TDR Analysis on Short Transmission Lines

2014 ◽  
Author(s):  
Nicholas Konkol
Keyword(s):  
Failure Analysis ◽  
Transmission Line ◽  
Transmission Lines ◽  
Time Domain ◽  
System Level ◽  
Electrical Failure ◽  
Advantages And Disadvantages ◽  
System A ◽  
Time Domain Reflectometer ◽  
Line Analysis

Abstract Transmission line analysis is done in electrical failure analysis labs in order to find root causes that result in system level failures. After a fault is narrowed to a particular signal in a system, a Time Domain Reflectometer (TDR) can be used to analyze the physical transmission line associated with the signal. The transmission lines on smartphones often have inaccessible signal vias, few or no ground vias, probe points that are difficult to see, and short transmission lines. One solution that can alleviate these problems is to design a TDR Accessory Card. This paper discusses the processes involved in testing long and short transmission lines, providing the comparison between the expected and actual TDR measurement and the advantages and disadvantages of TDR, explaining four main points for using a TDR Accessory Card and two reasons for not using the TDR Accessory Card.

scholarly journals Variations in Velocity and Sensitivity of Electromagnetic Waves in Transmission Lines Configured in Model Piles with Necking Defects Containing Soils

Sensors ◽  
2020 ◽  
Vol 20 (22) ◽  
pp. 6541
Author(s):  
Jung-Doung Yu ◽  
Sang Yeob Kim ◽  
Jong-Sub Lee
Keyword(s):  
Transmission Line ◽  
Transmission Lines ◽  
Time Domain ◽  
Electromagnetic Waves ◽  
Electrical Wire ◽  
Different Types ◽  
Bored Piles ◽  
Time Domain Reflectometer ◽  
Water Contents ◽  
Soil Water Contents

This study investigates variations in the velocity and sensitivity of electromagnetic waves in transmission lines configured in defective model piles for the detection of necking defects containing soil. Experiments are performed with model piles containing defects filled with different materials, such as air, sands, and clay. Five different types of transmission lines are configured in model piles. The electromagnetic waves are generated and detected using a time domain reflectometer. The velocity of electromagnetic waves is highest when the defect is filled with air, and it decreases with an increase in the water content. The velocity is lowest when the defect is filled with clay. The sensitivity of transmission lines for detecting defects decreases with an increase in soil water contents. The transmission line with a single electrical wire and epoxy-coated rebar exhibits the highest sensitivity, followed by that with three and two parallel electrical wires. Transmission lines with a single electrical wire and uncoated rebar and those with two parallel electrical wires wrapped with a sheath exhibit poor sensitivity when the defect is filled with clay. This study demonstrates that electromagnetic waves can be effective tools for detecting necking defects with wet and conductive soils in bored piles.

System Level FA on Transmission Line Issues

2010 ◽  
Author(s):  
Nicholas Konkol
Keyword(s):  
Failure Analysis ◽  
Transmission Line ◽  
Transmission Lines ◽  
Printed Circuit Boards ◽  
System Level ◽  
Circuit Boards ◽  
Printed Circuit

Abstract One issue that faces failure analysis at the system level is impedance mismatched transmission lines resulting from developers pushing the edge of trace layout recommendations. When transmission lines on printed circuit boards are routed in such a way as to allow for impedance mismatches, the effects can be unwanted on the signal that the line carries. Techniques can be used for discovering if capacitance, resistance, or split planes are creating the impedance mismatches that are resulting in the system level failure seen by the customer.

Analysis on De-Icing Methods for 4-Bundle 500kV Transmission Lines

2013 ◽  
Vol 694-697 ◽  
pp. 790-794
Author(s):  
Shun Xin Liu ◽  
You Han Guo
Keyword(s):  
Transmission Line ◽  
South China ◽  
Transmission Lines ◽  
Research Direction ◽  
Development Trend ◽  
Ice Melting ◽  
Power Networks ◽  
Advantages And Disadvantages ◽  
Prevention And Treatment ◽  
The Development Trend

In view of the massive transmission lines suffered disaster of ice coating at the beginning of 2008 in south China. In this paper, several typical schemes for the prevention and treatment of ice coating occurred in power networks home and abroad are analyzed. Common melting ice methods can be divided into three kinds: thermal ice-melting, mechanical de-icing and new de-icing. This paper describes a 500 kV transmission line and analyses each of these measures briefly. At the same time, the advantages and disadvantages of various measures and their applications were summarized. At last, the development trend and the research direction were pointed out．

scholarly journals Locating the frozen–unfrozen interface in soils using time-domain reflectometry

1982 ◽  
Vol 19 (4) ◽  
pp. 511-517 ◽  
Author(s):  
T. H. W. Baker ◽  
J. L. Davis ◽  
H. N. Hayhoe ◽  
G. C. Topp
Keyword(s):  
Transmission Lines ◽  
Time Domain ◽  
Freezing Temperature ◽  
Time Domain Reflectometry ◽  
Temperature Measurements ◽  
Soil Freezing ◽  
Electromagnetic Pulses ◽  
The Time Domain ◽  
Time Domain Reflectometer ◽  
Liquid And Solid Phases

The time-domain reflectometry technique was compared with the temperature measurement method for locating the frozen–unfrozen interface in water and sandy soils. This technique depends on the high-frequency (1–1000 MHz) electrical properties of water that change significantly and abruptly between the liquid and solid phases. Parallel wire transmission lines were inserted into the soil to guide electromagnetic pulses produced by a time-domain reflectometer (TDR). The frozen–unfrozen interface produced reflections measured by the TDR which were in turn used to locate the interface as it moved along the transmission line. In the laboratory it was possible to locate the interface using the TDR to within ±0.5 cm and in the field to within ±2.4 cm. These errors were equal to those associated with the temperature measurements. Keywords: soil freezing, temperature measurements, dielectric constant, time-domain reflectometry.

scholarly journals Sequence and spread spectrum time domain reflectometry for transmission line analysis

2007 ◽  
Author(s):  
Jacklyn Reis ◽  
Agostinho L. S. Castro ◽  
João C. W. A. Costa ◽  
Jaume R. I. Riu ◽  
Klas Ericson
Keyword(s):  
Transmission Line ◽  
Time Domain ◽  
Spread Spectrum ◽  
Time Domain Reflectometry ◽  
Line Analysis

scholarly journals Sequence Time Domain Reflectometry for Transmission Line Analysis

2007 ◽  
Author(s):  
Jacklyn Reis ◽  
Agostinho Castro ◽  
João Crisostomo Weyl Albuquerque Costa ◽  
Jaume Riu ◽  
Klas Ericson
Keyword(s):  
Transmission Line ◽  
Time Domain ◽  
Time Domain Reflectometry ◽  
Line Analysis

Frequency and Time-Domain Performance of LTCC Transmission Lines Fabricated Using Multiple Printing Techniques

2013 ◽  
Vol 2013 (CICMT) ◽  
pp. 000047-000053
Author(s):  
J. Phillip Bailey ◽  
Michael D. Glover ◽  
Emmanuel Decrossas ◽  
Kaoru Porter ◽  
Tom Cannon ◽  
...  
Keyword(s):  
Cross Sections ◽  
Transmission Lines ◽  
Time Domain ◽  
High Frequency ◽  
High Speed ◽  
Digital Signal ◽  
Simulation Models ◽  
Advantages And Disadvantages ◽  
Lower Insertion Loss ◽  
Printing Techniques

The many advantages of low temperature co-fired ceramic (LTCC) materials are increasing their use in multi-layer systems containing multiple high-frequency / high-speed digital interconnects. Although construction of such interconnects is possible with current fabrication techniques, the loss exhibited by transmission lines at high frequencies limits their application by increasing system power consumption or requiring complex transceivers. Use of non-standard metal printing processes provides one possibility for realizing lower insertion loss desired for these interconnects. We have fabricated and evaluated representative single-ended and differential stripline transmission line structures using single, double, and mirror printing techniques for Ag metalization in DuPont 9K7 LTCC, to explore their suitability for high-frequency/high-speed applications. Discussion of analysis performed on cross-sections of these structures to determine post-firing geometry, as well as the level of fabrication control afforded over these parameters will be presented. To predict their performance for high-speed interconnects, 3D electromagnetic (3DEM) simulation models for characterizing the frequency performance of single-ended and differential structures have been also been developed. These 3DEM models have also been used in time domain simulations to verify digital signal capability by demonstrating structure performance at data rates exceeding 25 Gbps. Measurements of fabricated structures corresponding to the 3DEM models have also been performed in both the time and frequency domain and will be compared to the simulation results to confirm 3DEM model accuracy. The culmination of results from simulation and measurement will be used to present the differences, advantages, and disadvantages of each fabrication technique.

ABCD Matrix: A Unique Tool for Linear Two-Wire Transmission Line Modelling

2003 ◽  
Vol 40 (3) ◽  
pp. 220-229 ◽  
Author(s):  
Pedro L. D. Peres ◽  
Carlos R. de Souza ◽  
Ivanil S. Bonatti
Keyword(s):  
Differential Equations ◽  
Transmission Line ◽  
Frequency Domain ◽  
Transmission Lines ◽  
Time Domain ◽  
Mathematical Concepts ◽  
Frequency Dependent ◽  
Abcd Matrix ◽  
The Time Domain

The aim of this note is to show that all the behaviour of a two-wire transmission line can be directly derived from the application of ABCD matrix mathematical concepts, avoiding the explicit use of differential equations. An important advantage of this approach is that the transmission line modelling arises naturally in the frequency domain. Therefore the consideration of frequency-dependent parameters can be carried out in a simple way compared with the time-domain. Some standard examples of transmission lines are analysed through the use of ABCD matrices and a case study of a balun network is presented.

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