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When load is not matched to the characteristic impedance of a cable

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stanford

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If the load is not matched to the characteristic impedance of the cable, not all of the power gets delivered to the load. Some bounces back and fourth between the source and the load.

Is it possible for this bouncing power to be absorbed by the source? When Rs is not equal to Zo?
 
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stanford said:
If the load is not matched to the characteristic impedance of the cable, not all of the power gets delivered to the load. Some bounces back and fourth between the source and the load.

Is it possible for this bouncing power to be absorbed by the source? When Rs is not equal to Zo?
Click to expand...
The bouncing power will eventually be absorbed by the source and/or the load depending upon their impedances as compared to the cable.
 

Maximum power transfer of 50% efficiency is achieved when the load matches the source. If standing waves occur for a given length and frequency then transmission reflections will occur due to mismatch of line to load and back again to source.

When matched there is low return signal reflected measured as a Return Loss. This becomes significant if length of cable is >10% of wavelength in the diectric using 2/3c
 

At the source end miss matched cable termination on the other end results in a complex impedance loading the source. Source delivers to such a load some true power and reactive power. In real world question is how much miss match source or transmitter can withstand physically.
 

Borber said:
At the source end miss matched cable termination on the other end results in a complex impedance loading the source. Source delivers to such a load some true power and reactive power. In real world question is how much miss match source or transmitter can withstand physically.
Click to expand...

100% reflected Power protection may be designed into some RF Amplifiers but that is not always the case.
Generally <15 dB Return Loss is inadequate ad 30dB is high quality for a cable.
 

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