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Mediterranean Conference on Control and Automation (MED)

作者： Shifali Kalra M. Nabi Indian Institute of Technology Delhi New Delhi India

ISBN: (数字)9781728157429

ISBN: (纸本)9781728157436

Model order reduction of input affine nonlinear systems via trajectory piecewise linear approximation is a well known practice. This method along with its variants is known to generate efficient and accurate reduced models of large order nonlinear systems. The selection of the order of the reduced model is however a heuristic choice that comes with experience. There is no concrete measure of an optimum selection of the reduced order that would lead to approximations with high accuracy and least computational cost. This paper provides a study of few variants of trajectory piecewise linear method and effect of the choice of reduced order on the accuracy of the approximations and the computational cost. The results have been studied on a nonlinear transmission line circuit. This study provides a performance analysis that exhibits a range of acceptable values of reduced order that may be preferred for generating accurate trajectory piecewise approximations of circuits similar to that discussed in this paper.

关键词： Integrated circuit modeling Trajectory Computational modeling Nonlinear systems distributed parameter circuits Computational efficiency Simulation

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Amplifier Innovations for Improvement of Rotary Traveling Wave Oscillators

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IEEE TRANSACTIONS ON circuits AND SYSTEMS I-REGULAR PAPERS 2018年第2期65卷 522-530页

作者： Martchovsky, Andrey Pedrotti, Kenneth D. Analog Devices Co San Jose CA 95134 USA Univ Calif Santa Cruz Dept Elect Engn Sch Engn Santa Cruz CA 95064 USA

Rotary traveling wave oscillators use a transmission line connected as a closed loop as their resonant element. This allows the use of spatial degrees of freedom, not available in typical L-C oscillator topologies, in the design of the amplifier needed to sustain the oscillating mode. Here, we present a novel amplifier design that takes advantage of this extra degree of freedom to improve performance of RTWOs in two ways. If no precautions are taken then the oscillation can start in either a clockwise or anti-clockwise direction. The Phased amplifier, introduced here, forces one direction of oscillation with a measured probability of reverse oscillation of less than 0.43 ppm with a confidence level of 99%. No reverse oscillations were observed in 107 trials. This is accomplished by adding additional phase-dependent degeneration transistors and phase shifting the various amplifier inputs by taking them from different locations on the transmission line. Additionally, this amplifier design reduces the phase noise by reducing the amplifier noise during the time that the oscillator is most sensitive to phase perturbation, resulting in a 1.2-dB reduction in phase noise measured 1 MHz from the peak and a 2.9-dB improvement in the figure of merit.

关键词： CMOS integrated circuits distributed parameter circuits oscillators phase noise

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On Nonuniform Transient Electromagnetic Field Coupling to Overhead Transmission Lines

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IEEE TRANSACTIONS ON ANTENNAS AND PROPAGATION 2018年第6期66卷 3087-3096页

作者： Guo, Jun Xie, Yan-Zhao Rachidi, Farhad Li, Ke-Jie Wang, Shao-Fei Xi An Jiao Tong Univ State Key Lab Elect Insulat & Power Equipment Natl Ctr Int Res Transient Electromagnet & Applic Sch Elect Engn Xian 710049 Peoples R China Ecole Polytech Fed Lausanne Electromagnet Compatibil Grp CH-1015 Lausanne Switzerland

Transient electromagnetic fields can couple to overhead power transmission and distribution lines, causing damage to the connected equipment. In real cases, incident electromagnetic fields exhibit different spatial and temporal waveform distributions along the line. Normally, to ensure the accuracy of the simulation results, a large number of observation points are needed along the line, which is difficult to obtain. This paper proposes a new approach to address this problem. The proposed approach is based on Agrawal et al.'s coupling model, in which the amplitude and phase distributions of the horizontal exciting electric field along the line are, respectively, represented by the Fourier series and polynomial functions in the frequency domain using two kinds of least squares methods. As a result, the source terms along the line can be accurately evaluated starting from a limited number of observation points. The proposed approach has been validated experimentally.

关键词： Curve fitting distributed parameter circuits least squares methods transient response transmission line theory

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Controlling Nonreciprocity Using Enhanced Brillouin Scattering

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IEEE TRANSACTIONS ON ANTENNAS AND PROPAGATION 2018年第7期66卷 3500-3511页

作者： Elnaggar, Sameh Y. Milford, Gregory N. Univ New South Wales Sch Engn & Informat Technol Canberra ACT 2600 Australia

The properties of space-time modulated media operating in the subsonic regime are discussed based on rigorous Bloch-Floquet theory. A geometrical description in the frequency-wavenumber plane is developed to provide insight into the possible interactions and their nature. It is shown that the secular equation has a singularity, which results in a weak/passive second harmonic generation process. In addition, bandgaps arising from the strong/active parametric interaction between an incident wave and its space-time harmonic result in an inelastic Brillouinlike scattering process. Hence, when the incident frequency is inside a forward (backward) bandgap, a Stokes' (anti-Stokes') scattered wave bounces back to the source. Although the forward and backward bandgaps do not generally occur at the same frequency bands, the insertion loss and gap width are equal. Requirement that both gaps do not overlap enforces a lower bound on the modulation speed. It is shown that although an increase in the modulation index is desirable, as it enhances the nonreciprocal behavior, it also limits the range of possible modulation speeds. It is shown that an alternative way to enhance the nonreciprocity, whenever the modulation index is constrained, is through the reduction of the modulation wavelength. The effective complex refractive index is calculated over a wide frequency range. It is shown that peaks appear in the extinction coefficient, indicating scattering to Stokes' and anti-Stokes' waves. Finally, a comprehensive numerical analysis based on the finite-difference time-domain method is developed to verify and demonstrate the intriguing properties of space-time modulated media.

关键词： Active circuits dispersion distributed parameter circuits electromagnetic propagation finite difference methods metamaterials microwave photonics multiwave mixing optical harmonic generation periodic structures time-varying systems

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Analysis and Design of a 30-to 220-GHz Balanced Cascaded Single-Stage distributed Amplifier in 130-nm SiGe BiCMOS

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IEEE JOURNAL OF SOLID-STATE circuits 2018年第5期53卷 1457-1467页

作者： Testa, Paolo Valerio Carta, Corrado Joerges, Udo Ellinger, Frank Tech Univ Dresden Chair Circuit Design & Network Theory CCN D-01187 Dresden Germany

This paper describes a novel distributed amplifier (DA) architecture for ultra-wide band of operation at millimeter-wave frequency. The DA consists of two cascaded single-stage DAs (CSSDAs) embedded in a balanced architecture. The implemented design retains the benefits of CSSDAs in terms of high maximum frequency, broad band of operation, and compact area, while significantly improving the amplifier input and output matching and its linearity with the balanced architecture, which are the major issues of this class of circuits. The small-signal analysis is provided in detail and explains the nature of the poor output matching typical of this class of DAs. Furthermore, the CSSDA gain is calculated as function of frequency and circuit parameters, extending available literature results, and providing direct design guidelines with a compact formula. Experimental validation is demonstrated with the fabrication of a circuit prototype in a 130-nm SiGe BiCMOS process. The circuit is able to provide an average of 16-dB gain over the frequency band 30-220 GHz, with input-and output-return losses above 10 dB, and a maximum measured output-referred 1-dB compression point of 4.5 dBm. To the best knowledge of the authors, the measured matching and linearity are the best reported for CSSDAs.

关键词： BICMOS integrated circuits distributed amplifier (DA) distributed parameter circuits millimetre-wave integrated circuits ultra-wideband technology

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A Semi-Analytical Method to Evaluate Lightning-Induced Overvoltages on Overhead Lines Using the Matrix Pencil Method

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IEEE TRANSACTIONS ON POWER DELIVERY 2018年第6期33卷 2837-2848页

作者： Guo, Jun Xie, Yan-Zhao Rachidi, Farhad Xi An Jiao Tong Univ Natl Ctr Int Res Transient Electromagnet & Applic State Key Lab Elect Insulat & Power Equipment Sch Elect Engn Xian 710049 Peoples R China

Lightning electromagnetic fields can couple to overhead power transmission and distribution lines, causing serious effects to the power system. Lightning electromagnetic fields that couple to overhead lines have a nonuniform distribution along the line conductors. Therefore, to ensure the accuracy of the numerical calculation results, a large number of discretization points are needed along the line, which might dramatically increase the computation time since the evaluation of lightning electromagnetic fields in the presence of a lossy soil involves, in general, Sommerfeld integrals, or, even in the case of a perfectly conducting ground, numerical integration along the channel. This paper proposes a new approach to address this problem. The proposed approach is based on the Agrawal et al. coupling model, in which the horizontal lightning electric field along the line is represented by the complex exponential functions in the frequency domain using the matrix pencil method. The method is highly efficient in terms of computation time since the lightning-induced response of the line can be solved semi-analytically. The proposed approach is validated by two different validation examples.

关键词： Lightning electromagnetic field transmission line theory distributed parameter circuits matrix pencil method transient response

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Dimensional Design of Dual Mode Waveguide Multiplexers 18

Dimensional Design of Dual Mode Waveguide Multiplexers

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18th Mediterranean Microwave Symposium (MMS)

作者： Boyacioglu, Gokhan Alicioglu, Bulent Yildirim, Nevzat Aselsan Inc Radar & Elect Warfare Syst Business Sect Ankara Turkey Aselsan Inc Ankara Turkey Middle East Tech Univ Dept Elect & Elect Engn Ankara Turkey

ISBN: (纸本)9781538671320

In this paper, a systematic design procedure is described for manifold type multiplexers formed by the classical circular dual mode waveguide filters. The design procedure starts with cascade synthesis of lumped quadruplet version of the filters with inverter couplings. Then the LC resonators are converted into SC transmission line (SCTL) resonators. The whole circuit is then impedance scaled by inverters at ports for realization of resonators as waveguides with desired cross-sectional dimensions thus forming a quadruplet with four waveguide resonators coupled by inverters. The resonator pairs on source and load side are treated as dual modes of single waveguides reducing the four waveguides into two. Then the in-line inverters are converted into constant reactances for realization as irises. This stage causes electrical lengths of the resonating dual modes to differ. They are equated by introducing proper tuning reactances to complete design of the circuit model of the filter. Several X-band and Ku band manifold type multiplexers are designed and optimized by using the circuit models of the filters. Then field models of the filters and multiplexers are formed on EM simulators and fine tuned for implementation.

关键词： Circular waveguide design methodology distributed parameter circuits dual-mode filters multiplexers equivalent circuits waveguide filters

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Improvement of Transmission Line Circuit on Lossy Substrate with Application on Phase Shifter Design

Improvement of Transmission Line Circuit on Lossy Substrate ...

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International Electrical Engineering Congress (iEECON)

作者： Chatrpol Pakasiri Thitipun Kongchayasukwat College of Advanced Manufacturing Innovation King Mongkut’s Institute of Technology Ladkrabang Bangkok Thailand

Lumped transmission line circuit design on lossy substrate is studied in this paper. Conventional single section lumped transmission line cannot perform well on lossy substrate as its electrical length gets longer. Multi-section transmission lines can be used to improve transmission line properties in this case. Phase shifter circuits are designed with a large electrical length transmission line. By using a multi-section transmission line, the resulting transmission line properties are better than those of single section transmission line.

关键词： Power transmission lines Propagation losses Substrates Phase shifters Impedance distributed parameter circuits

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Compact UWB Unequal Split Wilkinson Power Divider Using Nonuniform Transmission Lines

Compact UWB Unequal Split Wilkinson Power Divider Using Nonu...

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International Conference on Computer, Control, Electrical, and Electronics Engineering (ICCCEEE)

作者： Sahar Saleh Asem Alzoubi Mohammed Bataineh Electronics and Communications Engineering dept Faculty of Engineering Aden University Aden Yemen Telecommunication Engineering dept Hijjwai faculty for Engineering Technology Yarmouk University Irbid Jordan

ISBN: (纸本)9781538641248

This paper presents the design of compact Ultra Wide band (UWB) unequal split Wilkinson Power Divider (WPD) using nonuniform transmission lines (NTLs). Each uniform transmission line (UTL) in the divider is replaced by its equivalent nonuniform transmission line (NTL) with (33.33%) size reduction, so the divider becomes suitable for UWB wireless communication applications in which a good input matching is obtained with a good insertion loss at the output ports. The simulation is carried out using high frequency structure simulator (HFSS) software which is based on the Finite Element Method (FEM).

关键词： Resistors Power dividers distributed parameter circuits Power transmission lines Impedance Reflection coefficient Impedance matching

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New Design Methodology for Multiband Waveguide Filters Based on Multiplexing Techniques

New Design Methodology for Multiband Waveguide Filters Based...

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IEEE-Microwave-Theory-and-Techniques-Society International Microwave Symposium (IMS) / Session on Women in Microwaves (WIM)

作者： Cogollos, Santiago Mico, Pablo Vague, Joaquin Boria, Vicente E. Guglielmi, Marco Univ Politecn Valencia Inst Telecomunicac & Aplicac Multimedia iTEAM Camino Vera S-N E-46022 Valencia Spain

ISBN: (纸本)9781509063604

This paper introduces a new design methododology for multiband waveguide filters based on a manifold approach. The new design algorithm is based on a subtle modification of the well-known multiplexer design algorithm. Transmission zeros, enhancing the overall performance, are also shown to be naturally produced. In addition to theory, the measured performance of a multiband filter is shown indicating very good agreement with the simulated response, thereby fully validating the new design methodology.

关键词： Filtering network synthesis channel bank filters distributed parameter circuits multiplexing optimization

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