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Covers theoretical and practical aspects related to the behavioral modelling and predistortion of wireless transmitters and power amplifiers. It includes simulation software that enables the users to apply the theory presented in the book. In the first section, the reader is given the general background of nonlinear dynamic systems along with their behavioral modelling from all its aspects. In the second part, a comprehensive compilation of behavioral models formulations and structures is provided including memory polynomial based models, box oriented models such as Hammerstein-based and Wiener-based models, and neural networks-based models. The book will be a valuable resource for design engineers, industrial engineers, applications engineers, postgraduate students, and researchers working on power amplifiers modelling, linearization, and design.

This book covers the principles of modeling and simulation of nonlinear distortion in wireless communication systems with MATLAB simulations and techniques In this book, the author describes the principles of modeling and simulation of nonlinear distortion in single and multichannel wireless communication systems using both deterministic and.

A rigorous examination and analysis were conducted on a fault incident involving an SF6-insulated current transformer. The investigation revealed an intrinsic defect in the basin-type insulator within the current transformer, leading to a discharge pathway formation from the shell base flange to the secondary lead shielding tube. To further analyze the insulation characteristics of basin-type insulator, a three-dimensional simulation model of current transformers was established using simulation software to study the electric field distribution law of basin-type insulators with pores, metal impurity pollution, and microcracks. Simulation tests indicated that micro-cracks can result in severe electric field distortion in the basin-type insulator, followed by metal particle pollution, and bubbles cause the least degree of electric field distortion. The findings of this article can serve as a reference for the production of basin-type insulators and the operation, maintenance, and fault analysis of SF6-insulated current transformers.

The insulating properties of polypropylene (PP) film play a very important role in the operating status of direct current (DC) support capacitors. Charging and discharging currents in PP film under high DC electric fields and temperatures correspond to charge transportation and accumulation, which significantly influence the electrical insulating properties of PP. In this paper, we have comprehensively studied the dependence of charging/discharging currents in PP film on time, electric field (150–670 kV/mm), and temperature (40–120 °C). The results showed that the charging current increased by almost an order of magnitude from 150 kV/mm to 670 kV/mm and exhibits a steep increase with temperature above 80 °C. The discharging currents are about 10 times less than the corresponding charging currents. Carrier mobility varies little with the electric field and becomes slightly larger with an increase in temperature. The quantity of the accumulated charges was calculated by the integral of the charging and discharging current differentials and showed a significant increase with the electric field and temperature. The corresponding electric field distortion becomes larger above 80 °C compared to 20–60 °C. Both electric field and temperature have an important effect on PP film and capacitors based on charge transport and accumulation and their electric field distortion. This study is innovative in that it combines the operating status of DC support capacitors with traditional methods to research synthetically charged transport mechanisms of PP film. The findings are meaningful for understanding the insulation failure mechanisms of PP film and capacitors under complex stresses.

The icing of overhead high-voltage transmission lines not only caused accidents such as line dance down pole and flashover, but also lead to abnormal field strength on the line surface and distortion of electric field distribution, which threatens the normal operation of the power system. On 500KV transmission lines, a numerical model of the ice cover conductor considering the dielectric properties of the ice layer was established, considering the influence of the spacer strip. The local spatial electric field distribution inside and on the surface of the ice sheet under different ice cover severity was studied. The numerical calculation results showed that the electric field variation inside the ice sheet was amplified, and the electric field distortion rate in the ice cover case was larger than that in the ice-free case at the spacer strip, and both are larger than 150%. In the crescent-shaped transit ice, the aberration rate at the spacer bar inside the crescent-shaped ice decreases with the extension of the crescent-shaped ice, and the electric field aberration rate at the surface of the icicle in the overhanging transit ice was about 20%. The study showed that ice with different characteristics had a significant effect on the electric field around transmission lines, and the study of high-voltage transmission lines over ice could introduce changes in the electric field.

In response to the typical decay and fracture defects of composite insulators, a three-dimensional electrically and thermally coupled simulation physical model was constructed based on the finite element method, and the local electric field distortion and temperature rise were analyzed. The study confirms that the insulator interface’s axial electric and thermal fields show a U-shaped curve; the interface field strength is the largest. There is an electric field gradient difference between the mandrel and the sheath, and the thermal field is concentrated at the mandrel and the interface. The field strength at the edge of the defect is the largest, the aberrant electric field at the defect shows a sawtooth shape, and the temperature rise is concentrated in the defect area. The degradation is fast in the air gap, the etching hole diameter direction, and the carbonation channel axial direction. The larger the defect volume, the larger the aberration in the electric field and temperature rise. Water vapor air gaps, breakdown holes, and carbonized channels have the most pronounced electric field and temperature changes. The functional relationship between electric field aberration, temperature rise, and defect volume is established. The results provide a basis for the protection of insulator decay-like fracture.

This unique new book is your single resource for all issues related to intermodulation and multi-tone distortion in microwave and wireless circuits. Beginning with an overview of the general concepts of distortion in microwave and wireless devices, it delves into the theory and practical aspects of nonlinear distortion, tools for nonlinear analysis, mathematical representations of wireless circuits and devices, and design methods for minimizing distortion. The book presents the full range of distortion specs to help ensure you select the right telecommunications equipment for your needs. Choose from the full range of design methods for highly linear circuits to optimize linearity in small-signal and high-power amplifiers and mixers. Practical advice on modeling and computer-aided tools guides you toward successful analysis and design. Moreover, the book helps you design other highly-linear circuits and systems related to microwave and wireless communications and it includes the most comprehensive treatment of the application of Volterra methods in the technical literature.

The power system is evolving with the integration of new technologies, including electronic devices and renewable energy sources, which are increasingly used to support new applications, reduce dependence on fossil fuels, and drive system innovation. However, this shift brings a significant drawback: a reduction in power quality (PQ). The literature extensively discusses the impact of poor PQ on electrical assets and explores potential solutions to this new challenge. Building on this foundation, this paper introduces new PQ indices derived from existing metrics and validated on both synthetic and real signals to assess their effectiveness. The aim is to provide researchers and system operators with simple and efficient tools for the clear identification of PQ issues in monitored networks. These new indices are designed to be flexible and independent of acquisition conditions, making them suitable for a wide range of frequencies (e.g., 50 Hz–150 kHz) and applications. After an overview of the PQ landscape, the paper demonstrates the use of these indices on various voltage waveforms, including a case study from a measurement campaign. The promising results indicate that, when combined with existing indices, these new metrics can form a strong foundation for a deeper understanding and more accurate classification of PQ issues in power networks.

Opamps for multi-channel communication systems have strong demands on linearity performance. When these opamps are integrated in deep sub-micron CMOS technologies, the signal-swing has to occupy a large part of the rather low supply voltage to maintain the signal-to-noise-ratio. To obtain opamps with low distortion it is necessary to do a thorough analysis of the nonlinear behaviour of such circuits and this is the main subject of this title.

This paper evaluates an electronic current transformer’s wideband accuracy in the transformation of distorted current harmonics. The tests were performed in the range of frequencies from 50 Hz to 5 kHz. The utmost importance was dedicated to the transformation of the low-order higher harmonics. The novelty of this paper involves the analysis of the self-generation of the third and fifth higher harmonics caused by the nonlinearity of magnetic core magnetization characteristics. Therefore, what is considered new in this investigation is that this phenomenon has a significant influence on values of current errors and phase displacements despite the presence of the operational amplifiers and the Hall sensors in the output circuits. Another important factor to consider is the influence of the RMS value of the primary current and output load of the ECT on wideband accuracy. To show the backgrounds of the performed laboratory studies, we also discuss the operation principles of the ECTs with closed and open feedback loops. The accuracy of the tested ECT deteriorated—as with the inductive CT—by the self-generation phenomenon. This resulted in rapid changes in the values of current errors and phase displacements determined for the low-order higher harmonics.