bluuebunny/crossref_metadata_2025_split huggingface dataset:
Microstrip array antenna for fire‐detection applications
Authors: Vincetti L. , Polemi A. , Zoboli M. 
Published: June 2007

AbstractIn this paper, a first investigation on critical issues for a fire‐detection ground‐based Ku‐band radiometer antenna design is addressed. A printed technology with standard dielectrics has been employed, to reach low cost, simplicity in realization, and easy integrability with the electronic front‐end. The antenna has been designed as an array of patches, where number of elements, spacings, and feeding currents has been optimized to fulfill requirements of low side lobe level and good crosspolarization. For the radio frequency front‐end, the receiver architecture is a direct‐conversion topology, because it is well suited to be monolithically integrated in a single chip. © 2007 Wiley Periodicals, Inc. Microwave Opt Technol Lett 49: 2279–2282, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.22649
Multiwavelength Raman fiber laser inserting a sampled chirped fiber Bragg grating
Authors: Ning G. , Shum P. , Zhou J. Q. , Xia L. 
Published: June 2007

AbstractA simple multiwavelength Raman fiber ring laser with equalized peak power is proposed and demonstrated experimentally by inserting a sample chirped fiber Bragg grating. By adjusting the polarization controller (PC) in the ring cavity, up to ten stable wavelengths with equalized peak power are achieved at room temperature. The Raman fiber ring laser has many advantages such as simple structure, low loss, and multiwavelength lines with moderate output power. © 2007 Wiley Periodicals, Inc. Microwave Opt Technol Lett 49: 2242–2245, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.22652
A 1.5‐V 0.25‐μm CMOS up‐converter for 3–5 GHz low‐power WPANs
Authors: Sapone Giuseppina , Palmisano Giuseppe 
Published: June 2007

AbstractIn this article, the measured performance of a 3–5 GHz low‐power up‐converter is presented. The circuit is based on a current‐reuse topology with resistive load. It was implemented in a standard low‐cost 0.25‐μm CMOS technology. The up‐converter achieves a 3.8‐dB power gain, an output 1‐dB compression point of −10.8 dBm, and a 8‐dB single‐sideband noise figure, while drawing only 2.3 mA from a 1.5‐V supply voltage. An operating bandwidth of 1.5 GHz was measured. The proposed circuit complies with the wideband/low‐power requirements of 3–5 GHz ultrawideband WPANs. © 2007 Wiley Periodicals, Inc. Microwave Opt Technol Lett 49: 2209–2212, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.22654
Tunable (Ba, Sr)TiO3 interdigital capacitor onto Si wafer for reconfigurable radio
Authors: Kim Ki‐Byoung , Tae‐Soon Yun  , Lee Jong‐Chul , Chaker Mohamed , Wu Ke 
Published: June 2007

AbstractIn this article, the potential feasibility of integrating BST films into Si wafer by adopting tunable interdigital capacitor (IDC) with TiO2 thin film buffer layer is suggested. TiO2 as buffer layer is grown onto Si substrate by atomic layer deposition and the coplanar IDC on BaxSr1−xTiO3(500 nm)/TiO2(50 nm)/high resistivity Si (HR‐Si) is fabricated. BST interdigital tunable capacitors integrated on HR‐Si substrate with high tunability and low loss tangent are characterized for their microwave performances. BST/HR‐Si and BST/TiO2/HR‐Si IDCs show much enhanced tunability values of 31% and 40%, respectively as compared to the value of 21% obtained with BST film on MgO single crystal substrate at the bias of 5 kV/cm. BST/TiO2/HR‐Si structure shows much improved figure of merit of 504.4 as compared to 418.53 and 101.68 of BST/MgO and BST/HR‐Si structure, respectively. © 2007 Wiley Periodicals, Inc. Microwave Opt Technol Lett 49: 2144–2148, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.22657
Application of metamaterial unit cell in bandpass filter
Authors: Jiusheng Li , Tieying Du 
Published: June 2007

AbstractUsing microstrip technology, a novel metamaterial unit cell is presented. The metamaterial unit cell consists of microstrip gaps and via hole whose behavior is equivalent to the combination of series capacitors and shunt inductors, respectively. A new chamfered band structure bandpass filter is designed and fabricated using the presented metamaterial unit cell. The transmission loss S21 and return losses S11 of the proposed bandpass filter are equal to −0.41 and −25.5 dB, respectively. The experimental and simulation results closely correspond to each other. © 2007 Wiley Periodicals, Inc. Microwave Opt Technol Lett 49: 2109–2111, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.22659
Printable Yagi antenna with closely spaced elements
Authors: Lim Sungkyun , Ling Hao 
Published: June 2007

AbstractA two‐element, planar Yagi antenna with closely spaced elements is reported. Multiple folding in the driver is used to boost up the low radiation resistance due to the close spacing between the driver and the director. The antenna dimensions are first optimized in wire form and then transferred into a printed version on PET film. A prototype planar monopole Yagi is built and measured at 1 GHz. The maximum realized gain of the antenna on 50‐μm PET film is measured to be 9.56 dB. © 2007 Wiley Periodicals, Inc. Microwave Opt Technol Lett 49: 2106–2109, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.22660
Miniature wideband filter based on coupled‐line sections and quasi‐lumped element resonator
Authors: Zhurbenko Vitaliy , Krozer Viktor , Meincke Peter 
Published: June 2007

AbstractA new design of a wideband bandpass filter is proposed, based on coupled‐line sections and quasi‐lumped element resonator, taking advantage of the last one to introduce two transmission zeros and suppress a spurious response. The proposed filter demonstrates significantly improved characteristics in comparison with traditional coupled‐line filter and exhibits a very compact structure. © 2007 Wiley Periodicals, Inc. Microwave Opt Technol Lett 49: 2076–2079, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.22661
A novel switchable lowpass filter constructed with electromagnetic bandgap and illumination‐sensitive cadmium sulfide
Authors: Wu Jack , Qiu S. N. , Qiu C. X. , Shih I. 
Published: June 2007

AbstractA novel construction of microwave switchable lowpass filter based on electromagnetic bandgap (EBG) and cadmium sulfide (CdS) thin film is proposed. Linearly tapered slot‐array EBG structure is well known for its exceptional stopband ability and compact physical size. When the illumination‐sensitive CdS thin film is deposited on the perforations of the EBG structure, the stopband phenomenon induced by tapered slot‐array can be controlled by optical means. Innovative “conductive islands” were introduced to reside in the center of each perforation in order to enhance the optical switching. It has been demonstrated in both simulation and experimental measurement that the transmission coefficient is switched from 31.3 to 5.6 dB at 13 GHz when the gap width between the conductive island and the perforation is 30 μm. As the gap width decreases, the insertion loss can be reduced. Simulation result indicates that the insertion loss can be improved to around 1 dB at 13 GHz when the gap width is decreased to 5 μm. © 2007 Wiley Periodicals, Inc. Microwave Opt Technol Lett 49: 2238–2242, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.22665
Dual‐band planar rectangular ring microwave bandpass filter using high permittivity substrate
Authors: Hsu Cheng‐Hsing , Lin Chia‐Hsien , Huang Sen‐Hung , Hsu Chung‐I G. , Yu Cheng‐Chi , Tung Hsin‐Han 
Published: June 2007

AbstractDual‐band planar bandpass filter, using two microstrip rectangular ring resonators, is proposed for wireless LAN system such as IEEE 802.11 systems (2.4 or 5 GHz). The miniaturized bandpass filter is implemented using a high permittivity dielectric substrate. The full‐wave simulator IE3D is used to design the two coupled rectangular ring resonators. The responses of the implemented filter using Zr0.8Sn0.2TiO4 (εr = 37, tan δ = 0.00012) dielectric substrates are designed at dual‐band frequencies of 2.35 and 4.7 GHz. The compacted size and good agreement have been obtained between simulations and implementation results. © 2007 Wiley Periodicals, Inc. Microwave Opt Technol Lett 49: 2236–2238, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.22677
Ultrawideband aperture‐coupled vertical microstrip transition
Authors: Abbosh A. M. 
Published: June 2007

AbstractSimple design guidelines for an ultrawideband aperture‐coupled vertical microstrip–microstrip transition are presented. The proposed transition utilizes broadside coupling between elliptical‐shaped microstrip patches at the top and bottom layers via an elliptical‐shaped slot in the ground plane, which is located at the mid layer. The simulated and measured results show that the proposed transition has less than 0.75 dB insertion loss and more than 13 dB return loss across the frequency band 3.1–10.6 GHz. © 2007 Wiley Periodicals, Inc. Microwave Opt Technol Lett 49: 2207–2209, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.22667
Effect of Li/Nb ratio on holographic storage properties of In:LiNbO3 crystals
Authors: Nie Yiran , Wang Rui , Wang Biao 
Published: June 2007

AbstractIn:LiNbO3 crystals with different Li/Nb ratios in the melts (Li/Nb = 0.94, 1.0, 1.1, 1.2) have been grown. The changes of the crystal structure on the Li/Nb were analyzed by the ultraviolet–visible absorption spectra. The holographic storage properties of In:LiNbO3 crystals were investigated by two‐wave coupling technique. The diffraction efficiency, response time, and photoconductivity of the crystals were measured. With increase in the ratio of Li/Nb, the diffraction efficiency decreases, the response time shortens, and the photoconductivity increases. © 2007 Wiley Periodicals, Inc. Microwave Opt Technol Lett 49: 2169–2171, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.22669
Novel dual‐broadband design of semicircular slot antenna for wireless communication
Authors: Hsiao Hai‐Ming , Lu Jui‐Han , Wu Jeun‐Wen 
Published: June 2007

AbstractA novel design of semicircular slot antenna with dual‐broadband operation for 2.4/5 GHz wireless local network area (WLAN) is proposed. With the use of an arc‐shaped strip inset along the circle edge of the semicircular slot antenna, a new resonant mode close to the second operating mode of the regular semicircular slot antenna is excited to enhance the operating bandwidth of the high band, and the obtained impedance bandwidths for two operating bands can reach about 14.8% for 2.4 GHz band and 22.0% for 5 GHz band, which cover the required bandwidths of IEEE 802.11b/g (2.4–2.484 GHz) and IEEE 802.11a (5.150–5.950 GHz). The measured peak antenna gains for the operating frequencies across dual WLAN bands are measured to be, respectively, 4.7 and 4.9 dBi with the gain variations within 0.5 dBi. © 2007 Wiley Periodicals, Inc. Microwave Opt Technol Lett 49: 2165–2169, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.22670
Investigation of macrobending losses of standard single mode fiber with small bend radii
Authors: Wang Pengfei , Wang Qian , Farrell Gerald , Rajan Ginu , Freir Thomas , Cassidy John 
Published: June 2007

AbstractAn investigation of macrobending loss characteristics of a standard single mode fiber (SMF28) for small bend radii is presented theoretically and experimentally, which includes the bend loss of the SMF28 with coating layers and the bare SMF28 after stripping the coating layers and chemical etching of partial cladding. The significant influence of reflection occurring at the interface between the cladding and coating layer or the cladding layer and air on the bend loss is investigated theoretically and experimentally. © 2007 Wiley Periodicals, Inc. Microwave Opt Technol Lett 49: 2133–2138, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.22671
Chromatic dispersion effect on microwave photonic filter with a tunable linearly chirped fiber Bragg grating
Authors: Ning G. , Shum P. , Zhou Junqiang 
Published: June 2007

AbstractChromatic dispersion effect on a bandpass microwave photonic filter is presented using a tunable linearly chirped fiber Bragg grating (LCFBG). The 3‐dB bandwidth of the LCFBG is shifted nonlinearly with fixed centre wavelength to change its chromatic dispersion value. The bandpass notch filter is free from optically coherent interference and phase noise because of the two orthogonal axes of the Hi‐Bi fiber. Measured results agree with theoretical analysis. © 2007 Wiley Periodicals, Inc. Microwave Opt Technol Lett 49: 2131–2133, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.22672
Computation and optimization of resonant frequency and input impedance of a coax‐fed circular patch microstrip antenna
Authors: Gürel Çiğdem Seçkin , Aydın Elif , Yazgan Erdem 
Published: June 2007

AbstractMicrostrip antennas are important elements of today's wireless communication networks. In their various applications, it is critical to provide wide band operation around the resonant frequency providing good impedance match between the antenna element and the feed. In this study, new, simple, and accurate computation of resonant frequency and input impedance of double‐layered, coaxial fed circular disk microstrip antenna with air gap is performed. In the analysis, new effective radius and permittivity expressions are used in simple and modified form including modal effects. Then, a new approach is proposed to provide input impedance matching at resonant frequency via the application of microgenetic algorithm for wide band operation. The accuracy of theoretical calculations and impedance matching approach are presented for various structural parameters and operational modes of the antenna. © 2007 Wiley Periodicals, Inc. Microwave Opt Technol Lett 49: 2263–2267, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.22675
Accurate evaluation of singular potential integrals in an asymptotic‐phase method of moments formulation
Authors: Araújo M. G. , Taboada J. M. , Rodríguez J. L. , Obelleiro F. 
Published: June 2007

AbstractThe Khayat‐Wilton singularity cancellation technique has been adapted for computing the potential integrals involving the 3D Green's function and the linearly‐phased Rao‐Wilton‐Glisson (LP‐RWG) basis functions. The LP‐RWG basis functions are used to expand the induced currents in terms of current‐modes, which allows an efficient representation of the currents in large scatters using a fewer number of unknowns. The proposed procedure overcomes some drawbacks of other singularity schemes, such as the dependence of the triangular‐patch shape and the location of the observation points. In this sense, the proposed procedure is valid for singularities and “near” singularities on arbitrarily‐shaped triangular meshes. This significantly improves the reliability of the method of moments and related approaches in combination with the asymptotic phase formulation when dealing with arbitrary and automatically generated surface meshes. © 2007 Wiley Periodicals, Inc. Microwave Opt Technol Lett 49: 2189–2197, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.22680
Frequency‐tuned ultra wideband antenna with partial‐circular patch
Authors: Zhang Jingyun , Zhang Wenmei , Chen Xue , Gao Liping H. J. 
Published: June 2007

AbstractA novel frequency‐adjustable ultra wideband antenna with coplanar waveguide‐fed is proposed and the design formula is presented. The optimized antenna presents 6.7:1 ratio bandwidth and 148% impedance bandwidth for the return loss less than −10 dB. The bandwidth can be changed through adjusting the slice of partial‐circular patch. Also, the numerical sensitivity analysis for different dimensions has been done. Good agreement between the measurement and simulation has been achieved. © 2007 Wiley Periodicals, Inc. Microwave Opt Technol Lett 49: 2128–2131, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.22683
Design of a novel HTS open‐loop SIR filter with the relocation of its second passband
Authors: Jin Shichao , Wei Bin , Zhang Xiaoping , Cao Bisong , Guo Xubo , Peng Huili , Gao Longma , Gao Baoxin 
Published: June 2007

AbstractThis paper presents a novel open‐loop stepped impedance resonator (OLSIR), which has advantage of compact structure and its relocatable first spurious frequency. A four‐pole high temperature superconducting (HTS) filter made up of OLSIRs is designed and fabricated'and the measurement result has good agreement with the simulation. © 2007 Wiley Periodicals, Inc. Microwave Opt Technol Lett 49: 2097–2101, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.22685
Modeling, optimization, and experimental evaluation of remotely pumped double‐pass EDFA
Authors: Hossain Nadir , Naji A. W. , Mishra V. , Abbou F. M. , Al‐Mansoori M. H. , Mahdi M. A. , Faidz A. R. 
Published: June 2007

AbstractA simple rate equation model of double pass (DP) Erbium‐doped fiber amplifier (EDFA) is developed based on the Giles and Desurvire (1991) model of single pass (SP) EDFA. The mathematical equations to calculate stimulated absorption and emission rate between levels 1 and 2 of SP EDFA are modified by integrating the reflected backward propagating signal of DP EDFA. Reflection loss of signal by the reflector is included with the backward propagating signal of DP EDFA. The design parameters of DP EDFA are optimized using numerical simulation of the developed DP EDFA rate equation model to design remotely pumped optimized DP EDFA. Robustness and stability of the developed DP EDFA rate equation model are shown by analyzing the numerical results and output shapes, using various design parameters of DP EDFA. Finally, the developed DP EDFA rate equation model is validated with the help of experimental results. © 2007 Wiley Periodicals, Inc. Microwave Opt Technol Lett 49: 2257–2261, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.22687
Finline tapers using closed‐form expressions for millimeter wave integrated systems
Authors: Mittal Ashok , De Asok 
Published: June 2007

AbstractConventional techniques for designing waveguide‐to‐finline taper transitions are based on the design of a suitable impedance transformation profile used for pure TEM lines. Change of finline/slotline gap not only causes change in impedance but also correspondingly change in propagation constant. Thus the existing analysis, used for purely TEM lines, is inadequate in dealing with finline tapers. Analysis has also been carried out by varying the propagation constant using closed‐form expressions. Comparison of various taper profiles has been presented in this paper. Further in the present work, the width of the finline contour itself has been varied according to the function profiles as exponential, parabolic, cosine, and cosine squared forming the tapers. Broadband tapered transition from rectangular waveguide to offset slot asymmetric finline has been realized by gradually increasing the slot width using exponential taper profile. The designed asymmetric finline taper (two transition with one lambda spacing) using impedance variation with width exponential profile showed a very good result of 0.15–0.25 dB in the entire Ka‐band. © 2007 Wiley Periodicals, Inc. Microwave Opt Technol Lett 49: 2254–2257, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.22688
Tailoring of the subwavelength focus
Authors: Sydoruk O. , Shamonina E. , Solymar L. 
Published: June 2007

AbstractSubwavelength focusing by an ensemble of magnetically coupled metamaterial elements is studied theoretically for the case when all the dimensions are small relative to the electromagnetic wavelength. It is shown that in contrast to expectation a focus can be placed in any desired position for any transmitter‐lens configuration by the appropriate tuning of the receiver. A mathematical proof is provided and two examples are shown demonstrating a focal width of λ/60. © 2007 Wiley Periodicals, Inc. Microwave Opt Technol Lett 49: 2228–2231, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.22689
New set of 3D orthogonal edge basis functions for the vector wave equation solution
Authors: Gonçalves Marcos S. , Hernandez‐Figueroa Hugo E. , Bordonalli Aldário C. 
Published: June 2007

AbstractNew three‐dimension orthogonal basis functions for finite element solution of the vectorial wave equation are presented. These functions, based on the Whitney's edge elements, maintain the same properties as those of conventional basis functions, naturally generating diagonal matrices and enhancing numerical performance. © 2007 Wiley Periodicals, Inc. Microwave Opt Technol Lett 49: 2224–2228, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.22690
A novel spiral high impedance surface structure for size reduction
Authors: Lin Bao‐Qin , Zheng Qiu‐Rong , Yuan Nai‐Chang 
Published: June 2007

AbstractA novel electromagnetic Band‐Gap (EBG) scheme is presented for size reduction. The proposed structure can be considered as one kind of distorted Sievenpiper High Impedance Surface (HIS) in a spiral shape, while it becomes extremely compact in size. Its design is detailed in this study, and two experimental results are presented. © 2007 Wiley Periodicals, Inc. Microwave Opt Technol Lett 49: 2186–2189, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.22691
The small UWB hybrid antenna
Authors: Chan Yi‐Wah , Luk Kwai‐Man 
Published: June 2007

AbstractA small size end‐fire mode hybrid monopole/DR antenna is introduced and tested. The hybrid antenna combines an annular DRA and a quarter‐wave monopole antenna to perform ultrawideband response. The proposed technique is used to reduce the length of monopole antenna and improve the whole impedance bandwidth. The maximum gain and impedance bandwidth is 5.5 dBi and 100% (VSWR ≤ 2), respectively. © 2007 Wiley Periodicals, Inc. Microwave Opt Technol Lett 49: 2157–2159, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.22693
Compact ultra‐wideband bandpass filter using uniplanar compact photonic bandgap structure
Authors: Baik J. W. , Hyun D. H. , Jeong J. , Kim Y.‐S. 
Published: June 2007

AbstractA novel ultra‐wideband (UWB) bandpass filter in the whole UWB passband of 3.1–10.6 GHz is proposed and implemented using a uniplanar compact photonic bandgap (UC‐PBG) resonator for size reduction. Since the UC‐PBG structure has more distributed L‐C components than the conventional microstip multiple‐mode resonator (MMR), the size reduction is achieved, which is about 34% more than the UWB bandpass filter based on a conventional microstrip MMR. The proposed one‐stage UC‐PBG filter has four transmission poles, insertion loss < 1.2 dB and group delay variation < 0.14 ns, while the three‐stage one shows an insertion loss of < 2.2 dB and a group delay variation of < 0.4 ns in the whole UWB band. © 2007 Wiley Periodicals, Inc. Microwave Opt Technol Lett 49: 2122–2123, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.22695