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The approximate method of calculating directional characteristics of log-periodic antenna: directional patterns, directivity, and pattern factor is proposed. The analytical expressions are determined, and characteristics of antennas with straight metal dipoles and with in-phase radiators of the same dimensions are calculated. The advantage of using in-phase radiators is demonstrated. It is shown that...
The method of calculating directional characteristics of director antenna: directional patterns, directivity, pattern factor is proposed. The analytical expressions are determined, and characteristics of antennas with metal dipoles, with V-dipoles and with analogous in-phase radiators are calculated. The advantage of in-phase radiators is demonstrated. It is shown that the director antennas with linear...
The study of wave propagation along conductors located at or near a lossy planar interface is of interest in geoelectromagnetics for remote sensing applications as well as in the power engineering field for transmission line analysis. It is important to determine the effect of the interface on the propagation and radiation characteristics of the geometry, especially if it is highly lossy as in the...
In an MMIC (Monolithic Microwave Integrated Circuit), the dominant loss of the structure can be mainly attributed to the finite conductivity of its microstriplines. A typical microstripline as shown in figure 1 is formed by a rectangular strip conductor located on top of a grounded substrate.
Several efficient techniques to reduce the computational cost and memory storage requirements for the calculation of the electrical parameters of 3-D structures are presented in [1]. In this paper, the electrical parameters are employed in the calculation of crosstalk and radiated emissions from traces on printed circuit boards (PCBs). The inclusion of these aspects are very important in the analysis...
The determination of the propagation constants and fields for conductors embedded in a lossy half-space is of interest in low frequency radio transmission, remote sensing applications in geoelectromagnetics, and in the power engineering field for buried cable analysis. It is important to be able to determine the effect of the interface on the propagation and radiation characteristics of the geometry...
Electric characteristics of Aluminum Conductor Steel Reinforced (ACSR) components, aluminum and steel conductivity values, are usually provided by the ACSR manufacturers, but not the steel core permeability. In order to explore how important the steel core permeability is, the paper deals with the impact of this characteristic on ACSR impedance per unit length. For the estimation of this impact, numerous...
Present study considers distribution of currents and magnetic field in frame-type lightning protection systems (LPS). Influence of equipotentialization ring conductor (ERC) connecting vertical down-conductors at the ground level, as recommended by some normative documents, upon current distribution between mentioned conductors and magnetic field (MF) inside structures is numerically simulated. Analysis...
This paper presents an analytical computation method for determining the current distributions in high-current unshielded three-phase busducts of rectangular busbar. This method consists of using an exact formula of self and mutual inductance.
The underground mining environment can affect radio signal propagation in various ways. Understanding these effects is especially critical in evaluating communications systems used during normal mining operations and during mine emergencies. One of these types of communications systems relies on Medium Frequency radio frequencies. This paper presents the simulation and measurement results of recent...
In this paper, we proposed Improved Primary Characteristic Basis Function Method (IP-CBFM). This method enables us to analyze a scattering field in a specific coordinate plane with a high accuracy with small-scale matrix equations. IP-CBF is the combined CBF of Primary and Secondary CBF. By calculating the Radar Cross Section (RCS) of a perfect electric conductor plate, we evaluated the technique...
In this paper we investigate multi-layer tubular conductor for multi-MHz Wireless Power Transfer (WPT) systems high-Q (quality factor) resonators. The conductor layers thickness and current sharing between them are optimized at 13.56 MHz, showing significant reduction in conductor AC resistance (RAC). Capacitive ballast is used as a practical method for current sharing between layers and operation...
In this paper, an analysis method for multiconductor-transmission-line (MTL) systems by applying modal decomposition and Kirchhoff's circuit laws is proposed. By defining the input impedance matrix in each section of the structure, this method can be applied to the cases in which number of conductor changes, or additional terminations are included. Following the flowchart, the modal current as well...
To efficiently optimize antenna parameters, we need to know more physical insight of antenna operating principles. The theory of characteristic modes is one of the best methods to help us penetratingly understand the antenna's operating principles. This paper is devoted to apply the theory of characteristic modes to provide an in-depth physical insight into the behavior of some proposed antennas and...
In the paper, the direct current distribution in the rectangular cross-section strands of stranded conductor, in the case of crimped connection of two identical stranded conductors is studied. The influence of relative contact resistance and of the number of strands in conductor is analyzed. Two configurations are considered: interleaved and superposed strands. The contact resistances between adjacent...
In this paper, the authors perform HF analysis of a thin horizontal conductor fed in its center, and arbitrarily positioned above lossy homogeneous ground of known electrical parameters. The approach is based on the electric-field integral equation method, and formulation of the Hallén's integral equation. This equation is then solved for the current using the point-matching method. The Sommerfeld's...
The current capacity of an overhead contact system (OCS) is a basic design parameter for electric railways. When the OCS current capacity is being calculated, only the influences of the self and mutual impedances of the OCS conductors are considered in the traditional method. A new method for OCS current capacity calculation, which considers the influences of the return circuit, is proposed based...
Folded dipoles are typically used as elements in curtain arrays due to their high input impedance, but under this configuration, the bandwidth of the curtain array in antenna mode is limited. This paper proposes an improved folded dipole based on a branch model, which effectively increases the bandwidth of the input impedance and decreases the VSWR(Voltage Standing-Wave Ratio) by selecting appropriate...
It has been established that a method to determine the current distribution (or at least confirm its uniformity) is required to establish predictable acceleration of the flyer plate. To achieve this, a bespoke sensor array has been developed, termed the MIDOT (a relative Mutual Inductance sensor array). It has been specifically developed as a method of determining the current density distribution...
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