[amsat-bb] Re: Eagle efficiencies

Scott Townley nx7u at arrl.net
Sat Sep 9 12:04:20 PDT 2006


Clarification, or more fuel to the fire...
For a *fixed overall physical size (aperture)*, antenna gain is 
proportional to f^2
Pathloss is proportional to 1/f^2
So then the total link budget actually *increases* with increasing 
frequency (f^2*f^2/f^2=f^2), since you have an antenna at both ends, 
subject to the assumption stated initially.
There are several 2nd-order terms to consider overall, such as decreasing 
transmitter power as frequency increases, thermal/galactic noise variations 
with freq, etc., but *for a given size* higher is better.




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