bluuebunny/crossref_metadata_2025_split huggingface dataset:
Permittivity measurement of biological materials with improved microwave cavity perturbation technique
Authors: Wang Zhanxian , Che Wenquan , Chang Yumei 
Published: April 2008

AbstractThe resonant cavity perturbation technique is usually used to measure the complex permittivity of various dielectric materials at microwave frequency. The values of real and imaginary part of the complex permittivity of the material under test can be deduced from the measured shift of resonant frequency and the change of quality factor (Q factor) of the resonance cavity with inserted samples. In this article, an improved resonance cavity perturbation technique is employed to measure the complex permittivity of biological materials, including porcine fat, marrow, and liver, etc. The measured results agree well with the known data, demonstrating the potential validity of our method. This method can be expected to extend to permittivity measurement of other biological material even the tissues from human body. © 2008 Wiley Periodicals, Inc. Microwave Opt Technol Lett 50: 1800–1804, 2008; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.23490
Design of a 5.8 GHz narrow band‐pass filter with second harmonic suppression using the open stubs
Authors: Yoon Ki‐Cheol , Lee Jong‐Chul 
Published: April 2008

AbstractIn this article, λg/2 open stub bandpass filters with flexible narrow bandwidth on duroid substrate are presented. This filters show flexible bandwidth with variation of the position of the open stubs using the external quality factor, Qe without changing the impedance value at microwave range. On the other hand, by replacing the series quarter‐wavelength connecting‐lines with the equivalent T‐shaped line, a compact stub bandpass filter with second harmonic suppression can be obtained. This filter shows the insertion loss of 1.2 dB and the return loss of 21.9 dB at the center frequency of 5.8 GHz. © 2008 Wiley Periodicals, Inc. Microwave Opt Technol Lett 50: 1763–1766, 2008; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.23492
A broadband, circular switched parasitic array for portable and vehicular mobile DVB‐T applications at the V UHF band
Authors: Panagiotou Stylianos C. , Mitilineos Stelios A. , Dimousios Themistoklis D. , Capsalis Christos N. 
Published: April 2008

AbstractA broadband, circular switched parasitic array with two active elements, suitable for DVB‐T applications at the V‐UHF band is designed with the aid of a genetic algorithm. Numerical as well as measurements results are presented for a single switch position. Simulation results are also presented for switched‐beam array operation, using the measured antenna radiation patterns. © 2008 Wiley Periodicals, Inc. Microwave Opt Technol Lett 50: 1727–1732, 2008; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.23494
Broadband planar dipole antenna for DTV/GSM operation
Authors: Lee Cheng‐Tse , Wong Kin‐Lu 
Published: April 2008

AbstractThis article presents a new broadband planar dipole antenna for DTV signal reception in the UHF band (470 ∼ 862 MHz) and mobile communications in the GSM850/900 band (824 ∼ 894/890 ∼ 960 MHz), which requires an operating bandwidth (3:1 VSWR) of 490 MHz or about 69% centered at 715 MHz. The antenna has two radiating arms (arm 1 and arm 2) with a total length 230 mm and a width 14 mm, which are easily printed on an FR4 substrate. Broadband operation is obtained from successful excitation of the half‐ and one‐wavelength modes of the antenna, which is achieved by shifting the antenna's feeding point away from the dipole center through adding a tuning strip to arm 1 and embedding a tuning slot to arm 2. The tuning strip is extended across the tuning slot, and both are also formed as an internal matching circuit for achieving good impedance matching of the excited half‐ and one‐wavelength modes of the antenna. The proposed antenna is presented and studied. © 2008 Wiley Periodicals, Inc. Microwave Opt Technol Lett 50: 1900–1905, 2008; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.23500
Exact design of evanescent‐wave amplification using bilayer periodic circuit structures
Authors: Lin Xian Qi , Feng Ma Hui , Liu Ruopeng , Cheng Qiang , Cui Tie Jun 
Published: April 2008

AbstractAn efficient method is presented to design the evanescent wave amplification exactly by cascading two layers of periodic series‐shunt capacitors and inductors, which simulate a bilayer of magnetic and electric plasmas. Based on the presented method, equivalent lumped parameters of circuit structures are retrieved, from which the evanescent‐wave amplification (EWA) is obtained at a designed frequency. Full‐wave simulations show that the relative offset of the EWA frequency is less than 0.1%. The structure has been fabricated and measured, and the measurement results have good agreements with the simulation results. The proposed method can be used to design other periodic circuit structures, and the exact design of EWA can be used in the fabrication of novel components. © Wiley Periodicals, Inc. Microwave Opt Technol Lett 50: 1870–1873, 2008; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.23501
Compact cross‐coupled hairpin filter design using ceramic substrates
Authors: Huang Cheng‐Liang , Shen Chun‐Hsu , Lin Ling‐Mei 
Published: April 2008

AbstractCross‐coupled hairpin filter design using electrical‐coupling with asymmetric feed on ceramics was reported. The band‐pass filters are designed at center frequency of 2.0 (GHz) with bandwidth of 10%. In addition, this article presents an analytical technique for positioning the locations of two transmission zeros for a microstrip band‐pass filters. The band‐pass filter uses two resonators with two transmission zeros to obtain lower insertion loss than a conventional cross‐coupled microstrip filter. Also, by using high Q, high permittivity dielectric materials as substrates, the filters demonstrate high selectivity, compact size, and can be used in many wireless communication systems. A bandwidth of 10% with −0.75 dB insertion loss and −34 dB attenuation was achieved with chip size of 2.5 × 0.85 cm2. © 2008 Wiley Periodicals, Inc. Microwave Opt Technol Lett 50: 1795–1800, 2008; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.23505
Broadband and high gain slot antenna with adjustable polarization
Authors: Chu Yu‐Yi , Row Jeen‐Sheen 
Published: April 2008

AbstractThis article presents a wide slot antenna whose polarization can be adjusted by rotating a conducting strip. To obtain an optimum gain of the slot antenna, a parasitic patch and a metallic reflector were placed at the front and rear of the wide slot, respectively. A prototype of the proposed antenna was implemented and measured. Experimental results exhibit that the prototype can provide one linear polarization and dual circular polarization operations over a 10 dB‐return‐loss impedance bandwidth of 21%; moreover, the antenna gain is around 10 dBi for each polarization operation. Simulation results performed by HFSS are also shown and they agree with the measured results. © 2008 Wiley Periodicals, Inc. Microwave Opt Technol Lett 50: 1793–1795, 2008; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.23506
MIMO handheld antenna design approach using characteristic mode concepts
Authors: Ethier Jonathan , Lanoue Eric , McNamara Derek 
Published: April 2008

AbstractIn handheld communications devices there is not much room for the placement of antennas. This problem is exacerbated when more than one antenna is needed for use in a MIMO communications system. It is then useful to be able to utilize some of the existing device structure to form the required antennas. In this article, we show how the characteristic mode theory can be used to achieve this in a way that results in antennas with the low envelope correlation preferred for MIMO antennas. © 2008 Wiley Periodicals, Inc. Microwave Opt Technol Lett 50: 1724–1727, 2008; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.23509
Implementation of tunable erbium doped fiber laser using a broadband fiber mirror
Authors: Liaw Shien‐Kuei , Jhong Guo‐Sing , Cho Li‐Ting , Chang Chu‐Lin 
Published: April 2008

AbstractBy using a broadband fiber mirror (BFM), a wavelength tunable erbium‐doped fiber laser (TEDFL) is demonstrated composed with tunable fiber Bragg grating (TFBG). The BFM acts as a broadband reflector both for the lasing signal and pump source. At pumping power of 100 mW, stable laser output power of 21.35 dBm is obtained at a low threshold pumping power of 4.7 mW. A side mode suppression ratio (SMSR) of 57.9 dB and 16 nm wavelength scan range are demonstrated using a single TFBG. The tunable fiber laser may be a good candidate for vast applications in optical network technologies. © 2008 Wiley Periodicals, Inc. Microwave Opt Technol Lett 50: 1722–1724, 2008; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.23510
Even/odd mode resonance frequency of electromagnetically coupled microstrip ring resonator with flexible positional overlay of dielectric strips
Authors: Ghanbari H. 
Published: April 2008

AbstractEffect of perturbation by flexible dielectric strip overlay (Alumina εr = 9.8) on even/odd mode resonance frequency of electromagnetically coupled microstrip ring resonator (EMC‐MRR) is reported. Change in even and odd mode resonance frequencies is found to obey cosine and sine wave function, respectively. Even mode resonance frequency tends to vary linearly with both width and thickness of the strip overlay while for odd mode it is independent of overlay thickness. Based on the experimental results empirical equations for both the even and odd mode resonance frequencies are reported. © 2008 Wiley Periodicals, Inc. Microwave Opt Technol Lett 50: 1931–1934, 2008; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.23513
Broadband dual‐band CPW‐fed closed rectangular ring monopole antenna with a vertical strip for WLAN operation
Authors: Zhang Li , Jiao Yong‐Chang , Zhao Gang , Song Yue , Zhang Fu‐Shun 
Published: April 2008

AbstractA novel CPW‐fed closed rectangular ring monopole antenna with a vertical strip is proposed for WLAN applications. The antenna with a very simple structure is easily fabricated. The measured results explore broadband dual‐frequency operation with (10 dB) impedance bandwidths of 23.4%, range from 2.24 to 2.82 GHz, and 22.9%, ranging from 4.86 to 6.18 GHz, at bands of 2.48 and 5.76 GHz, respectively, which cover the 2.4/5.2/5.8 GHz WLAN operating bands. Also, good omni‐directional radiation patterns and antenna gains over the operating bands have been obtained. © 2008 Wiley Periodicals, Inc. Microwave Opt Technol Lett 50: 1929–1931, 2008; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.23514
An ultra‐wide bandpass filter with good out‐of‐band performance
Authors: Li Zhong , Wang Guang‐Ming , Zhang Chen‐Xin , Long Ge‐Nong 
Published: April 2008

AbstractAn ultra‐wideband microstrip filter with good out‐of‐band performance is designed and demonstrated. The filter design is based on a circuit model for an optimum short‐circuited stub transmission‐line filter whose unit elements or connecting lines are nonredundant. Substituting the connecting lines by the lowpass filter using stepped impedance hairpin resonator, the undesired spurious bands can be efficiently suppressed, and the designed filter length is reduced. According to the different requirements, the broadband bandpass and lowpass filter can be independently designed and modified, which makes the filter more convenient and easily implemented. © 2008 Wiley Periodicals, Inc. Microwave Opt Technol Lett 50: 1735–1737, 2008; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.23517
Improving the solution accuracy of thin dielectric approximation with a vertical electric field component
Authors: Lu Cai‐Cheng 
Published: April 2008

AbstractThe traditional thin dielectric sheet approximation (TDS) method models the electromagnetic scattering by thin dielectric sheet using surface integral equation. In this approximation, only the tangential current within the dielectric sheet is considered, and the vertical component is ignored. This article proposes a method that uses the volume integral equation solution to predict the vertical volume current and hence to improve the overall solution accuracy. The formulation is based on the hybrid surface (SIE) and volume integration equation (VIE) in which, the thin dielectric is modeled with SIE, and the thin layers are modeled by VIE. It is shown that the inclusion of the vertical current component does not increase memory and solution time. Numerical examples will be provided to demonstrate the effectiveness of this approach. © Wiley Periodicals, Inc. Microwave Opt Technol Lett 50: 1978–1982, 2008; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.23518
Design of a miniaturized planar antenna for FCC‐UWB communication systems
Authors: Lizzi L. , Viani F. , Azaro R. , Massa A. 
Published: April 2008

AbstractIn this letter, the design of a planar antenna compliant with FCC requirements for ultra‐wideband (UWB) transmission systems is described. With reference to a planar geometry on a dielectric substrate, the shape of the antenna is described by means of a spline‐based representation and it is determined by means of an optimization process aimed at finding the optimal descriptive parameters that allow to fit the user‐defined electrical and dimensional requirements. The reliability and effectiveness of the antenna prototype are assessed through simulations as well as experimental measurements. © Wiley Periodicals, Inc. Microwave Opt Technol Lett 50: 1975–1978, 2008; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.23519
Propagation characteristics of periodic guided wave structures with a compact finite‐difference frequency‐domain method
Authors: Wang Xiao‐Hua , Wang Bing‐Zhong 
Published: April 2008

AbstractTo simulate periodic structures efficiently, Floquet's theorem is applied to a compact finite‐difference method for the analysis of dispersion characteristics of general periodic guided wave structures. By solving the full‐field‐component Eigen equations, dispersion characteristics and modes are obtained. The proposed method shows good applicability to the periodic guided structures where complex mode pairs, radiation modes, or leaky modes, etc., may exist. © 2008 Wiley Periodicals, Inc. Microwave Opt Technol Lett 50: 1941–1944, 2008; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.23520
Wideband circular slot antenna with tri‐band rejection characteristics at 2.45/5.45/8 GHz
Authors: Yeo Junho 
Published: April 2008

AbstractA novel wideband circular slot antenna with tri‐band rejection characteristics at 2.45, 5.45, and 8 GHZ is proposed. Two different types of slots are used to obtain band‐notched characteristics at three frequencies; one is a split ring and the other is an inverted L‐shaped slot. These slots are employed inside a circular patch of the circular slot antenna and the rejection bands can be adjusted by selecting the lengths of two slots. It is demonstrated that tri‐band rejection characteristics at 2.45, 5.45, and 8 GHz with desired bandwidths can be obtained by using two different types of slots. © 2008 Wiley Periodicals, Inc. Microwave Opt Technol Lett 50: 1910–1914, 2008; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.23521
A star patch antenna for generating multiple radiation patterns
Authors: Mehta A. , Mirshekar‐Syahkal D. , Nakano H. 
Published: April 2008

AbstractA novel form of star patch antenna for generating multiple radiation patterns, namely, tilted, axial and doughnut is presented and analyzed. These three patterns can be switched to scan all directions in front of the antenna. Each of these patterns can be generated by exciting one of the six feeding points on the antenna. By examining the current distributions corresponding to the radiation patterns of the antenna, qualitative reasoning's for the radiation mechanisms are also presented. © 2008 Wiley Periodicals, Inc. Microwave Opt Technol Lett 50: 1908–1910, 2008; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.23522
Low cost ultra wideband amplifier in 0.35 μm CMOS process
Authors: Modha Kuldip N. , Hayes‐Gill Barrie , Harrison Ian 
Published: April 2008

AbstractA two stage ultra wideband (UWB) amplifier is presented. This amplifier incorporates multiple bandwidth enhancing techniques and is implemented in Austria micro systems (AMS) 0.35 μm CMOS process technology. The amplifier consumes 39.5 mW of power, exhibits a maximum gain of 13 dB, has input and output reflections below −9 and −10 dB, respectively over a −3 dB bandwidth of 4 GHz. The average measured noise figure is 6 dB and 1 dB compression point at 3 GHz is −12 dBm. © 2008 Wiley Periodicals, Inc. Microwave Opt Technol Lett 50: 1879–1881, 2008; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.23525
FDTD analysis of microstrip patch antenna on ferrite substrate
Authors: Alsunaidi M. A. 
Published: April 2008

AbstractThe finite‐difference time‐domain (FDTD) method is used to model the response of microstrip patch antennas on magnetized ferrite substrates. The proposed FDTD model utilizes the auxiliary differential equation approach to represent the frequency dependent permeability tensor in the time domain equations. The resulting 3D full‐wave numerical model is tested and verified against experimental data showing very good agreement. This model, being efficient, stable, and robust, is expected to assist in the design and characterization of wideband ferrite‐based antenna structures. © Wiley Periodicals, Inc. Microwave Opt Technol Lett 50: 1848–1851, 2008; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.23526
A modified scheme of sparse‐matrix canonical‐grid method using Chebyshev interpolating Green′s function
Authors: Huang S. W. , Xia M. Y. 
Published: April 2008

AbstractA modified scheme of sparse‐matrix canonical‐grid (SMCG) method for simulation of rough surface scattering is developed. It employs an interpolating Green's function based on Chebyshev polynomial approximation to replace the Taylor series expansion in the previous SMCG methods, which becomes intractable for high‐order terms. This modified scheme is more efficient and flexible, and suitable for arbitrary roughness. © Wiley Periodicals, Inc. Microwave Opt Technol Lett 50: 1844–1848, 2008; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.23527
Controllable terahertz wave attenuator
Authors: Li Jiusheng , Yao Jianquan 
Published: April 2008

AbstractA new type of optically controllable terahertz wave attenuator using high‐resistivity silicon wafer is developed and tested. Without optical excitation, the high‐resistivity silicon is a lossless dielectric material at terahertz wave region. When the high‐resistivity silicon wafer is optically excited, free carriers are generated, and the silicon wafer becomes a lossy dielectric. We study theoretically and demonstrate experimentally light‐controllable terahertz wave of the high‐resistivity silicon wafer. The results show that more than 10‐dB attenuation of the novel terahertz wave attenuator is obtained at frequency of 0.3 THz. The proposed device can be used in future terahertz wave communication systems. © 2008 Wiley Periodicals, Inc. Microwave Opt Technol Lett 50: 1810–1812, 2008; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.23528
Resonant microstrip meander line antenna element for wide scan angle active phased array antennas
Authors: Beenamole K. S. , Kutiyal Prem N. S. , Revankar U. K. , Pandharipande V. M. 
Published: April 2008

AbstractA compact, wide bandwidth, wide beamwidth resonant microstrip meander line antenna element is reported for active phased array applications. The antenna element offers a return loss better than −10 dB over a bandwidth of 12% in S‐band with a beamwidth of 130° in E‐plane. The element has been tested in an array for its wide‐angle scan performance. Simulated and measured results are presented. © 2008 Wiley Periodicals, Inc. Microwave Opt Technol Lett 50: 1737–1740, 2008; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.23531
A slot‐loaded slot antenna fed by inset CPW for dual frequency operation
Authors: Rhee Seungyeop 
Published: April 2008

AbstractBroadband operation of a dual‐frequency rectangular slot antenna is achieved by embedding a pair of narrow slots in a rectangular patch inside a loop antenna with a CPW feed. With the proposed antenna design, the impedance bandwidths of 9.4% at the lower frequency band and 3.0% at the upper band are obtained. Details of the antenna design and experimental result are presented and discussed. © Wiley Periodicals, Inc. Microwave Opt Technol Lett 50: 1984–1986, 2008; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.23532
All fiber‐optic sensor for liquid level measurement
Authors: Nath Pabitra , Datta Pranayee , Ch Sarma Kanak 
Published: April 2008

AbstractIn this article, a simple intensity‐modulated fiber optic sensor for liquid level measurement is presented. The sensor principle is based on frustrated total internal reflection effect caused by refractive index change of a medium surrounding an optical fiber. The end face of a step‐index multimode optical fiber is polished to form a hemispherical tip so that a part of the forward propagating modes is reflected in the reverse direction by the effect of total internal reflection. The change of medium (due to contact of the tip with the liquid) modifies the critical angle for the back reflected light thus giving modulated output power. The experimental results of the sensor obtained for different liquids (pure water, ethanol) confirm the sensor potential for liquid level determination with high accuracy nearly 5 μm and repeatability. © Wiley Periodicals, Inc. Microwave Opt Technol Lett 50: 1982–1984, 2008; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.23533
Single mode operation of a Fabry–Perot laser locked by a tunable laser
Authors: Hua Zhu Ning , Han Wei , Li Wei , Chen Wei , Wen Ji Min , Liu Yu , Xie Liang 
Published: April 2008

AbstractIn this article, the single mode operation of a Fabry‐Perot laser (FP‐LD) subject to the optical injection from a tunable laser is investigated. The maximum side mode suppression ratio (SMSR) is 53 dB, and the locked wavelength range is about 46 nm, which can cover 58 International Telecommunication Union (ITU) wavelengths with 100 GHz spacing or 115 ITU wavelengths with 50 GHz spacing for wavelength division multiplexing (WDM) system. In the wavelength range from 1535 to 1569 nm, the SMSR is over 46 dB, and the frequency response of the injection‐locked FP‐LD can be improved with the proper wavelength detuning. © 2008 Wiley Periodicals, Inc. Microwave Opt Technol Lett 50: 1888–1892, 2008; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.23538