Electrical / Electronic Theory and Learning Center > Learning Center Miscellaneous

Antennas & Transmission Lines (feedlines)

<< < (13/13)

muDped:

--- Quote from: poynt99 --- ...so the reflection is canceled before making its way back to the transceiver.

--- End quote ---

Which sounds like it might be an 'impedance transformation' which
produces a match by limiting the resonant condition to the antenna
end of the line.  No?
 

poynt99:
It has no effect on the antenna at all; the antenna still produces a reflection.

muDped:
True, it doesn't physically alter the mismatch at the antenna
but it does alter the standing wave impedance characteristics
within the region of resonance which should result in more
radiated energy.  Reflections must go somewhere.

poynt99:
It shouldn't make a significant difference in the radiated power actually. Without a "tuning" stub, the reflected power gets re-reflected from the transmitter so all the energy eventually goes out the antenna anyway.

The stub prevents large VSWR at the transmitter and may also eliminate the long trip the reflection must take to the transmitter and back again. So in that sense, it may facilitate slightly more power pushed out the antenna by reducing line loss.

Navigation

[0] Message Index

[*] Previous page