bluuebunny/crossref_metadata_2025_split huggingface dataset:
SiGe BiCMOS subharmonic Gilbert mixer using lumped‐element rat‐race couplers
Authors: Tseng S.‐C. , Meng C. C. , Huang G.‐W. 
Published: May 2007

AbstractA single‐ended down‐conversion subharmonic mixer is implemented using 0.35‐μm SiGe BiCMOS technology. Two lumped‐element rat‐race couplers are applied to generate differential LO and RF signals. This single‐ended rat‐race mixer has the conversion gain of 25 dB, −90‐dB 2×LO‐to‐RF isolation and −78‐dB 2×LO‐to‐IF isolation at the RF frequency of 10 GHz. The input return loss is about −10 dB. © 2007 Wiley Periodicals, Inc. Microwave Opt Technol Lett 49: 2018–2020, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.22563
Design of diffractive elements at millimeter wavelengths using subwavelength cylindrical microstructures
Authors: Mirotznik Mark S. , Creazzo Timothy , Mathews Scott 
Published: May 2007

AbstractWe describe a design methodology for synthesizing diffractive elements based on two‐dimensional subwavelength cylindrical microstructures. We combine a numerical and experimental approach to demonstrate that by varying the diameter, pitch, and depth of subwavelength cylindrical occlusions in a homogenous substrate it is possible to produce multiphase diffractive elements. © 2007 Wiley Periodicals, Inc. Microwave Opt Technol Lett 49: 1880–1884, 2007; Published online in Wiley Inter‐Science (www.interscience.wiley.com). DOI 10.1002/mop.22571
A robust parameter extraction method for HBT small‐signal equivalent circuit
Authors: Ho Sung‐Jin , Choi Min Ki , van der Weide Daniel W. 
Published: May 2007

AbstractAn improved pad‐deembedding technique for InGaP/GaAs HBT reducing uncertainty in measurement and equivalent circuit is proposed. Intrinsic elements are obtained by iteratively determining the external and internal base resistance. The extracted equivalent circuits demonstrate good agreement with the measured S‐parameters obtained from 45 MHz to 40 GHz for different sizes of HBTs. © 2007 Wiley Periodicals, Inc. Microwave Opt Technol Lett 49: 1845–1848, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.22573
Novel suspended‐line microstrip coupler using BCB as supporting layer
Authors: Corona‐Chavez A. , Llamas‐Garro I. , Kim Jung‐Mu , Kim Yong‐Kweon 
Published: May 2007

AbstractIn this letter a novel λ/4 micromachined directional coupler is presented with a 10 μm benzocyclobutene (BCB) layer used to suspend one transmission line over another one in order to achieve a 3‐dB coupling. The coupler is centered at a frequency of 24 GHz. © 2007 Wiley Periodicals, Inc. Microwave Opt Technol Lett 49: 1813–1814, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.22574
Novel ultrawideband and multiband triangular planar inverted F antenna for wireless applications
Authors: Nashaat Dalia M. 
Published: May 2007

AbstractA novel multi‐ and ultrawideband operation of a single feed triangular antenna are presented. For multi and UWB operation, the proposed design are achieved by inserting U shaped slot on the triangular PIFA with unequal arms, choosing between multi and ultrawide band by adjusting feeding position. Five resonant band of multi band operation is obtained in S‐band, Q‐band, bluetooth band, and WLAN band with acceptable impedance bandwidth. There is an increase in the number of resonant operating frequencies by etching U slot on the shorting feed plate. Ultrawideband is achieved by adjusting coaxial feed to obtained impedance bandwidth 27%. Enhancement impedance bandwidth by using folded shorting plate to improving bandwidth to achieve ultrawide bandwidth around 53%. The proposed antennas have acceptable gain around 11.5 dB. © 2007 Wiley Periodicals, Inc. Microwave Opt Technol Lett 49: 2039–2043, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.22576
The multigrid preconditioned flexible GMRES solver for hierarchical TVFEM analysis
Authors: Zhu J. , Tang Wanchun 
Published: May 2007

AbstractThe H1(curl) conforming finite element method is applied for the finite‐element modeling of electromagnetic structures. A p‐version multigrid method combined with flexible GMRES solver is introduced to solve the finite element system. In this scheme, the p‐version multigrid is applied as the preconditioner and the flexible GMRES solver is performed as outer iteration. Therefore, the proposed technique can efficiently eliminate the low frequency components of the error of the numerical solution and can achieve fast convergence. Numerical simulation demonstrates the superior numerical convergence of the proposed method. © 2007 Wiley Periodicals, Inc. Microwave Opt Technol Lett 49: 2012–2018, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.22577
Multiband dual patch antennas with polarization compensation for WLAN applications
Authors: He Wei , Jin Ronghong , Geng Junping , Lampe Mattias 
Published: May 2007

AbstractIn this article, an antenna system with orthogonal spiral‐patches design capable of multiband operation at about 2.38–2.5 GHz and 4.20–6.00 GHz is presented. Simulated and measured results for main parameters such as return loss, impedance bandwidth, radiation pattern, and gains are presented and discussed herein. By combining two patches and exploiting the simple antenna diversity scheme supported by today's WLAN chip sets with related algorithms as maximal ratio combining (MRC), nonideal circular polarizing and nonsymmetrical radiation patterns can be compensated and a semispherical radio coverage can be approximated, which make this design a suitable candidate for IEEE 802.11a/b/g/n WLAN applications. © 2007 Wiley Periodicals, Inc. Microwave Opt Technol Lett 49: 1907–1911, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.22584
Stepped coupled‐line balun design for enhanced bandwidth operation
Authors: Chen Guan‐Yu , Sun Jwo‐Shiun 
Published: May 2007

AbstractThis letter presents a practical design method for the stepped impedance coupled‐line balun using an effective and simple way to increase the balanced output bandwidth of the coupled lines in the conventional planar Marchand balun. A new structure of collateral multi‐section with quarter wavelength coupled‐line balun is developed to increase at least 40% more balanced bandwidth and to achieve a better return loss than the traditional planar Marchand coupled‐line balun. The structure of the designed planar microstrip circuit is fairly simple, practical and easy to fabricate. The measured results of the design show fine agreements with the simulated data. © 2007 Wiley Periodicals, Inc. Microwave Opt Technol Lett 49: 1877–1879, 2007; Published online in Wiley Inter‐Science (www.interscience.wiley.com). DOI 10.1002/mop.22585
Wideband microstrip bandpass filter based on intercoupled split‐ring resonator
Authors: Wu Jack , Qiu S. N. , Qiu C. X. , Shih I. 
Published: May 2007

AbstractA new design of wideband microwave bandpass filter based on intercoupled split‐ring resonator is proposed. The split‐ring resonator structure is well‐know for its unique resonance feature that exhibit a negative permeability. By implementing the split‐ring resonator directly on a microstrip transmission line, a bandpass filter with a large fractional bandwidth has been achieved. The novel periodic intercoupled split‐ring resonator bandpass filter is compatible with microwave planar technology and the passband region is controllable. The filter design has been validated and demonstrated in both simulations and experimental measurements. A bandpass filter with a fractional bandwidth of 50% at a center frequency of 14 GHz was achieved with a maximum insertion loss of 0.75 dB in the passband region. Meanwhile, the fractional bandwidth has been demonstrated to be controllable and this was reduced to 37% by sacrificing the periodicity of the intercoupled split‐ring resonator structure. Therefore, the flexible characteristics and the simple implementation method may render the proposed filter to be very useful in many frequency‐selective and oscillation‐suppression applications. © 2007 Wiley Periodicals, Inc. Microwave Opt Technol Lett 49: 1809–1813, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.22588
Defected‐ground coupled microstrip lines bandpass filter with suppressed spurious resonances
Authors: Salah‐Eddin Muhammad A. , Safwat Amr M. E. 
Published: May 2007

AbstractDefected‐ground coupled microstrip lines (DCL) bandpass filter is proposed. The length of the proposed filter is quarter the length of conventional coupled‐line filter and it has a wide stopband and suppressed spurious resonances up to 4f0, where f0 is the filter central frequency. Five hundred and fifty megahertz single‐section and two‐section DCL filters were designed and fabricated. Simulations and measurements show that the rejection levels of the spurious resonances at 2f0, 3f0 as well as 4f0 are better than −11 and −14 dB for single‐section DCL and double‐section DCL, respectively. © 2007 Wiley Periodicals, Inc. Microwave Opt Technol Lett 49: 2038–2039, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.22590
Investigation on quality factor of substrate‐integrated waveguide resonance cavity
Authors: Che Wenquan , Wang Dapeng , Xu Lei , Li Cuixia 
Published: May 2007

AbstractAn investigation has been made on the quality factor of substrate‐integrated waveguide (SIW) resonance cavity. The ohmic losses at the sidewalls, front/end walls, and top/bottom planes of the SIW resonance cavity are derived, respectively, resulting in the quality factor formula of the SIW resonance cavity for the first time. The sidewalls and the front/end walls of the SIW resonance cavity are formed by cylinder posts, the discrete integral on the surfaces of the cylinder posts must be considered. The calculated quality factor from this formula at several frequency bands have been obtained, agreeing well with the numerical simulations. The maximum deviations at S‐, X‐ and K‐bands are 1.52%, 1.84%, and 2.98%, respectively, all less than 3%, demonstrating the validity of the proposed quality factor formula for the SIW resonance cavity. © 2007 Wiley Periodicals, Inc. Microwave Opt Technol Lett 49: 2007–2010, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.22592
A dual‐band antenna design for GPS and UMTS applications
Authors: Sim Chow‐Yen‐Desmond , Row Jeen‐Sheen , Chen Shing‐Hau 
Published: May 2007

AbstractThe design of an integrated dual‐band antenna for global positioning system (GPS) and universal mobile telecommunications system (UMTS) is presented. A circularly polarized square‐ring corner truncated microstrip antenna is designed for GPS application, and a monopolar shorted square patch antenna embedded within the center of the square‐ring is designed for UMTS application. Both proposed antenna elements demonstrated desirable isolation, radiation pattern; polarization, and bandwidth requirement. © 2007 Wiley Periodicals, Inc. Microwave Opt Technol Lett 49: 1935–1939, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.22597
A planar bandpass filter using butterfly radial stub
Authors: Joshi Ravi Kumar , Harish A. R. 
Published: May 2007

AbstractA bandpass filter using a single‐slotted butterfly radial stub connected in shunt with a short‐circuited section of a microstrip transmission line is proposed. A two pole filter based on the proposed structure has been designed, analyzed, and fabricated. A good agreement between the measured and the simulated results is observed. © 2007 Wiley Periodicals, Inc. Microwave Opt Technol Lett 49: 1872–1875, 2007; Published online in Wiley Inter‐Science (www.interscience.wiley.com). DOI 10.1002/mop.22600
Comparative approach of printed reflectarray with/without electromagnetic bandgap ground plate
Authors: Liu Zhen‐Guo , Zhang Wen‐Xun , Wu Zhi‐Hang , Ge Zhi‐Chen 
Published: May 2007

AbstractIn this article, the printed reflectarray with/without electromagnetic bandgap (EBG) ground plate are compared. The result shows that incorporating EBG structure into reflectarray cannot always improve the gain as said in reference except in some special situation. The theoretical discussion is given as well as the specific design samples to verify the results. At the same time, the third‐dimension‐directional radiation mechanism for 2D EBG structure within bandgap is also discussed. © 2007 Wiley Periodicals, Inc. Microwave Opt Technol Lett 49: 1968–1971, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.22610
Compact microstrip bandpass filter using composite right/left‐handed transmission lines
Authors: Li Jiusheng , Yunyun Zhuang 
Published: May 2007

AbstractA compact microstrip bandpass filter utilizing composite right/left‐handed (CRLH) transmission lines (TLs) is designed, fabricated, and measured. The simulated and measured results show that the proposed filter has low insertion loss in passband, compact dimensions, easy fabrication, and low cost. The novel measured performances of the bandpass filter based on CRLH TL are almost identical with the simulated results. © 2007 Wiley Periodicals, Inc. Microwave Opt Technol Lett 49: 1929–1931, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.22613
Push‐push voltage controlled dielectric resonator oscillator using a LTCC technology
Authors: Yom In‐Bok , Shin Dong‐Hwan , Oh Seung‐Hyeub , Ryu Keun‐Kwan 
Published: May 2007

AbstractA push–push voltage‐controlled dielectric resonator oscillator (VCDRO) with a modified frequency tuning structure is investigated. The push–push VCDRO designed at 16 GHz is manufactured using a low temperature cofired ceramic (LTCC) technology to reduce the circuit size. The frequency tuning structure is embedded in a layer of A6 substrate by an advantage of LTCC process. Experimental results show that the fundamental frequency suppression is above 30 dBc, and a phase noise of push–push VCDRO presents a good performance of −103 dBc/Hz at 100 kHz offset frequency from carrier. © 2007 Wiley Periodicals, Inc. Microwave Opt Technol Lett 49: 1824–1827, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.22619
Q‐band to V‐band 1D and 2D elliptical lens antenna arrays
Authors: Yang Lu , Domier Calvin W. , Luhmann N.C. 
Published: May 2007

AbstractAn investigation of the receiving properties of both 1D 13‐element and 2D 8 × 4‐element dual dipole antenna arrays on an elliptical MACOR lens from Q‐ to V‐band is reported. Theoretical and measurement results agree well. The intended application is for millimeter wave plasma radar reflectometric imaging, although the results have broader applicability (Munsat et al., Rev Sci Instrum 74 (2003) 1426–1432). © 2007 Wiley Periodicals, Inc. Microwave Opt Technol Lett 49: 1798–1801, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.22620
Optical mm‐wave generation based on phase modulation along with optical filtering
Authors: Ma Jianxin , Yu Jianjun , Jia Zhensheng , Yu Chongxiu , Chang Gee Kung 
Published: May 2007

AbstractWe have investigated the generation and transmission of optical millimeter (mm)‐wave signal based on optical phase modulator (PM) and fiber Bragg grating (FBG) filter. With an optimized modulation depth of PM and a higher carrier suppression ratio via a notch filter, the generated optical mm‐wave can be transmitted over a long‐distance without fading. We have also theoretically analyzed the impact of time shift on the eye closure of optical and electrical signal due to the fiber dispersion, which is well in accord with the experimental results. © 2007 Wiley Periodicals, Inc. Microwave Opt Technol Lett 49: 1787–1793, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.22622
A novel via‐free composite right‐ and left‐handed transmission line using defected ground structure
Authors: Park Jae‐Hyun , Ryu Young‐Ho , Lee Jae‐Gon , Lee Jeong‐Hae 
Published: May 2007

AbstractIn this letter, a novel via‐free composite right‐ and left‐handed transmission line (CRLH TL) is proposed using defected ground structure (DGS). The required shunt inductance and series capacitance for left‐handed transmission line are provided by the mender‐line of DGS and inter‐digital gap in signal line, respectively. The dispersion relations are analyzed using the derived equivalent circuit and Bloch‐Floquet theory. The measured results of dispersion curves of CRLH TLs have good agreements with those of simulation and theory. A proposed via‐free CRLH TL has broad LH bandwidth of 88.7% below 1 GHz. © 2007 Wiley Periodicals, Inc. Microwave Opt Technol Lett 49: 1989–1993, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.22624
New general formulation of the Cauchy method for the accurate model extraction of higher order microwave systems
Authors: Traina Daniele , Macchiarella Giuseppe , Sarkar Tapan K. 
Published: May 2007

AbstractIt is well known that a Vandermonde matrix generates an ill‐conditioned system matrix when applied with finite numerical precision. This deficiency affects the Cauchy method by restricting its application to only lower order systems. This paper presents an innovative and accurate general formulation of the Cauchy method to rectify this limitation and make the Cauchy method suitable for the model extraction of a higher order microwave systems. It has been successfully verified using examples of microwave base‐station filters and duplexers. © 2007 Wiley Periodicals, Inc. Microwave Opt Technol Lett 49: 1957–1961, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.22627
Compact L‐shaped notched printed antennas with dual slits for multiband and wideband applications
Authors: Kiran K. U. , Yadahalli R. M. , Vani R. M. , Farida Sara F. , Hunagund P. V. 
Published: May 2007

AbstractIn this paper, compact L‐shaped notched printed antennas with dual slits for multiband and wideband applications are presented. Here, an L‐shaped notch is cut on one side of the nonradiating edge of the rectangular patch with dual narrow slits cut on the other side. This patch is kept 2 mm away from the ground plane. The size of the ground plane is taken to be 38 × 10.8 mm2. Here, the study consists of the study of the proposed antenna with two types of ground planes, one with rectangular ground plane and the other with modified ground plane. Using rectangular ground plane, wideband and multiband operation is achieved with overall bandwidth of 6.84 GHz (110%). Again, by using modified ground plane, the overall bandwidth of the antenna is further increased to 7.86 GHz (114.5%). Moreover, the overall size of the proposed antennas is quite compact i.e., 38 × 38 mm2. © 2007 Wiley Periodicals, Inc. Microwave Opt Technol Lett 49: 2022–2026, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.22638
Broadband planar DTV antenna in the portable media player held by the user's hands
Authors: Li Wei‐Yu , Wong Kin‐Lu , Row Jeen‐Sheen 
Published: May 2007

AbstractEffects of the user's hands on the broadband planar DTV antenna in the portable media player (PMP) are studied. The antenna has a wide operating bandwidth covering the 470–806 MHz band for DTV signal reception and a one‐layer equivalent simulation hand model including the user's forearm with a relative permittivity of 33.5 and a conductivity of 0.47 S/m is used for the simulation study. Three different conditions of the user's hands (right hand only, left hand only, and both hands) holding the PMP are studied, and their effects on the return loss, radiation efficiency, and radiation patterns of the studied DTV antenna are analyzed. In addition, effects of the user's hands holding the PMP at different positions relative to the studied DTV antenna are analyzed. Results have shown that, for the worst case, the radiation efficiency of the studied DTV antenna is still larger than 60% over the operating band, making the antenna very promising for practical applications. © 2007 Wiley Periodicals, Inc. Microwave Opt Technol Lett 49: 1841–1844, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.22639
Assessment of solvent effects: do weak alignment media affect the structure of the solute?
Authors: Shahkhatuni Astghik A. , Shahkhatuni Aleksan G. , Panosyan Henry A. , Sahakyan Aleksandr B. , Byeon In‐Ja L. , Gronenborn Angela M. 
Published: May 2007

AbstractAlignment media used for measuring residual dipolar couplings, such as solutions of filamentous phages, phospholipid mixtures, polyacrylamide gels and various lyotropic liquid crystalline systems were investigated with respect to solvent effects on molecular structure. Structural parameters of the small rigid model compound13C‐acetonitrile were calculated from dipolar couplings and variations from expectation values were used for assessment of solvent effects. Only minor solvent effects were observed for most of the media employed and the measured structural data are in good agreement with microwave data and theoretical predictions. Copyright © 2007 John Wiley & Sons, Ltd.
Guttiferic acid, a novel rearrangement product from minor chromenoxanthone pigments of Garcinia morella Desr.
Authors: Rajagopal Rao D. , Gurudutt K. N. , Mamatha S. , Mohan Rao L. J. 
Published: May 2007

AbstractMorellic and isomorellic acids (2 and 3), present in the seed coat as well as resinous exudate of Garcinia morella Desr., are geometric isomers and structurally related to morellin (1), the major chromenoxanthone pigment. Both form crystalline complexes with pyridine and afford guttiferic acid (7), a novel skeletal rearrangement product, when heated with mild alkali. Structure of the latter has been deduced mainly by a comparative study of 1H and 13C NMR spectra of methyl morellate (5), methyl‐O‐methyl morellate (6), guttiferic acid (7) and dimethyl guttiferate (8). Copyright © 2007 John Wiley & Sons, Ltd.
Janocchio—a Java applet for viewing 3D structures and calculating NMR couplings and NOEs
Authors: Evans David A. , Bodkin Michael J. , Baker S. Richard , Sharman Gary J. 
Published: May 2007

AbstractWe present a Java applet, based on the open source Jmol program, which allows the calculation of coupling constants and NOEs from a three‐dimensional structure. The program has all the viewing features of Jmol, but adds the capability to calculate both H–H and H–C 3‐bond couplings constants. In the case of HH couplings, the Altona equation is used to perform this. The program also calculates NOEs using the full relaxation matrix approach. All these calculations are driven from a simple point and click interface. The program can calculate values for multi‐structure files, and can produce input files for the conformational fitting program NAMFIS. Copyright © 2007 John Wiley & Sons, Ltd.