bluuebunny/crossref_metadata_2025_split huggingface dataset:
Analysis of slot‐loaded stacked disk patch antenna
Authors: Ansari J. A. , Singh Prabhakar , Dubey Satya Kesh , Khan R. U. , Vishvakarma Babau R. 
Published: July 2008

AbstractIn the present article circular disk loaded with slot as well as stacking with parasitic element is analyzed in which it is found that bandwidth of the antenna improves by loading it with slot as well as parasitic element. The resonance frequency and matching of the antenna depends on slot dimensions and substrate thickness (h1 and h2). The theoretical results are compared with the simulated results using IE3D. © 2008 Wiley Periodicals, Inc. Microwave Opt Technol Lett 50: 2625–2629, 2008; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.23738
Near‐zero permittivity substrates for horizontal antennas: Performance enhancement and limitations
Authors: Hirvonen Mervi , Tretyakov Sergei A. 
Published: July 2008

AbstractIn this letter the advantages offered by ε‐near‐zero materials as substrates for horizontal dipole antennas near a ground plane are theoretically studied. From the previous work it is known that substrates with extremely low values of permittivity dramatically enhance radiation from horizontal currents over a ground plane. On the other hand, as reported in this letter, frequency dispersion and the finite size of the substrate limit the achievable enhancement in antenna performance. © 2008 Wiley Periodicals, Inc. Microwave Opt Technol Lett 50: 2674–2677, 2008; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.23739
11.8 GHz GAINP/GAAS HBT dynamic frequency divider using HLO‐FF technique
Authors: Wei Hung‐Ju , Meng Chinchun , Chang YuWen , Huang Guo‐Wei 
Published: July 2008

AbstractAn integrated GaInP/GaAs heterojunction bipolar transistor (HBT) dynamic frequency divider based on HLO‐FF (high‐speed latching operating flip‐flop) structure is demonstrated at 4.1–11.8 GHz. In this experiment, a conventional static frequency divider using the same cut‐off‐frequency device is also fabricated for comparison. By biasing the HBT transistors around the peak of fT and optimizing the Iread/Ilatch ratio, the maximum operating frequency of the HLO‐FF is greatly improved due to higher slew‐rate and smaller voltage swing. The speed of HLO‐FF is faster about 48% than that of static structure. The core current is 13 mA at the supply voltage of 5 V. © 2008 Wiley Periodicals, Inc. Microwave Opt Technol Lett 50: 2642–2645, 2008; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.23740
Design of a broadband dual circularly polarized square slot antenna
Authors: Zhao G. , Chen L.‐N. , Jiao Y.‐C. 
Published: July 2008

AbstractIn this article, a new design of a broadband dual circularly polarized square slot antenna loaded with metallic strips is presented. The proposed dual circular polarization (CP) radiations are achieved by loading the square slot with a T‐shaped strip and two microstrip T‐junctions. The designed antenna is implemented and measured. The experimental results show that the proposed antenna has good dual CP characteristics and a 3‐dB axial ratio bandwidth is more than 19%. The isolation between two ports is better than 20 dB within the CP operating band. © 2008 Wiley Periodicals, Inc. Microwave Opt Technol Lett 50: 2639–2642, 2008; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.23741
Design of a compact and wideband microstrip bandstop filter
Authors: Çakir Gonca 
Published: July 2008

AbstractA novel bandstop filter (BSF), with a stop band covering GSM‐900, GSM1800, Bluetooth, and future 5 GHz applications which possesses the characteristics of compact size and wide bandwidth is proposed and fabricated. Parameters are optimized via numerical simulations. The simulations are performed via an in‐house‐prepared three dimensional (3D) finite‐difference time‐domain (FDTD) package. Measurements are carried out using an HP‐8510C network analyzer. The simulated and measured results show that the filter has wide stopband of 126% (1.7–7.8 GHz) for 3‐dB bandwidth. There is a good agreement between the simulated and experimental results. © 2008 Wiley Periodicals, Inc. Microwave Opt Technol Lett 50: 2612–2614, 2008; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.23742
Application of segmentation analysis to a matched U‐slot patch antenna
Authors: Lee S. K. , Ooi S. F. , Sambell A. , Korolkiewicz E. , Scott S. 
Published: July 2008

AbstractA wide impedance matching bandwidth or multi‐band response can be obtained using a single layer U‐slot rectangular antenna with a probe feed. However, the determination of the input impedance of this antenna has not been reported. In this letter using segmentation analysis a new explicit matrix input impedance formula has been derived. The U‐slot rectangular antenna is partitioned into rectangular segments and the system of coplanar matrix circuit equations is reduced by cojoining pairs of equations. The reduced system is then solved to obtain a new explicit matrix input impedance formula. This technique has the potential to be applied to other multi‐segmented antenna geometries. Two antennas operating at 2.45 GHz were fabricated, one with a substrate of thickness 1.575 mm and the other with a substrate of thickness of 3.175 mm. For both antennas there is an excellent agreement between the predicted, simulated, and measured results for the input impedance. © 2008 Wiley Periodicals, Inc. Microwave Opt Technol Lett 50: 2608–2611, 2008; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.23743
A 90‐NM CMOS low‐power down‐converter for 3‐ to 5‐GHz ultra‐wideband wireless systems
Authors: Sapone Giuseppina , Palmisano Giuseppe 
Published: July 2008

AbstractThis article presents the design and the measurement results of a 3‐to 5‐GHz down‐converter fabricated in a 90‐nm CMOS technology. The circuit consists of a single‐ended low‐noise amplifier and two I/Q double‐balanced mixers. A transformer‐based on‐chip single‐ended‐to‐differential conversion allows gain and noise performance to be optimized at a very low power. The down‐converter achieves a 23‐dB conversion gain, a noise figure of 3.4 dB, and an input third‐order intercept point of −8 dBm, while drawing only 9 mA from a 1.2‐V supply voltage. The down‐converter exhibits competitive performance compared to the best state‐of‐the‐art ultra‐wideband circuits in the same frequency range. © 2008 Wiley Periodicals, Inc. Microwave Opt Technol Lett 50: 2577–2581, 2008; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.23744
Varactor‐tuned microstrip bandpass filter with wide tuning range
Authors: Kim Jeongpyo , Choi Jaehoon 
Published: July 2008

AbstractIn this study, a tunable bandpass filter with a hairpin line resonator and loading capacitors using varactor diodes was proposed. The filter was modified by adding varactor diodes to the coupling part to compensate for losses. The designed filter had a simple structure and the characteristics of wide tuning range of 87.9% from 430 to 1105 MHz and low insertion loss of less than 4.42 dB. © 2008 Wiley Periodicals, Inc. Microwave Opt Technol Lett 50: 2574–2577, 2008; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.23745
Optical fiber‐based macrobend free air flow sensor using a hinge joint: A preliminary report
Authors: Vijayan Anu , Thakare Vishal , Karekar R. N. , Aiyer R. C. 
Published: July 2008

AbstractA novel idea of hinge joint is explored to cause macrobend in optical fiber and is explored for its use as a flow sensor. The bending of the fiber at the hinge changes the intensity of light traveling through the optical fiber. This can ideally be used in areas where air flow upto 10 lit/min needs to be monitored continuously. © 2008 Wiley Periodicals, Inc. Microwave Opt Technol Lett 50: 2543–2546, 2008; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.23746
Design of three prime‐focus 12‐mm‐wavelength horns for the Parkes radio telescope
Authors: Granet Christophe , Gough Russell 
Published: July 2008

AbstractThree prime‐focus horns have been optimized to cover different frequency bands around the 12‐mm‐wavelength radio‐astronomy bands. © 2008 Wiley Periodicals, Inc. Microwave Opt Technol Lett 50: 2537–2543, 2008; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.23747
Leaky mode analysis of optical waveguides by Legendre and Laguerre pseudospectral method
Authors: Huang Chia‐Chien 
Published: July 2008

AbstractIn this letter, an efficient multidomain pseudospectral method is implemented to solve leaky waveguides. The exterior subdomains with the evanescent and oscillatory mode shapes, the optical fields are, respectively, expanded by Laguerre‐Gauss functions and Legendre polynomials incorporating simple Mur's absorbing boundary condition. Numerical results verify the effectiveness of the present approach and are in good agreement with exact data. © 2008 Wiley Periodicals, Inc. Microwave Opt Technol Lett 50: 2507–2509, 2008; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.23748
A novel structure of the power equalizer for millimeter wave applications
Authors: Zhang Yong 
Published: July 2008

AbstractPower equalizer is often used to adjust the output power of traveling wave tubes (TWT) or high power solid state amplifiers. Traditionally, a power equalizer is composed of coaxial line with electromagnetic wave absorber or microstrip line with resistance in resonance circuit. However, those structures only adapt to microwave frequency band. In this article, a millimeter wave power equalizer is fulfilled by waveguide resonant cavity with electromagnetic wave absorber. The measured results and the simulated results show a very good agreement. © 2008 Wiley Periodicals, Inc. Microwave Opt Technol Lett 50: 2504–2506, 2008; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.23749
Finite element analysis of multiconductor transmission lines in multilayered dielectric media
Authors: Musa Sarhan M. , Sadiku Matthew N. O. 
Published: July 2008

AbstractIn this work, we illustrate the analysis of inhomogeneous quasi‐TEM multiconductor transmission lines in multilayered dielectric media using finite element method. We specifically determine the per unit length of capacitance and the inductance matrices of two circular wires in layer surrounded by two different dielectric layers, three conductors in three different dielectric layers, and four conductors in three different dielectric layers between two grounds. Excellent agreement with results obtained previously by integrated equation method and method of moment is demonstrated. © 2008 Wiley Periodicals, Inc. Microwave Opt Technol Lett 50: 2743–2747, 2008; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.23750
Topology gradient optimization in 2‐D and 3‐D for the design of microwave components
Authors: Khalil Hassan , Assadihaghi Atousa , Bila Stéphane , Baillargeat Dominique , Aubourg M. , Verdeyme Serge , Puech Jerome , Lapierre Luc 
Published: July 2008

AbstractA numerical model defined by a finite element method coupled with a topology gradient method is used for optimizing the shape of microwave components with respect to electrical specifications. The approach, which consists in minimizing a cost function with respect to the physical property of individual topological elements, which define the shape of the component, is first described. Regarding the given electrical specifications, the technique is applied for optimizing, respectively, in 2D, the distribution of metal upon the surface of a planar component and, in 3D, the distribution of dielectric material within a waveguide component. © 2008 Wiley Periodicals, Inc. Microwave Opt Technol Lett 50: 2739–2743, 2008; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.23751
Diffusion characteristics of a joint‐proton source for the wet etch of LiNbO3
Authors: Ting Tien‐Lun , Huang Wen‐Hung , Chen Liang‐Yin , Wang Way‐Seen 
Published: July 2008

AbstractDiffusion characteristics of a joint‐proton source for proton exchange in LiNbO3 are presented. With a concentration‐dependent diffusivity derived from experimental results, the diffusion process is simulated to estimate the proton‐exchanged wet‐etched depth. Good agreement between simulated and measured depth is obtained. In addition, an S‐shaped ridge waveguide is fabricated to demonstrate the improvement in power transmission efficiency. © 2008 Wiley Periodicals, Inc. Microwave Opt Technol Lett 50: 2736–2738, 2008; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.23752
Ultra‐wideband loop antenna coupled‐FED by a monopole feed for penta‐band folder‐type mobile phone
Authors: Wong Kin‐Lu , Tu Shu‐Yang 
Published: July 2008

AbstractAn ultra‐wideband coupled‐fed loop antenna for penta‐band operation in the folder‐type mobile phone is presented. The antenna comprises a loop strip and a monopole feed; the latter not only serves as a coupling feed for the loop strip to generate a 0.5‐wavelength loop resonant mode, but also provides a 0.25‐wavelength monopole resonant mode for enhancing the operating bandwidth of the antenna. Hence, with an occupied volume of 2.6 cm3only, the antenna can provide a very wide operating band of larger than 100% or about 1.7 GHz (from 790 to 2480 MHz), allowing the antenna to cover GSM850/900/DCS/PCS/UMTS penta‐band operation with radiation efficiencies larger than 70% for the folder‐type mobile phone in the open state (talk condition). For the antenna in the close state (idle condition), it can still provide a very wide operating band just by including a matching circuit of a series chip capacitor at the antenna's feeding point, and the radiation efficiencies over the five operating bands are still better than 53%. Details of the proposed antenna are studied. © 2008 Wiley Periodicals, Inc. Microwave Opt Technol Lett 50: 2706–2712, 2008; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.23753
Tunable all‐fiber Er3+‐doped laser based on a double‐clad Er3+/Yb3+ co‐doped fiber amplifier
Authors: Shumin Zhang , Dan Li , Guangzhen Zhao 
Published: July 2008

AbstractIn this study, a continuously tunable Er‐doped fiber laser based on a double‐clad Er3+/Yb3+ co‐doped fiber amplifier is demonstrated. By using the nonlinear polarization rotation technique, the tunable laser operating can be an all‐fiber structure and have tuning range, power variation, and laser line width of 15 nm, 0.37 dBm, and less than 0.06 nm, respectively. By using an Er3+/Yb3+ co‐doped fiber amplifier, the amplified spontaneous emission intensity can be more than 40 dBm suppressed over the tunable range, and the power conversion efficiency is about 10.5%. © 2008 Wiley Periodicals, Inc. Microwave Opt Technol Lett 50: 2671–2674, 2008; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.23754
Evaluation of coplanar waveguide‐to‐microstrip transitions for precision S‐parameter measurements
Authors: O'Neil Benton K. , Young Jeffery L. 
Published: July 2008

AbstractThe metric of unaccounted power is introduced as a sufficient condition to successful thru‐reflect‐line (TRL) calibrations for microstrip circuits. It is then demonstrated how this metric can be used both a priori, with simulation data, and a posteriori, with measured data, to evaluate the efficacy of coplanar waveguide to microstrip transitions in TRL calibrations. This demonstration is performed with four different transition topologies, two of which utilize coaxial edge mount connectors and two of which utilize ground‐signal‐ground coplanar probes. © 2008 Wiley Periodicals, Inc. Microwave Opt Technol Lett 50: 2667–2671, 2008; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.23755
Synthesis of ultrawideband bandpass filter by multisection of commensurate stepped‐impedance resonators
Authors: Chen Chun‐Ping , Ma Zhewang , Anada Tetsuo 
Published: July 2008

AbstractA novel filter prototype composed of multisection of stepped impedance resonators (SIRs) is proposed to realize the ultra‐wideband bandpass (UWB) filter. The relation between the modes number and stage number of resonators is first discussed, followed by the derivation of the corresponding Chebyshev filtering function. Furthermore, the equivalent circuit model of this new filter prototype is established based on the transmission‐line theory for filter synthesis. As an example, a FCC UWB filter is synthesized with the proposed filter prototype to possess a passband from 3.1 to 10.6 GHz (fractional bandwidth is about 110%). The synthesized circuit model are further optimized by EM simulator, fabricated in microstrip line, and characterized by network analyzer. The good agreement between the measured and predicted frequency responses validates the effectiveness of newly proposed synthesis approach. In addition, the designed filter exhibits good characteristics of comparatively low insertion loss, quite sharp skirts, very flat group delay, and good stopband (especially in lower one) as well. © 2008 Wiley Periodicals, Inc. Microwave Opt Technol Lett 50: 2635–2639, 2008; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.23756
A VCO with on chip tank for IEEE 802.11a
Authors: Khemchandani S. L. , Suarez J. del Pino , Goñi‐Iturri Amaya , Diaz Roberto , Hernandez Antonio 
Published: July 2008

AbstractIn the last years, wireless LAN market has shown an incredible growth, exceeding expectations. This article presents a fully integrated LC voltage controlled oscillator in a low cost 0.35 μm BiCMOS process for the 5–6 GHz band, according to the IEEE 802.11a wireless LAN standard. The tank inductor has been designed by electromagnetic simulations. To test the VCO performance, a synthesizer for IEEE 802.11a has been designed. This work demonstrates the feasibility of a low cost silicon technology for the design of 5–6 GHz band circuits. © 2008 Wiley Periodicals, Inc. Microwave Opt Technol Lett 50: 2632–2635, 2008; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.23757
Simplified propagation channel characterization considering the disturbance of antennas in the case of a multipath cluster
Authors: Vu Van Yem , Kohmura Akiko , Braga A. Judson , Begaud Xavier , Huyart Bernard 
Published: July 2008

AbstractIn this article, a simple approach of antenna calibration for the radio propagation channel measurements in the case of a multipath cluster is presented. The method is based on the concept of “power wave transfer functions.” Practical experiments are performed for the characterization of a multipath propagation channel using printed dipole antennas, quasi‐Yagi antennas, and their array in the 2–3 GHz frequency range. © 2008 Wiley Periodicals, Inc. Microwave Opt Technol Lett 50: 2604–2608, 2008; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.23758
Compact dual‐band diversity antenna for mobile handset applications
Authors: Byun Joonho , Jo Jae‐Hoon , Lee Byungje 
Published: July 2008

AbstractA dual band diversity antenna for PCS and WiMAX bands is proposed and designed with compact dimension. The proposed diversity antenna consists of two dual‐band PIFAs arranged front to front with the same structure. With polarization diversity, jointed shorting structure, and suspended line, the proposed antenna gives high radiation efficiency (>50%), high isolation (>15 dB), and low correlation coefficient (ρe < 0.05. © 2008 Wiley Periodicals, Inc. Microwave Opt Technol Lett 50: 2600–2604, 2008; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.23759
Compact paper‐clip‐shaped wire antenna for 2.4 and 5.2 GHz WLAN operation
Authors: Su Saou‐Wen , Chou Jui‐Hung , Liu Yung‐Tao 
Published: July 2008

AbstractA compact dual‐WLAN‐band antenna, in the shape of a paper clip, is presented. The antenna can be easily manufactured by bending few times a single copper wire with a length of about 65 mm, and it operates in the 2.4 and 5.2 GHz bands in the WLAN environment. In addition to the simple configuration, the antenna is easily fed by a 50‐Ω mini‐coaxial cable which allows it to be flexible in a defined location for installation. An experimental prototype of the proposed antenna with the overall dimensions of about 5 mm × 23.5 mm is constructed, tested, and demonstrated. © 2008 Wiley Periodicals, Inc. Microwave Opt Technol Lett 50: 2572–2574, 2008; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.23760
The fabrication and analysis of lateral pressure fiber sensor based on fiber Bragg grating
Authors: Huang Hsi‐Shan , Liang Tsair‐Chun 
Published: July 2008

AbstractThis article mainly depicts the sensitivity of the pressure sensor based on fiber Bragg grating coated with polymers of different ratio hardener and silicone sealant. The result shows that when the ratio is 1:13, the effect of the sensitivity of 1.94 × 10−2/MPa can be obtained. © 2008 Wiley Periodicals, Inc. Microwave Opt Technol Lett 50: 2535–2537, 2008; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.23761
Displacement of phase center location in circular microstrip antennas
Authors: Shafai Lotfollah , Pour Zahra Allahgholi 
Published: July 2008

AbstractIt is shown that the phase center of a dual‐mode circular microstrip antenna depends on the excitation of its modes. For a single mode, the phase center is located on the geometrical center of the antenna. However, if two or more modes are combined, the phase center can be moved away from the antenna center, and make its location dependent on the mode excitations. For the two adjacent TM11 and TM21 modes the problem is investigated and the dependence of the phase center location on the relative excitation of the two modes is determined. © 2008 Wiley Periodicals, Inc. Microwave Opt Technol Lett 50: 2531–2535, 2008; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.23762
Synthetic asymptote formula for coupled microstrip line on two layer grounded substrates
Authors: Tang Wanchun , Cai Wenbo , Yu Zhengyong 
Published: July 2008

AbstractThis article presents the derivation of simple CAD formula for coupled microstrip line on a grounded substrate of two layers by synthetic asymptote. The formulas are simple, accurate, and give good physical insights to the design properties. By simply introducing an imaginary part in the permittivity of the bottom layer substrate, the formulas in this article can be applied for coupled microstrip line of silicon‐based RFIC. Not only the even and odd mode characteristic impedances, but also the attenuation and propagation constants are compared with numerical results. Good agreements are obtained. © 2008 Wiley Periodicals, Inc. Microwave Opt Technol Lett 50: 2500–2504, 2008; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.23763
A Kretschmann‐type absorption‐based surface plasmon resonance waveguide sensor
Authors: Shibayama Jun 
Published: July 2008

AbstractThe Kretschmann‐type surface plasmon resonance (SPR) waveguide sensor is numerically investigated for detecting a change in the imaginary part of the refractive index. SPR responses are found to be quite sensitive to the change, suggesting the possibility of realizing a compact absorption‐based waveguide sensor integrated into optical circuits. © 2008 Wiley Periodicals, Inc. Microwave Opt Technol Lett 50: 2497–2500, 2008; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.23764