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

Define the binary counting - counters, Define the Binary Counting - Counter...

Define the Binary Counting - Counters? The Binary counter is capable to be constructed from J-K flip-flops by taking the output of one cell to the clock input of the next The J

How phase angle measurement are carried out, Q.   Explain how phase angle m...

Q.   Explain how phase angle measurement are carried out with vector impedance meter.     Sol. Impedance measurements are concerned with both the magnitude (Z) and the phase

Power electronics, principle of 120 degree mode of operation of voltage sou...

principle of 120 degree mode of operation of voltage source intverter

Find the equivalent series impedance, Q. 10-kVA, 4800:240-V, 60-Hz, single-...

Q. 10-kVA, 4800:240-V, 60-Hz, single-phase transformer has an equivalent series impedance of 120 + j300  referred to the primary high- voltage side. The exciting current of the tr

Binary number system - number systems , Binary  Number Systems As men...

Binary  Number Systems As mentioned  earlier this  number is used by  digital  systems like  microprocessor  and other  digital  circuits. This  number  systems  use only two

Clippers, what is shunt clipper?

what is shunt clipper?

Show maximum power transfer, Q. Show Maximum Power Transfer? In order t...

Q. Show Maximum Power Transfer? In order to investigate the power transfer between a practical source and a load connected to it, let us consider Figure , in which a constant v

What is a coprocessor, What is a coprocessor? It is a specially designe...

What is a coprocessor? It is a specially designed microprocessor which take care of mathematical calculations including integer and floating point data .it is intended to work

Find the per-phase impedance of the load, Q. The two-wattmeter method for m...

Q. The two-wattmeter method for measuring three-phase power is applied on a balanced wye-connected load, and the readings are given by W C = 836W and W A = 224 W If the system

Cpu based exchange, CPU Based Exchange:   In centralized control, all contr...

CPU Based Exchange:   In centralized control, all control equipment is replaced by a single processor which should be quite powerful. It should be capable of processing 10 to 100 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