bluuebunny/crossref_metadata_2025_split huggingface dataset:
Symmetric microstrip interdigital capacitor‐compensated high directivity directional‐coupler
Authors: Baek Donghyun , Kim Youngjin 
Published: August 2008

AbstractThis article describes a symmetric capacitor‐compensated microstrip directional‐coupler design with very high directivity. The compensation capacitors are incorporated between the coupling lines as interdigital type on the PCB board. The prototype directional‐coupler shows 19.6 dB coupling factor and achieves very high directivity of more than 45 dB at 1.9 GHz. © 2008 Wiley Periodicals, Inc. Microwave Opt Technol Lett 50: 2801–2803, 2008; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.23800
Improvement of optical beam‐forming networks based on broadband optical source and chirped fiber grating
Authors: Zhou Bo , Zheng Xiaoping , Ye Yabin , Zhang Hanyi , Guo Yili , Zhou Bingkun 
Published: August 2008

AbstractWe propose a photonic beam‐forming network scheme based on a broadband optical source (BS), double sideband suppressed carrier (DSB‐SC) modulation, and a chirped fiber grating (CFG). The principle and feasibility are proved by both theoretical analysis and experiments. In 20–32 GHz microwave band, experimental results show a good delay time consistency and the ratio of RF signal to noise met the practical application demands. The time consistency errors are smaller than 3 ps in 20–40GHz band. Specially, compared with traditional double sideband (DSB) modulation scheme, in the proposed approach the dispersion‐induced RF power degradation is effectively mitigated over 24 dB at 30 GHz, and the experimental results agree well with the theoretical ones. © 2008 Wiley Periodicals, Inc. Microwave Opt Technol Lett 50: 2992–2994, 2008; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.23802
A 1‐GHz GaN HEMT based class‐E power amplifier with 80% efficiency
Authors: Lee Yong‐Sub , Lee Mun‐Woo , Jeong Yoon‐Ha 
Published: August 2008

AbstractThis article reports a highly efficient 1‐GHz class‐E power amplifier based on a GaN HEMT. The compensation elements with a series capacitor and a shunt inductor are used to compensate for the internal parasitic components of the packaged transistor. To improve output power and efficiency by suppressing harmonic powers, an output matching circuit using the transmission lines is used. The peak PAE and drain efficiency of 79.2 and 80.4% with a power gain of 18.14 dB is achieved at an output power of 41.14 dBm for a continuous wave. © 2008 Wiley Periodicals, Inc. Microwave Opt Technol Lett 50: 2989–2992, 2008; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.23803
An RF module integrated with a dual‐band DRO oscillating at X‐ and K‐band simultaneously
Authors: Yang Ru‐Yuan , Weng Min‐Hang , Hung Cheng‐Yuan , Wu Hung‐Wei 
Published: August 2008

AbstractIn this article, a high quality vehicle RF module integrated with a temperature stable dual‐band dielectric resonator oscillator (DRO) oscillating at X‐ and K‐band simultaneously is implemented. The DRO shows the first oscillating frequency at 11.545 GHz and the second oscillating frequency at 23.09 GHz using the fundamental TE01 and enhanced TE02 mode of the dielectric resonator (DR), respectively. The used DR is (Zr, Sn)TiO4 ceramic with a dielectric constant (εr) of 36, a quality factor (Q×f) of 60,000 and a temperature coefficient of resonant frequency (τf) of ± 1 ppm/°C. The design procedure is clearly described in this article. The propagation mode behaviors and equivalent circuits of the DRO are used to predict the circuit performances of the RF module. For practical testing, the RF module combining with a horn antenna, the DRO and a surface‐mounted mixer is fabricated and measured. The results are close matched with the circuit simulation. © 2008 Wiley Periodicals, Inc. Microwave Opt Technol Lett 50: 2961–2965, 2008; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.23805
Bow‐tie antenna using high‐impedance ground plane
Authors: Lee Yi‐Chieh , Sun Jwo‐Shiun 
Published: August 2008

AbstractThis presents a high‐impedance ground plane (HIGP) structure for bow–tie antenna in order to improve its radiation performances. The HIGP is a kind of electromagnetic bandgap (EBG) structure to decrease surface waves and to bring an improvement of side lobe level, and reduce the mutual coupling between the two antennas. As compared to proposed antenna without HIGP, the measurement results show a fairly good antenna gain and a 5–10 dB reduction in the back lobes. Several properties of the proposed antenna for WLAN operation such as impedance bandwidth, radiation pattern, and measured gain have been investigated in detail, numerically and experimentally. © 2008 Wiley Periodicals, Inc. Microwave Opt Technol Lett 50: 2928–2931, 2008; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.23807
Compact band‐notched ultrawideband Y‐shaped antenna with dual inverted‐L slots
Authors: Choi By Sun‐Ho , Jeong Gye‐Taek , Park Ho‐Hwan , Lee Hwa‐Choon , Kwak Kyung‐Sup 
Published: August 2008

AbstractIn this work, a novel band‐notched ultrawideband (3.1–10.6 GHz) Y‐shaped microstrip patch antenna with dual inverted‐L slots is presented. The proposed antenna consists of a wideband Y‐shaped monopole antenna and dual inverted‐L slots, producing band‐notch characteristics. To obtain sufficient bandwidth when the return loss (RL) < −10 dB, but still generate band‐notch characteristics, we propose that a partial ground plane, a coaxial probe source, and two inverted‐L slots can be used. The measured bandwidth of the fabricated antenna is from 2.96 to 4.85 GHz (from 6.05 to 12.65 GHz when the RL < −10 dB), and the frequency notch band is from 5.15 to 5.825 GHz. The measured gain is 3.66–4.58 dBi, which drops to −3.80 dBi in the notch band. The azimuth and elevation of the experimental 3‐dB beam width (HPBW) are 72.58° and 88.59° at 7.0 GHz, respectively. © 2008 Wiley Periodicals, Inc. Microwave Opt Technol Lett 50: 2797–2799, 2008; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.23814
Ultra‐wide bandpass filters with sharpened roll‐off skirts, extended upper‐stopband, and controllable notch‐band
Authors: Wong Sai Wai , Zhu Lei 
Published: August 2008

AbstractThis article presents a novel ultra‐wide bandpass filter on microstrip line with sharpened roll‐off skirts, extended upper‐stopband, and controllable notch‐band. A shunt stub structure with two split symmetrical open end stubs is purposed, aiming to create a pair of transmission zeros at the lower and upper ends of the concerned ultra‐wideband range from 3.1 to 10.6 GHz. Then, this open stub loaded with dissimilar low‐impedance sections is studied to create a notch band that is located at 5.6 GHz. To further widen the upper‐stopband and sharpen the roll‐off skirts, an electromagnetic‐bandgap structure is inserted between the two identical coupled lines. Finally, a filter prototype with notch band are designed, fabricated, and tested. Its overall size is only about 0.19λ2. © 2008 Wiley Periodicals, Inc. Microwave Opt Technol Lett 50: 2958–2961, 2008; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.23818
Design of ultra‐wideband bandstop filter with three transmission zeros
Authors: Kanti Mandal Mrinal , Krishna Velidi Vamsi , Sanyal Subrata , Bhattacharya Amitabha 
Published: August 2008

AbstractIn this article, a compact microstrip coupled‐line configuration has been presented to design a wideband bandstop filter with three transmission zeros. These transmission zeros are utilized to obtain sharp rejection characteristics. A loss‐less transmission line model is used to obtain the filter design parameters. To validate the theoretical prediction, a single section sharp‐rejecting, compact, bandstop filter having a 20‐dB rejection bandwidth of ∼100% at 1.5 GHz has been fabricated. © 2008 Wiley Periodicals, Inc. Microwave Opt Technol Lett 50: 2955–2957, 2008; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.23819
A new design method of microstrip dual‐band bandstop filters
Authors: Kikuchi Katsunori , Ma Zhewang , Anada Tetsuo 
Published: August 2008

AbstractA generic lumped‐element circuit of dual‐band bandstop filter (DBBSF) is proposed based on novel composite shunt resonators, and its design method is developed with closed‐form formulas. As an example, a DBBSF with center frequencies of 1.7 and 2.3 GHz is designed and fabricated using microstrip lines. The measured frequency response agrees excellently with the theoretical predictions, validating well the proposed design theory and filter structure. © 2008 Wiley Periodicals, Inc. Microwave Opt Technol Lett 50: 2888–2892, 2008; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.23822
Magneto‐dielectric properties of the Y3Fe5O12 and Gd3Fe5O12 dielectric ferrite resonator antennas
Authors: Fechine P. B. A. , Moretzsohn R. S. T. , Costa R. C. S. , Derov J. , Stewart J. W. , Drehman A. J. , Junqueira C. , Sombra A. S. B. 
Published: August 2008

AbstractThe main objective of this work was to study the magnetic and dielectric properties of Y3Fe5O12 and Gd3Fe5O12 garnets resonator antennas obtained from a new procedure in the solid state ceramic technique. These ferrite resonator antennas (FRAs) had the ability to change their characteristics as a function of the applied magnetic field. The Y3Fe5O12 resonator was able to increase the antenna frequency range with application of external magnetic field. Some of the properties of dielectric resonator antennas (DRAs) can be actively controlled by using low‐loss ferrite materials. When unbiased, these ferrite resonator antennas (FRAs) exhibit similar behavior to DRAs. However, when a DC magnetic bias is applied, the tensor nature of the ferrite permeability is invoked, and various parameters can be controlled electronically. We also studied the magnetic behavior of the antennas and did a numerical study of the gain and directivity of the ferrite resonator antennas. These results can be important to develop wideband third‐generation (3G) cellular phones and other wireless products. © 2008 Wiley Periodicals, Inc. Microwave Opt Technol Lett 50: 2852–2857, 2008; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.23824
Dual‐mode filters based on substrate integrated waveguide by multilayer LTCC technology
Authors: Wei Qi‐Fu , Li Zheng‐Fan , Shen Hai‐Gen 
Published: August 2008

AbstractThis letter presents the design and experiment of a single‐cavity dual‐mode bandpass filter and a double‐cavity dual‐mode bandpass filter realized by substrate integrated waveguide (SIW) structure. Both the filters are designed and simulated by network theory and high frequency structure simulator (HFSS), and fabricated using multilayer low‐temperature co‐fired ceramic (LTCC) technology. The measured results show good agreement with the simulated results and validate the structures of the proposed dual‐mode filters. © 2008 Wiley Periodicals, Inc. Microwave Opt Technol Lett 50: 2788–2790, 2008; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.23829
A small RFID tag antenna using proximity‐coupling to identify metallic objects
Authors: Choi Wonkyu , Kim Jungsuk , Bae Ji‐Hoon , Choi Gilyoung 
Published: August 2008

AbstractThis article presents the design of a small‐ and low‐profile radio frequency identification tag antenna in the UHF band that can be stuck to metallic objects. The designed tag antenna, which uses a ceramic material as an antenna substrate, consists of a radiating patch and microstrip lines for a proximity‐coupled feeding structure. Impedance matching can be simply obtained between the antenna and tag chip without any matching network using the antenna structure. The return‐loss bandwidth for S11 < 10 dB and radiation efficiency are about 9.5 MHz and 40% at 911 MHz, respectively. The read range is approximately from 3 to 3.5 m when the tag antenna is mounted on a metallic surface. © 2008 Wiley Periodicals, Inc. Microwave Opt Technol Lett 50: 2978–2981, 2008; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.23831
Inverse class‐F power amplifier using the metamaterial structure on the harmonic control circuit
Authors: Kim Hyoungjun , Seo Chulhun 
Published: August 2008

AbstractIn this study, the inverse class‐F power amplifier at 1.8 GHz using the harmonic control circuit based on a metamaterial structure is proposed and experimentally tested. The harmonic control circuit has been used with transmission line and metamaterial structure to open the 2nd harmonics, to short the 3rd harmonics, and to match the fundamental frequency to 50 Ω. The interesting properties of the metamaterial structure allow a size reduction of the harmonic control circuit as well simplification of the design. A detailed analysis of the metamaterial structures based on the equivalent circuit model is provided. The proposed harmonic control circuit has been used to design the inverse class‐F power amplifier with maximum PAE of 70.4%. © 2008 Wiley Periodicals, Inc. Microwave Opt Technol Lett 50: 2881–2884, 2008; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.23836
A novel low‐cost multisensor‐tag for RFID applications in healthcare
Authors: Catarinucci Luca , Cappelli Mauro , Colella Riccardo , Tarricone Luciano 
Published: August 2008

AbstractHealthcare represents one of the most promising sectors for future RFID applications. RFID, indeed, candidates as a natural solution to a large amount of biomedical problems, from care giving to telemedicine. For a large scale introduction into this market, the integration of RFID systems with a sensor network could be the turnpoint. We focus here on the implementation of a multisensor RFID system able to send information about the physiological status of a patient by simply exploiting its intrinsic characteristics. Without changing the digital design of the chip (hence its basic cost), it is possible to transmit extra‐information on sensor parameter variations. Results proposed with respect to the wireless remote monitoring of the patient temperature demonstrate the quality of the proposed technology, and the possibility to be extended to many other biomedical sensors. © 2008 Wiley Periodicals, Inc. Microwave Opt Technol Lett 50: 2877–2880, 2008; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.23837
Low numerical dispersion locally one‐dimensional FDTD method based on compact higher‐order scheme
Authors: Liang Feng , Wang Gaofeng , Ding Wen 
Published: August 2008

AbstractA two‐dimensional (2D) locally one‐dimensional finite‐difference time‐domain (LOD‐FDTD) method with low numerical dispersion is introduced by virtue of a parameter‐optimized compact fourth‐order scheme. The numerical dispersion error and anisotropy of numerical phase velocity of this new method are proven to be significantly reduced compared with the original second‐order method. © 2008 Wiley Periodicals, Inc. Microwave Opt Technol Lett 50: 2783–2787, 2008; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.23842
An ultra‐wide stopband low‐pass filter using dual reverse U‐shaped DGS
Authors: Hsiao Pai‐Yi , Weng Ro‐Min 
Published: August 2008

AbstractOn the basis of the characteristics of defected ground structures (DGSs), a low‐pass filter (LPF) with a sharp rejection and an ultra‐wide stopband is constructed. The proposed LPF comprises of a dual reverse U‐shaped DGS along with two H‐shaped patterns on the ground plane and a microstrip line on the top layer. The attenuations are 2 and 32.8 dB at 3.7 and 3.85 GHz, respectively. The maximum attenuation rate is 205 dB/GHz. The proposed LPF achieves an ultra‐wide stopband with overall 20 dB attenuation from 3.75 GHz up to 20 GHz. © 2008 Wiley Periodicals, Inc. Microwave Opt Technol Lett 50: 2780–2783, 2008; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.23843
Single probe fed cavity backed circularly polarized antenna
Authors: Luo Guo Qing , Sun Ling Ling , Dong Lin Xi 
Published: August 2008

AbstractThe concept of a novel single probe feed cavity backed circularly polarized antenna based on substrate integrated waveguide technique has been investigated in this article. The proposed antenna provides high circularly polarized radiation performance and keeps advantages of low profile and convenient fabrication. © 2008 Wiley Periodicals, Inc. Microwave Opt Technol Lett 50: 2996–2998, 2008; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.23848
New THZ excitation of planar Goubau line
Authors: Treizebré Anthony , Bocquet Bertrand , Xu Yansheng , Bosisio Renato G. 
Published: August 2008

AbstractQuite recently, it has been found that conducting wires lying on a flat dielectric substrate can propagate Terahertz (THz) waves in the same way as conducting wires entirely coated with a dielectric (Goubau line). This phenomenon is interesting because it is a basic requirement to fabricate integrated circuits at THz frequencies. The excitation of planar Goubau line (PGL) waves was found to have a very strong Goubau mode on conducting wire. The excitation was made with a coplanar waveguide transition fed with a THz signal obtained from a vector network analyzer. The Goubau mode on PGL was excited with high efficiency (up to 75%.). This is a first step in the design of THz BioMEMS dedicated to living cell investigations. © 2008 Wiley Periodicals, Inc. Microwave Opt Technol Lett 50: 2998–3001, 2008; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.23850
Novel diplexer using composite right/left‐handed transmission lines
Authors: Hu Xin , He Sailing 
Published: August 2008

AbstractA new type of notch filter based on a balanced composite right/left‐handed (CRLH) transmission line is proposed. Combining such two notch filters with a Y‐junction divider, a novel diplexer is designed and studied. The diplexer has a wide and flat‐top pass‐band and very good isolation between the two outputs. Both theoretical analysis and experimental results are given and they agree with each other. © 2008 Wiley Periodicals, Inc. Microwave Opt Technol Lett 50: 2970–2973, 2008; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.23851
A microstrip grid array antenna optimized by a parallel genetic algorithm
Authors: Xing Chen , Kain Chen , Kama Huang 
Published: August 2008

AbstractIn this article, a novel microstrip grid array antenna is presented. For achieving a high gain and good impedance match, its structural parameters were optimized by a parallel genetic algorithm. A prototype antenna measures a gain of 18.3 dBi with an input return loss of −15.0 dB at its working frequency of 2.45 GHz. © 2008 Wiley Periodicals, Inc. Microwave Opt Technol Lett 50: 2976–2978, 2008; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.23856
Novel UWB BPF design using modified trisection MMR
Authors: Chen Lian‐Yu , Lee Ching‐Her , Hsu Chung‐I G. 
Published: August 2008

AbstractA novel ultrawideband (UWB) bandpass filter (BPF) is proposed and designed using a multimode resonator (MMR) that is modified from a conventional trisection stepped‐impedance resonator (TSSIR). With the first five resonant modes of the TSSIR and the coupling peaks of the input/output interdigital parallel‐coupled lines properly located in the UWB passband, a seven‐transmission‐pole UWB BPF was realized. Open stubs were embedded in the MMR to produce a transmission zero for improving the upper‐stopband rejection. A prototype of the proposed UWB BPF has been fabricated and measured for performance verification. Besides a measured return loss of higher than 11 dB between the lowest and highest transmission poles, the measured results show a minimum insertion loss of 0.3 dB and a group delay variation of less than 0.07 ns in the UWB passband. © 2008 Wiley Periodicals, Inc. Microwave Opt Technol Lett 50: 2904–2907, 2008; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.23860
Design of a new dual‐band microstrip bandpass filter with multiple transmission zeros
Authors: Li Lin , Li Zheng‐Fan 
Published: August 2008

AbstractA novel dual‐band microstrip bandpass filter with multiple transmission zeros has been proposed in this article. Dual‐band resonators composed of one shunt short‐circuited stub and one shunt open‐circuited stub are connected by dual‐band admittance inverters (J‐inverters) to create dual‐passband responses. The three transmission zeros brought by the resonator plus the transmission zero resulted from the inverter will produce sharp attenuations near the passbands, and large isolations between the passbands. Design formulas of this type of filters are also provided in detail. To verify the presented concept, a filter with a dual‐band response has been designed and fabricated with microstrip technology. The measured results are in good agreement with the full‐wave simulation results. © 2008 Wiley Periodicals, Inc. Microwave Opt Technol Lett 50: 2874–2877, 2008; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.23861
Properties of mixed‐mode S‐parameters
Authors: Zhou Yonggang , Chen Yinchao 
Published: August 2008

AbstractThe paper explores the properties of mixed‐mode (MM) S‐parameters, which are widely used in computer PCB and wireless RF industries and have not received serious discussion in the current literature. In this paper, to compare these MM S‐parameter properties to the corresponding ones of the conventional single‐ended S‐parameters, we have developed the symmetric and unitary properties in terms of the mixed‐mode S‐parameter matrix. Also, we have developed a method to deal with the reference plane shift, which is expressed in a mixed‐mode S‐parameter fashion for the cases of both the coupled and uncoupled transmission lines. To validate the developed mixed‐mode S‐parameter properties, we have herein analyzed a 10‐dB coupled line‐directional coupler constructed by a pair of coupled transmission lines. © 2008 Wiley Periodicals, Inc. Microwave Opt Technol Lett 50: 2869–2874, 2008; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.23862
Non‐steroidal anti‐inflammatory drugs and cardiac failure: meta‐analyses of observational studies and randomised controlled trials
Authors: Scott Paul A , Kingsley Gabrielle H. , Scott David L 
Published: August 2008

AbstractAims:To determine the risks of cardiac failure with non‐steroidal anti‐inflammatory drugs (NSAIDs) and the specific risks with Cox‐2 specific NSAIDs (COXIBs).Methods:We performed meta‐analyses examining the risks of developing cardiac failure in observational studies and in randomised controlled trials (RCTs) involving patients with arthritis and non‐rheumatic disorders. Electronic databases and published bibliographies were systematically searched (1997–2008).Results:Five case—control studies (4657 patients, 45,862 controls) showed a non‐significant association between NSAIDs and cardiac failure in a random effect model (odds ratio (OR) 1.36; 95% CI 0.99–1.85). Two cohort studies (27,418 patient years, 55,367 control years) showed a significant risk of cardiac failure with NSAIDs (relative risk 1.97; 95% CI 1.73–2.25). Six placebo‐controlled trials (naproxen, rofecoxib and celecoxib) in non‐rheumatic diseases (15,750 patients) showed more cardiac failure with NSAIDs (Peto OR 2.31; 95% CI 1.34, 4.00). Six RCTs comparing conventional NSAIDs and COXIBs in arthritis (62,653 patients) showed no difference in cardiac failure risk (Peto OR 1.14; 95% CI 0.85–1.53).Conclusion:Observational studies and RCTs all show that NSAIDs increase the risk of cardiac failure. Overall risks are relatively small and are similar with conventional NSAIDs and COXIBs. Pre‐existing cardiac failure increases risk.