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Re: Antenna Questions



>From: "Tim Cunningham" <tim_cunningham@mindspring.com>
>Are there any studies or data that show the effects (attenuation)
>when one of 2 circular polarized antennas with compatible sense
>are off-pointed at various angles ?

I'm not sure of studies, but what you are asking about is well known to
experienced AO-10 and AO-13 operators.

>This would produce what I believe to be an elliptical pattern, but
>is  there any data to support the perceived attenuation at the
>receiving station provided it is pointed at the off-pointed CP
>antenna.

You are correct, and not only that. For increasing squint angles
polarization sense will become linear and then reverse as seen by the
observer.  The answer is to use a CP antenna with polarization switching.
That way you never experience more than -3 dB fades due to this effect.
Squint angle polarization effects are addressed in chapter 7 of the
Satellite Experimenters Handbook.

Hope that answers your question.

Ed 
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