Transmission Line

2020 ◽  
pp. 43-71
Keyword(s):  
Transmission Line ◽  
Transmission Lines ◽  
Magnetic Energy ◽  
Propagation Constant ◽  
Characteristic Impedance ◽  
Electric Energy ◽  
Electromagnetic Energy ◽  
The Other ◽  
Electrical Characteristics ◽  
Lumped Elements

A transmission line (TL) is simply a medium that is capable of guiding or propagating electromagnetic energy. The transmission line stores the electric (E) and magnetic (M) energies and distributes them in space by alternating them between the two forms. This means that at any point along a TL, energy is stored in a mixture of E and M forms and, for an alternating signal at any point on the TL, converted from one form to the other as time progresses. Transmission line is usually modelled using lumped elements (i.e., inductors for magnetic energy, capacitors for electric energy, and resistors for modelling losses). The electrical characteristics of a TL such as the propagation constant, the attenuation constant, the characteristic impedance, and the distributed circuit parameters can only be determined from the knowledge of the fields surrounding the transmission line. This chapter gives a brief overview of various transmission lines, with more detailed discussions on the microstrip and the SIW.

scholarly journals Applying the Retarded Solutions of Electromagnetic Fields to Transmission Line RLGC Modeling

2017 ◽  
Vol 6 (1) ◽  
pp. 56
Author(s):  
P. Ye ◽  
B. Gore ◽  
P. Huray
Keyword(s):  
Transmission Line ◽  
Transmission Lines ◽  
Analytical Approach ◽  
Propagation Constant ◽  
Unit Length ◽  
Characteristic Impedance ◽  
Simulation Methods ◽  
Arbitrary Length ◽  
Small Segment ◽  
Numerical Simulation Methods

The RLGC model, and its variations, is one of the most common techniques to simulate Transmission Lines. The RLGC model uses circuit network elements consisting of Resistance R, Inductance L, Conductance G and Capacitance C (per unit length) to represent a small segment of the Transmission Line, and then cascades multiple segments to simulate the Transmission Line of arbitrary length. Typically the parameters in RLGC model are extracted from the propagation constant and characteristic impedance of the transmission line, which are found using numerical simulation methods. These resulting RLGC parameters for multi-GHz signaling are usually frequency-dependent. This paper introduces an analytical approach to extract RLGC parameters to simulate transmission line, which results in a different model, the RLGC(p) model.

Transmission Line Theories for the Analysis of Electromagnetic Transients in Coil Windings

2013 ◽  
pp. 1-44
Author(s):  
Akihiro Ametani ◽  
Teruo Ohno
Keyword(s):  
Transmission Line ◽  
Propagation Constant ◽  
Characteristic Impedance ◽  
Electromagnetic Transients ◽  
Distributed Parameter ◽  
System A ◽  
Three Phase ◽  
Distributed Parameter Circuit ◽  
Transformer Winding ◽  
Phase Transmission

The chapter contains the basic theory of a distributed-parameter circuit for a single overhead conductor and for a multi-conductor system, which corresponds to a three-phase transmission line and a transformer winding. Starting from a partial differential equation of a single conductor, solutions of a voltage and a current on the conductor are derived as a function of the distance from the sending end. The characteristics of the voltage and the current are explained, and the propagation constant (attenuation and propagation velocity) and the characteristic impedance are described. For a multi-conductor system, a modal theory is introduced, and it is shown that the multi-conductor system is handled as a combination of independent single conductors. Finally, a modeling method of a coil is explained by applying the theories described in the chapter.

scholarly journals Solving the Complexity Problem in the Electronics Production Process by Reducing the Sensitivity of Transmission Line Characteristics to Their Parameter Variations

Complexity ◽  
2019 ◽  
Vol 2019 ◽  
pp. 1-11 ◽  
Author(s):  
Talgat R. Gazizov ◽  
Indira Ye. Sagiyeva ◽  
Sergey P. Kuksenko
Keyword(s):  
Transmission Line ◽  
Production Process ◽  
Transmission Lines ◽  
Unit Length ◽  
Characteristic Impedance ◽  
Optimal Choice ◽  
Wide Range ◽  
Complexity Problem ◽  
Parameter Variations ◽  
Parameter Values

In this paper we consider the complexity problem in electronics production process. Particularly, we investigate the ways to reduce sensitivity of transmission line characteristics to their parameter variations. The reduction is shown for the per-unit-length delay and characteristic impedance of several modifications of microstrip transmission lines. It can be obtained by means of making an optimal choice of parameter values, enabling proper electric field redistribution in the air and the substrate. To achieve this aim we used an effective simulation technique and software tools. Taken together, for the first time, they have allowed formulating general approach which is relevant to solve a wide range of similar tasks.

scholarly journals Optimal Location of IPFC That Handles Operating Constraints for Reducing Transmission Lines Utilization Levels in Electric Power Grid

2021 ◽  
Vol 6 (2) ◽  
pp. 31-39
Author(s):  
S Adetona ◽  
M Iyayi ◽  
R Salawu
Keyword(s):  
Transmission Line ◽  
Transmission Lines ◽  
Energy Demand ◽  
Reactive Power ◽  
Power Grid ◽  
Electric Energy ◽  
Load Flow ◽  
Optimal Location ◽  
Test Bed ◽  
Operating Constraints

The day-to-day increase in electric energy demand with increasing population and urbanization is causing transmission facilities to transfer load at their upper limits; therefore, the probability of failures of these facilities increases. One of the ways of mitigating failures is by constructing more transmission lines; which would serve as alternatives to reduce the transmission line utilization levels (TLUL). However, there are constraints in adopting this method; therefore, the use of Interline Power Flow Controller (IPFC) has been suggested by many researchers; but very few of these studies proposed the IPFC that has capability of handling operating constraints (IPFCthC) in solving power transmission systems issues. Some of the studies that proposed the IPFCthC use trial and error approach in identifying the optimal location for its injection in multi-buses power grid. Also, some of the studies that proposed the IPFCthC do not employ it to investigate its capability in reducing TLUL. In order to reduce the TSUL in the multi-bus grid, this paper therefore proposes optimal location for the injection of IPFCthC using Transmission Line Performance Index (TLPI) and Transmission Line Reactive Power Loss (TLRPL) in Newton-Raphson Load Flow (NRLF) algorithm. The proposed algorithm was tested on IEEE-30 Test-bed in Matlab environment. The results obtained reveal that the TLUL of each of the transmission lines of the Test-bed that is not connected to PV bus is reduced averagely by 4.00 % each, with the injection of the IPFCthC in an optimally location established by the proposed algorithm.

Highly compact wideband double-section rat-race hybrid with harmonic suppression using series and shunt stepped impedance transmission lines

2016 ◽  
Vol 9 (4) ◽  
pp. 797-803 ◽  
Author(s):  
Kanaparthi V. Phani Kumar ◽  
S. S. Karthikeyan
Keyword(s):  
Transmission Line ◽  
Transmission Lines ◽  
Communication Systems ◽  
Printed Circuit Board ◽  
Circuit Board ◽  
Harmonic Suppression ◽  
Quarter Wavelength ◽  
Bonding Wires ◽  
Via Holes ◽  
Lumped Elements

This paper presents the design of a size miniaturized and harmonic suppressed wideband double-section rat-race coupler (RRC). Series and shunt stepped-impedance transmission line units are proposed to replace the quarter wavelength transmission lines in the conventional design of wideband (50% fractional bandwidth) two-stage rat-race coupler. Design equations are derived using the lossless transmission line model. The proposed double-section RRC occupies only 14% area of the conventional coupler, with good return loss and isolation performances. In addition, the full-wave simulation and measured responses exhibit harmonic suppression up to at least fifth harmonic. The proposed design can be easily implemented using the standard printed circuit board etching process without any via-holes, bonding wires, and lumped elements, which make it very useful for wireless communication systems

scholarly journals Highly Sensitive Reflective-Mode Defect Detectors and Dielectric Constant Sensors Based on Open-Ended Stepped-Impedance Transmission Lines

Sensors ◽  
2020 ◽  
Vol 20 (21) ◽  
pp. 6236
Author(s):  
Pau Casacuberta ◽  
Jonathan Muñoz-Enano ◽  
Paris Vélez ◽  
Lijuan Su ◽  
Marta Gil ◽  
...  
Keyword(s):  
Dielectric Constant ◽  
Transmission Line ◽  
Transmission Lines ◽  
Characteristic Impedance ◽  
Reference Sample ◽  
Phase Variation ◽  
Dielectric Constants ◽  
High Impedance ◽  
Line Section ◽  
Highly Sensitive

In this paper, reflective-mode phase-variation sensors based on open-ended stepped-impedance transmission lines with optimized sensitivity for their use as defect detectors and dielectric constant sensors are reported. The sensitive part of the sensors consists of either a 90° high-impedance or a 180° low-impedance open-ended sensing line. To optimize the sensitivity, such a sensing line is cascaded to a 90° transmission line section with either low or high characteristic impedance, resulting in a stepped-impedance transmission line configuration. For validation purposes, two different sensors are designed and fabricated. One of the sensors is implemented by means of a 90° high impedance (85 Ω) open-ended sensing line cascaded to a 90° low impedance (15 Ω) transmission line section. The other sensor consists of a 180° 15-Ω open-ended sensing line cascaded to a 90° 85-Ω line. Sensitivity optimization for the measurement of dielectric constants in the vicinity of that corresponding to the Rogers RO4003C substrate (i.e., with dielectric constant 3.55) is carried out. The functionality as a defect detector is demonstrated by measuring the phase-variation in samples consisting of the uncoated Rogers RO4003C substrate (the reference sample) with arrays of holes of different densities.

Renormalization of the energies stored around a Wiener–Hopf structure: I

1991 ◽  
Vol 69 (7) ◽  
pp. 875-890 ◽  
Author(s):  
George Mitsioulis
Keyword(s):  
Parallel Plate ◽  
Magnetic Energy ◽  
Visible Region ◽  
Electric Energy ◽  
Lower Boundary ◽  
Electromagnetic Energy ◽  
Wave Number

A programme of renormalization of the electromagnetic energy stored around a structure admitting a solution through the Wiener–Hopf technique is proposed. The infinites of the stored magnetic energy also appear in the stored electric energy and they are suppressed freely. There are divergencies due to spatial integrations that prove to be completely renormalizable. Moreover the Wiener–Hopf procedure for the solution of the radiation from the semi-infinite parallel-plate duct gives rise to two other kinds of divergencies. First, the form of the spectrum eigenfunction causes a contribution to the stored energies from the wave-number visible region where the eigenfunction is "peaked" at certain points. Second, the squared spectrum eigenfunctions have a nonsummable singularity at the lower boundary of the visible region. The renormalizability of the formulae of the energies in both of these cases is proved.

scholarly journals Matching the termination of radiating non-uniform transmission-lines

2013 ◽  
Vol 11 ◽  
pp. 259-264 ◽  
Author(s):  
R. Rambousky ◽  
J. Nitsch ◽  
H. Garbe
Keyword(s):  
Transmission Line ◽  
Transmission Lines ◽  
Characteristic Impedance ◽  
Local Effect ◽  
Single Wire ◽  
Concentrated Load ◽  
Frequency Dependent ◽  
Radiated Power ◽  
Maximum Value ◽  
Cooperative Process

Abstract. In this contribution a concept of matching the termination of radiating non-uniform transmission-lines is proposed. Using Transmission-Line Super Theory, position and frequency dependent line parameters can be obtained. Therefore, a characteristic impedance can be determined which is also position and frequency dependent. For a single wire transmission-line it could be shown that the maximum value of that characteristic impedance is an optimal termination in the sense of minimizing the variation of the current on the line. This indicates that matching is not a local effect at the position of the concentrated load but a cooperative process including the whole non-uniform transmission-line. In addition this choice of termination minimizes the variation of the radiated power over frequency.

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