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

Evaluate parameters of a bjt, Q. The parameters of a BJT are given by α = 0...

Q. The parameters of a BJT are given by α = 0.98, I CBO = 90 nA, and i C = 7.5 mA. Find β, iB, and iE.

Enhancement operation of p-channel enhancement mosfet, Q. Show the Enhancem...

Q. Show the Enhancement operation of p-channel enhancement mosfet? As the gate terminal is insulated from the channel by the silicon dioxide layer, we can also apply a negative

What is discrete signals, Q. What is Discrete signals? Discrete signals...

Q. What is Discrete signals? Discrete signals, on the other hand, exist only at specific instances of time, and as such, their functional description is valid only for discrete

Find the fourier transform of the signal, Problem (a) Give an example...

Problem (a) Give an example of a power signal and one example of an energy signal. (b) Given a periodic signal x (t) = A sin (2Bft). Calculate the power Px. (c) Diffe

The filter capacitor , It is needed to use a half-wave rectifier for a dc p...

It is needed to use a half-wave rectifier for a dc power supply that gives an average dc output voltage of 15 V and a maximum ±1V ripple is permitted. The rectifier feeds a load of

[email protected], a sensorless brushless DC motor control with back emf ...

a sensorless brushless DC motor control with back emf (zero crossing point ) technique, using Arduino Microcontroller board control and describe in C. program language.

Draw a block diagram of a 4-bit pipo register, Q. Draw a block diagram of a...

Q. Draw a block diagram of a 4-bit PIPO register and briefly describe its operation. Q. Taking parallel data from a computer to be fed out over a single transmission line needs

Describe the processor technology used for embedded system, a. Write the ad...

a. Write the advantages of choosing a single purpose processor over a general purpose processor. b. List out the hardware units that must be there in the embedded systems. c.

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