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What is the effect of standing wave on transmission line?
Transmission lines may be damaged by the high maximum amplitudes of standing waves. Voltage antinodes may break down insulation between conductors, and current antinodes may overheat conductors.
How are standing waves formed?
Standing wave, also called stationary wave, combination of two waves moving in opposite directions, each having the same amplitude and frequency. The phenomenon is the result of interference; that is, when waves are superimposed, their energies are either added together or canceled out.
What happens when there is mismatch of impedance between transmission line and load?
Whenever there is a mismatch of impedance between transmission line and load, reflections will occur. If the incident signal is a continuous AC waveform, these reflections will mix with more of the oncoming incident waveform to produce stationary waveforms called standing waves.
Why is the impedance of a cable important?
Why impedance matching is important here is if the load impedance and the cable’s characteristic impedance are the same (Z load = Zo), then the transmitter sees the load as if the transmission line was not there. The transmitter can transfer all the energy to the load.
How to calculate the impedance of a line?
By plotting the normalized load impedance on a Smith Chart, the input impedance as a function of line length can be found. The Smith Chart also provides the value of the reflection coefficient,power delivered to load, as well as the voltage standing wave ratio (VSWR) Distance measurements are given in terms of wavelengths. 2 Center at1+j0
What is the normalized impedance for a transmission line?
The normalized input impedance for that transmission line is read from the Smith Chart to be1 – j0.75. This is read from the point where the circle you drew intersects theRe{ Z