bluuebunny/crossref_metadata_2025_split huggingface dataset:
Wideband balun and vertical transition between microstrip and parallel‐strip transmission line
Authors: Kwon Do‐Hoon 
Published: April 2007

AbstractA wideband vertical transition between microstrip and parallel‐strip transmission lines is presented. It performs as an unbalanced‐to‐balanced transformer as well. Its back‐to‐back configuration is fabricated, and the transition characteristics are measured. Measurement results reveal low insertion loss over wide frequency band. The performance of the microstrip transition is compared with those of the vertical transitions involving a coplanar waveguide and a conductor‐backed coplanar waveguide, and comments on the comparison results are provided. © 2007 Wiley Periodicals, Inc. Microwave Opt Technol Lett 49: 1530–1532, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.22482
Transmission through and wave guidance on metal plates perforated by periodic arrays of through‐holes of subwavelength coaxial cross‐section
Authors: Lomakin Vitaliy , Li Shuqing , Michielssen Eric 
Published: April 2007

AbstractPerfect electrically conducting (PEC) plates perforated by doubly periodic arrays of through‐holes of subwavelength coaxial cross‐section permit enhanced transmission of plane waves and support surface wave guidance. The transmission enhancement is attributed to coupling of free‐space fields to TEM and TE11modal fields in holes and occurs via two distinct mechanisms. The first couples incident fields to local resonances (cavity modes) supported by individual holes. The second couples scattered fields (diffraction modes) to global resonances (surface waves). The surface waves arise due to strong interactions between the holes and can have a large propagation wavenumber. The presented PEC model is adequate in the microwave and terahertz regimes and insights into related wave phenomena at optical frequencies.© 2007 Wiley Periodicals, Inc. Microwave Opt Technol Lett 49: 1554–1558, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.22484
Axial mode helix antenna with exponential spacing
Authors: Chen Can‐Hui , Yung E.K.N. , Hu Bin‐Jie , Xie Sheng‐Li 
Published: April 2007

AbstractA novel wideband CP helix antenna with exponential spacing is presented in this paper. Since traveling wave current over a wide range of frequencies has been excited, it possesses better performance. Both numerical results and experimental results show that the axial ratio bandwidth of the exponential spacing helix (ESH) antenna is 58.6% greater than that of the linear spacing helix (LSH) antenna in the same conditions. The characteristics of impedance, power gains, and radiation patterns for the ESH antenna are also investigated and compared with LSH antenna. © 2007 Wiley Periodicals, Inc. Microwave Opt Technol Lett 49: 1525–1530, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.22485
Optical properties of SIC/SIO2 composite thin film
Authors: Yi Jian , He XiaoDong , Sun Yue , Li Yao 
Published: April 2007

AbstractSiC film was deposited by electron beam‐physical vapor deposition on thermal oxidized silicon substrates at 750°C, and SiC/SiO2 composite thin film was prepared. The obtained composite film was analyzed by Fourier‐transform infrared (FTIR) transmission and reflection spectroscopy, and the film reveals an amorphous structure and a high emissivity.© 2007 Wiley Periodicals, Inc. Microwave Opt Technol Lett 49: 1551–1553, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.22487
TEM horn antenna with an elliptic profile
Authors: Malherbe J. A. G , Barnes N. 
Published: April 2007

AbstractA variety of profiles for the cross section of wideband TEM horns have been proposed, employing an optimal impedance function or exponential taper in order to minimize reflection losses. In this article, an elliptic longitudinal sectional profile, combined with an optimal impedance function, is proposed and evaluated.© 2007 Wiley Periodicals, Inc. Microwave Opt Technol Lett 49: 1548–1551, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.22488
A very compact dielectric waveguide directional coupler utilizing a double‐negative slab core
Authors: Huang Meng , Xu Shanjia 
Published: April 2007

AbstractA novel dielectric waveguide directional coupler with a double‐negative slab lies in the coupling region is analyzed by the staircase approximation method, which combines the building block approach and multimode network theory with a rigorous mode‐matching procedure. Particular attention is directed toward the coupling characteristics under different structural and constitutive parameters of the coupler. Numerical results indicate that the transition and coupling length of the proposed coupler is only 70% and 42% of related lengths in the conventional coupler, respectively. © 2007 Wiley Periodicals, Inc. Microwave Opt Technol Lett 49: 1545–1548, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.22491
Reconfigurable multiwavelength erbium‐doped fiber laser using two multimode fiber Bragg gratings
Authors: Yan Jin‐Hua , Fu Hong‐Yan , He Sailing 
Published: April 2007

AbstractA reconfigurable multiwavelength erbium‐doped fiber laser, using two multimode fiber Bragg gratings (MFBGs), is presented. Two MFBGs in L‐band are cascaded to form two overlapping resonant cavities. Various configurations of four‐, three‐, or two‐wavelength lasing are demonstrated experimentally by appropriately controlling the two polarization controllers inside the cavities. © 2007 Wiley Periodicals, Inc. Microwave Opt Technol Lett 49: 1509–1511, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.22493
Ultra‐wideband printed fork‐shaped monopole antenna with a band‐rejection characteristic
Authors: Liu Wen‐Chung , Chen Shu‐Ming 
Published: April 2007

AbstractA novel ultra‐wideband design of a printed fork‐shaped monopole antenna with a band‐rejection characteristic is presented. The proposed antenna with a simpler structure has a larger impedance bandwidth, defined by voltage standing wave ratio ≤ 2, covering the range from 3.09 to 11 GHz, and a tunable cutoff band throughout adjustment of the centre strip length of the fork‐shaped monopole. Measured monopole‐like radiation patterns and in‐band antenna gains ≥ 2 dBi have also been obtained, simultaneously, with good agreement to the simulated results. © 2007 Wiley Periodicals, Inc. Microwave Opt Technol Lett 49: 1536–1538, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.22495
Directional coupler for UHF mobile RFID reader
Authors: Jung Jin‐Wook , Nae Kwan‐Kyu , Thakur Jay Prakash , Cho Hong‐Gu , Park Jun‐Seok 
Published: April 2007

AbstractIn order to offer RFID services on mobile phones, the RFID reader must be embedded on the handset as a chip. However, the directional coupler was used as a ceramic passive component in conventional handsets. RFID system using an identical Tx/Rx carrier frequency has a significant volume limitation compared with active components. This article presents the directional coupler design for UHF RFID mobile reader using IPD (Integrated Passive Device) process. T and π‐type coupler with dimensions of 1.74 × 1.6 and 1.32 × 1.4 mm2 were assembled. © 2007 Wiley Periodicals, Inc. Microwave Opt Technol Lett 49: 1501–1504, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.22497
Measurement of a reciprocal four‐port transmission line structure using the 16‐term error model
Authors: Zhang Yun , Silvonen Kimmo , Zhu Ning H. 
Published: April 2007

AbstractA new method to measure reciprocal four‐port structures, using a 16‐term error model, is presented. The measurement is based on 5 two‐port calibration standards connected to two of the ports, while the network analyzer is connected to the two remaining ports. Least‐squares‐fit data reduction techniques are used to lower error sensitivity. The effect of connectors is deembedded using closed‐form equations. © 2007 Wiley Periodicals, Inc. Microwave Opt Technol Lett 49: 1511–1515, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.22498
Design of triangular slot antenna for triple‐band (2.4/5.2/5.8 GHz) antenna with fork‐like tuning stub
Authors: Yoon J. H. , Han G. H. , Kim D. H. , Lee J. C. , Woo S. M. , Kim H. H. 
Published: April 2007

AbstractA novel design for a triangular slot antenna with fork‐like tuning stub for 2.4/5.2/5.8 GHz triple‐band applications is presented in this article. The prototype consists of a triangular slot and a fork‐like tuning stub. The triangular slot is fed by a 50‐Ω microstrip line with a fork‐like tuning stub, which is printed on the opposite side of the microwave substrate. As seen in the experimental results, the impedance bandwidth (VSWR 1:2) of the proposed bandwidth is about 550 MHz for the 2.4‐GHz band and 1.736 GHz for the 5‐GHz band. This is a microstrip antenna for IEEE 802.11a/b wireless local area networks applications. Simulated and experimental results for the return loss, radiation patterns, and gains are presented and discussed.© 2007 Wiley Periodicals, Inc. Microwave Opt Technol Lett 49: 1561–1565, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.22499
A singular value decomposition based approach for far‐field reconstruction from irregularly spaced planar wide‐mesh scanning data
Authors: D'Agostino F. , Ferrara F. , Gennarelli C. , Guerriero R. , Migliozzi M. , Riccio G. 
Published: April 2007

AbstractAn efficient technique is developed in this article to evaluate the antenna far field from the knowledge of nonuniformly distributed near‐field data measured by a probe via a planar wide‐mesh scanning facility. To this end, the singular value decomposition method is properly applied to reconstruct the uniformly spaced samples, whose positions are fixed by a nonredundant sampling representation of the electromagnetic field. Then, the plane‐rectangular near‐field data needed to perform the classical probe compensated near‐field‐far‐field transformation are efficiently evaluated via an optimal sampling interpolation algorithm. Numerical tests, assessing the effectiveness and the stability of the far‐field reconstruction process, are reported. © 2007 Wiley Periodicals, Inc. Microwave Opt Technol Lett 49: 1768–1772, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.22502
Building a resonant cavity for the measurement of microwave dielectric permittivity of high loss materials
Authors: Rubinger C. P. L. , Costa L. C. 
Published: April 2007

AbstractThe design of a cavity resonator implies to solve the Maxwell equations inside that cavity, respecting the boundary conditions. As a consequence, the resonance frequencies appear as conditions in the solutions of the differential equation involved. The measurement of the complex permittivity, ϵ* = ϵ′‐iϵ″, can be made using the small perturbation theory. In this method, the resonance frequency and the quality factor of the cavity, with and without a sample, can be used to calculate the complex dielectric permittivity of the material. We measure the shift in the resonant frequency of the cavity, Δf, caused by the insertion of the sample inside the cavity, which can be related to the real part of the complex permittivity, ϵ′, and the change in the inverse of the quality factor of the cavity, Δ(1/Q), which can be related with the imaginary part, ϵ″. This is valid for very small perturbations of the electric field inside the cavity by the insertion of a sample. For materials with high losses, the perturbation can be very high, making impracticable the use of this technique. The solution is to use high volume cavities. In this work we report the design and the performance tests of a cavity to be used with high loss materials. © 2007 Wiley Periodicals, Inc. Microwave Opt Technol Lett 49: 1687–1690, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.22506
Two novel transmission lines with vertical conductors added to ground planes
Authors: Duyar Mehmet , Akan Volkan , Yazgan Erdem , Bayrak Mehmet 
Published: April 2007

AbstractIn this article, two different novel Coplanar Waveguides (CPW) structures have been proposed and analyzed. The CPW structures proposed provide flexibility for practical applications. For the analyses, conformal mapping techniques were employed. The closed form analytical expressions are generally suitable for usage in CAD‐oriented microwave circuit design. Both the structures have been simulated for quasi‐TEM mode in a 3D commercially available software. In addition, the results obtained in this work have been compared with the others available in the literature. Simulations and comparisons give support to the validity of the obtained analytical expressions in this study. © 2007 Wiley Periodicals, Inc. Microwave Opt Technol Lett 49: 1653–1656, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.22508
Use of genetic algorithms in linear and planar antenna array synthesis based on Schelkunoff method
Authors: Recioui A. , Azrar A. 
Published: April 2007

AbstractGenetic algorithms coupled with the Schelkunoff synthesis method are used to synthesize equispaced linear and planar arrays. The purpose is to find the different excitation amplitudes and phases to achieve good matching between the desired and calculated radiation patterns. Examples which demonstrate the versatility of the approach presented in this article are considered for various patterns including the steered pattern case. The planar array is treated as a set of two separate linear arrays upon which Schelkunoff method is applied separately. © 2007 Wiley Periodicals, Inc. Microwave Opt Technol Lett 49: 1619–1623, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.22510
Dual‐frequency dual‐polarization antenna of high isolation with embedded mushroom‐like EBG cells
Authors: Lee Dong Hyun , Kim Jae Hee , Jang Jong Hun , Park Wee Sang 
Published: April 2007

AbstractA dual‐frequency dual‐polarization (DFDP) antenna of high isolation between two ports with embedded 2 × 1 mushroom‐like electromagnetic bandgap (EBG) cells is presented. The equivalent circuit of a suspended microstrip line over 2 × 1 EBG cells is introduced. The numerical analysis from the equivalent circuit and measured results show that the microstrip line with embedded EBG cells has a distinctive and sharp rejection band that provides near 0 dB insertion loss outside the rejection band. By embedding the EBG cells under feedlines of a DFDP antenna, the isolation between two ports of the proposed antenna is enhanced by more than 20 dB, when compared with that of a conventional DFDP antenna. The proposed DFDP antenna is fabricated and measured. The simulated and measured results show a good agreement. © 2007 Wiley Periodicals, Inc. Microwave Opt Technol Lett 49: 1764–1768, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.22513
A novel design of a microstrip‐fed shorted square‐ring slot antenna for circular polarization
Authors: Chang Kow‐Ming , Lin Ren‐Jie , Deng I‐Chung , Ke Qing‐Xiang 
Published: April 2007

AbstractThe design of a circularly polarized slot antenna fed by a single microstrip line is presented. The circularly polarized radiation is achieved by means of using a shorted square‐ring slot. This proposed antenna has the fundamental resonant frequency of 2.4 GHz with the minimum return loss of −50.44 dB. The impedance bandwidth is 930 MHz or 38.7% referred to the resonant frequency, and it also has the 3‐dB axial‐ratio (AR) bandwidth of 310 MHz or 12.9% referred to the resonant frequency. In addition, this proposed antenna shows good performance of circular polarization (CP) radiation with the range of the lower 3‐dB AR value covering elevation angles between −40 to 40 degrees. © 2007 Wiley Periodicals, Inc. Microwave Opt Technol Lett 49: 1684–1687 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.22517
Circuit model and full wave analysis of a compact wideband quadrature hybrid
Authors: Jaiswal Adarsh K. , Kishk Ahmed A. 
Published: April 2007

AbstractA printed, compact, and wideband quadrature hybrid is simulated and fabricated by utilizing the multi‐section technique for bandwidth enhancement and equivalent transmission line technique for size reduction. The compact quadrature hybrid has a size reduction of 50% as compared with the conventional quadrature hybrid. The compact hybrid achieves over 50% bandwidth at a centre frequency of 2 GHz. A circuit model and a full wave model are introduced and analyzed using Agilent Advanced design system. Excellent agreement between the simulated and the fabricated hybrid is achieved, which indicates that the circuit and full wave models are indeed a good representation of the fabricated compact wideband quadrature hybrid. © 2007 Wiley Periodicals, Inc. Microwave Opt Technol Lett 49: 1650–1652, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.22519
Design, realization, and test of a 900 MHz ceramic oscillator
Authors: Pisa Stefano , Piuzzi Emanuele , Tommasino Pasquale , Trifiletti Alessandro , Galli Alessandro , Giolo Giancarlo , Tafuto Antonio 
Published: April 2007

AbstractThe design of a 900 MHz ceramic oscillator, delivering a power of 10 dBm, has been carried out by using the negative‐resistance condition. A new procedure based on the Nyquist criterion, implemented within microwave CADs has been used to test the onset of oscillations at the desired frequency and the presence of spurious oscillation. An excellent agreement between nonlinear simulations and measurements performed on a prototype has been observed. © 2007 Wiley Periodicals, Inc. Microwave Opt Technol Lett 49: 1713–1717, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.22528
Study of the slow fading in indoor environment using parabolic equations
Authors: Magno Fátima N. B. , Souza João F. , Valente Zínia A. , Costa Jessé C. , Cavalcante Gervásio P. S. 
Published: April 2007

AbstractThis article compares slow fading component of the propagation loss calculated through parabolic wave equation and some models of the literature with results obtained during measurement campaign, in indoor environment. The frequency used was 850 MHz; a complex refractive index was considered. The implicit finite difference scheme of the Crank‐Nicolson type was applied in order to get the solution of the parabolic equation. The propagation was considered in 15° with direction paraxial. © 2007 Wiley Periodicals, Inc. Microwave Opt Technol Lett 49: 1676–1679, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.22530
A low noise 3.1 10.6 GHz pMOS distributed amplifier for ultra‐wideband applications
Authors: Wei Chien‐Cheng , Chiu Hsien‐Chin , Feng Wu‐Shiung 
Published: April 2007

AbstractA low noise pMOS distributed amplifier for Ultra‐wideband (UWB) application is presented in this study. The amplifier is a two‐stage design fabricated in a standard 0.18‐μm CMOS process. The pMOS‐based distributed amplifier as input stage is used to achieve a better noise figure and a wider bandwidth; besides, the nMOS common‐source amplifier as output stage is applied to obtain sufficient gain over the band, respectively. The fully amplifier exhibits a power gain of 9 dB with a gain flatness of 0.8 dB, and noise figures are approximately lower than 5.3 dB from 3.1 to 10.6 GHz. The 1‐dB compression point and input third‐order intercept points are −8 dBm and 3.5 dBm with total power consumption of 22.5 mW, respectively. Experimental results indicate that the proposed architecture exhibits low noise and high gain performance for UWB applications. © 2007 Wiley Periodicals, Inc. Microwave Opt Technol Lett 49: 1641–1644, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.22532
Studies of small dualband annular‐ring slot antenna with a pair of implanted spur‐like slits
Authors: Sze Jia‐Yi , Hsu Chung‐I G. , Hsu Sheng‐Chin 
Published: April 2007

AbstractIn this article, a compact annular‐ring slot antenna for dualband operations is proposed and studied. A pair of spur‐like slits was implanted in the center patch of an annular‐ring slot antenna to excite two resonant modes with their resonant frequencies easily adjusted by changing the dimensions of these slits, resulting in a large range of dual‐frequency ratios (1.07–2.2). For the first excited resonant mode, the routes of the equivalent magnetic current distribution in the slot region can be lengthened by these slits. The resultant lowered first resonant‐band center frequency (from that of the unperturbed annular‐ring slot antenna) thus made the proposed antenna effectively miniaturized. The proposed antenna was found to have very good linearly polarized broadside radiation patterns and very low cross polarization levels in both operating bands.© 2007 Wiley Periodicals, Inc. Microwave Opt Technol Lett 49: 1578–1581, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.22536
Cylindrical double‐ridged waveguide as a basic unit of microwave heating applicators
Authors: Komarov Vyacheslav V. , Pchelnikov Yuriy N. , Yakovlev Vadim V. 
Published: April 2007

AbstractThis paper deals with a circular double‐ridged waveguide (CDRW) as a key element of traveling‐wave systems for microwave thermal processing. Approximate formulas for estimation of basic characteristics of CDRW partially filled with dielectric are derived with the use of the equivalent circuit technique. For accurate analysis, 3D FDTD models are developed and used for computation of coupling, electric field, and dissipated power in a coaxially excited five‐section CDRW applicator with three spherical loads. © 2007 Wiley Periodicals, Inc. Microwave Opt Technol Lett 49: 1708–1713, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.22539
QUASI‐static solutions of elliptical, cylindrical‐coupled parallel coplanar waveguide, and coupled parallel coplanar waveguide with finite ground planes
Authors: Duyar Mehmet , Akan Volkan , Yazgan Erdem , Bayrak Mehmet 
Published: April 2007

AbstractThis article presents the quasi‐static analyses of elliptical‐coupled parallel coplanar waveguide (ECP CPW), cylindrical‐coupled parallel coplanar waveguide (CCP CPW), and coupled parallel coplanar waveguide (CP CPW) with finite ground planes. Conformal‐mapping techniques have been used through the analyses. The obtained results show good agreement with IE3D electromagnetic‐circuit solver software's simulations for the planar case. In addition, the results have been compared with others available in the literature. © 2007 Wiley Periodicals, Inc. Microwave Opt Technol Lett 49: 1702–1708, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.22540
A new wideband three‐way power divider
Authors: Chen Guan‐Yu , Sun Jwo‐Shiun 
Published: April 2007

AbstractA new three‐way power divider that provides equal power split over a wide bandwidth implemented on a single‐layer printed circuit board (PCB) is presented. It can be easily extended to an arbitrary number of output ports. The proposed power divider exhibits fairly good performance validated by measurement and simulation. Measured results show that the three output ports across the bandwidth from 1.8 to 10.5 GHz for 10 dB return loss are attainable. © 2007 Wiley Periodicals, Inc. Microwave Opt Technol Lett 49: 1600–1603, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.22547