Why 50 ohms at the load side in Txion lines?

[tarakapraveen]

Hi friends ,

1) Why we are using 50 ohs load in Transmission line s ?

2) Is there any advantage other than maximum power transfer?

Plz clarify me?
Thanks in advance

Goud

 

[xxargs]

Hi friends ,

1) Why we are using 50 ohs load in Transmission line s ?

2) Is there any advantage other than maximum power transfer?

Plz clarify me?
Thanks in advance

Goud

Maximum power transfer is same if you using 300 Ohm, 75 OHm, and 50 Ohm whole way (but 75 Ohm have sligtly less loss compare to used amount of metal).

but 50,75 and 300 Ohm standards comming from beginning of used antenna characteric impedance (and 600 Ohm and 100, 110 Ohm comming from used conductor lines impedance from telephone world)

loop antenna have around 300 Ohm and using in beginning for TV, and after time easly converted to 75 Ohm on antenna to feed more easy flexible coaxial cable compare to more leaky 300 Ohm ribbon cable and now TV-standard.


Land mobile radio using GP-antenna (73 Ohm) and dipolantenna (50 Ohm) with 50 Ohm impedance very long time - and instrument makers as HP, RoS etc. make much widespread measure equipment for 50 Ohm compare to few goverment owned TV-channel (and only buy few 75 Ohm matched measure instruments) - so now is 50 Ohm as 'standard' in RF-design world simular microsoft windows for operativ system... ie 50 Ohm is a big standard, you have more and cheaper choice
between antenna, connectors, cables, filters etc. compare to 75 Ohm system - and this have very high impact to RF-systems price to customer...