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Transmission Lines (transmission + line)
Kinds of Transmission Lines Terms modified by Transmission Lines Selected AbstractsTo compact ring branch-line coupler using nonuniform transmission lineMICROWAVE AND OPTICAL TECHNOLOGY LETTERS, Issue 11 2009F. Hosseini Abstract A compact ring Branch-Line Coupler (BLC) with size reduction of about 50%(in circuit area) of conventional BLCs at frequency 2 GHz is introduced. The coupler is designed by using nonuniform transmission lines (NTL) instead of Uniform Transmission Lines in each arm. The normalized width w (z)/h function of the NTLs is expanded in a truncated Fourier series. The reduced size couplers are potential building blocks for the growing wireless communication markets. © 2009 Wiley Periodicals, Inc. Microwave Opt Technol Lett 51: 2679,2682, 2009; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.24703 [source] A combined S-transform and fuzzy expert system for phase selection in digital relayingEUROPEAN TRANSACTIONS ON ELECTRICAL POWER, Issue 5 2008S. R. Samantaray Abstract This paper presents a new approach for faulty phase selection in transmission line based on combined S-transform and Fuzzy Expert System (FES). The S-transform with complex window is used to generate S-contours (time,frequency contours), which ,time-localizes' the fault. Features such as standard deviation (sd) and change in energy (ce) of the S-contours for half cycle post fault current samples are calculated and fuzzified with simple triangular membership function. The fuzzified inputs are fed to the FES and the corresponding fuzzy rule is fired to provide the output as "1" for faulty phase and ground involved and "0" for no-fault. The proposed integrated approach is tested for all 11 types of shunt faults with a wide range of operating conditions of the power system network. For testing the robustness of the proposed technique, the same is applied for the faults created on experimental set up with different operating conditions and provides accurate results. The output from the FES shows the fastness of the proposed technique and thus suitable for online application. Copyright © 2007 John Wiley & Sons, Ltd. [source] High-frequency behavior of power inductor windings using an accurate multiconductor transmission line model: input impedance evaluationEUROPEAN TRANSACTIONS ON ELECTRICAL POWER, Issue 5 2008J. A. Brandão Faria Abstract This research and tutorial paper is the second part of a work dedicated to the analysis and computation of the electromagnetic behavior of inductor windings operating at high-frequency regimes,a critical issue for very fast transient overvoltage studies. The inductor winding, wound around a ferromagnetic core, containing a total number of N dielectric coated cylindrical turns, is modeled by using a multiconductor transmission line (MTL) approach (proximity effects being accounted) whose constitution and characterization was presented in a former paper. In the present work, we make use of the R, G, L, and C constitutive matrices of the structure in order to develop a modal analysis technique-based formulation aimed at the evaluation of the winding's input impedance in the frequency-domain. Results obtained show that the input impedance critically depends not only on the number of layers of the winding but also, and, more importantly, on the frequency, where resonance phenomena play a key role. Frequency-domain analysis is complemented with simulation results in the time-domain that clearly illustrate how critical and sensitive the system response can be under minute changes of the winding's excitation current. Copyright © 2007 John Wiley & Sons, Ltd. [source] Design and implementation of a new neural network-based high speed distance relayEUROPEAN TRANSACTIONS ON ELECTRICAL POWER, Issue 4 2008M. Sanaye-Pasand Abstract This paper presents a new neural network-based transmission line distance protection module. The proposed module uses samples of voltage and current signals to learn the hidden relationship existing in the input patterns. Using a power system model, simulation studies are preformed and influence of changing system parameters such as fault resistance and power flow direction is studied. The proposed neural network has also been implemented on a digital signal processor (DSP) board and its behavior is investigated using suitable developed hardware. Details of the implementation and experimental studies are given in the paper. Performance studies results show that the proposed algorithm is able to distinguish various transmission line faults rapidly and correctly. It shows that the proposed network is fast, reliable, and accurate. Copyright © 2007 John Wiley & Sons, Ltd. [source] Dynamic performance analysis of novel unified power flow controller with computer simulation and scaled-model experimentEUROPEAN TRANSACTIONS ON ELECTRICAL POWER, Issue 3 2008Byung M. Han Abstract This paper describes dynamic performance analysis of Unified Power Flow Controller (UPFC) composed of cascaded H-bridge and single-phase multi-winding transformers for isolation. The operational characteristic was analyzed through simulations with PSCAD/EMTDC, and experimental works with a scaled model. The UPFC proposed in this paper can be directly connected to the transmission line without series injection transformers. It has flexibility to expand the operation voltage by increasing the number of H-bridges. Copyright © 2007 John Wiley & Sons, Ltd. [source] Mitigation of the produced voltages in AC overhead power-lines/pipelines parallelism during power frequency and lightning conditionsEUROPEAN TRANSACTIONS ON ELECTRICAL POWER, Issue 4 2005I. A. Metwally Abstract This paper presents a theoretical simulation for a pipeline running in parallel to AC overhead power lines using the ,CONCEPT II' package. This package is based on the method of moment combined with a transmission-line model. A 1,km long, 132,kV, three-phase, double-circuit transmission line, and a 2,km long, 40,cm diameter, 1,m high above-ground pipeline are modelled. Extra shielding wires (ESW) under the phase conductors are investigated. Produced voltages in the pipeline are computed under steady-state power frequency (50,Hz) as well as under direct and indirect lightning strikes to the power line. Different current waveforms are simulated to cover the whole range of those of the anticipated lightning. Under lightning strikes, the voltages across line insulators are computed, too. The results reveal that the ESW give many advantages; namely, (1) reducing the power-frequency electric and magnetic fields at the ground level to meet the regularity limits, (2) improving the shielding effectiveness during lightning strikes by reducing the insulator voltages, (3) mitigating the induced voltages in any metallic structure near the power lines, e.g., pipelines, and (4) using them as optical ground wires for telecommunication purposes, where the probability of lightning strikes to such ESW is much lower than that for the normally used grounding wire(s) at the tower top. Copyright © 2005 John Wiley & Sons, Ltd. [source] Cable model with frequency dependent parameters calculated by using subconductorsEUROPEAN TRANSACTIONS ON ELECTRICAL POWER, Issue 1 2003L. Hofmann A cable model with frequency dependent parameters in the time domain for the simulation of transients in the short time range is presented. The model is based on the division of the transmission line into m short lossless delay line segments of length ,xk = l/m, which are connected to each other by damping-networks consisting of constant ohmic resistances and by distortion-networks simulating the frequency dependence of the series impedance per unit length. The damping-networks consider ohmic line losses as well as leakage losses by shunt conductances. The distortion-networks are represented by state space equations in the time domain. One advantage of the model in comparison to generally used models is the direct determination of the model parameters from the geometrical dimensions of the line-ground configuration. This model also provides a fast and accurate algorithm. [source] Electromagnetic torque of a synchronous machine during a single out-of-phase reclosingEUROPEAN TRANSACTIONS ON ELECTRICAL POWER, Issue 4 2000A. C. Ammari The adoption of single-pole switching for a radial transmission line which connects large synchronous machines to the power system would submit these machines to repetitive mechanical stress. To evaluate the total mechanical stress, it is first necessary to determine the electromagnetic torque and to evaluate its transient maximum values at reclosing. In this paper, maximum values of the electromagnetic transient torque at single-pole reclosing are first computed using a simplified analytical approach. The analytical results are then validated by numerical simulations and by an experimental test on a laboratory synchronous machine. It will be shown that single-pole reclosing would be, in the worst case, as restricting as three out-of-phase synchronisation. [source] System aspects of 1100 kV AC transmission technologies in JapanIEEJ TRANSACTIONS ON ELECTRICAL AND ELECTRONIC ENGINEERING, Issue 1 2009Eiichi Zaima Senior Member Abstract This paper describes the system aspects of 1100 kV AC transmission technologies with the UHV transmission project in Japan. For realization of technical and economical optimization throughout the design of the transmission line and the substation, solutions for network problems and insulation coordination specific to UHV AC transmission systems were studied in Japan. They include fast multiphase reclosing systems by HSGS (High Speed Grounding Switch) and overvoltage control by the application of surge arresters and circuit breakers with closing/opening resistors. These sophisticated technologies provide highly reliable and economical 1100 kV substations and transmission lines. Copyright © 2009 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc. [source] A transmission line modelling (TLM) method for steady-state convection,diffusionINTERNATIONAL JOURNAL FOR NUMERICAL METHODS IN ENGINEERING, Issue 9 2007Alan Kennedy Abstract This paper describes how the lossy transmission line modelling (TLM) method for diffusion can be extended to solve the convection,diffusion equation. The method is based on the correspondence between the convection,diffusion equation and the equation for the voltage on a lossy transmission line with properties varying exponentially over space. It is unconditionally stable and converges rapidly to highly accurate steady-state solutions for a wide range of Peclet numbers from low to high. The method solves the non-conservative form of the convection,diffusion equation but it is shown how it can be modified to solve the conservative form. Under transient conditions the TLM scheme exhibits significant numerical diffusion and numerical convection leading to poor accuracy, but both these errors go to zero as a solution approaches steady state. Copyright © 2007 John Wiley & Sons, Ltd. [source] A transmission line model for metallic carbon nanotube interconnectsINTERNATIONAL JOURNAL OF CIRCUIT THEORY AND APPLICATIONS, Issue 1 2008A. Maffucci Abstract A transmission line (TL) model describing the propagation of electric signals along metallic single wall carbon nanotube (CNT) interconnects is derived in a simple and self-consistent way within the framework of the classical electrodynamics. The conduction electrons of metallic CNTs are modelled as an infinitesimally thin cylindrical layer of a compressible charged fluid with friction, moving in a uniform neutralizing background. The dynamic of the electron fluid is studied by means of the linearized hydrodynamic equations with the pressure assumed to be that of a degenerate spin-½ ideal Fermi gas. Transport effects due to the electron inertia, quantum fluid pressure and electron scattering with the ion lattice significantly influence the propagation features of the TL. The simplicity and robustness of the fluid model make the derivation of the TL equations more straightforward than other derivations recently proposed in the literature and provide simple and clear definitions of the per unit length (p.u.l.) TL parameters. In particular, this approach has provided a new circuit model that can be used effectively in the analysis of networks composed of CNT transmission lines and lumped elements. The differences and similarities between the proposed model and those given in the literature are highlighted. Copyright © 2006 John Wiley & Sons, Ltd. [source] High-frequency transmission through metallic single-walled carbon nanotube interconnectsINTERNATIONAL JOURNAL OF NUMERICAL MODELLING: ELECTRONIC NETWORKS, DEVICES AND FIELDS, Issue 5 2009M. S. Tahvili Abstract In this paper, high-frequency transmission behavior of metallic single-walled carbon nanotube (SWCNT) interconnects is investigated. The SWCNT is assumed to be lying over a doped Si substrate, in a transmission line configuration. A hybrid approach, combining quantum theory with classical distributed-element model is utilized to predict dynamical performance of the metallic SWCNT as a nano transmission line. Several aspects of high-frequency performance of such interconnect, including the effect of SWCNT length and substrate doping level, is studied. A novel modification is proposed to take damping mechanisms effect caused by the imperfect conductance of substrate into account. The results show that the impact of limited conductivity of the substrate determines the dynamical behavior of short SWCNTs; whereas in case of long nanotubes, damping effects that arise from scattering mechanisms are dominant. Copyright © 2009 John Wiley & Sons, Ltd. [source] Transition probability coefficients and the stability of finite difference schemes for the diffusion and Telegraphers' equationsINTERNATIONAL JOURNAL OF NUMERICAL MODELLING: ELECTRONIC NETWORKS, DEVICES AND FIELDS, Issue 3 2002Michal J. Malachowski A probabilistic approach has been used to analyse the stability of the various finite difference formulations for propagation of signals on a lossy transmission line. If the sign of certain transition probabilities is negative, then the algorithm is found to be unstable. We extend the concept to consider the effects of space and time discretizations on the signs of the coefficients in a probabilistic finite difference implementation of the Telegraphers' equation and draw parallels with the transmission line matrix (TLM) technique. Copyright © 2002 John Wiley & Sons, Ltd. [source] A three-dimensional current cell (TCC) for the TLM methodINTERNATIONAL JOURNAL OF NUMERICAL MODELLING: ELECTRONIC NETWORKS, DEVICES AND FIELDS, Issue 2 2001F. Mauro Faccioni This paper presents a new design for a three-dimensional cell for the TLM method, and its application in the resonator analysis. The new proposed cell is based on ,, - type' transmission line, and it uses incident and reflected currents. A condensed scattering matrix is developed. The computational results are compared with the analytical results and with TLM-SCN (symmetrical condensed node) computational results. Copyright © 2001 John Wiley & Sons, Ltd. [source] Modeling and synthesis of the interdigital/stub composite right/left-handed artificial transmission lineINTERNATIONAL JOURNAL OF RF AND MICROWAVE COMPUTER-AIDED ENGINEERING, Issue 5 2009R. Siragusa Abstract An efficient design procedure, including both analysis and synthesis, is proposed for Composite Right/Left Handed (CRLH) interdigital/stub structures. Improved models are developed for both the interdigital capacitor and the shorted stub inductor including its ground via hole. Subsequent optimal formulas are recommended to model these components with their parasitic effects. The models and formulas are verified by both full-wave and experimental results. A CAD program with a friendly GUI, available online, is provided and its operation is described in details. This program allows a very fast design of the CRLH structure, and its synthesis parameters are proven very accurate without any full-wave optimization. © 2009 Wiley Periodicals, Inc. Int J RF and Microwave CAE, 2009. [source] From lumped-element circuits to monolithic integrated circuits: A contribution to RF and microwave mixer designINTERNATIONAL JOURNAL OF RF AND MICROWAVE COMPUTER-AIDED ENGINEERING, Issue 4 2005Peter Waldow Abstract This article deals with the mixer design for UHF-, microwave- and millimeter-wave applications. Thereby, several aspects such as the chosen technology (lumped elements, hybrid- or monolithic integration) and the applied transmission line (printed circuits, strip-, slot- or coplanar line) are considered. During the course of this contribution, the authors point out the developments in mixer design from lumped-element circuits to monolithic integrated circuits on the example of research activities in Duisburg and Kamp-Lintfort, Germany. The results of these scientific investigations, regarding both the theoretical and experimental aspects, show the feasibility of the proposed techniques. © 2005 Wiley Periodicals, Inc. Int J RF and Microwave CAE, 2005. [source] Distributed MEMS transmission lines for tunable filter applicationsINTERNATIONAL JOURNAL OF RF AND MICROWAVE COMPUTER-AIDED ENGINEERING, Issue 5 2001Yu Liu Abstract This paper describes the design and fabrication of a distributed MEMS transmission line (DMTL), used to realize a transmission-line with a voltage-variable electrical length for microwave circuits. The DMTL is a coplanar waveguide periodically loaded with continuously-variable MEMS capacitors. A tunable bandpass filter was designed and fabricated on 700 ,m thick glass substrates using three capacitively coupled DMTL sections as variable shunt resonators. The measured results demonstrate a 3.8% tuning range at 20 GHz with 3.6 dB minimum insertion loss. Issues for future improvement are discussed. © 2001 John Wiley & Sons, Inc. Int J RF and Microwave CAE 11: 254,260, 2001. [source] Transmission line maintenance robots capable of crossing obstacles: State-of-the-art review and challenges aheadJOURNAL OF FIELD ROBOTICS (FORMERLY JOURNAL OF ROBOTIC SYSTEMS), Issue 5 2009Kristopher Toussaint Power line inspection and maintenance already benefit from developments in mobile robotics. This paper presents a comprehensive review of the state of the art. It focuses on mobile robots designed to cross obstacles found on a typical transmission line while using the conductor as support for traveling. Promising areas of research and development as well as challenges that remain to be solved are discussed with a view to developing fully autonomous technologies. Maintenance tasks, including inspection and repairs, are identified as high-value applications in transmission live-line work. Conclusions are drawn from experience, and the future of mobile robotics applied to transmission line maintenance is discussed. © 2009 Wiley Periodicals, Inc. [source] Dynamic Analysis of Tendon Driven Robotic MechanismsJOURNAL OF FIELD ROBOTICS (FORMERLY JOURNAL OF ROBOTIC SYSTEMS), Issue 5 2003Jyh-Jone Lee In this paper, a systematic methodology for the dynamic analysis of tendon-driven robotic mechanisms is presented. The approach utilizes the recursive Newton-Euler equations to compute the kinematic and dynamic equations of all links that locate on the transmission line of a tendon-driven robotic mechanism. The inertias of the intermediate links in the mechanism are taken into account. It is shown that the dynamic equations can be established in a recursive manner from the end-effector links toward the proximal links and can be solved at the proximal end without the need of solving the simultaneous system equations. The joint reaction forces and the tension in each segment of tendon can be also obtained. The methodology can be applied to both endless and open-ended tendon drives. © 2003 Wiley Periodicals, Inc. [source] Employing complementary split-ring resonators for the wide stopband microstrip lowpass filter designMICROWAVE AND OPTICAL TECHNOLOGY LETTERS, Issue 11 2010Ching-Wen Tang Abstract In this article, a novel microstrip lowpass filter with complementary split-ring resonators (CSRRs) is presented. By properly controlling the width of the transmission line and rotating the angle of CSRRs, a wide stopband with sufficient rejection level can be achieved. The full-wave electromagnetic simulator IE3D is used; moreover, the prototypical microstrip lowpass filter is fabricated and measured. Simulated results and experimental responses are compared; moreover, the match between simulation and measurement validates the proposed structure. © 2010 Wiley Periodicals, Inc. Microwave Opt Technol Lett 52:2592,2594, 2010; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.25541 [source] Broadband Wilkinson balun using pure left-handed transmission lineMICROWAVE AND OPTICAL TECHNOLOGY LETTERS, Issue 7 2010Young-Ho Ryu Abstract Utilizing the opposite phase shift property of a microstrip line (MSL) and a pure left-handed transmission line (PLH TL), the broadband Wilkinson balun is designed. The PLH TL without a right-handed (RH) branch is designed using effectively negative elements obtained by a cross connection of vias to ground. The PLH TL gives inherently phase-advanced response properties because of negative phase velocity, whereas a conventional MSL has a phase-lag response. The property of a broadband left-handed branch of a PLH TL applies to the implementation of broadband balun. The proposed balun has a good return loss, a good isolation between output ports, an equal-power division, and a 180° ± 10° phase difference in a wide fractional bandwidth of ,71%. Furthermore, the wideband balun that has the fractional bandwidth of 107.8% is theoretically designed with the modified PLH TL having four unit cells. © 2010 Wiley Periodicals, Inc. Microwave Opt Technol Lett 52: 1665,1668, 2010; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.25242 [source] A compact multiband antenna based on CRLH-TL ZOR for wireless mobile systemMICROWAVE AND OPTICAL TECHNOLOGY LETTERS, Issue 12 2009Jeong Keun Ji Abstract A compact multiband antenna using a composite right/left-handed transmission line (CRLH-TL) zeroth-order resonator (ZOR) for global system for mobile communications (GSM900/1800/1900, 880-960/1710-1880/1850-1990 MHz), wideband code division multiple access (WCDMA, 1920,2170 MHz), and wireless broadband (WiBro, 2.3,2.4 GHz) operations is presented. The proposed antenna having a total volume of 35 mm × 5 mm × 3 mm comprises a lower band ZOR antenna part and an upper band ZOR antenna part. The zeroth-order resonant properties are described and analyzed using dispersion diagrams based on the CRLH-TL ZOR theory and the full-wave simulation. The radiation patterns are the same as the omnidirectional characteristics and the maximum gains are 1.64, 2.47, and 3.32 dBi at 0.92, 1.88, and 2.2 GHz, respectively. © 2009 Wiley Periodicals, Inc. Microwave Opt Technol Lett 51: 2852,2855, 2009; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.24799 [source] Signal reshaping in a transmission line with negative group velocity behaviorMICROWAVE AND OPTICAL TECHNOLOGY LETTERS, Issue 11 2009Giuseppina Monti Abstract An analytical, numerical, and experimental study of the dispersion of a transmission line with negative group velocity is presented. The propagation of amplitude-modulated signals in the transmission line anomalous dispersion region is specifically analyzed, investigating the effects on the pulse reshaping of the system losses. © 2009 Wiley Periodicals, Inc. Microwave Opt Technol Lett 51: 2627,2633, 2009; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.24688 [source] To compact ring branch-line coupler using nonuniform transmission lineMICROWAVE AND OPTICAL TECHNOLOGY LETTERS, Issue 11 2009F. Hosseini Abstract A compact ring Branch-Line Coupler (BLC) with size reduction of about 50%(in circuit area) of conventional BLCs at frequency 2 GHz is introduced. The coupler is designed by using nonuniform transmission lines (NTL) instead of Uniform Transmission Lines in each arm. The normalized width w (z)/h function of the NTLs is expanded in a truncated Fourier series. The reduced size couplers are potential building blocks for the growing wireless communication markets. © 2009 Wiley Periodicals, Inc. Microwave Opt Technol Lett 51: 2679,2682, 2009; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.24703 [source] Composite right/left-handed transmission line based on Koch fractal shape slot in the ground and UWB filter applicationMICROWAVE AND OPTICAL TECHNOLOGY LETTERS, Issue 9 2009Jian An Abstract A novel composite right/left-handed transmission line is presented which is synthesized by etching Koch fractal shape slot in the ground plane and series capacitive gap in the conductor strip. Unlike the structures loaded with complementary split ring resonators, the proposed structure can operate at very wideband and is used to design an ultra-wideband (UWB) filter. The UWB filter is fabricated and tested. The relative bandwidth of the ,10 dB return loss is 128% and the insertion loss is larger than ,1.5 dB except at high frequencies. The equivalent circuit model of the proposed structure is presented and the electrical parameters are also extracted. The circuit model results are compared with the simulation and measurement results which verify that not only the extracted parameters are exact but also the equivalent circuit model is reasonable. © 2009 Wiley Periodicals, Inc. Microwave Opt Technol Lett 51: 2160,2163, 2009; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.24553 [source] Ultra-wideband bandpass filter using simplified left-handed transmission line structureMICROWAVE AND OPTICAL TECHNOLOGY LETTERS, Issue 11 2008Wenjia Han Abstract A novel ultra-wideband bandpass filter has been proposed based on a simplified left-handed transmission line (LH-TL) structure. The main design procedure is to define and realize the LH-TL unit cell according to the desired pass band. The filter has been realized in theory, verified by both full-wave electromagnetic simulation and microwave circuit simulation, and confirmed by the measurement with a return loss higher than 12 dB, and the group delay about 0.25 ns over the central band with variation of 0.2 ns. © 2008 Wiley Periodicals, Inc. Microwave Opt Technol Lett 50: 2758,2762, 2008; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.23789 [source] A novel implementation of composite right/left-handed transmission lineMICROWAVE AND OPTICAL TECHNOLOGY LETTERS, Issue 9 2008Jia-Jun Ma Abstract A novel composite right/left-handed transmission line is presented in this letter. The proposed CRLH structure can be considered as a CPW version composed with a pair of parallel spiral interdigital and a conjunctive stub. The spiral interdigital enlarges the series capacitance, and the adjustable conjunctive stub increases the shunt inductance. So, this structure is simpler and more compact compared with the conventional one. Its left-handed material property is confirmed by simulation and measurement results. © 2008 Wiley Periodicals, Inc. Microwave Opt Technol Lett 50: 2379,2381, 2008; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.23672 [source] A positive/negative refractive index coplanar transmission line in CMOS for controlled insertion phaseMICROWAVE AND OPTICAL TECHNOLOGY LETTERS, Issue 8 2008Podilchak Symon Abstract A positive/negative refractive index coplanar transmission line is presented and used for phase control in CMOS circuits. Good performance has been achieved. © 2008 Wiley Periodicals, Inc. Microwave Opt Technol Lett 50: 2227,2230, 2008; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.23622 [source] Planar broadband millimeter-wave antenna based on open loop ring resonatorsMICROWAVE AND OPTICAL TECHNOLOGY LETTERS, Issue 2 2008Guo-Min Yang Abstract A compact planar broadband millimeter-wave antenna is presented in this article. The proposed millimeter-wave (MM-W) antenna is realized by connecting two pairs of open loop ring resonators (OLRRs). A tapered transmission line is adopted to improve the return loss performance in the required band. Combining these two structures, a new broadband MM-W antenna is obtained. The measured results show that the proposed MM-W antenna has a wide bandwidth from 26 to 40 GHz, and all the return losses are less than ,15 dB in this band combined with excellent radiation characteristics. © 2007 Wiley Periodicals, Inc. Microwave Opt Technol Lett 50: 324,328, 2008; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.23081 [source] Ultra wideband filter design based on composite right-/left-handed transmission lineMICROWAVE AND OPTICAL TECHNOLOGY LETTERS, Issue 10 2007Bin Li Abstract A novel design method of ultra wideband filter based on the composite right-/left-handed transmission line theory is presented in this article. Defected ground structure and microstrip interdigital capacitor are introduced to satisfy the necessity of ultra wideband (UWB) filter. A four-cell composite right/left-handed UWB filter is fabricated and measured. © 2007 Wiley Periodicals, Inc. Microwave Opt Technol Lett 49: 2379,2381, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.22733 [source] | ||||||||||||||||||||||||||||