bluuebunny/crossref_metadata_2025_split huggingface dataset:
Propagation and radiation characteristics of dielectric‐loaded axial‐mode helical antenna
Authors: Chandra Gupta Ramesh , Singh S. P. 
Published: March 2009

AbstractThis article presents theoretical and/or experimental study of the propagation and radiation characteristics of dielectric‐loaded axial‐mode helical antenna at 8.985 and 10.0 GHz. Characteristic equations for the sheath helix model are derived for three different dielectric loadings viz. loading with two coaxial dielectric layers, single dielectric layer, and air. These equations are solved for the propagation constant and hence the phase velocity for n = 1 higher order spatial harmonic mode. The variation in phase velocity with wavelength normalized helix circumference is studied for different ratio of outer to inner helix radii, ratio of outer to inner radii of the dielectric tube containing a solid dielectric cylinder inside the helix, and the dielectric constant of the dielectrics used. The results for variation in phase velocity of the wave for n = 1 mode propagating in sheath helix with wavelength normalized helix circumference for pitch angle of 7° are compared with the available theoretical data. The theoretical expression for the radiation field of the helical antenna is obtained through the application of magnetic vector potential for n = 1 mode. The theoretical Eθand Eϕpatterns of the helical antenna with three different dielectric loadings are compared among themselves and also with respective experimental results at 8.985 and 10.0 GHz in X‐band. The gain, input VSWR, and axial ratio of antenna with three different dielectric loadings are also measured at 8.985 and 10.0 GHz. The work presented here can provide useful design guidelines for development of optimum dielectric‐loaded helical antenna, which may find potential application in satellite communication. © 2009 Wiley Periodicals, Inc. Microwave Opt Technol Lett 51: 1195–1203, 2009; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.24286
Compact asymmetric coplanar strip‐fed antenna for wideband applications
Authors: Laila D. , Deepu V. , Sujith R. , Aanandan C. K. , Vasudevan K. , Mohanan P. 
Published: March 2009

AbstractAn asymmetric coplanar strip‐fed uniplanar antenna for wideband applications is presented. The resulting antenna offers a 2:1 VSWR bandwidth greater than 100% from 1.58 to 5.48 GHz covering the DCS/PCS/IEEE 802.11a/WiMAX bands. The antenna has an overall dimension of 44 × 35 mm2 when printed on a substrate of dielectric constant 4.4 and height 1.6 mm. The design equation is also presented in this article. The antenna exhibits good radiation characteristics and moderate gain in the entire operating band. © 2009 Wiley Periodicals, Inc. Microwave Opt Technol Lett 51: 1170–1172, 2009; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.24287
On the inapplicability of a negative‐phase‐velocity condition as a negative‐refraction condition for active materials
Authors: Lakhtakia Akhlesh , Mackay Tom G. , Geddes Joseph B. 
Published: March 2009

AbstractA negative‐phase‐velocity condition derived by Depine and Lakhtakia (Microwave Opt Technol Lett 41 (2004) 315–317) for isotropic, homogeneous, passive, dielectric‐magnetic materials is inapplicable as a negative‐refraction condition for active materials. © 2009 Wiley Periodicals, Inc. Microwave Opt Technol Lett 51: 1230, 2009; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.24289
Stacked aperture‐coupled coplanar patch antenna
Authors: Morsy Mohamed M. , Harackiewicz Frances J. 
Published: March 2009

AbstractA new concept of aperture‐coupled microstrip coplanar stacked patch antenna is investigated to obtain large bandwidth, reasonable front to back ratio using new techniques to overcome regular aperture‐coupled disadvantages. © 2009 Wiley Periodicals, Inc. Microwave Opt Technol Lett 51: 1228–1230, 2009; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.24290
CPS‐fed printed pentagonal‐loop antenna with high gain and broad beam
Authors: Sun Xiao‐Meng , Yang Xue‐Xia , Wang Hua‐Hong 
Published: March 2009

AbstractA CPS‐fed printed pentagonal‐loop antenna with high gain, and broad beam is proposed. This antenna has not only the high gain of 11.7 dB, but also the low cross‐polarization level less than −44 dB. Furthermore, the broad beam width with more than 60°HPBW (Half Power Beam Width) in the E plane is able to avoid the demand of precise main beam alignment. With these advantages, it can be used in the low power density applications of rectenna systems and radio frequency front‐ends. For measuring, a balun from the CPS to the microstrip line is designed. The measured results are in agreement with the simulated ones. © 2009 Wiley Periodicals, Inc. Microwave Opt Technol Lett 51: 1188–1191, 2009; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.24292
Extremely generalized planar Smith chart based on Möbius transformations
Authors: Wu Yongle , Liu Yuanan , Huang Haiyu 
Published: March 2009

AbstractIn this article, extremely generalized planar Smith chart (EGPSC) is proposed based on Mőbius transformations (MTs). And the rigid mathematical circles equations of this proposed EGPSC are obtained. The EGPSC includes omnipotent Smith chart (OSC) and other different kinds of generalized Smith charts which have been reported recently. Finally, according to the rigid mathematical equations, the corresponding characteristics of EGPSC are comprehensively analyzed and illustrated through numerical simulations. © 2009 Wiley Periodicals, Inc. Microwave Opt Technol Lett 51: 1164–1167, 2009; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.24293
Application of a simplified probe feed impedance formula to the design of a dual frequency patch antenna
Authors: Lu Q. , Shaikh Z. H. , Korolkiewicz E. 
Published: March 2009

AbstractA simplified probe feed input impedance for a rectangular patch antenna based on the Green's function is used to design a dual frequency matched antenna. The predicted results at design frequencies of 1.9 and 2.4 GHz are in close agreement with experimental measurements. © 2009 Wiley Periodicals, Inc. Microwave Opt Technol Lett 51: 1161–1164, 2009; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.24294
Dual‐backlight unit based on a single light source integrated with a beam splitting reflector
Authors: Park Chan‐Kyu , Lee Hak‐Soon , Lee Sang‐Shin 
Published: March 2009

AbstractA dual‐backlight unit incorporating a single light source integrated with a beam splitting reflector was demonstrated, providing a surface light beam for both the keypad and display section simultaneously. The reflector was realized by aligning a groove substrate with a matching cover, and a light guiding module comprising a stack of light guide panels and prism/diffuser sheets was attached to both sides of the reflector. A light emanating from the light source—placed in the middle of the substrate—undergoes a series of reflections through the reflector to reach the input of the light guiding module. Then it is transformed into a surface light beam, which is used to irradiate the keypad and display sections. As for the accomplished dual‐backlight unit, the measured average luminance and the spatial luminance uniformity were respectively about 420 cd/m2 and 70% for the keypad section, and 640 cd/m2 and 80% for the display section. © 2009 Wiley Periodicals, Inc. Microwave Opt Technol Lett 51: 1257–1260, 2009; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.24297
Uniplanar coupled‐fed printed PIFA for WWAN/WLAN operation in the mobile phone
Authors: Lee Cheng‐Tse , Wong Kin‐Lu 
Published: March 2009

AbstractA coupled‐fed printed planar inverted‐F antenna (PIFA) with a compact uniplanar structure for easy implementation in the mobile phone for WWAN/WLAN operation is presented. The printed PIFA occupies a small area of 10 × 60 mm2 and provides two wide operating bands (the lower and upper bands) at about 900 and 2000 MHz for covering GSM850/900/DCS/PCS/UMTS/WLAN six‐band operation. The printed PIFA is formed by two coupled‐fed PIFAs of different sizes, a longer radiating/coupling portion and a shorter radiating/coupling portion. Owing to the use of the coupling feed, both of the two portions can generate dual‐resonance excitation, with the longer portion providing a wide lower band for GSM850/900 operation and the shorter portion providing a wide upper band for DCS/PCS/UMTS/WLAN operation. In addition, the lower and upper bands of the printed PIFA can generally be controlled separately by the longer and shorter portions, making it easy for fine tuning of the desired operating bands in practical applications. © 2009 Wiley Periodicals, Inc. Microwave Opt Technol Lett 51: 1250–1257, 2009; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.24298
Analysis of optical and terahertz multilayer systems using microwave and feedback thoery
Authors: Lee Dong‐Joon , Whitaker John F. 
Published: March 2009

AbstractThe principles of microwave and feedback theory are independently applied to the analysis of both optical and terahertz‐regime multilayer systems. An analogy between the two approaches is drawn, and useful recursion relations, along with a signal‐flow approach, are presented for both reflection and transmission cases. These relations, in terms of S‐parameters, allow an exact analytical solution for even arbitrary, active, stratified structures, not only for any wavelength in the radio‐frequency spectrum, but also for optical wavelengths. This approach also provides a bridge between the microwave and optical bands and leads to beneficial design solutions for intermediate bands such as the THz regime. Comparisons with conventional methodologies are provided using practical multilayer simulations. In addition, graphical design techniques from microwave theory are used along with examples for efficient design and understanding. © 2009 Wiley Periodicals, Inc. Microwave Opt Technol Lett 51: 1308–1312, 2009; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.24301
Numerical analysis of electrically small structures embedded in a layered medium
Authors: Chen Yongpin P. , Xiong Jie L. , Chew Weng Cho , Nie Zaiping P. 
Published: March 2009

AbstractAccurate numerical analysis of electrically small structures embedded in a layered medium is presented in this letter. In our approach, the matrix‐friendly layered medium Green's function is implemented for its elegant expression and singularity of lowest order. The current is decomposed into divergence‐free part and nondivergence‐free part according to quasi‐Helmholtz decomposition when frequency tends to zero, to capture both capacitance and inductance physics. Frequency normalization is applied after analyzing frequency scaling properties of different blocks of the matrix system. Similar to the free space case, connection matrix is utilized to make the electro‐quasi‐static block amenable to iterative solvers. © 2009 Wiley Periodicals, Inc. Microwave Opt Technol Lett 51: 1304–1308, 2009; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.24302
Microwave properties of arrowroot and its medical applications
Authors: Kalappura Ullas G. , Augustine Robin , Mathew K. T. 
Published: March 2009

AbstractArrowroot (Maranta arundinacea) is an edible starch, commercially available as powder, prepared from the roots of the plant family Marantaceae. Arrowroot is well known for its medicinal effects and use as chief ingredient in infant cookies. Arrowroot in film form is prepared and its microwave absorption characteristics, permittivity, loss factor, conductivity, skin depth, and heating coefficient are analyzed. The results are quite promising and can be concluded that arrowroot in film form is a potential candidate for several applications in medical field, when compared with well studied chitosan film. © 2009 Wiley Pe riodicals, Inc. Microwave Opt Technol Lett 51: 1267–1270, 2009; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.24304
Computer‐aided modeling of circular conductors
Authors: Musa Sarhan M. , Sadiku Matthew N. O. 
Published: March 2009

AbstractCircular conductors have manufacturing advantage compared with rectangular conductors in building microwave components such as filters and couplers which make it very popular for microwave designers. The accurate and efficient evaluation results of the capacitance, inductance, and characteristic impedance of circular conductors can help the designers to optimize the layout of the integrated circuits. In this article, we use the finite element method to compute the capacitance per unit length, inductance per unit length, and characteristic impedance of circular conductors. Mainly, we focus our computation and modeling on four types of systems as follows: a single circular wire above ground plane in a dielectric layer, a single circular conductor above a ground plane in a lossy dielectric layer, parallel coupled slab lines with homogenous dielectric layer, and three circular rod arrays in a rectangular trough with homogenous dielectric layer. Comparisons with published results demonstrate excellent agreement with the modeling. © 2009 Wiley Periodicals, Inc. Microwave Opt Technol Lett 51: 1366–1372, 2009; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.24307
Cascaded dual‐mode square‐loop resonators using Hilbert‐curve perturbation for wide bandpass filter applications
Authors: Liu Ji‐Chyun , Li Chiung‐Hung , Kuei Ching‐Pin , Zeng Bing‐Hao 
Published: March 2009

AbstractThe cascaded dual‐mode square‐loop resonator (DMSLR) with Hilbert‐curve perturbation is introduced to design wide band‐pass filter in this article. To obtain low insertion loss (−0.85 dB), high out‐of‐band rejection level (−51.82 dB), and wider band (BW 62.3%) responses, using Hilbert‐curve perturbation and cascaded technique are proposed here. The equivalent circuit and Chebyshev response are presented for approximation and analysis. Results including surface current distributions and frequency responses are presented and discussed. © 2009 Wiley Periodicals, Inc. Microwave Opt Technol Lett 51: 1294–1298, 2009; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.24311
Microwave photonic bandpass filter using a multi‐wavelength laser with a bell‐shaped power profile
Authors: Zhou J. Q. , Aditya S. , Shum P. , Cheng L. H. , Parhusip B. P. , Wong Vincent , Lim Desmond 
Published: March 2009

AbstractA low cost sidelobe suppressed tunable microwave photonic bandpass filter is proposed and experimentally demonstrated. The filter is based on a multi‐wavelength ring laser and a segment of single mode fiber as a dispersive element. Through adjustment of the power profile of the multi‐wavelength laser to a bell shape, a filter frequency response without sidelobes is achieved. © 2009 Wiley Periodicals, Inc. Microwave Opt Technol Lett 51: 1329–1332, 2009; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.24316
A fully integrated single core VCO with a wide tuning range for DVB‐H
Authors: Lalchand Khemchandani Sunil , del Pino Suarez Javier , Diaz Ortega Roberto , Hernandez Antonio 
Published: March 2009

AbstractThis article presents a fully integrated LC VCO in a low cost 0.35 μm BiCMOS technology for DVB‐H standard. The VCO was designed for a direct conversion receiver architecture. To facilitate the integration of inductors and capacitors, the circuit oscillates at twice the required UHF frequency. Techniques like emitter degeneration, capacitor divider, and optimum bias and tank design have been used to improve phase noise requirements. The obtained phase noise is −112 dBc/Hz at 100 kHz offset and the tuning range is 47.6%. © 2009 Wiley Periodicals, Inc. Microwave Opt Technol Lett 51: 1338–1343, 2009; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.24318
Novel triangular‐type electromagnetic bandgap structure for ultra‐broadband suppression of simultaneous switching noise
Authors: Kwon Jong‐Hwa , Sim Dong‐Uk , Kwak Sang‐Il , Gwan Yook Jong 
Published: March 2009

AbstractTo build a stable power distribution network for high‐speed digital systems, simultaneous switching noise (SSN) in multilayer PCBs and packages needs to be sufficiently suppressed. In this article, a novel triangular‐type uniplanar compact electromagnetic band‐gap with different bridges designed for power/ground planes is proposed for the ultra‐broadband suppression of SSN. The SSN suppression performance of the proposed structure is validated both numerically and experimentally. A −30 dB suppression bandwidth for SSN is achieved starting at 800 MHz and extending to 15 GHz and beyond, that is, almost the entire noise band. © 2009 Wiley Periodicals, Inc. Microwave Opt Technol Lett 51: 1356–1358, 2009; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.24322
Ultra‐lightweight dual‐polarized X‐band array antenna for airborne weather radar applications
Authors: Ren Yu‐Jiun , Zhang Yan 
Published: March 2009

AbstractA dual‐polarized X‐band array antenna for advanced airborne weather hazard monitoring radar applications is presented. This low‐profile array is composed of 8 × 8 circular patch antenna elements with a hybrid feed‐line network providing dual‐polarization function and high isolation (∼40 dB) between H‐ and V‐ports. The antenna operation bandwidth is from 9.9 to 10 GHz, and has a radiation gain of 19 dBi and cross‐polarization of 31 dB. The array can be easily placed on the aircraft fuselage because of its ultra‐thin thickness (0.13 mm), ultra‐lightweight, and conformal structure, and it has potential applications in radar surveillance, remote sensing, and wireless communications. © 2009 Wiley Periodicals, Inc. Microwave Opt Technol Lett 51: 1324–1326, 2009; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.24323
Closed‐form design method for unequal lumped‐elements Wilkinson power dividers
Authors: Wu Yongle , Liu Yuanan 
Published: March 2009

AbstractThe unequal Wilkinson power dividers using flexible and miniaturized lumped‐elements are proposed in this article. First, two kinds of lumped‐elements structures including Pi‐network and T‐network are developed as the transformers between two different resistances. Then the closed‐form design method for the proposed power dividers based on these transformers is presented. Furthermore, the frequency characteristics of some examples are simulated according to the calculated results got by the closed‐from design method. Finally, three types of circuit layouts are fabricated to realize the lumped‐element unequal Wilkinson power dividers flexibly. © 2009 Wiley Periodicals, Inc. Microwave Opt Technol Lett 51: 1320–1324, 2009; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.24324
Characterization and lumped circuit model of ultra‐wideband flip‐chip transitions (DC 110 GHz) for WAFER‐scale packaging
Authors: Seek Cho Young , Franklin Drayton Rhonda 
Published: March 2009

AbstractAn ultra‐wideband flip‐chip transition is proposed for wafer level packaging applications. The locally matched flip‐chip scheme has an air cavity underneath a flip‐chip die and local trenches in the flip‐chip bond pad area to provide matching. The measured response up to 110 GHz has a return loss below 20 dB across 96% of the band and has an insertion loss improvement of 2.2 dB at 110 GHz. The design approach is simple and requires no additional space. Also presented is lumped element circuit model for the transition region of conventional and locally matched flip‐chip interconnect. © 2009 Wiley Periodicals, Inc. Microwave Opt Technol Lett 51: 1281–1285, 2009; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.24326
A planar hybrid antenna for UWB application
Authors: Chen Wen‐Shan , Lin Chi‐Huang 
Published: March 2009

AbstractA novel hybrid antenna formed by a printed monopole slot (open‐ended slot) and a printed monopole for Ultra‐Wideband (UWB) operation is presented. The monopole slot and monopole are fed in series using a 50 Ω microstrip feed line and printed on a FR4 substrate of small size 30 × 34 mm2. The monopole is on the top edge of the proposed antenna and can provide a wide impedance bandwidth for UWB upper band operation (6.15 GHz–10.6 GHz). The monopole slot is printed below the monopole and is used to excite a quarter‐wavelength resonant mode at about 4 GHz for UWB lower band operation (3.1 GHz–4.8 GHz). Detailed results and parametric studies of the proposed hybrid antenna are presented and discussed. © 2009 Wiley Periodicals, Inc. Microwave Opt Technol Lett 51: 1243–1246, 2009; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.24328
Design of a compact dual‐mode patch resonator band‐pass filter
Authors: Li Jia‐Lin , Qu Shi‐Wei , Xue Quan 
Published: March 2009

AbstractIn this article, a compact dual‐mode patch resonator for band‐pass filter applications is developed. The size reduction of the studied filter is simply achieved by etching a dual‐cross slot on the patch. Studies indicate that with this arrangement, the size can be reduced to 26.7% as compared to the conventional patch resonator. Meanwhile, a pair of transmission zeros close to the pass band improves its selectivity. A demonstrator filter is optimally designed, fabricated and measured. Both measurements and simulations are presented and compared in the article. © 2009 Wiley Periodicals, Inc. Microwave Opt Technol Lett 51: 1382–1385, 2009; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.24329
A “thru‐short” method for noise de‐embedding of MOSFETs
Authors: Nan Lan , Xiong Yong‐Zhong , Mouthaan Koen , Issaoun Ammar , Shi Jinglin , Ooi Ban‐Leong 
Published: March 2009

AbstractA “thru‐short” noise de‐embedding method for MOSFETs is presented. The capability of the “thru‐short” method has been validated through a comparison of measured and de‐embedded noise parameters using different methods. It is shown that the “thru‐short” method is reliable for on‐wafer de‐embedding of both S‐parameters and noise parameters up to 18 GHz. Noise contributions from the parasitics due to the contact pads and interconnections surrounding the MOSFET can be determined and removed accurately. © 2009 Wiley Periodicals, Inc. Microwave Opt Technol Lett 51: 1379–1382, 2009; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.24330
Improved phase noise for dielectric resonators oscillators with broadband tuning
Authors: Zhou Liang , Wu Zhuo 
Published: March 2009

AbstractIn this article, we describe a method of design of very low phase noise dielectric resonators oscillators at 13 GHz. By using two Silicon Germanium transistors with total gains 8 dB and lower flicker noise corner between 10 kHz and 40 kHz, the phase noise of the oscillators can be achieved −125 dBc/Hz at 10 kHz offset. The resonator has unloaded Q around 14,000 at operating frequency and is then optimized and coupled to the amplifiers for minimum phase noise whereQL/Q0= 1/2 henceS21= −6 dB. To incorporate tuning, phase shifter is also investigated. The phase noise measurement system is also presented using two identical oscillators phase locked at the same frequency.© 2009 Wiley Pe riodicals, Inc. Microwave Opt Technol Lett 51: 1312–1316, 2009; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.24334