied to the measured B‐scan GPR data. Focused GPR images of different objects were obtained for both the simulated and the experimental data. © 2007 Wiley Periodicals, Inc. Microwave Opt Technol Lett 49: 671–676, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.22230
Dual‐band circularly polarized antenna with a QUAD‐EMC structure
Authors: Chang The‐Nan , Ni Guo‐Yang 
Published: January 2007

AbstractIn this paper, a method for obtaining a single‐feed dual‐band circularly polarized (CP) antenna with QUAD‐EMC structure is presented. The proposed dual‐band CP design was achieved by four small patches displayed on the upper surface of a first substrate, and fed electromagnetically by a large patch etched on the lower surface of the same substrate. A second FR4 and a third air substrate were added behind the first substrate to enhance the gain of the antenna. Then, by tuning the sizes of upper and lower patches and truncating patch corners respectively and properly, the proposed antenna can perform dual‐band CP radiation using a single probe feed. Prototypes of the proposed antennas designed for RFID operations in the 915‐MHz and 2.45‐GHz bands are presented and experimentally demonstrated. © 2007 Wiley Periodicals, Inc. Microwave Opt Technol Lett 49: 645–647, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.22231
Hybrid mode matching and auxiliary sources technique for horn antenna analysis
Authors: Diamantis S. G. , Orfanidis A. P. , Kyriacou G. A. , Sahalos J. N. 
Published: January 2007

AbstractA hybrid technique for the analysis of horn antennas is described based on a rigorous description of the horn aperture‐free space discontinuity. The transition from the feeding waveguide to the radiating aperture is analyzed by using the mode matching technique (MMT) employing a stepped‐waveguide approach. The discontinuity between the horn aperture and the free space is modeled by combining the method of auxiliary sources with the MMT for the stepped waveguide section. Results for the input standing wave ratio are given and compared with the available measurements, which demonstrate the very good performance of the method. © 2007 Wiley Periodicals, Inc. Microwave Opt Technol Lett 49: 734–739, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.22233
A jumping genes paradigm for the design of wide‐band patch antenna with double shorting wall
Authors: Yeung S. H. , Luk W. T. , Ng H. K. , Man K. F. , Chan C. H. 
Published: January 2007

AbstractA newly developed evolutionary computing algorithm, Jumping Genes Evolutionary Algorithm is applied to optimize the dimensions of a folded patch antenna with double shorting walls. In the optimized design, an impedance bandwidth (VSWR ≤2) of 101% is recorded, which shows an improvement by 29% comparing with its original design. © 2007 Wiley Periodicals, Inc. Microwave Opt Technol Lett 49: 706–709, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.22234
Circularly polarized omnidirectional millimeter wave monopole with parasitic strip elements
Authors: Fernández J. M. , Masa‐Campos J. L. , Sierra‐Pérez M. 
Published: January 2007

AbstractA circularly polarized omnidirectional millimeter wave monopole with parasitic strip elements for a system of arrival signal direction detection in millimeter band is presented. As a consequence of the radiation pattern requirements, the proposed antenna consists of a conical skirt monopole with a polarizer radome. The polarizer converts a wave from linear to circular polarization. The proposed antenna has the advantage to be robust, low cost, and easy to fabricate with conventional materials and printed circuit technology. The study presents simulation and experimental results obtained with an antenna prototype that validate the design. © 2007 Wiley Periodicals, Inc. Microwave Opt Technol Lett 49: 664–668, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.22237
A novel miniaturized triband PIFA for MIMO applications
Authors: Manteghi Majid , Rahmat‐Samii Yahya 
Published: January 2007

AbstractMultiband antennas are vital in meeting the modern telecommunication demands of mobile terminals. Using the spatial properties of multipath channels, multiple‐input multiple‐output (MIMO) communication systems employ antenna arrays to increase their communication capacity. This article presents a novel printed inverted “F” antenna (PIFA), which has been used to design a miniaturized triband antenna. In turn, the triband antenna has been used as an element in various arrays of MIMO applications. Specifically, the antenna element has been constructed and applied, in arrays of two and four, in a laptop PCMCIA wireless LAN card. The size of the four element MIMO antenna array is 50 mm × 13 mm × 8 mm, which translates to 0.4λ × 0.1λ × 0.06λ at 2.45 GHz. The input impedance of the single element antenna has been measured at UCLA. The antenna has a return loss lower than −10 dB within the 2.4–2.5 GHz, 5.15–5.35 GHz, and 5.7–5.85 GHz bands. The measured scattering matrices of two and four element arrays have been used to calculate the total active reflection coefficient (TARC). TARC has been calculated for different combinations of excitation signals applied at each port. Each excitation signal has a unity magnitude and a random phase, thus leading to innumerable signal combinations. Our results reveal that “off” diagonal elements of the scattering matrix (couplings between elements) are as important as diagonal elements in calculating the TARC and the radiation efficiency of arrays. Furthermore, increasing the number of elements in a MIMO system with a limited volume will increase the channel capacity but lower the radiation efficiency. The experimental and simulation results have been in agreement. © 2007 Wiley Periodicals, Inc. Microwave Opt Technol Lett 49: 724–731, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.22239
Silicon gap‐loaded microstrip slit‐tetragonal resonator under IR‐irradiation
Authors: Zouganelis G. , Budimir D. 
Published: January 2007

AbstractA microstrip slit‐tetragonal resonator gap‐loaded with a piece of silicon is proposed as optical tuning element. Change of photoconductivity of silicon, after irradiation of it with an infrared lamp, results a significant change of density (∼25 dB) of the first resonant peak (n = 1/2) of resonator. This behavior makes this device a possible candidate for optical tuning of microwave transmission lines at specific operating frequency. Measured S‐parameters of the proposed device are in good agreement with simulated ones found from finite difference time domain method. Calculation of S‐parameters based on a transmission line model is included for comparison. © 2007 Wiley Periodicals, Inc. Microwave Opt Technol Lett 49: 699–702, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.22240
Planar monopole antenna with wideband operation
Authors: Tseng Ching‐Fang , Huang Cheng‐Liang 
Published: January 2007

AbstractA simple printed monopole antenna with wideband operation is presented. The proposed antenna has excellent impedance bandwidth coving the range from 1.926 to 4.9 GHz. The obtained impedance bandwidth reaches ∼123.9% (10‐dB return loss) for 2.4 GHz, which meets the required bandwidth specifications of IEEE 802.11 b/g standards. The simulated return loss shows good agreement with the measured data. Good antenna gain and radiation patterns of the proposed antenna have also been observed across the operating band. Details of the proposed antenna design and experimental results are presented and discussed. © 2007 Wiley Periodicals, Inc. Microwave Opt Technol Lett 49: 696–699, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.22241
Ultra‐wideband planar elliptical slot antenna with finite‐ground coplanar waveguide‐fed
Authors: Li Jia‐Lin , Qu Shi‐Wei , Xue Quan 
Published: January 2007

AbstractA planar elliptical slot antenna designed for ultra‐wideband applications is investigated. With elliptical radiation slots and finite‐ground coplanar waveguide feeding structure, the proposed antenna exhibits excellent broadband properties, stable radiation patterns, and compact size. Meanwhile, by introducing a V‐shaped slot on the transition region between the feeding line and the slots, a narrow band‐rejection operation can be realized. Simulated and measured results are presented and discussed. © 2007 Wiley Periodicals, Inc. Microwave Opt Technol Lett 49: 662–664, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.22242
Linear tunable dispersion compensation device using selective stretching in chirped fiber Bragg grating
Authors: Romero R. , Frazão O. 
Published: January 2007

AbstractA linear tunable dispersion compensation device based on a chirped grating (CFBG) mounted on a stretching mechanical structure is described. The tunability is obtained changing the CFBG bandwidth without modification of the total length structure. © 2007 Wiley Periodicals, Inc. Microwave Opt Technol Lett 49: 720–722, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.22245
Correction factor to be applied to the SAR in phantom models for occupational electromagnetic exposure
Authors: Joseph Wout , Vermeeren Günter , Martens Luc 
Published: January 2007

AbstractA correction factor dependent upon frequency, type of phantom, and incident polarization, which should be applied to the measured specific absorption rate is proposed for homogeneous phantoms. It is shown for an application of occupational exposure in the neighborhood of a base station antenna that this correction factor not underestimates realistic exposure of workers. © 2007 Wiley Periodicals, Inc. Microwave Opt Technol Lett 49: 652–655, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.22249
Boosting the sampling efficiency ofq‐ball imaging using multiple wavevector fusion
Authors: Khachaturian Mark H. , Wisco Jonathan J. , Tuch David S. 
Published: January 2007

Abstractq‐Ball imaging (QBI) is a high‐angular‐resolution diffusion imaging (HARDI) method that is capable of resolving complex, subvoxel white matter (WM) architecture. QBI requires time‐intensive sampling of the diffusion signal and large diffusion wavevectors. Here we describe a reconstruction scheme for QBI, termed multiple wavevector fusion (MWF), that substantially boosts the sampling efficiency and signal‐to‐noise ratio (SNR) of QBI. The MWF reconstruction operates by nonlinearly fusing the diffusion signal from separate low and high wavevector acquisitions. The combination of wavevectors provides the benefits of the high SNR of the low wavevector signal and the high angular contrast‐to‐noise ratio (CNR) and peak separation of the high wavevector signal. The MWF procedure provides a framework for combining diffusion tensor imaging (DTI) and QBI. Numerical simulations show that MWF of DTI and QBI provides a more accurate estimate of the diffusion orientation distribution function (ODF) than QBI alone. The accuracy improvement can be translated into an efficiency gain of 274–377%. An intravoxel peak connectivity metric (IPCM) is presented that calculates the peak connectivity between an ODF and its neighboring voxels. In human WM, MWF reveals more detailed WM architecture than QBI as measured by the IPCM for all sampling schemes presented. Magn Reson Med 57:289–296, 2007. © 2007 Wiley‐Liss, Inc.
Restricted field of view magnetic resonance imaging of a dynamic time series
Authors: Pisani Laura , Bammer Roland , Glover Gary 
Published: January 2007

AbstractA restricted field of view (rFOV) approach for imaging a dynamic time series of volumes of limited spatial extent within a larger subject is described. The shorter readout with rFOV‐MRI can be exploited to either limit image artifacts or increase spatial resolution. To accomplish rFOV imaging of a multislice volume for a dynamic series, an outer volume suppression (OVS) preparation that saturates signal external to a cylinder through the subject is followed by slice‐selective excitation and a spiral readout. The pass‐ and stopband efficiencies of the OVS in an agar gel phantom were 97% (±1.5%) and 3% (±1%), respectively. Profiles of the temporal signal‐to‐noise ratio (SNR) were measured in a phantom and an adult brain. The rFOV sequence reduced distortions from off‐resonance signal and T‐induced blurring compared to a conventional sequence. Sequence utility is demonstrated for high‐resolution rFOV functional MRI (fMRI) in the visual cortex. The rFOV sequence may prove to be useful for other multislice dynamic and high‐resolution imaging applications. Magn Reson Med 57:297–307, 2007. © 2007 Wiley‐Liss, Inc.
Sensitivity‐encoded (SENSE) proton echo‐planar spectroscopic imaging (PEPSI) in the human brain
Authors: Lin Fa‐Hsuan , Tsai Shang‐Yueh , Otazo Ricardo , Caprihan Arvind , Wald Lawrence L. , Belliveau John W. , Posse Stefan 
Published: January 2007

AbstractMagnetic resonance spectroscopic imaging (MRSI) provides spatially resolved metabolite information that is invaluable for both neuroscience studies and clinical applications. However, lengthy data acquisition times, which are a result of time‐consuming phase encoding, represent a major challenge for MRSI. Fast MRSI pulse sequences that use echo‐planar readout gradients, such as proton echo‐planar spectroscopic imaging (PEPSI), are capable of fast spectral‐spatial encoding and thus enable acceleration of image acquisition times. Combining PEPSI with recent advances in parallel MRI utilizing RF coil arrays can further accelerate MRSI data acquisition. Here we investigate the feasibility of ultrafast spectroscopic imaging at high field (3T and 4T) by combining PEPSI with sensitivity‐encoded (SENSE) MRI using eight‐channel head coil arrays. We show that the acquisition of single‐average SENSE‐PEPSI data at a short TE (15 ms) can be accelerated to 32 s or less, depending on the field strength, to obtain metabolic images of choline (Cho), creatine (Cre), N‐acetyl‐aspartate (NAA), and J‐coupled metabolites (e.g., glutamate (Glu) and inositol (Ino)) with acceptable spectral quality and localization. The experimentally measured reductions in signal‐to‐noise ratio (SNR) and Cramer‐Rao lower bounds (CRLBs) of metabolite resonances were well explained by both the g‐factor and reduced measurement times. Thus, this technology is a promising means of reducing the scan times of 3D acquisitions and time‐resolved 2D measurements. Magn Reson Med 57:249–257, 2007. © 2007 Wiley‐Liss, Inc.