scholarly journals An enhancement of instruments for solution of general transmission line equations with method of lines, impedance-/admittance and field transformation in combination with finite differences

Author(s):  
Waldemar Spiller

Abstract The Method of Lines (MoL) in combination with impedance-/admittance and field transformation (IAFT) is used to analyze electromagnetic waves. The used cases are wave-guiding structures in microwave technology and optics. The core of the theory is the solution of generalized transmission line equations (GTL). In the case of complex structures, a combination with finite differences (FD) can be used. The quality of this solution essentially depends on the effectiveness of the used interpolation of the differences. The individual steps of the FD are permanently linked to the steps of the fully vectorial impedance-/admittance and/or field transformation, so standard libraries cannot be used. Two approaches based on the linear and quadratic interpolation were built into the impedance-/admittance and field transformation in the past. However, the degree of improvement due to one or another kind of interpolation depends on the concrete behavior of the solution sought. In the case of complex structures, choosing the appropriate type of interpolation should be an effective aid. In this paper, an extension of the family of built-in methods is proposed - with the possibility of being able to build any known numerical method from the class of one-step or multi-step methods into the GTL solution. These can be higher-order methods, including fast explicit methods, or particularly stable implicit methods. The transmission matrices for the impedance-/admittance and field transformation serve as the building site. To illustrate the procedure, some different methods are integrated into the GTL solution. The accuracy of the solutions is tested on selected complex structures and compared with each other and with existing solutions. It is shown that the optimal choice of method and the quality of the solution can depend on concrete structures. Keywords: Method of lines, generalized transmission line equations, impedance/admittance transformation, waveguide structures, finite differences, finite differences with second order accuracy.

2015 ◽  
Vol 105 (05) ◽  
pp. 263-268
Author(s):  
P. H. Nebeling

Das dynamische Verhalten von Werkzeugmaschinen ist für die Stabilität während der Bearbeitung sowie die Qualität der erzeugten Werkstücke von besonderer Bedeutung. Ein Einflussfaktor darauf ist die Dämpfung. Im Bereich der Maschinengestelle kommen seit langer Zeit unterschiedliche Materialien zum Einsatz. In diesem Fachbeitrag werden die Dämpfungskennwerte unterschiedlicher Gestellwerkstoffe an geometrisch gleichen Proben vergleichend gegenübergestellt. Als weitere Kenngröße wurde die Lage der (1. Biege-) Eigenfrequenz als Maß für die massebezogene dynamische Steifigkeit verwendet. Die Effekte beim Übergang von einfachen Bauteilen zu komplexen Strukturen runden den Fachartikel ab.   The dynamic behaviour of machine tools is of great importance for stability and quality of the machined work pieces. One influencing factor in this area is damping. In the field of machine bases different materials have been use since long time. In this article the damping values of different materials with equal geometric properties are compared. As further parameter the first bending Eigenfrequency as dimension for mass related stiffness is use. The transition from simple components to complex structures is touched at the end of the paper.


Author(s):  
M. Amreev ◽  
R. Safin ◽  
T. Pavlova ◽  
E. Temyrkanova ◽  
Y. Garmashova

The use of video surveillance systems is used in the areas of security, law and order, in the territories of protected objects, in monitoring the movement of road vehicles and in other areas. The main disadvantage of a video surveillance system is its susceptibility to weather influences (rain, fog, snowfall, etc.), which degrades the quality of the video system by reducing the signal level. Therefore, the urgency of finding new ways and possibilities to improve the quality of video signals is one of the priority areas of signal processing. The main task of this work was to determine the main parameters, simulate the transmission line and amplifier, and select the schematic diagram of the transmitting and receiving path with the voltage and current ratings. Both the receiver and the cable video transmitter have different means of adjusting to different transmission line lengths. The signal at the output of each receiver should be in the range from 0.9 to 1.1 V, and the spread of the total ohmic resistance of the wires of the video transmission line at the input of the receiver should be no more than 2 – 3%. Based on these parameters, the equipment is configured for transmitting video over the channel. The magnitude of the mismatch is regulated by potentiometers, which allow smooth adjustment of the video transmission equipment [1]. As a rule, video transmission over the channel is carried out at a distance of 50 to 1500 m. If it is necessary to transmit video at distances less than 50 m, additional resistances are connected in series at the receiver input so that the total line resistance is 30 - 50 Ohm [1].


2017 ◽  
Vol 6 (2) ◽  
Author(s):  
Peng Wang

The most critical component of a wind power plant is the transmission line, which carries two key tasks – the transpor-tation and distribution of electricity. The transmission line is also responsible for the various substations, wind power stations to contact to its safe and smooth operation. As the competition order of wind power projects is more chaotic, the quality of the project cannot be supervised and controlled by the whole process. The quality control of the project is not up to standard, and the overall quality of the transmission line will be affected. This paper focuses on two aspects of the elaboration, one is the wind turbine transmission line project common quality problems; the other is how to build wind power plant transmission line quality assurance system.


2015 ◽  
Vol 770 ◽  
pp. 739-743 ◽  
Author(s):  
A.S. Yuanyushkin ◽  
D.V. Lobanov ◽  
D.A. Rychkov

The key task of the tool manufacturing is to create or to choose such a type of tool, which would permit to provide high processing efficiency, the best tool`s workability and the quality of the machined surfaces with minimum expenses and resources. The optimal choice of the constructive tool modifications from a variety of options takes much time required for the preparation of the tool to work. To solve this problem, we have developed software that allows you to create, organize and carry out a comparative analysis of structural instruments in order to identify rational option for the given conditions of production. Ordering and selection of a rational design of the instrument is carried out in accordance with established procedures of modeling and comparative analysis of design solutions. Application software can reduce design time technological process by 80...90%, and get a substantial annual economic effect.


2019 ◽  
Vol 2019 ◽  
pp. 1-11 ◽  
Author(s):  
Francisco Mederos-Henry ◽  
Sophie Hermans ◽  
Isabelle Huynen

This paper presents a novel approach for the characterization of microwave properties of carbon-based nanopowders, decorated or not with magnetic nanoparticles. Their microwave parameters, dielectric constant, electrical conductivity, and complex magnetic permeability are extracted from measurements performed using a single transmission line acting as a test cell. Two geometries of transmission line were tested, and successful results were obtained with each one of them. The measurement results are assessed by a phenomenological model enabling to fit the measurement of the dielectric constant and conductivity, providing an insight on the compacity quality of the powder sample. Also, the extraction of the permeability is validated by the detection of a ferromagnetic resonance showing a linear dependence on external DC magnetic field.


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