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

Long-term plans for technical loss reduction, Long-Term Plans for Technical...

Long-Term Plans for Technical Loss Reduction Long-term measures for technical loss reduction include all measures that require to be taken for the improvement of quality and r

Determine the ranges of values of the gain constant, A unity negative feedb...

A unity negative feedback control system has an open loop transfer function consisting of two poles, two zeros and a variable positive gain K. The zeros are located at -2 and -1, a

Discuss description of insulating materials, Discuss description of insulat...

Discuss description of insulating materials on the basis of physical and chemical structure Insulating materials, on the basis of their physical and chemical structure may be d

Determine the doppler frequency, We are given an M=32 pulse sequence of slo...

We are given an M=32 pulse sequence of slow time data, collected with PRF = 10 kHz.  We want to use a Cooley-Tukey radix 2 FFT algorithms to compute the Doppler spectrum of the dat

Energy conservation building codes, Energy Conservation Building Codes ...

Energy Conservation Building Codes It encompass the norms and standards of energy consumption expressed in terms of per square meter of the area wherein energy is used. The

A, A microstrip antenna system operating at 915MHz must be designed using R...

A microstrip antenna system operating at 915MHz must be designed using Rogers RO3010 substrate with the thickness of 0.635mm.

Find out which of the two motors, Find out which of the two motors: Tw...

Find out which of the two motors: Two three-phase induction motors while connected across a 400 V, 50 Hz supply are running at 1440 and 940 RPM respectively. Find out which of

Execute a pspice program to solve for the node voltages, Q. For the circuit...

Q. For the circuit given in Figure, develop and execute a PSpice program to solve for the node voltages.

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