Define waves and transmission lines, Electrical Engineering

Assignment Help:

Q. Define waves and transmission lines?

In basic circuit theory we neglect the effects of the finite time of transit of changes in current and voltage and the finite distances over which these changes occur. We assume that changes occur simultaneously at all points in the circuits. But there are situations in which we must consider the finite time it takes for an electrical or magnetic wave to travel and the distance it will travel. It is in these situations that one must employ traveling-wave theory. Traveling-wave concepts must be used whenever the distance is so great or the frequency so high that it takes an appreciable portion of a cycle for the wave to travel the distance.

For sinusoidal signals, a wavelength λ is defined as the distance that a wave travels in one cycle or period. Since electric waves in free space travel at the velocity of light c(≅ 3×108 m/s), the free-space wavelength is given by c/f. Table shows some free-space wavelengths at selected frequencies. If the traveling-wave technique is to be employed for distances greater than 1/10 wavelength, a distance of 3 mm at 10 GHz would require the use of this technique, whereas the same distance at 100 MHz would not. On the other hand, a distance of 1 km is insignificant at power-line frequencies, but not in the broadcast band.

2161_Define waves and transmission lines.png

The connection of the high-power output of a transmitter located on a building to the transmitting antenna on a tower is often made by special conductors called transmission lines, which guide thewaves and usually consist of two ormore parallel conductors,which are separated  by insulating (dielectric) materials.While transmission lines are available in many forms, Figure illustrates cross sections of some common types. The two-wire line of Figure (a) isused to connect some television antennas. The coaxial cable of Figure (b) is themost widely used of the many possible cable-type transmission lines. For printed-circuit and integrated-circuit applications, transmission lines sketched in Figures (c) through (f) are commonly employed.

513_Define waves and transmission lines1.png

 


Related Discussions:- Define waves and transmission lines

Explain temperature effect on electrical conductivity metals, Explain the e...

Explain the effect of temperature on electrical conductivity of metals. As the temperature is increased, there is a greater thermal motion of atoms which decreases the regulari

What is the maximum entrance angle max, Calculate the N.A of a step index f...

Calculate the N.A of a step index fibre having n 1 =1.48 and n 2 =1.46. What is the maximum entrance angle ψ max for this fibre if the outer medium is air with n 1 =1.0? Given

Demultiplexer, full sub tractor using demultiplexer

full sub tractor using demultiplexer

Project, You have to look up the data sheets for the LM317 (Not LT317), LT1...

You have to look up the data sheets for the LM317 (Not LT317), LT1006. V1 is a standard 9 volt battery, and the resistors are “through hole”. Label the test points in, V+, gnd, and

Determine the electromagnetic force on the plunger, Q. Consider the electro...

Q. Consider the electromagnetic plunger shown in Figure. The λ-i relationship for the normal working range is experimentally found to be λ = Ki 2/3 /(x+t), where K is a constant. D

Types of meter test, Types of Meter Test A meter should pass the subse...

Types of Meter Test A meter should pass the subsequent two types of tests: Type Tests Routine Tests Meters are calibrated such in which the whole

Name all the switching schemes used in a digital exchange, Q. Name all the ...

Q. Name all the switching schemes used in a digital exchange. How call processing occur? Ans: The basic types of switching systems used are: 1.  Stronger Switching System

Determine the hysteresis and eddy-current losses, Q. The total core loss fo...

Q. The total core loss for a specimen of magnetic sheet steel is found to be 1800 W at 60 Hz. When the supply frequency is increased to 90 Hz, while keeping the flux density consta

Find percent error of both meters when measuring a current, Q. Error specif...

Q. Error specifications on a 10-A digital ammeter are given as 0.07% of the reading, 0.05% of full scale, 0.005% of the reading per degree Celsius, and 0.002% of full scale per deg

Write Your Message!

Captcha
Free Assignment Quote

Assured A++ Grade

Get guaranteed satisfaction & time on delivery in every assignment order you paid with us! We ensure premium quality solution document along with free turntin report!

All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd