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

Antinoise systems — noise cancellation, Q. Antinoise Systems — Noise Cancel...

Q. Antinoise Systems — Noise Cancellation? Traditionally sound-absorbing materials have been used quite effectively to reduce noise levels in aircraft, amphitheaters, and other

Determine the value of capacitance to give resonance, Determine the value o...

Determine the value of capacitance to give resonance: A circuit shown in Figure having a resistance of 5 Ω, an inductance of 0.4 H and a variable capacitance in series is conn

Transient, The winding of an electromagnet has an inductance of 3H and a re...

The winding of an electromagnet has an inductance of 3H and a resistance of 15?. When it is connected to a 120 V d.c. supply, Determine:

Define integrated circuits, Q. Define Integrated circuits? For the fabr...

Q. Define Integrated circuits? For the fabrication of semiconductor circuits, there are three distinct technologies employed: 1. Discrete-component technology, in which each

Fundamental of metal casting, Fundamental of Metal Casting: Fundament...

Fundamental of Metal Casting: Fundamental of Metal Casting : Casting process is based on the property of a liquid to take up the shape of vessel containing it. Molten metal

What is occur in density flux state- ferromagnetic material, In a ferromagn...

In a ferromagnetic material the state of flux density is as follows when external magnetic field is applied to it. (A) Increased (B) Becomes zero (C) Remains unchang

Calculate k for n-channel enhancement mosfet, Q. An n-channel enhancement M...

Q. An n-channel enhancement MOSFET operates in the active region with very large V A , v GS = 6V, V = 4 V, and i = 1 mA. Calculate K.

Strain gauge bridge circuit, Explain kinds of strain gauge bridge circuits ...

Explain kinds of strain gauge bridge circuits and resistance strain gauges.

Communication systems/theory, have 18 multiple choice questions i need answ...

have 18 multiple choice questions i need answered by 9am cst and will pay Need ASAP

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