bluuebunny/crossref_metadata_2025_split huggingface dataset:
Analysis of the double negative metamaterials using FDTD
Authors: Fu Jia‐Hui , Meng Fan‐Yi , Yang Guo‐Hui , Wu Qun 
Published: March 2008

AbstractUsing the finite‐difference time‐domain method models ideal Drude of DNG metamaterials. The Z‐transform is applied to model the Drude model that materials characterized by frequency dispersive behavior. Thus, we certificate the DNG metamaterials and its unique characteristics such as negative refraction, convergence, back‐wave, phase compensation and verify the existence of DNG Metamaterials. © 2008 Wiley Periodicals, Inc. Microwave Opt Technol Lett 50: 1411–1414, 2008; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.23371
Design and implementation of capacitive coupled‐line structure bandstop filters
Authors: Her Man‐Long , Hsu Ming‐Wei , Ko Wen , Wang Yu‐Lin , Wang Kuo‐Ming , Wang Chia‐An , Hsu Chou‐Jung 
Published: March 2008

AbstractIn this article, we propose and design bandstop filters with capacitive coupled‐line structure. The coupled‐line structure has small area, wide bandwidth, and steep insertion loss response. In simulation, we used Serenade and Sonnet EM simulation tools to analyze the characteristics of filters. In circuit implementation, we selected FR‐4 substrates. We used coupled‐lines on capacitive coupling bandstop filters to reduce the size about 58% and to create two attenuated poles for increasing bandwidth. First we derived the relation between the odd‐mode and even‐mode impedance theoretically. Then, we applied EM software tools to choose a proper coupling distance to implement circuit layout. Finally, the measured results were compared with the simulated results, and we found that coupled‐lines can effectively improve the reduction size of the filters. © 2008 Wiley Periodicals, Inc. Microwave Opt Technol Lett 50: 1363–1368, 2008; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.23374
Design of a compact CPW‐fed UHF RFID tag antenna for metallic objects
Authors: Um Youngman , Kim Uisheon , Choi Jaehoon 
Published: March 2008

AbstractA compact CPW‐fed UHF RFID tag antenna for metallic objects is proposed. It is less sensitive to the size of metallic objects and has a low profile and a long reading distance. The antenna consists of shorting walls, CPW feed line, a tag IC, and a radiating patch with Ishaped slits. The overall dimensions of the antenna are 55 mm × 26 mm ×2.2 mm. The tag IC has an input impedance of 43 ‐ j800 Ω at 915 MHz. When the antenna is mounted on 200 mm × 200 mm, 400 mm × 400 mm, and 600 mm × 600 mm planar metallic plates, the maximum reading distances are 5.1, 5, and 4.5 m, respectively. © 2008 Wiley Periodicals, Inc. Microwave Opt Technol Lett 50: 1439–1443, 2008; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.23378
Theoretical analysis and numerical verification of waveguide‐type directional coupler constructed into thin double‐layer dielectric substrate
Authors: Che Wenquan , Xu Lei , Dong Shiwei , Russer Peter 
Published: March 2008

AbstractThe waveguide‐type directional couplers constructed into double‐layer thin dielectric substrates have been investigated in this article. Based on coupling theory, the theoretical formulas of coupling factor and isolation for directional couplers with two different coupling structures have been derived. Good agreement between calculation and numerical simulations can be observed well, demonstrating the validity and accuracy of our formulas. These theoretical formulas are expected to find possible applications in the design of integrated direction couplers in LTCC or multilayer PCB technologies. © 2008 Wiley Periodicals, Inc. Microwave Opt Technol Lett 50: 1397–1402, 2008; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.23380
A miniaturized patch antenna at 2.4 GHz using uni‐planar compact photonic band gap structure
Authors: Eldek Abdelnasser A. 
Published: March 2008

AbstractThis article presents a miniaturized patch antenna for wireless applications at 2.4 GHz. A conventional microstrip‐fed patch antenna is firstly designed to operate close to 10 GHz. Then, the antenna is modified to operate at lower frequency without changing the antenna dimensions. First, the ground plane is replaced with a uniplanar‐compact‐photonic‐band‐gap (UC‐PBG) structure. Then, a backed conductor is placed close to the UC‐PBG and connected to it through four vias. These two modifications are utilized to decrease the lower operating frequency of the antenna from 9.7 to 2.42 GHz. Thus, a 75% size reduction factor is obtained. © 2008 Wiley Periodicals, Inc. Microwave Opt Technol Lett 50: 1360–1363, 2008; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.23381
Erratum: Application of new tools for the FDTD analysis of UWB antennas on dielectric substrates
Authors: Capoglu Ilker R. , Smith Glenn S. 
Published: March 2008

AbstractNew techniques are described for the FDTD analysis of radiating structures mounted on infinite planar dielectric substrates. These techniques are the near‐field‐to‐far‐field transform and the totalfield/scattered‐field boundary, or the plane‐wave injector. For demonstrating the use of these techniques, a practical ultra‐wideband antenna on an ungrounded dielectric substrate is analyzed. © 2008 Wiley Periodicals, Inc. Microwave Opt Technol Lett 50: 1447–1451, 2008; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.23392
Design of novel miniaturized and high quality Sierpinski square resonators
Authors: Weng Min‐Hang , Chang Lin‐Shen , Chen Wei‐Yu , Hung Cheng‐Yuan , Yang Ru‐Yuan 
Published: March 2008

AbstractIn this article, miniaturized fractal‐shaped Sierpinski square resonators are presented. As the order of the Sierpinski square resonator increases, the resonant frequency decreases quickly and quality factor is enhanced. A high quality resonator based on the 3rd order Sierpinski square was fabricated on commercial substrate of RT/Duroid 5880 and measured using a network analyzer. The design procedure and limitation are clearly discussed in detail in this article. Measured results also have a good agreement with the simulated results. © 2008 Wiley Periodicals, Inc. Microwave Opt Technol Lett 50: 1469–1471, 2008; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.23393
Application of the preconditioned GMRES to the Crank‐Nicolson finite‐difference time‐domain algorithm for 3D full‐wave analysis of planar circuits
Authors: Yang Y. , Fan Z. H. , Ding D. Z. , Liu S. B. 
Published: March 2008

AbstractThe increase of the time step size significantly deteriorates the property of the coefficient matrix generated from the Crank‐Nicolson finite‐difference time‐domain (CN‐FDTD) method. As a result, the convergence of classical iterative methods, such as generalized minimal residual method (GMRES) would be substantially slowed down. To address this issue, this article mainly concerns efficient computation of this large sparse linear equations using preconditioned generalized minimal residual (PGMRES) method. Some typical preconditioning techniques, such as the Jacobi preconditioner, the sparse approximate inverse (SAI) preconditioner, and the symmetric successive over‐relaxation (SSOR) preconditioner, are introduced to accelerate the convergence of the GMRES iterative method. Numerical simulation shows that the SSOR preconditioned GMRES method can reach convergence five times faster than GMRES for some typical structures. © 2008 Wiley Periodicals, Inc. Microwave Opt Technol Lett 50: 1458–1463, 2008; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.23396
An improved small‐signal equivalent circuit model for 4H‐SIC power mesfets
Authors: Xu Yuehang , Guo Yunchuan , Xu Ruimin , Yan Bo , Wu Yunqiu 
Published: March 2008

AbstractThe frequency‐dependence of parasitic resistances (Rs and Rd) for 4H‐SiC power MESFETs is empirical modeled by adding two disperse parameters based on conventional small‐signal equivalent circuit (CSEC). And a new extraction procedure for the modified SEC parameters is also proposed. The calculated S‐parameters using the modified SEC model (MSEC) fit the measured ones very well up to 20 GHz. © 2008 Wiley Periodicals, Inc. Microwave Opt Technol Lett 50: 1455–1458, 2008; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.23397
Reduced‐size microstrip four‐pole bandpass filter using two‐layer structure with quarter‐wavelength resonators and open stub inverters
Authors: Djaiz Azzeddine , Denidni Tayeb A. , Boutayeb Halim 
Published: March 2008

AbstractA new miniature microstrip four‐pole bandpass filter using a two‐layer structure with quarter‐wavelength resonators and open stub inverters is proposed. The coupling between the resonators in the two layers is achieved via a slot etched on a common ground plane located between the layers. The open stub inverters are used to increase the selectivity of the filter and to avoid connection to ground plane that is generally required for quarter‐wavelength resonators of bandpass filter. A four‐pole bandpass filter with elliptic‐type performance is designed and tested at 2.45 GHz. © 2008 Wiley Periodicals, Inc. Microwave Opt Technol Lett 50: 1485–1487, 2008; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.23401
Printed‐circuit filters for wireless dual‐ and triple‐band applications
Authors: Rambabu K. , Tan Adrian E. C. , Chia Michael Y. W. , Bornemann Jens 
Published: March 2008

AbstractSimple dual‐ and triple‐band printed‐circuit filters for wireless applications are presented. By using a single dual‐behavior resonator for each individual band, two transmission zeros between passbands are obtained, thus providing high levels of rejection. Moreover, there is no limit on the ratio of highest to lowest passband. Several measured prototype performances show very good agreement with computations. © 2008 Wiley Periodicals, Inc. Microwave Opt Technol Lett 50: 1495–1497, 2008; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.23408
Microstrip band rejection filter using open loop resonator
Authors: Jitha B. , Bybi P. C. , Aanandan C. K. , Mohanan P. 
Published: March 2008

AbstractDesign of a compact microstrip band reject filter is proposed. The device consists of an Open Loop Rectangular Resonator (OLRR) coupled to a microstrip line. The transmission line has a U‐bend which enhances the coupling with the OLRR element and reduces the size of the filter. The filter can be made tunable by mounting variable capacitance to the system. Simulated and experimental results are presented. © 2008 Wiley Periodicals, Inc. Microwave Opt Technol Lett 50: 1550–1551, 2008; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.23415
Millimeter‐wave low‐loss transmission lines and resonators in standard 0.18‐μm CMOS technology
Authors: Lin Shui‐Yang , Yang Li‐Wu , Sun Xiao‐Wei 
Published: March 2008

AbstractDesign methodologies of CMOS transmission lines (T‐lines) and resonators at millimeter‐wave frequencies are presented. Three different T‐lines including thin film microstrip line, coplanar waveguide, coplanar waveguide with ground, are designed and fabricated in standard 0.18‐μm CMOS technology. After on‐wafer testing to 40 GHz and SLOT de‐embedding calibration, their S‐parameters are extracted and analyzed. To achieve a small size, meandering quarter‐wavelength line resonator and stepped impedance resonator resonating near 30 GHz are designed, with their Q‐factor of 12 and 10.5, respectively. A good agreement between the predicted and measured results has been observed up to 40 GHz. © 2008 Wiley Periodicals, Inc. Microwave Opt Technol Lett 50: 1579–1582, 2008; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.23424
MEMS based reconfigurable dual band antenna
Authors: Gupta R. K. , Sharma U. C. , Sayanu P. , Kumar G. 
Published: March 2008

AbstractIn this study, a novel MEMS technology based reconfigurable dual band monopole antenna implementing RF‐MEMS switch is proposed for satellite communications applications. The prototyped Dual band antenna is designed, fabricated, and tested. The proposed antenna is fabricated on Quartz and high receptivity silicon (HRS) using an ideal MEMS switch. The antenna structure consists of two elements—one element couples weakly to other element in OFF state while in ON state it couples strongly. This electromagnetic coupling, through a MEMS switch, gives rise to reconfigurable dual band antenna. The measured VSWR < 2 at 3.7–4.2 GHz frequency band when the switch is OFF, while in the ON state's VSWR < 2 at 5.9–6.4 GHz frequency band. The measured VSWR and radiation patterns indicate the suitability of this antenna for satellite applications. The fabricated switch exhibits an isolation of more than 40 dB while its insertion loss is <0.3 dB in the frequency range of interest. © 2008 Wiley Periodicals, Inc. Microwave Opt Technol Lett 50: 1570–1575, 2008; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.23426
A novel radiation pattern reconfigurable microstrip antenna for wide‐angle scanning application in phased antenna array
Authors: Ouyang Jun , Yang Feng , Yang Shiwen 
Published: March 2008

AbstractThis article presents a novel pattern reconfigurable microstrip antenna that operates in 3 GHz. The antenna pattern can be transformed in between two situations. The two patterns can cover the area from −70° to +70°. Specifically, this radiation pattern reconfigurable microstrip antenna has potential applications in phased antenna arrays in wide‐angle scanning. Measured results of the proposed antenna are provided. The future work about improving the operating bandwidth is also discussed. © 2008 Wiley Periodicals, Inc. Microwave Opt Technol Lett 50: 1539–1540, 2008; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.23429
Effects of raised‐cosine pulse shaping on processing gain in acousto‐optic correlators
Authors: Bazzi O. , Mohanna Y. , Khalil F. , Assaad J. 
Published: March 2008

AbstractThe effects of raised‐cosine filtering on the processing gain of acousto‐optic correlators (AOC) in direct‐sequence spread‐spectrum receivers are considered. For ideal AOCs, analytical expressions are derived for the full roll‐off filter characteristics. The results are given in terms of the ratio β of the code rate to the filter bandwidth. For real AOCs, results are obtained from numerical simulation and are compared to previous results obtained for other types of filters. © 2008 Wiley Periodicals, Inc. Microwave Opt Technol Lett 50: 1558–1561, 2008; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.23431
A 5.5‐GHz SiGe HBT Doherty amplifier using diode linearizer and lumped‐element hybrid coupler
Authors: Liu Haiwen , Yoshimasu Toshihiko 
Published: March 2008

AbstractA 5.5‐GHz Doherty amplifier using commercial 0.35‐μm SiGe HBT technology is proposed in this article. To improve the linearity, a predistortion using diode linearizer is adopted for biasing the peak amplifier. Moreover, to realize in fully on‐chip with circuit reduction, a 90° 3‐dB hybrid coupler and quarter‐wave transmission lines are implemented by lumped‐elements. In this design, 819 μm2 HBTs are used for carried and peak amplifiers, respectively, and 26 μm2 HBT is used for linearizer. Results verify that the power gain, P1dB, and power added efficiency (PAE) of the proposed Doherty amplifier at 5.5 GHz are 8.4 dB, 31 dBm, and 30%, respectively. Also, the adjacent channel power ratio (ACPR) and the output signal's spectrum mask are given using the 54Mcps 64QAM modulated signal at 10 MHz offset. © 2008 Wiley Periodicals, Inc. Microwave Opt Technol Lett 50: 1554–1558, 2008; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.23432
A fully integrated 2.4 GHz CMOS RF transmitter for 802.15.4 ZigBee applications
Authors: Seong Eo Yun , Jin Ryu Hyun , Lee Sang‐Shin , Don Choi Kyu , Hyun Baek Dong 
Published: March 2008

AbstractA fully integrated 2.4 GHz direct up conversion RF transmitter compliant with low‐power ZigBee (IEEE 802.15.4) standard is presented. The linear and gain controlled current mirror amplifier is used for up conversion mixer. It consumes 8 mA with 1.8‐V power supply. The obtained transmitter's maximum power is 4.7 dBm and the achieved EVM is 8.4% at 0.5 dBm output. The die area of transmitter is 1.4 mm × 0.9 mm. © 2008 Wiley Periodicals, Inc. Microwave Opt Technol Lett 50: 1616–1619, 2008; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.23434
Circular fractal monopole antenna based on descartes circle theorem for UWB application
Authors: Naeem Khan Salman , Hu Jun , Xiong Jiang , He Sailing 
Published: March 2008

AbstractAn apollonian shaped ultra‐wideband circular monopole antenna based on descartes circle theorem is presented. Different self similar geometries from DCT are analyzed and optimized for UWB applications. The proposed design is slightly modified to ensure an overall smooth current distribution limited by the junction point nature of the fractal geometries. The experimental results are compared with conventional circular disk monopole and annular monopole antenna. The measured return loss of the proposed design below −10 dB is from 2.4 to over 40 GHz and its radiation pattern is omni‐directional compared with circular disk and annular antennas in most of its impedance bandwidth. Moreover due to the fractal shape, the proposed design has less weight and wind loading effect. © 2008 Wiley Periodicals, Inc. Microwave Opt Technol Lett 50: 1605–1608, 2008; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.23437
Multiway microwave planar power divider/combiner based on substrate‐integrated rectangular waveguide directional couplers
Authors: Wang Chao , Che Wenquan , Li Chao , Liu Dongtian 
Published: March 2008

AbstractOne kind of novel microwave planar power dividers/combiners is proposed and investigated in this article. The narrow‐side directional couplers constructed into substrate‐integrated rectangular waveguide are employed to implement the proposed multiway power divider/combiner. The design considerations of the multiway power divider/combiner are introduced. One three‐way power divider/combiner is designed and fabricated to demonstrate the validity of the proposed strategies. Good agreement between the experiments and the simulations can be observed, demonstrating 12% reflection bandwidth at −15 dB and 10% isolation bandwidth at −20 dB. © 2008 Wiley Periodicals, Inc. Microwave Opt Technol Lett 50: 1600–1605, 2008; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.23438
Automatic calibration method for phased arrays with arbitrary aperture shape
Authors: Son Seong Ho , Jeon Soon Ik , Hwang Woonbong 
Published: March 2008

AbstractA simple and automatic phase calibration method is proposed for phased arrays with even conformal aperture shape. The method is based on finding the optimal phase set such that the detected power of the receiving array from a transmitting extra antenna or, by reciprocity, that of a receiving extra antenna from the transmitting array is only maximized, using a continuous genetic algorithm (GA). This method provides a much faster and almost exact solution, when compared with exhaustive search and traditional binary GA. © 2008 Wiley Periodicals, Inc. Microwave Opt Technol Lett 50: 1590–1592, 2008; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.23441
A second‐order band‐pass frequency selective surface using nonresonant subwavelength periodic structures
Authors: Behdad Nader 
Published: March 2008

AbstractA new class of band‐pass frequency selective surface (FSS) with nonresonant constituting elements and sub‐wavelength unit‐cell dimensions and periodicities is presented and experimentally demonstrated. Using this technique, low profile first‐ and second‐order FSSs with reduced sensitivity to the angle of incidence for both TE and TM polarizations are designed, a prototype is fabricated and the FSS measurement results are presented and discussed. © 2008 Wiley Periodicals, Inc. Microwave Opt Technol Lett 50: 1639–1643, 2008; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.23445
Printed coplanar two‐antenna element for 2.4/5 GHz WLAN operation in a MIMO system
Authors: Su Saou‐Wen , Chou Jui‐Hung , Liu Yung‐Tao 
Published: March 2008

AbstractA printed coplanar two‐antenna element suited for WLAN operation in the 2.4‐ and 5‐GHz bands for dual‐module applications in a MIMO system is proposed. The two‐antenna element is comprised of one planar inverted‐F antenna (PIFA) and one monopole antenna, both printed and integrated in a coplanar configuration on a narrow dielectric substrate with the dimensions 50 mm × 11 mm. The two antennas are excited using two separate feeds with a common ground plane. By utilizing two proposed elements spaced 10‐mm apart in the lateral direction with an optimized arrangement, the four‐antenna MIMO system obtained can achieve optimal isolation between any two of the four antennas. In comparison with the conventional dual‐band antenna with a single feed, the proposed two‐antenna element allows the 2.4‐ and 5‐GHz signals to be simultaneously received or transmitted with no external switch circuit between the antenna and modules required. © 2008 Wiley Periodicals, Inc. Microwave Opt Technol Lett 50: 1635–1638, 2008; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.23540
Photorefractive properties of double‐doped Hf:Ce:LiNbO3 crystals
Authors: Zhou Wei , Wang Biao , Yuan Wei , Ling Furi , Ma Decai , Nie Yiran 
Published: March 2008

AbstractIn this article, the double‐doped Hf:Ce:LiNbO3 crystals were grown by the Czochralski method and its photorefractive properties were systematically studied. Samples were treated with different oxidation/reduction. The photorefractive properties of Hf:Ce:LiNbO3 crystals were investigated by the two‐beam coupling method. The results shown that the photorefractive properties of Hf:Ce:LiNbO3 crystals were improved as compared with that of Ce:LiNbO3 crystals. The oxidation/reduction treatment had great effect on the photorefractive properties and the doping mechanism was also discussed. © 2008 Wiley Periodicals, Inc. Microwave Opt Technol Lett 50: 1693–1695, 2008; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.23448
Novel wideband filter with a transmission zero based on split‐ring resonator DGS
Authors: Hou Zheng‐Zheng 
Published: March 2008

AbstractA wideband microstrip filter composed of split‐ring resonator DGS and lumped chip capacitor is presented in this article, which has a transmission zero at the right out‐of‐band. By using the equivalent‐circuit analysis and parameter extracting technology for the split‐ring resonator DGS, a band‐pass filter with a wide passband from 1 GHz to 2.4 GHz is fabricated and measured, making use of lumped chip capacitors and T‐shaped open‐circuit stub to achieve series and shunt capacitance, respectively. © 2008 Wiley Periodicals, Inc. Microwave Opt Technol Lett 50: 1691–1693, 2008; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.23452