belal
New Member
Posts: 1
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Post by belal on Dec 22, 2011 12:53:55 GMT -5
We know that there is an horizontal polarization and vertical polarization (V and H), but some sits wrote the frequencies like this
Freq: 3843 R or 3843 L , the question is :
What mean these two letters (R and L)
If there is an explanation about this please tell me
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Post by arkon8000 on Feb 8, 2012 13:11:30 GMT -5
Hi,
L = LHCP = Left Hand Circular Polarisation
R = RHCP = Right Hand Circular Polarisation
At approximately 4GHz (C-Band) using Circular polarisation enhances Cross-Polar Isolation (XPI) which helps when it rains !
Intelsat chose to use Circular in the very early days of satellites and they remained that way, whereas 'domestic' USA satellite companies chose to use Linear polarisation (Vertical and Horizontal).
You can convert LHCP > V and RHCP > H by using a 'depolarising' insert of teflon or PTFE in the feedhorn !
Cheers, Arkon.
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