bluuebunny/crossref_metadata_2025_split huggingface dataset:
Small global positioning system patch antennas with self‐biased NiCo‐ferrite films
Authors: Yang Guo‐Min , Obi Ogheneyunume , Sun Nian X. 
Published: March 2011

AbstractMagneto‐dielectric substrates with thin ferrite films show great potential in realizing small antennas with improved omni‐directional performance than those realized on dielectric substrates.This article introduces self‐biased NiCo‐ferrite films as a practical means to tune a patch antenna by loading a commercially available dielectric substrate. Novel antenna designs with self‐biased ferrite films were investigated, and these magnetic antennas have improved the axial ratio from 1.45 to 1.0 dB with respect to the central frequency ranging from 1.575 to 1.561 GHz in the simulations. Experimental global positioning system patch antennas with/without ferrite films were fabricated and tested. The measured results demonstrate that antennas with ferrite films can miniaturize the geometrical dimension by shifting down the resonance. © 2011 Wiley Periodicals, Inc. Microwave Opt Technol Lett 53:1162–1165, 2011; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.25909
A Ka‐band low‐noise amplifier using semicircle stacked‐GCPW transmission line
Authors: Chiu Hsien‐Chin , Chen Ting‐Huei , Fu Jeffrey S. , Nirmalathas T. A. 
Published: March 2011

AbstractA high‐gain Ka‐band 0.18‐μm CMOS low‐noise amplifier with semicircle stacked grounded coplanar waveguide (SCS‐GCPW) structure transmission line is proposed. SCS‐GCPW transmission line is adopted to reduce the signal loss by shaping the electric fields under the signal line especially at microwave and millimeter wave applications. The SCS‐GCPW demonstrated a similar electric field distribution of coaxial cable and achieved a substrate dielectric attenuation constant of 0.075 Np/m. It is superior to 0.081 Np/m and 0.144 Np/m of traditional microstrip transmission line and CPW transmission line, respectively. By adopting the low loss SCS‐GCPW transmission line, the Ka‐band LNA demonstrated a 24.5 dB gain together with a noise figure (NF) of 7.5 dB at 33 GHz operation. The measured output power 1 dB compression point (P1 dB) was −2 dBm. The dc power consumption was 40 mW and chip size was 0.6 × 1 mm2 for this Ka‐band LNA. © 2011 Wiley Periodicals, Inc. Microwave Opt Technol Lett 53:1131–1134, 2011; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.25910
Single‐layer microstrip reflectarray with double elliptical ring elements for bandwidth enhancement
Authors: Li Yuezhou , Biakowski Marek E. , Sayidmarie Khalil H. , Shuley Nicholas V. 
Published: March 2011

AbstractThe design of a microstrip reflectarray formed by 81 variable size double elliptical rings illuminated by a conical feed is presented.Because of double resonance, the double elliptical rings provide an increased phasing range of unit cells that exceeds the required minimum of 360°. Printed on a single substrate and supported by a layer of foam and a conducting ground, they also offer a slow phase slope as a function of their size, and thus provide an increased operational bandwidth and a good manufacturing error tolerance. The performance of the designed reflectarray is investigated via full‐wave electromagnetic simulations and measurements on the manufactured prototype. The presented results show a wideband performance of the designed reflectarray. © 2011 Wiley Periodicals, Inc. Microwave Opt Technol Lett 53:1083–1087, 2011; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.25912
Optical OFDM signal generation by an optical phase modulator and its application in a 40‐GHZ ROF symmetric system with turbo coding
Authors: Chen Lin 
Published: March 2011

AbstractWe have experimentally demonstrated optical orthogonal frequency division multiplexing (OFDM) signal generation by an optical phase modulator and a 40 GHz radio‐over‐fiber symmetric system with turbo coding technique. The power penalty for the 2.5 Gb/s downlink data carried by 40‐GHz millimeter‐wave after transmission over 50‐km SMF‐28 is smaller than 0.5 dB. The OFDM signals without coding and with coding after transmission at a BER of 1 × 10−3 is −17.5 and −20 dBm, respectively. © 2011 Wiley Periodicals, Inc. Microwave Opt Technol Lett 53:1050–1053, 2011; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.25913
Fabrication of microfiber loop resonator‐based comb filter
Authors: Lim K. S. , Harun S. W. , Jasim A. A. , Ahmad H. 
Published: March 2011

AbstractMicrofiber loop resonator (MLR) is fabricated by coiling of a microfiber, which was obtained by the fast stretching of a heated single mode fiber. The MLR is embedded in low refractive index material to keep the system robust. Two comb filters with a constant spacing of 0.16 nm and 0.71 nm are successfully achieved, which the extinction ratio can be adjusted by controlling the state of polarization of the input light. It was also found that the wavelength of each peak and the spacing remain unchanged regardless of the state of polarization of the input light. This MLR does not have major issues with input–output coupling and presents a completely integrated fiberized solution. © 2011 Wiley Periodicals, Inc. Microwave Opt Technol Lett 53:1119–1121, 2011; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.25916
Strong and weak FEM formulations of higher order for quasi‐static analysis of shielded planar transmission lines
Authors: Mančić Žaklina J. , Petrovic Vladimir V. 
Published: March 2011

AbstractWe present strong and weak Finite Element Method formulations for 2D closed electrostatic problems. Special hierarchical higher (arbitrary) order basis functions are applied. Results for characteristic impedance of shielded planar transmission lines, obtained by the two formulations are compared with results from the literature, and their specific advantages briefly commented. © 2011 Wiley Periodicals, Inc. Microwave Opt Technol Lett 53:1114–1119, 2011; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.25917
Half mode substrate integrated waveguide miniaturization using complementary split ring resonators
Authors: Qiang Li , Lu Hong‐Min , Zhao Wei , Qin Hong‐Bo , Liu Bing 
Published: March 2011

AbstractA miniaturization technology of half mode substrate integrated waveguide (HMSIW) is realized by complementary split ring resonators (CSRRs) in this article. The HMSIW etched with CSRRs can be regarded as the one filled with a dielectric material with higher εr. With specific CSRR arrays introduced, the CSRR‐loaded structure can be 15% more compact than the original one. Moreover, the above CSRRs can be also used to enhance the rejection skirt of the bandpass filter in this article. Finally, a compact and sharp rejection ultra‐wideband bandpass filter with designed notched‐band is fabricated. Very good agreement is observed between measurement and simulation results. © 2011 Wiley Periodicals, Inc. Microwave Opt Technol Lett 53:1074–1077, 2011; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.25918
Application of simple subgridding technique for antenna radiation patterns
Authors: Ji Ki‐Man , Kim Sung‐Wan , Lee Soo‐Jin , Chung Eui‐Seung 
Published: March 2011

AbstractA simple finite‐difference time‐domain subgridding technique to obtain radiation patterns of antennas mounted on an electrically large ground plane is introduced. Unilateral perfectly matched layer is inserted between regional interfaces so as to eliminate late‐time instability. The ratio of the time steps is the same as the ratio of the space steps and can be large. © 2011 Wiley Periodicals, Inc. Microwave Opt Technol Lett 53:1160–1162, 2011; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.25922
Novel design of an ultra‐wideband microstrip antenna employing a lobster‐shaped resonant structure
Authors: Abbaspour A. , Naser‐Moghadasi Mohammad , Katouli Morteza 
Published: March 2011

AbstractIn this article, a microstrip‐fed planar monopole antenna incorporating a lobster‐shaped resonant structure, which is etched on its back plane is presented.Simulated Impedance bandwidth of the proposed antenna is ∼115% over an ultra‐wideband frequency range between 3 and 11.2 GHz satisfying FCC's frequency band. © 2011 Wiley Periodicals, Inc. Microwave Opt Technol Lett 53:1121–1125, 2011; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.25925
Dual‐band circularly polarized antenna using combined C‐shaped and L‐shaped slots excited by a microstrip line
Authors: Chang The‐Nan , Han Yeah‐Lin 
Published: March 2011

AbstractAn L‐shaped slot loaded inside a C‐shaped slot is used to realize a dual‐band antenna fed by a microstrip line. Two circularly polarized waves are generated at the 1.57 and the 2.45 GHz band. The width in the C‐slot is uniform, whereas the width in the L‐slot is nonuniform. In the L‐slot, the width in the vertical part is made wider than that in the horizontal part. We found that the width in the vertical part of the L‐slot is an efficient tuning parameter. The antenna can achieve about 6% axial ratio bandwidth at both bands. © 2011 Wiley Periodicals, Inc. Microwave Opt Technol Lett 53:1041–1044, 2011; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.25928
An extremely low‐profile offset‐fed curl antenna over an AMC ground
Authors: Mehrabani Ali M. , Shafai Lotfollah 
Published: March 2011

AbstractPerformance of an offset‐fed curl antenna over artificial magnetic conductor (AMC) ground planes is investigated.An extensive parametric study is carried out and shown that by proper selection of the AMC ground plane and spiral parameters, a moderate axial ratio and wide impedance bandwidths can be obtained. The performance results for a design example are provided and discussed. The effect of the air gap between the AMC and antenna substrates is also studied and shown that the operating frequency moves to higher frequencies. The results are verified by experiment. The simulation studies were carried out using the finite element software HFSS v10.1. © 2011 Wiley Periodicals, Inc. Microwave Opt Technol Lett 53:1036–1041, 2011; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.25929
A transconductance‐boosted complementary Colpitts voltage‐controlled oscillator
Authors: Liu Cheng‐Chen , Jang Sheng‐Lyang , Wang Cheng‐Cih , Juang Miin‐Horng 
Published: March 2011

AbstractA gm‐boosted complementary Colpitts differential voltage‐controlled oscillator (VCO) is proposed and implemented in a 0.18‐μm CMOS 1P6M process.It consists of two single‐ended p‐core Colpitts oscillators via gm‐enhanced cross‐coupled Colpitts transistors to obtain a differential output. At the supply voltage of 1.45 V, the output phase noise of the differential VCO is −119.2 dBc/Hz at 1 MHz offset frequency from the carrier frequency of 8.69 GHz, and the figure of merit is −190.2 dBc/Hz. Total VCO core power consumption is 5.99 mW. Tuning range is 1.01 GHz, from 8.69 to 9.7 GHz, while the control voltage was tuned from 0 to 2.0 V. © 2011 Wiley Periodicals, Inc. Microwave Opt Technol Lett 53:1183–1186, 2011; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.25934
Novel ultra‐wideband coplanar‐waveguide bandpass filter with inductance‐loaded Y‐shaped resonators
Authors: Song Kaijun , Xue Quan 
Published: March 2011

AbstractA novel ultra‐wideband (UWB) coplanar waveguide (CPW) bandpass filter (BPF) with the inductance‐loaded Y‐shaped resonator has been presented in this letter.The proposed UWB BPF has been constructed by integrating the broadside‐coupled microstrip‐CPW structures into the inductance‐loaded Y‐shaped resonator. The broadside‐coupled microstrip‐CPW structures can get tight coupling for UWB performance. The external quality factor has been analyzed to design the proposed UWB filter. An UWB CPW BPF is designed, simulated, and fabricated to demonstrate the performance of the proposed filter structure. The measured results show good agreement with the simulated ones. The fabricated UWB CPW BPF exhibits excellent performance, including 3‐dB insertion loss and 10‐dB return loss bandwidths over the entire UWB band with a minimum insertion loss of 0.37 dB at 5.4 GHz, as well as 1‐dB insertion loss bandwidth of 3.25–10.2 GHz and group delay variation from 0.18 to 0.28 ns over the frequency range of 3.9–11 GHz. © 2011 Wiley Periodicals, Inc. Microwave Opt Technol Lett 53:1134–1137, 2011; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.25940
UWB cylindrical microwave imaging system employing virtual array antenna concept for background effect removal
Authors: Bialkowski Marek , Wang Yifan 
Published: March 2011

AbstractIn this letter, an Ultra Wideband (UWB) Microwave Imaging System with a novel image reconstruction algorithm aiming at detecting and locating small targets in a homogenous circular cylindrical body is presented. The system uses a double circular scan in which the second scan is achieved after rotating the antenna sub‐system or the imaged body by a small angle. The obtained two sets of data serve the purpose of removing a large background signal that masks a small signal due to a target. This is done by forming difference signals for adjacent antenna positions. The procedure is equivalent to using a virtual 2‐element 180° out‐of‐phase fed array antenna. By assuming that the imaged body is symmetric with respect to the axis of the virtual array, the background effect is removed while the signal due to an off‐axis target is detected. The difference data is scaled and mapped to produce an image showing the target location. The validity of the proposed image reconstruction algorithm is demonstrated in an example of a cylindrical plastic container filled with a vegetable oil and small diameter cylindrical water targets. © 2011 Wiley Periodicals, Inc. Microwave Opt Technol Lett 53:1100–1104, 2011; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.25941
Crosstalk effects of quantum key distribution via a quantum router
Authors: Yooplao P. , Pongwongtragull P. , Mitatha S. , Yupapin P. P. 
Published: March 2011

AbstractWe propose a new system of quantum cryptography for internet security using Gaussian pulses propagating within a nonlinear ring resonator system, quantum processor and a wavelength router.To increase the channel capacity and security, the multiplexer is operated incorporating a quantum processing unit via an optical multiplexer. The transmission part can be used to generate the high capacity quantum codes within the series of microring resonators and an add/drop filter. The receiver part can be communicated by using the quantum key (quantum bit, qubit) via a wavelength router and quantum processors. The reference states can be recognized by using the cloning unit, which is operated by the add/drop filter, where the communication between Alice and Bob can be performed. The results obtained have shown that the correlated photons can be generated and formed the entangled photon pair, which is allowed to form the secret key between Alice and Bob. In application, the embedded system within the computer processing unit is available for quantum computer. © 2011 Wiley Periodicals, Inc. Microwave Opt Technol Lett 53:1094–1099, 2011; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.25942
Triple‐band rectangular ring monopole antenna for WLAN/WiMAX applications
Authors: Ren Xueshi , Yin Yingzeng , Zheng Shufeng , Zuo Shaoli , Liu Bowen 
Published: March 2011

AbstractIn this article, a novel rectangular ring monopole with triple‐band operation for wireless local area network (WLAN) and worldwide interoperability for microwave access (WiMAX) applications is presented.The antenna is composed of a rectangular ring, two different types of strips on the inner edges of the ring and a partial ground plane. With the two strips, the rectangular ring monopole antenna can realize triple impedance bandwidths (VSWR ≤ 2) of 320 MHz (2.29–2.61 GHz), 1170 MHz (3.19–4.36 GHz), and 1360 MHz (4.95–6.31 GHz), which make it easy to cover the required bandwidths for WLAN bands (2.4–2.483, 5.15–5.35, and 5.725–5.825 GHz) and WiMAX bands (2.4–2.6, 3.3–3.8, and 5.25–5.85 GHz) applications. Details of the proposed triple‐band antenna design are presented and discussed. © 2011 Wiley Periodicals, Inc. Microwave Opt Technol Lett 53:974–978, 2011; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.25943
Power‐over‐fibre for wireless applications
Authors: Sittakul Vitawat , Clare L. R. , Burrow Stephen G. , Li X. C. , Cryan Martin J. 
Published: March 2011

AbstractThis paper demonstrates the use of the power‐over‐fiber concept for wireless applications, which removes the need for DC power supplies at the remote network.The article shows results using low cost lasers, photodiodes, a highly efficient voltage booster circuit (>80%), and rechargeable batteries. Results show that with the best choice of each component, the system can operate for 8 h per day over 200 m MMF for 41 days. System modeling shows that the system can operate indefinitely for 5 h a day over 200 m MMF. Finally, the system was tested for a 802.11 g WLAN application over 200 m MMF and a maximum range of 4 m at 500 kbps can be obtained. © 2011 Wiley Periodicals, Inc. Microwave Opt Technol Lett 53:1027–1032, 2011; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.25947
Linear and nonlinear behaviors of light in a silicon ring resonator
Authors: Vanishkorn B. , Kusalajeerung C. , Chiangga S. , Pitukwongsaporn S. , Jukgoljun B. , Yupapin P. P. 
Published: March 2011

AbstractWe have investigated the nonlinear switching characteristics of an optical device using a double‐coupler silicon ring resonator in the presence of the linear losses, the Kerr nonlinearity, two‐photon absorption, free‐carrier‐induced absorption and dispersion, and thermo‐optic, in which the general features of the nonlinear switching of the throughput and drop port signals are similar to a single‐couple ring resonator and nonlinear Fabry–Perot resonator results, respectively. The interesting results of the double‐coupler silicon ring resonator are the low switching power conditions and the linear amplification gain, in which the various applications can provide by controlling the input–output characteristic of silicon‐based resonators, for instance, by controlling the coupling ratio, free‐carrier lifetime, and input wavelength, which can provide the multiple applications for optical switches, logic gates, and memories. © 2011 Wiley Periodicals, Inc. Microwave Opt Technol Lett 53:997–1000, 2011; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.25948
Compact dual‐band printed square quadrifilar helix antenna for global navigation satellite system receivers
Authors: Zheng Li , (Shichang) Gao Steven 
Published: March 2011

AbstractA miniaturized dual‐band printed square quadrifilar helix antenna (QHA) is proposed for global navigation satellite systems (GNSS) receivers applications.The antenna consists of four printed helices forming a cube with a very small size of 1 cm3 only. It can cover both L1 and L2 bands, centered at 1.575 and 1.227 GHz, respectively. It can achieve good impedance matching and circularly polarized radiation patterns within both L1 and L2 bands. The antenna is very light weight and easy for fabrication. The feed network for the antenna is also designed. To prove the concept, a prototype is developed, fabricated and measured. Both measured and simulated results are presented and discussed. Because of its advantages of compact size, low mass and low cost, the antenna is useful for GNSS receiver onboard small satellites, and mobile terminals on the ground. © 2011 Wiley Periodicals, Inc. Microwave Opt Technol Lett 53:993–997, 2011; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.25949
Planar UWB antenna with multi‐slotted ground plane
Authors: Azim Rezaul , Islam M. Tariqul , Misran Norbahiah , Cheung S. W. , Yamada Y. 
Published: March 2011

AbstractA planar antenna with a multi‐slotted ground plane has been proposed for UWB applications. The compact antenna having a total size of 30 × 22 mm2 consists of a square patch and a partial ground plane. The rectangular slots on the top side of the ground plane help to increase the bandwidth. The measured result shows that the proposed antenna achieves a bandwidth (VSWR ≤ 2) ranges from 2.57 to 16.72 GHz. Details of the proposed antenna and measured results are presented and discussed. © 2011 Wiley Periodicals, Inc. Microwave Opt Technol Lett 53:966–968, 2011; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.25950
Parameter synthesis and design of a novel 14‐pole CQ bandpass filter for CDMA2000 applications
Authors: Jie Ma , Laiyun Ji , Jun Sun , Ruixia Yang , Zhiwei Zhang 
Published: March 2011

AbstractParameter synthesis of a new 14‐pole narrowband bandpass filter for CDMA2000 applications is presented, which has two pairs of transmission zeros (TZs) for group delay self‐equalization and one pair of TZs at finite frequencies for high selectivity requirement. Cascaded quadruplet structures are used to realize above filtering function TZs. The coupling matrix of the filter is optimized by a cost function on transfer and reflection response using Levenberg‐Marquardt algorithm. The simulated and measured results demonstrate the excellent performance of the proposed filter and verify the feasibility of the proposed synthesis procedure. © 2011 Wiley Periodicals, Inc. Microwave Opt Technol Lett 53:1190–1193, 2011; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.25952
Environmental Factors in Multiple Sclerosis: Epstein‐Barr Virus, Vitamin D, and Cigarette Smoking
Authors: Wingerchuk Dean M. 
Published: March 2011

AbstractMultiple sclerosis is an inflammatory demyelinating disease of the central nervous system. Although its cause is not known, genetic and environmental factors both influence susceptibility to the disease. From the large array of environmental risk factors that have been examined over the past century, infection with Epstein‐Barr virus, ultraviolet light exposure/vitamin D status, and cigarette smoking stand out because of the strength of supporting evidence. Epstein‐Barr virus infection early in life appears to be necessary permissive step for disease development and probably acts in adolescence and early adulthood. Vitamin D–related mechanisms and cigarette smoking probably modify baseline disease risk and could plausibly do so at several stages of life; smoking appears to negatively affect disease course. This review summarizes current evidence for these 3 putative multiple sclerosis risk factors and early attempts to develop risk models and examine gene‐environment interactions for this complex disease. Mt Sinai J Med 78:221–230, 2011 © 2011 Mount Sinai School of Medicine